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Keeler JM, Listman JB, Hite MJ, Heeger DJ, Tourula E, Port NL, Schlader ZJ. Arterial Oxygen Desaturation Hinders Gamified Working Memory Performance. Mil Med 2024:usae376. [PMID: 39101550 DOI: 10.1093/milmed/usae376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 07/16/2024] [Accepted: 07/18/2024] [Indexed: 08/06/2024] Open
Abstract
INTRODUCTION Hypoxia presents a physiological challenge to the Warfighters during military aviation and subterranean warfare operations by decreasing the supply of oxygen to the brain, which results in a reduced cognitive function depending on the magnitude and duration of hypoxic exposure. Moderate hypoxic exposures, fractions of inspired oxygen (FiO2) of 0.11 to 0.14, show no effects on simple tasks, but complex tasks like working memory may be hindered. Unfortunately, people often cannot recognize their own symptoms of hypoxemia, which are individualistic at moderate hypoxic exposure. Thus, screening tools, like gamified cognitive assessments, during moderate hypoxia may provide personnel objective feedback to initiate safety protocols before a possible accident. However, whether gamified assessments of working memory are sensitive to moderate hypoxia is unknown. Therefore, we tested the hypothesis which moderate normobaric hypoxia decreases gamified working memory performance when accounting for the individualistic responses of arterial blood oxygen saturations. MATERIALS AND METHODS Following 3 consecutive days of 2 practice sessions per day, 30 healthy adults (25 ± 5 years, 10 women) completed three 1-min rounds of the tablet-based working memory game (Backtracker, Statespace Labs, Inc.) at baseline and 60 and 90 min after exposure to FiO2 (= 0.138 ± 0.002 [hypoxia] and 0.201± 0.004 [normoxia] oxygen). Both conditions were completed on the same day and administered in a single-blind, block randomized manner. Arterial oxyhemoglobin saturation was estimated via forehead pulse oximetry (SpO2). Data were analyzed using linear mixed effects modeling. RESULTS Compared to normoxia (99 ± 1%), SpO2 was lower (P < .001) at 60 (90 ± 2%) and 90 (90 ± 2%) min of hypoxia. A decrease in SpO2 was associated with a statistically significant decrease in the proportion of both tiles with the correct location (P < .02; -0.016) and correct order of appearance recalled (P < .01; -0.016). A decrease in SpO2 was associated with a statistically significant decrease in median time to first tap (P < .01; -0.041 s) and median time between taps (P < .01; -0.030 s). A significant interaction effect between the SpO2 decrease and baseline performance was found for proportion of tiles with the correct location recalled (P < .05; -0.014), median time to first tap (P < .01; -0.070 s), and median time between taps (P < .01; -0.037 s). A significant interaction effect between the SpO2 decrease and the path length was found for the proportion of tiles with the correct location recalled (P < .01; +0.021), median time to first tap (P < .01; -0.036 s), and median time between taps (P < .01; -0.043 s). CONCLUSIONS These findings indicate that greater decreases in SpO2 during moderate hypoxic exposure hinder performance on a gamified assessment of working memory as measured by the proportion of correctly identified order and location of tiles. Considering the statistically significant decrease in both median time to first tap and median time between taps associated with the decrease in SpO2, participants are taking less time to plan or execute movements, which may compound or independently contribute to spatial and temporal memory mistakes.
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Affiliation(s)
- Jason M Keeler
- H.H. Morris Human Performance Laboratories, Department of Kinesiology, Indiana University School of Public Health, Bloomington, IN 47405, USA
| | | | - M Jo Hite
- H.H. Morris Human Performance Laboratories, Department of Kinesiology, Indiana University School of Public Health, Bloomington, IN 47405, USA
| | | | - Erica Tourula
- H.H. Morris Human Performance Laboratories, Department of Kinesiology, Indiana University School of Public Health, Bloomington, IN 47405, USA
| | - Nicholas L Port
- School of Optometry, Indiana University, Bloomington, IN 47405, USA
| | - Zachary J Schlader
- H.H. Morris Human Performance Laboratories, Department of Kinesiology, Indiana University School of Public Health, Bloomington, IN 47405, USA
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De Wachter J, Roose M, Proost M, Habay J, Verstraelen M, De Bock S, De Pauw K, Meeusen R, Van Cutsem J, Roelands B. Prefrontal cortex oxygenation during a mentally fatiguing task in normoxia and hypoxia. Exp Brain Res 2024; 242:1807-1819. [PMID: 38839618 PMCID: PMC11208267 DOI: 10.1007/s00221-024-06867-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 05/28/2024] [Indexed: 06/07/2024]
Abstract
Mental fatigue (MF) and hypoxia impair cognitive performance through changes in brain hemodynamics. We want to elucidate the role of prefrontal cortex (PFC)-oxygenation in MF. Twelve participants (22.9 ± 3.5 years) completed four experimental trials, (1) MF in (normobaric) hypoxia (MF_HYP) (3.800 m; 13.5%O2), (2) MF in normoxia (MF_NOR) (98 m; 21.0%O2), (3) Control task in HYP (CON_HYP), (4) Control in NOR (CON_NOR). Participants performed a 2-back task, Digit Symbol Substitution test and Psychomotor Vigilance task before and after a 60-min Stroop task or an emotionally neutral documentary. Brain oxygenation was measured through functional Near Infrared Spectroscopy. Subjective feelings of MF and physiological measures (heart rate, oxygen saturation, blood glucose and hemoglobin) were recorded. The Stroop task resulted in increased subjective feelings of MF compared to watching the documentary. 2-back accuracy was lower post task compared to pre task in MF_NOR and CON_NOR, while no differences were found in the other cognitive tasks. The fraction of inspired oxygen did not impact feelings of MF. Although performing the Stroop resulted in higher subjective feelings of MF, hypoxia had no effect on the severity of self-reported MF. Additionally, this study could not provide evidence for a role of oxygenation of the PFC in the build-up of MF.
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Affiliation(s)
- Jonas De Wachter
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Manon Roose
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
- Department of Radiology, UZ Brussel, Brussels, Belgium
| | - Matthias Proost
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Jelle Habay
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
- Research Foundation Flanders (FWO), Brussels, Belgium
| | - Matthias Verstraelen
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Sander De Bock
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
- BruBotics, Vrije Universiteit Brussel, Brussels, Belgium
| | - Kevin De Pauw
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
- BruBotics, Vrije Universiteit Brussel, Brussels, Belgium
| | - Romain Meeusen
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
- BruBotics, Vrije Universiteit Brussel, Brussels, Belgium
| | - Jeroen Van Cutsem
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium
- VIPER Research Unit, Royal Military Academy, Brussels, Belgium
| | - Bart Roelands
- Human Physiology and Sports Physiotherapy Research Group, Vrije Universiteit Brussel, Brussels, Belgium.
- BruBotics, Vrije Universiteit Brussel, Brussels, Belgium.
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Su R, Jia S, Zhang N, Wang Y, Li H, Zhang D, Ma H, Su Y. The effects of long-term high-altitude exposure on cognition: A meta-analysis. Neurosci Biobehav Rev 2024; 161:105682. [PMID: 38642865 DOI: 10.1016/j.neubiorev.2024.105682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 04/14/2024] [Accepted: 04/16/2024] [Indexed: 04/22/2024]
Abstract
Long-term high altitudes (HA) exposure's impact on cognition has yielded inconsistent findings in previous research. To address this, we conducted a meta-analysis of 49 studies (6191 individuals) to comprehensively evaluate this effect. Moderating factors such as cognitive task type, altitude (1500-2500 m, 2500-4000 m, and above 4000 m), residential type (chronic and lifelong), adaptation level and demographic factors were analyzed. Cognitive tasks were classified into eight categories: perceptual processes, psychomotor function, long-term memory, working memory, inhibitory control, problem-solving, language, and others. Results revealed a moderate negative effect of HA on cognitive performance (g = -.40, SE =.18, 95% CI = -.76 to -.05). Psychomotor function and long-term memory notably experience the most pronounced decline, while working memory and language skills show moderate decreases due to HA exposure. However, perceptual processes, inhibitory control, and problem-solving abilities remain unaffected. Moreover, residing at altitudes above 4000 m and being a HA immigrant are associated with significant cognitive impairment. In summary, our findings indicate a selective adaptation of cognitive performance to HA conditions.
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Affiliation(s)
- Rui Su
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China; Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Shurong Jia
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Niannian Zhang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Yiyi Wang
- Department of Psychology, University of Chicago, Chicago, IL 60637, United States
| | - Hao Li
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Delong Zhang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China; School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Hailin Ma
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Yanjie Su
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China.
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McMorris T, Hale BJ, Pine BS, Williams TB. Creatine supplementation research fails to support the theoretical basis for an effect on cognition: Evidence from a systematic review. Behav Brain Res 2024; 466:114982. [PMID: 38582412 DOI: 10.1016/j.bbr.2024.114982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 02/15/2024] [Accepted: 04/02/2024] [Indexed: 04/08/2024]
Abstract
Creatine supplementation has been put forward as a possible aid to cognition, particularly for vegans, vegetarians, the elderly, sleep deprived and hypoxic individuals. However, previous narrative reviews have only provided limited support for these claims. This is despite the fact that research has shown that creatine supplementation can induce increased brain concentrations of creatine, albeit to a limited extent. We carried out a systematic review to examine the current state of affairs. The review supported claims that creatine supplementation can increases brain creatine content but also demonstrated somewhat equivocal results for effects on cognition. It does, however, provide evidence to suggest that more research is required with stressed populations, as supplementation does appear to significantly affect brain content. Issues with research design, especially supplementation regimens, need to be addressed. Future research must include measurements of creatine brain content.
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Affiliation(s)
- Terry McMorris
- Institue of Sport, Nursing and Allied Health, University of Chichester, College Lane, Chichester PO19 6PE, United Kingdom; Department of Sport and Exercise Science, University of Portsmouth, Spinnaker Building, Cambridge Road, Portsmouth PO12ER, United Kingdom.
| | - Beverley J Hale
- Institue of Sport, Nursing and Allied Health, University of Chichester, College Lane, Chichester PO19 6PE, United Kingdom
| | - Beatrice S Pine
- Institue of Sport, Nursing and Allied Health, University of Chichester, College Lane, Chichester PO19 6PE, United Kingdom
| | - Thomas B Williams
- Department of Sport and Exercise Science, University of Portsmouth, Spinnaker Building, Cambridge Road, Portsmouth PO12ER, United Kingdom
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Wang NN, Yu SF, Dang P, Su R, Li H, Ma HL, Liu M, Zhang DL. The neuroimmune pathway of high-altitude adaptation: influence of erythrocytes on attention networks through inflammation and the autonomic nervous system. Front Neurosci 2024; 18:1373136. [PMID: 38638694 PMCID: PMC11024340 DOI: 10.3389/fnins.2024.1373136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/19/2024] [Indexed: 04/20/2024] Open
Abstract
Introduction Many studies have shown that the functional adaptation of immigrants to high-altitude is closely related to oxygen transport, inflammatory response and autonomic nervous system. However, it remains unclear how human attention changes in response to hypoxia-induced neurophysiological activity during high-altitude exposure. Methods In the present study, we analyzed the relationship between hypoxic-induced neurophysiological responses and attention networks in 116 immigrants (3,680 m) using an attention network test to simultaneously record electroencephalogram and electrocardiogram in combination with specific routine blood markers. Results Our analysis revealed that red blood cells exert an indirect influence on the three attention networks, mediated through inflammatory processes and heart rate variability. Discussion The present study provides experimental evidence for the role of a neuroimmune pathway in determining human attention performance at high- altitude. Our findings have implications for understanding the complex interactions between physiological and neurocognitive processes in immigrants adapting to hypoxic environments.
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Affiliation(s)
- Nian-Nian Wang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
- Key Laboratory of Brain, Cognition, and Education Sciences, Ministry of Education, Guangzhou, China
- School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Si-Fang Yu
- Key Laboratory of Brain, Cognition, and Education Sciences, Ministry of Education, Guangzhou, China
- School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Peng Dang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Rui Su
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Hao Li
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Hai-Lin Ma
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Ming Liu
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
- Key Laboratory of Brain, Cognition, and Education Sciences, Ministry of Education, Guangzhou, China
- School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - De-Long Zhang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
- Key Laboratory of Brain, Cognition, and Education Sciences, Ministry of Education, Guangzhou, China
- School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
- School of Educational Sciences, Kashi University, Kashi, China
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Coronel-Oliveros C, Medel V, Whitaker GA, Astudillo A, Gallagher D, Z-Rivera L, Prado P, El-Deredy W, Orio P, Weinstein A. Elevating understanding: Linking high-altitude hypoxia to brain aging through EEG functional connectivity and spectral analyses. Netw Neurosci 2024; 8:275-292. [PMID: 38562297 PMCID: PMC10927308 DOI: 10.1162/netn_a_00352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 11/17/2023] [Indexed: 04/04/2024] Open
Abstract
High-altitude hypoxia triggers brain function changes reminiscent of those in healthy aging and Alzheimer's disease, compromising cognition and executive functions. Our study sought to validate high-altitude hypoxia as a model for assessing brain activity disruptions akin to aging. We collected EEG data from 16 healthy volunteers during acute high-altitude hypoxia (at 4,000 masl) and at sea level, focusing on relative changes in power and aperiodic slope of the EEG spectrum due to hypoxia. Additionally, we examined functional connectivity using wPLI, and functional segregation and integration using graph theory tools. High altitude led to slower brain oscillations, that is, increased δ and reduced α power, and flattened the 1/f aperiodic slope, indicating higher electrophysiological noise, akin to healthy aging. Notably, functional integration strengthened in the θ band, exhibiting unique topographical patterns at the subnetwork level, including increased frontocentral and reduced occipitoparietal integration. Moreover, we discovered significant correlations between subjects' age, 1/f slope, θ band integration, and observed robust effects of hypoxia after adjusting for age. Our findings shed light on how reduced oxygen levels at high altitudes influence brain activity patterns resembling those in neurodegenerative disorders and aging, making high-altitude hypoxia a promising model for comprehending the brain in health and disease.
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Affiliation(s)
- Carlos Coronel-Oliveros
- Latin American Brain Health Institute (BrainLat), Universidad Adolfo Ibáñez, Santiago, Chile
- Global Brain Health Institute (GBHI), University of California, San Francisco (UCSF), San Francisco, CA, USA and Trinity College Dublin, Dublin, Ireland
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Universidad de Valparaíso, Valparaíso, Chile
| | - Vicente Medel
- Latin American Brain Health Institute (BrainLat), Universidad Adolfo Ibáñez, Santiago, Chile
- Brain and Mind Centre, The University of Sydney, Sydney, Australia
- Department of Neuroscience, Universidad de Chile, Santiago, Chile
| | - Grace Alma Whitaker
- Advanced Center for Electrical and Electronics Engineering (AC3E), Federico Santa María Technical University, Valparaíso, Chile
- Chair of Acoustics and Haptics, Technische Universität Dresden, Dresden, Germany
| | - Aland Astudillo
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Universidad de Valparaíso, Valparaíso, Chile
- Centro de Investigación y Desarrollo en Ingeniería en Salud, Universidad de Valparaíso, Valparaíso, Chile
- NICM Health Research Institute, Western Sydney University, Penrith, New South Wales, Australia
| | - David Gallagher
- School of Psychology, Liverpool John Moores University, Liverpool, England
| | - Lucía Z-Rivera
- Advanced Center for Electrical and Electronics Engineering (AC3E), Federico Santa María Technical University, Valparaíso, Chile
| | - Pavel Prado
- Latin American Brain Health Institute (BrainLat), Universidad Adolfo Ibáñez, Santiago, Chile
- Escuela de Fonoaudiología, Facultad de Odontología y Ciencias de la Rehabilitación, Universidad San Sebastián, Santiago, Chile
| | - Wael El-Deredy
- Advanced Center for Electrical and Electronics Engineering (AC3E), Federico Santa María Technical University, Valparaíso, Chile
- Centro de Investigación y Desarrollo en Ingeniería en Salud, Universidad de Valparaíso, Valparaíso, Chile
| | - Patricio Orio
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Universidad de Valparaíso, Valparaíso, Chile
- Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Alejandro Weinstein
- Advanced Center for Electrical and Electronics Engineering (AC3E), Federico Santa María Technical University, Valparaíso, Chile
- Centro de Investigación y Desarrollo en Ingeniería en Salud, Universidad de Valparaíso, Valparaíso, Chile
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Liu B, Yuan M, Yang M, Zhu H, Zhang W. The Effect of High-Altitude Hypoxia on Neuropsychiatric Functions. High Alt Med Biol 2024; 25:26-41. [PMID: 37815821 DOI: 10.1089/ham.2022.0136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023] Open
Abstract
Liu, Bo, Minlan Yuan, Mei Yang, Hongru Zhu, and Wei Zhang. The effect of high-altitude hypoxia on neuropsychiatric functions. High Alt Med Biol. 25:26-41, 2024. Background: In recent years, there has been a growing popularity in engaging in activities at high altitudes, such as hiking and work. However, these high-altitude environments pose risks of hypoxia, which can lead to various acute or chronic cerebral diseases. These conditions include common neurological diseases such as acute mountain sickness (AMS), high-altitude cerebral edema, and altitude-related cerebrovascular diseases, as well as psychiatric disorders such as anxiety, depression, and psychosis. However, reviews of altitude-related neuropsychiatric conditions and their potential mechanisms are rare. Methods: We conducted searches on PubMed and Google Scholar, exploring existing literature encompassing preclinical and clinical studies. Our aim was to summarize the prevalent neuropsychiatric diseases induced by altitude hypoxia, the potential pathophysiological mechanisms, as well as the available pharmacological and nonpharmacological strategies for prevention and intervention. Results: The development of altitude-related cerebral diseases may arise from various pathogenic processes, including neurovascular alterations associated with hypoxia, cytotoxic responses, activation of reactive oxygen species, and dysregulation of the expression of hypoxia inducible factor-1 and nuclear factor erythroid 2-related factor 2. Furthermore, the interplay between hypoxia-induced neurological and psychiatric changes is believed to play a role in the progression of brain damage. Conclusions: While there is some evidence pointing to pathophysiological changes in hypoxia-induced brain damage, the precise mechanisms responsible for neuropsychiatric alterations remain elusive. Currently, the range of prevention and intervention strategies available is primarily focused on addressing AMS, with a preference for prevention rather than treatment.
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Affiliation(s)
- Bo Liu
- Mental Health Center and Psychiatric Laboratory, West China Hospital of Sichuan University, Chengdu, China
- Zigong Mental Health Center, Zigong, China
| | - Minlan Yuan
- Mental Health Center and Psychiatric Laboratory, West China Hospital of Sichuan University, Chengdu, China
| | - Mei Yang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China School of Basic Medical Sciences and Forensic Medicine, Chengdu, Sichuan
| | - Hongru Zhu
- Mental Health Center and Psychiatric Laboratory, West China Hospital of Sichuan University, Chengdu, China
| | - Wei Zhang
- Mental Health Center and Psychiatric Laboratory, West China Hospital of Sichuan University, Chengdu, China
- West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, China
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Keeler JM, Listman JB, Hite MJ, Heeger DJ, Tourula E, Port NL, Schlader ZJ. Arterial oxygen desaturation during moderate hypoxia hinders sensorimotor performance. PLoS One 2024; 19:e0297486. [PMID: 38394255 PMCID: PMC10889874 DOI: 10.1371/journal.pone.0297486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 01/06/2024] [Indexed: 02/25/2024] Open
Abstract
INTRODUCTION Moderate hypoxia may impact cognitive and sensorimotor performance prior to self-recognized impairments. Therefore, rapid and objective assessment tools to identify people at risk of impaired function during moderate hypoxia is needed. PURPOSE Test the hypothesis that reductions in arterial oxygen saturation during moderate normobaric hypoxia (FiO2 = 14%) decreases gamified sensorimotor performance as measured by alterations of motor acuity. METHODS Following three consecutive days of practice, thirty healthy adults (25 ± 5 y, 10 females) completed three bouts of the tablet-based gamified assessment (Statespace Labs, Inc.) of motor acuity at Baseline and 60 and 90 min after exposure to 13.8 ± 0.2% (hypoxia) and 20.1 ± 0.4% (normoxia) oxygen. The gamified assessment involved moving the tablet to aim and shoot at targets. Both conditions were completed on the same day and were administered in a single-blind, block randomized manner. Performance metrics included shot time and shot variability. Arterial oxyhemoglobin saturation estimated via forehead pulse oximetry (SpO2). Data were analyzed using linear mixed effects models. RESULTS Compared to normoxia (99±1%), SpO2 was lower (p<0.001) at 60 (89±3%) and 90 (90±2%) min of hypoxia. Shot time was unaffected by decreases in SpO2 (0.012, p = 0.19). Nor was shot time affected by the interaction between SpO2 decrease and baseline performance (0.006, p = 0.46). Shot variability was greater (i.e., less precision, worse performance) with decreases in SpO2 (0.023, p = 0.02) and depended on the interaction between SpO2 decrease and baseline performance (0.029, p< 0.01). CONCLUSION Decreases in SpO2 during moderate hypoxic exposure hinders sensorimotor performance via decreased motor acuity, i.e., greater variability (less precision) with no change in speed with differing decreases in SpO2. Thus, personnel who are exposed to moderate hypoxia and have greater decreases in SpO2 exhibit lower motor acuity, i.e., less precise movements even though decision time and movement speed are unaffected.
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Affiliation(s)
- Jason M. Keeler
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, School of Public Health-Bloomington, Indiana University, Bloomington, IN, United States of America
| | | | - M. Jo Hite
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, School of Public Health-Bloomington, Indiana University, Bloomington, IN, United States of America
| | - David J. Heeger
- Statespace Labs, Inc. New York, NY, United States of America
| | - Erica Tourula
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, School of Public Health-Bloomington, Indiana University, Bloomington, IN, United States of America
| | - Nicholas L. Port
- School of Optometry, Indiana University, Bloomington, IN, United States of America
| | - Zachary J. Schlader
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, School of Public Health-Bloomington, Indiana University, Bloomington, IN, United States of America
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Kiuchi M, Uno T, Hasegawa T, Koyama K, Horiuchi M. Influence of short-term hypoxic exposure on spatial learning and memory function and brain-derived neurotrophic factor in rats-A practical implication to human's lost way. Front Behav Neurosci 2024; 18:1330596. [PMID: 38380151 PMCID: PMC10876868 DOI: 10.3389/fnbeh.2024.1330596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/22/2024] [Indexed: 02/22/2024] Open
Abstract
The present study aimed to investigate the effects of a short period of normobaric hypoxic exposure on spatial learning and memory, and brain-derived neurotrophic factor (BDNF) levels in the rat hippocampus. Hypoxic conditions were set at 12.5% O2. We compared all variables between normoxic trials (Norm), after 24 h (Hypo-24 h), and after 72 h of hypoxic exposure (Hypo-72 h). Spatial learning and memory were evaluated by using a water-finding task in an open field. Time to find water drinking fountains was significantly extended in Hypo 24 h (36.2 ± 21.9 s) compared to those in Norm (17.9 ± 12.8 s; P < 0.05), whereas no statistical differences between Norm and Hypo-72 h (22.7 ± 12.3 s). Moreover, hippocampal BDNF level in Hypo-24 h was significantly lower compared to Norm (189.4 ± 28.4 vs. 224.9 ± 47.7 ng/g wet tissue, P < 0.05), whereas no statistically differences in those between Norm and Hypo-72 h (228.1 ± 39.8 ng/g wet tissue). No significant differences in the changes in corticosterone and adrenocorticotropic hormone levels were observed across the three conditions. When data from Hypo-24 h and Hypo-72 h of hypoxia were pooled, there was a marginal negative relationship between the time to find drinking fountains and BDNF (P < 0.1), and was a significant negative relationship between the locomotor activities and BDNF (P < 0.05). These results suggest that acute hypoxic exposure (24 h) may impair spatial learning and memory; however, it recovered after 72 h of hypoxic exposure. These changes in spatial learning and memory may be associated with changes in the hippocampal BDNF levels in rats.
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Affiliation(s)
- Masataka Kiuchi
- Graduate School Department of Interdisciplinary Research, University of Yamanashi, Kofu, Yamanashi, Japan
| | - Tadashi Uno
- Division of Human Environmental Science, Mount Fuji Research Institute, Fujiyoshida, Yamanashi, Japan
| | - Tatsuya Hasegawa
- Division of Human Environmental Science, Mount Fuji Research Institute, Fujiyoshida, Yamanashi, Japan
| | - Katsuhiro Koyama
- Faculty of Sport Science, Yamanashi Gakuin University, Kofu, Yamanashi, Japan
| | - Masahiro Horiuchi
- Division of Human Environmental Science, Mount Fuji Research Institute, Fujiyoshida, Yamanashi, Japan
- Faculty of Sports and Life Science, National Institute of Fitness and Sports in Kanoya, Kanoya, Kagoshima, Japan
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Ando S, Tsukamoto H, Stacey BS, Washio T, Owens TS, Calverley TA, Fall L, Marley CJ, Iannetelli A, Hashimoto T, Ogoh S, Bailey DM. Acute hypoxia impairs posterior cerebral bioenergetics and memory in man. Exp Physiol 2023; 108:1516-1530. [PMID: 37898979 PMCID: PMC10988469 DOI: 10.1113/ep091245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 10/03/2023] [Indexed: 10/31/2023]
Abstract
Hypoxia has the potential to impair cognitive function; however, it is still uncertain which cognitive domains are adversely affected. We examined the effects of acute hypoxia (∼7 h) on central executive (Go/No-Go) and non-executive (memory) tasks and the extent to which impairment was potentially related to regional cerebral blood flow and oxygen delivery (CDO2 ). Twelve male participants performed cognitive tasks following 0, 2, 4 and 6 h of passive exposure to both normoxia and hypoxia (12% O2 ), in a randomized block cross-over single-blinded design. Middle cerebral artery (MCA) and posterior cerebral artery (PCA) blood velocities and corresponding CDO2 were determined using bilateral transcranial Doppler ultrasound. In hypoxia, MCA DO2 was reduced during the Go/No-Go task (P = 0.010 vs. normoxia, main effect), and PCA DO2 was attenuated during memorization (P = 0.005 vs. normoxia) and recall components (P = 0.002 vs. normoxia) in the memory task. The accuracy of the memory task was also impaired in hypoxia (P = 0.049 vs. normoxia). In contrast, hypoxia failed to alter reaction time (P = 0.19 vs. normoxia) or accuracy (P = 0.20 vs. normoxia) during the Go/No-Go task, indicating that selective attention and response inhibition were preserved. Hypoxia did not affect cerebral blood flow or corresponding CDO2 responses to cognitive activity (P > 0.05 vs. normoxia). Collectively, these findings highlight the differential sensitivity of cognitive domains, with memory being selectively vulnerable in hypoxia. NEW FINDINGS: What is the central question of this study? We sought to examine the effects of acute hypoxia on central executive (selective attention and response inhibition) and non-executive (memory) performance and the extent to which impairments are potentially related to reductions in regional cerebral blood flow and oxygen delivery. What is the main finding and its importance? Memory was impaired in acute hypoxia, and this was accompanied by a selective reduction in posterior cerebral artery oxygen delivery. In contrast, selective attention and response inhibition remained well preserved. These findings suggest that memory is selectively vulnerable to hypoxia.
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Affiliation(s)
- Soichi Ando
- Graduate School of Informatics and EngineeringThe University of Electro‐CommunicationsTokyoJapan
| | - Hayato Tsukamoto
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
- Faculty of Sports ScienceWaseda UniversitySaitamaJapan
| | - Benjamin S. Stacey
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
| | - Takuro Washio
- Department of Biomedical EngineeringToyo UniversityKawagoeSaitamaJapan
| | - Thomas S. Owens
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
| | - Thomas A. Calverley
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
| | - Lewis Fall
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
| | - Christopher J. Marley
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
| | - Angelo Iannetelli
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
| | | | - Shigehiko Ogoh
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
- Department of Biomedical EngineeringToyo UniversityKawagoeSaitamaJapan
| | - Damian M. Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
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11
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Garrido E, Hüfner K. An Episode of "Third Person" Phenomenon Involving Somesthetic and Visual Hallucinations in a World-Class Extreme Altitude Climber. Wilderness Environ Med 2023; 34:549-552. [PMID: 37620238 DOI: 10.1016/j.wem.2023.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/14/2023] [Accepted: 07/14/2023] [Indexed: 08/26/2023]
Abstract
Psychotic symptoms can occur at high altitude. However, most reports are in the mountaineering literature and lack a clear medical assessment and interpretation. Here we report an episode of isolated high-altitude psychosis. It consisted of a "third person" phenomenon involving 2 sensory modalities: somesthetic (felt presence) and visual (the light of 2 flashlights) hallucinations. This episode occurred in a highly experienced climber when he was at an altitude of approximately 7500 m while descending at dusk from the summit of Gasherbrum I (8068 m). The symptoms lasted approximately 3 h and had fully resolved on reaching high camp (7150 m). No other physical or mental symptoms were reported. In addition to hypoxia, a number of other risk factors could have contributed to the occurrence of psychosis in this climber. These included sleep deprivation, exhaustion, dehydration, electrolyte disturbance, reduced visibility, feeling of isolation, and perceived danger. The climber has participated in many extreme altitude expeditions, and neither before nor since this episode has the climber experienced psychotic symptoms.
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Affiliation(s)
- Eduardo Garrido
- Hypobaria and Biomedical Physiology Service, Department of Physiological Sciences II, University of Barcelona-Bellvitge University Campus, Barcelona, Spain.
| | - Katharina Hüfner
- Department for Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, University Clinic for Psychiatry II (Psychosomatic Medicine), Medical University Innsbruck, Innsbruck, Austria
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12
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Hencz A, Magony A, Thomas C, Kovacs K, Szilagyi G, Pal J, Sik A. Mild hypoxia-induced structural and functional changes of the hippocampal network. Front Cell Neurosci 2023; 17:1277375. [PMID: 37841285 PMCID: PMC10576450 DOI: 10.3389/fncel.2023.1277375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 09/15/2023] [Indexed: 10/17/2023] Open
Abstract
Hypoxia causes structural and functional changes in several brain regions, including the oxygen-concentration-sensitive hippocampus. We investigated the consequences of mild short-term hypoxia on rat hippocampus in vivo. The hypoxic group was treated with 16% O2 for 1 h, and the control group with 21% O2. Using a combination of Gallyas silver impregnation histochemistry revealing damaged neurons and interneuron-specific immunohistochemistry, we found that somatostatin-expressing inhibitory neurons in the hilus were injured. We used 32-channel silicon probe arrays to record network oscillations and unit activity from the hippocampal layers under anaesthesia. There were no changes in the frequency power of slow, theta, beta, or gamma bands, but we found a significant increase in the frequency of slow oscillation (2.1-2.2 Hz) at 16% O2 compared to 21% O2. In the hilus region, the firing frequency of unidentified interneurons decreased. In the CA3 region, the firing frequency of some unidentified interneurons decreased while the activity of other interneurons increased. The activity of pyramidal cells increased both in the CA1 and CA3 regions. In addition, the regularity of CA1, CA3 pyramidal cells' and CA3 type II and hilar interneuron activity has significantly changed in hypoxic conditions. In summary, a low O2 environment caused profound changes in the state of hippocampal excitatory and inhibitory neurons and network activity, indicating potential changes in information processing caused by mild short-term hypoxia.
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Affiliation(s)
- Alexandra Hencz
- Institute of Physiology, Medical School, University of Pecs, Pecs, Hungary
| | - Andor Magony
- Institute of Physiology, Medical School, University of Pecs, Pecs, Hungary
- Institute of Transdisciplinary Discoveries, Medical School, University of Pecs, Pecs, Hungary
| | - Chloe Thomas
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Krisztina Kovacs
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Gabor Szilagyi
- Institute of Biochemistry and Medical Chemistry, Medical School, University of Pecs, Pecs, Hungary
| | - Jozsef Pal
- Institute of Physiology, Medical School, University of Pecs, Pecs, Hungary
| | - Attila Sik
- Institute of Physiology, Medical School, University of Pecs, Pecs, Hungary
- Institute of Transdisciplinary Discoveries, Medical School, University of Pecs, Pecs, Hungary
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
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13
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Chen X, Zhang J, Lin Y, Li Y, Wang H, Wang Z, Liu H, Hu Y, Liu L. Mechanism, prevention and treatment of cognitive impairment caused by high altitude exposure. Front Physiol 2023; 14:1191058. [PMID: 37731540 PMCID: PMC10507266 DOI: 10.3389/fphys.2023.1191058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/05/2023] [Indexed: 09/22/2023] Open
Abstract
Hypobaric hypoxia (HH) characteristics induce impaired cognitive function, reduced concentration, and memory. In recent years, an increasing number of people have migrated to high-altitude areas for work and study. Headache, sleep disturbance, and cognitive impairment from HH, severely challenges the physical and mental health and affects their quality of life and work efficiency. This review summarizes the manifestations, mechanisms, and preventive and therapeutic methods of HH environment affecting cognitive function and provides theoretical references for exploring and treating high altitude-induced cognitive impairment.
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Affiliation(s)
- Xin Chen
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Jiexin Zhang
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
- Faculty of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, Hubei, China
| | - Yuan Lin
- Sichuan Xincheng Biological Co., LTD., Chengdu, Sichuan, China
| | - Yan Li
- Department of General Surgery, The 77th Army Hospital, Leshan, Sichuan, China
| | - Han Wang
- Department of Cardiology, Affiliated Hospital of Southwest Jiaotong University, The Third People’s Hospital of Chengdu, Chengdu, Sichuan, China
| | - Zhanhao Wang
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Huawei Liu
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Yonghe Hu
- Faculty of Medicine, Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Lei Liu
- Medical Research Center, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
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14
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Bakker ME, Djerourou I, Belanger S, Lesage F, Vanni MP. Alteration of functional connectivity despite preserved cerebral oxygenation during acute hypoxia. Sci Rep 2023; 13:13269. [PMID: 37582847 PMCID: PMC10427674 DOI: 10.1038/s41598-023-40321-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 08/08/2023] [Indexed: 08/17/2023] Open
Abstract
Resting state networks (RSN), which show the connectivity in the brain in the absence of any stimuli, are increasingly important to assess brain function. Here, we investigate the changes in RSN as well as the hemodynamic changes during acute, global hypoxia. Mice were imaged at different levels of oxygen (21, 12, 10 and 8%) over the course of 10 weeks, with hypoxia and normoxia acquisitions interspersed. Simultaneous GCaMP and intrinsic optical imaging allowed tracking of both neuronal and hemodynamic changes. During hypoxic conditions, we found a global increase of both HbO and HbR in the brain. The saturation levels of blood dropped after the onset of hypoxia, but surprisingly climbed back to levels similar to baseline within the 10-min hypoxia period. Neuronal activity also showed a peak at the onset of hypoxia, but dropped back to baseline as well. Despite regaining baseline sO2 levels, changes in neuronal RSN were observed. In particular, the connectivity as measured with GCaMP between anterior and posterior parts of the brain decreased. In contrast, when looking at these same connections with HbO measurements, an increase in connectivity in anterior-posterior brain areas was observed suggesting a potential neurovascular decoupling.
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Affiliation(s)
- Marleen E Bakker
- École d'Optométrie, Université de Montréal, 2500 Chem. De Polytechnique, Montréal, QC, H3T 1J4, Canada.
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montréal, Canada.
| | - Ismaël Djerourou
- École d'Optométrie, Université de Montréal, 2500 Chem. De Polytechnique, Montréal, QC, H3T 1J4, Canada
| | | | - Frédéric Lesage
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montréal, Canada
- Montréal Heart Institute, Montréal, Canada
| | - Matthieu P Vanni
- École d'Optométrie, Université de Montréal, 2500 Chem. De Polytechnique, Montréal, QC, H3T 1J4, Canada
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15
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Keeler JM, Tourula E, Hite MJ, Listman JB, Heeger DJ, Port NL, Schlader ZJ. Gamified assessment of cognitive performance during moderate hypoxia. PLoS One 2023; 18:e0288201. [PMID: 37459310 PMCID: PMC10351691 DOI: 10.1371/journal.pone.0288201] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 06/21/2023] [Indexed: 07/20/2023] Open
Abstract
INTRODUCTION There is a need for rapid and objective assessment tools to identify people at risk of impaired cognitive function during hypoxia. PURPOSE To test the hypotheses that performance on gamified cognitive tests examining the cognitive domains of executive function (Gridshot), working memory (Capacity) and spatial tracking (Multitracker) will be reduced during normobaric exposure to moderate normobaric hypoxia. METHODS Following three consecutive days of practice, twenty-one healthy adults (27 ± 5 y, 9 females) completed five 1-min rounds of the tablet-based games Gridshot, Capacity, and Multitracker (Statespace Labs, Inc.) at Baseline and 60 and 90 min after exposure to 14.0 ± 0.2% (hypoxia) and 20.6 ± 0.3% (normoxia) oxygen. Both conditions were completed on the same day and were administered in a single-blind, block randomized manner. Arterial oxyhemoglobin saturation was estimated via forehead pulse oximetry (SpO2). Data were analyzed using ANCOVA with a covariate of Baseline. RESULTS Compared to normoxia (98 ± 1%), SpO2 was lower (p < 0.001) at 60 (91 ± 3%) and 90 (91 ± 2%) min of hypoxia. No condition x time interaction effects were identified for any gamified cognitive tests (p ≥ 0.32). A main effect of condition was identified for Capacity (p = 0.05) and Multitracker (p = 0.04), but not Gridshot (p = 0.33). Post hoc analyses of the composite scores for both Capacity (p = 0.11) and Multitracker (p = 0.73) demonstrated no difference between conditions. CONCLUSION Performance on gamified cognitive tests was not consistently affected by acute normobaric moderate hypoxic exposure.
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Affiliation(s)
- Jason M. Keeler
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, School of Public Health, Indiana University, Bloomington, Indiana, United States of America
| | - Erica Tourula
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, School of Public Health, Indiana University, Bloomington, Indiana, United States of America
| | - M. Jo Hite
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, School of Public Health, Indiana University, Bloomington, Indiana, United States of America
| | | | - David J. Heeger
- Statespace Labs, Inc. New York, New York, United States of America
| | - Nicholas L. Port
- School of Optometry, Indiana University, Bloomington, Indiana, United States of America
| | - Zachary J. Schlader
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, School of Public Health, Indiana University, Bloomington, Indiana, United States of America
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16
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Aboouf MA, Thiersch M, Soliz J, Gassmann M, Schneider Gasser EM. The Brain at High Altitude: From Molecular Signaling to Cognitive Performance. Int J Mol Sci 2023; 24:10179. [PMID: 37373327 DOI: 10.3390/ijms241210179] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/13/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
The brain requires over one-fifth of the total body oxygen demand for normal functioning. At high altitude (HA), the lower atmospheric oxygen pressure inevitably challenges the brain, affecting voluntary spatial attention, cognitive processing, and attention speed after short-term, long-term, or lifespan exposure. Molecular responses to HA are controlled mainly by hypoxia-inducible factors. This review aims to summarize the cellular, metabolic, and functional alterations in the brain at HA with a focus on the role of hypoxia-inducible factors in controlling the hypoxic ventilatory response, neuronal survival, metabolism, neurogenesis, synaptogenesis, and plasticity.
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Affiliation(s)
- Mostafa A Aboouf
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Department of Biochemistry, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Markus Thiersch
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Jorge Soliz
- Institute Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Faculty of Medicine, Université Laval, Québec, QC G1V 4G5, Canada
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Edith M Schneider Gasser
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Institute Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Faculty of Medicine, Université Laval, Québec, QC G1V 4G5, Canada
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, 8057 Zurich, Switzerland
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17
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Prosperi P, Verratti V, Taverna A, Rua R, Bonan S, Rapacchiale G, Bondi D, Di Giulio C, Lorkowski J, Spacone A. Ventilatory function and oxygen delivery at high altitude in the Himalayas. Respir Physiol Neurobiol 2023:104086. [PMID: 37257573 DOI: 10.1016/j.resp.2023.104086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 05/22/2023] [Accepted: 05/26/2023] [Indexed: 06/02/2023]
Abstract
This study aimed to evaluate changes in lung function assessed by spirometry and blood gas content in healthy high-altitude sojourners during a trek in the Himalayas. A group of 19 Italian adults (11 males and 8 females, mean age 43 ±15 years, and BMI 24.2 ±3.7kg/m2) were evaluated as part of a Mount Everest expedition in Nepal. Spirometry and arterial blood gas content were evaluated at baseline in Kathmandu (≈1400m), at the Pyramid Laboratory - Observatory (peak altitude of ≈5000m), and on return to Kathmandu 2-3 days after arrival at each site. All participants took 250mg of acetazolamide per os once daily during the ascent. We found that arterial hemoglobin saturation, O2 and CO2 partial pressures, and the bicarbonate level all decreased (in all cases, p<0.001 with R2=0.70-0.90), while pHa was maintained stable at the peak altitude. Forced vital capacity (FVC) remained stable, while forced expiratory volume in 1sec (FEV1) decreased (p=0.010, n2p=0.228), resulting in a lower FEV1/FVC ratio (p<0.001, n2p=0.380). The best predictor for acute mountain sickness was the O2 partial pressure at the peak altitude (p=0.004, R2=0.39). Finger pulse oximetry overestimated peripheral saturation relative to arterial saturation. We conclude that high-altitude hypoxia alters the respiratory function and the oxygen saturation of the arterial blood hemoglobin. Additionally, air rarefaction and temperature reduction, favoring hypoxic bronchoconstriction, could affect respiration. Pulse oximetry seems not enough to assist medical decisions at high altitudes.
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Affiliation(s)
- Pierpaolo Prosperi
- Department of Pneumology and Respiratory Physiopathology, S. Spirito Hospital, 66020 Pescara, Italy.
| | - Vittore Verratti
- Department of Psychological, Health and Territorial Sciences, 'G. d'Annunzio' University of Chieti-Pescara, 66100 Chieti, Italy.
| | - Alberto Taverna
- Department of Translational Medicine and for Romagna, University of Ferrara, 44121 Ferrara, Italy.
| | - Riccardo Rua
- Department of Anesthesia, Critical Care, and Emergency, University of Turin, 10126 Turin, Italy.
| | - Sofia Bonan
- Department of Medicine and Aging Sciences, 'G. d'Annunzio' University of Chieti-Pescara, 66100 Chieti, Italy.
| | - Giorgia Rapacchiale
- Department of Pneumology and Respiratory Physiopathology, S. Spirito Hospital, 66020 Pescara, Italy.
| | - Danilo Bondi
- Department of Neuroscience, Imaging and Clinical Sciences, 'G. d'Annunzio' University of Chieti-Pescara, 66100 Chieti, Italy.
| | - Camillo Di Giulio
- Department of Neuroscience, Imaging and Clinical Sciences, 'G. d'Annunzio' University of Chieti-Pescara, 66100 Chieti, Italy.
| | - Jacek Lorkowski
- Department of Orthopedics, Traumatology, and Sports Medicine, Central Clinical Hospital of the Ministry of Internal Affairs and Administration, 02-507 Warsaw, Pol.
| | - Antonella Spacone
- Department of Pneumology and Respiratory Physiopathology, S. Spirito Hospital, 66020 Pescara, Italy.
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Bao X, Zhang D, Li X, Liu M, Ma H. Long-term high-altitude exposure influences task-related representations in visual working memory. Front Neurol 2023; 14:1149623. [PMID: 37273714 PMCID: PMC10236478 DOI: 10.3389/fneur.2023.1149623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 04/27/2023] [Indexed: 06/06/2023] Open
Abstract
Objective Human working memory is impaired when individuals are exposed to high altitudes, however, whether the capacity of visual working memory is affected remains unclear. This study combined a lateralized change detection task and event-related potentials analysis to explore changes in visual working memory capacity among individuals who emigrated from a low-altitude environment to Tibet (a high-altitude environment). Materials and methods Thirty-five college students were recruited from Tibet University as the high-altitude (HA) group, and thirty-six low-altitude (LA) students were enrolled from South China Normal University (sea level) as the LA group. We measured participants' contralateral delay activity (CDA) under different memory loads. Results ERP component analysis showed that both the HA and LA groups reached an asymptote at memory load four. However, the contralateral and ipsilateral activity of the HA and LA groups shows different patterns. The results showed a significantly larger contralateral activity for the LA group than for the HA group at memory load one (p = 0.04, Cohen's d = 0.52) and load three (p = 0.02, Cohen's d = 0.61). Additionally, we found marginally larger contralateral activity at memory load four for the LA group (p = 0.06, Cohen's d = 0.47), but not at memory load two (p = 0.10) or load five (p = 0.12). No significant differences were observed for ipsilateral activity. In addition, we observed that the HA group performed larger ipsilateral activity than contralateral activity under each memory load, compared with the LA group. Conclusion These findings demonstrated that the attentional resource of long-term HA exposure is more captured by task-irrelevant information, potentially due to impaired inhibitory control, which makes it difficult for them to exclude the interference of task-irrelevant information.
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Affiliation(s)
- Xiaohua Bao
- Faculty of Psychology, Tianjin Normal University, Tianjin, China
| | - Delong Zhang
- Plateau Brain Science Research Center, South China Normal University, Guangzhou, China
- Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University, Guangzhou, China
| | - Xiaoyan Li
- Plateau Brain Science Research Center, Tibet University, Lhasa, China
| | - Ming Liu
- Plateau Brain Science Research Center, South China Normal University, Guangzhou, China
- Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University, Guangzhou, China
| | - Hailin Ma
- Plateau Brain Science Research Center, Tibet University, Lhasa, China
- Academy of Plateau Science and Sustainability, People's Government of Qinghai Province, Xining, China
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19
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Aarskog NR, Iuell RS, Dunlop O, Sevre K, Bendz B, Rostrup M. Neuropsychological function is associated with hypocapnia at simulated high altitude. Acta Physiol (Oxf) 2023; 237:e13949. [PMID: 36772955 DOI: 10.1111/apha.13949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023]
Affiliation(s)
- Nikolai Ravn Aarskog
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Acute Medicine, Division of Medicine, Oslo University Hospital, Oslo, Norway
| | | | - Oona Dunlop
- Department of Acute Medicine, Division of Medicine, Oslo University Hospital, Oslo, Norway
| | - Knut Sevre
- Department of Cardiology, Division of Cardiovascular & Pulmonary Diseases, Oslo University Hospital, Oslo, Norway
| | - Bjørn Bendz
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Cardiology, Division of Cardiovascular & Pulmonary Diseases, Oslo University Hospital, Oslo, Norway
| | - Morten Rostrup
- Department of Acute Medicine, Division of Medicine, Oslo University Hospital, Oslo, Norway
- Department of Behavioural Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
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20
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Prete G, Bondi D, Mammarella N, Verratti V, Tommasi L. Investigating Auditory Perception at Europe's Highest Mountain Lodge. Percept Mot Skills 2023; 130:929-937. [PMID: 36939848 DOI: 10.1177/00315125231165165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
Altitude hypoxia can impair sensory and cognitive functions, from causing slowed responses to sensory hallucinations. In a field study, we tested 12 expeditioners at varied altitudes (low: 1696 m; high: 4556 m) with a simple auditory detection task and a dichotic listening paradigm in which a voice was presented, lateralized, within a binaural white noise stream. Slower reaction times and a reduced right ear advantage might be expected at high (vs. low) altitude, due to hypoxia. The participants' performances on both tasks did not differ between conditions, revealing that these functions are resistant to short-term hypoxia in young healthy adults.
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Affiliation(s)
- Giulia Prete
- Department of Psychological, Health and Territorial Sciences, 9301"G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - Danilo Bondi
- Department of Neuroscience, Imaging and Clinical Sciences, 9301"G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - Nicola Mammarella
- Department of Psychological, Health and Territorial Sciences, 9301"G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - Vittore Verratti
- Department of Psychological, Health and Territorial Sciences, 9301"G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - Luca Tommasi
- Department of Psychological, Health and Territorial Sciences, 9301"G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
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21
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Tunalı CH, Ünal S, Kamışlı S. A frontotemporal dementia-like case after high-altitude climbing. THE EGYPTIAN JOURNAL OF NEUROLOGY, PSYCHIATRY AND NEUROSURGERY 2023. [DOI: 10.1186/s41983-023-00610-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Abstract
Background
We report a case who developed long-term neuropsychiatric sequelae similar to frontotemporal dementia after suffering a "high altitude sickness" while climbing a high mountain without taking precautions against acute hypoxia.
Case presentation
The 57-year-old patient showed symptoms of acute mountain sickness after climbing 3500 m. A few months after descending the mountain, he developed symptoms such as loss of empathy, decreased speech, perseveration, echolalia, and increased interest in sugary foods. The patient's MRI and PET/CT results were consistent with frontotemporal neurodegeneration. After the start of donepezil, persecution delusions developed, and the clinical picture worsened. In the process, he developed visual agnosia and anomic aphasia. Although there was no significant change in personality traits at the beginning, the patient developed apathy, loss of inhibition, lack of empathy, progressive aphasia, and problems perceiving and expressing emotions. A significant loss of function occurred within 4 years. The patient met the criteria for "probable behavioral variant frontotemporal dementia", but was defined as a frontotemporal dementia-like case due to possible relevance to a medical condition affecting the brain.
Conclusions
This case suggests that clinicians should be more careful about the chronic consequences of high-altitude diseases and avoid cholinesterase inhibitors such as donepezil, as it can worsen behavioral symptoms of frontotemporal dementia-like symptomatology.
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22
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Reiser AE, Furian M, Lichtblau M, Buergin A, Schneider SR, Appenzeller P, Mayer L, Muralt L, Mademilov M, Abdyraeva A, Aidaralieva S, Muratbekova A, Akylbekov A, Sheraliev U, Shabykeeva S, Sooronbaev TM, Ulrich S, Bloch KE. Effect of acetazolamide on visuomotor performance at high altitude in healthy people 40 years of age or older-RCT. PLoS One 2023; 18:e0280585. [PMID: 36662903 PMCID: PMC9858039 DOI: 10.1371/journal.pone.0280585] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 01/04/2023] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE Altitude travel is increasingly popular also for middle-aged and older tourists and professionals. Due to the sensitivity of the central nervous system to hypoxia, altitude exposure may impair visuomotor performance although this has not been extensively studied. Therefore, we investigated whether a sojourn at moderately high altitude is associated with visuomotor performance impairments in healthy adults, 40y of age or older, and whether this adverse altitude-effect can be prevented by acetazolamide, a drug used to prevent acute mountain sickness. METHODS In this randomized placebo-controlled parallel-design trial, 59 healthy lowlanders, aged 40-75y, were assigned to acetazolamide (375 mg/day, n = 34) or placebo (n = 25), administered one day before ascent and while staying at high altitude (3100m). Visuomotor performance was assessed at 760m and 3100m after arrival and in the next morning (post-sleep) by a computer-assisted test (Motor-Task-Manager). It quantified deviation of a participant-controlled cursor affected by rotation during target tracking. Primary outcome was the directional error during post-sleep recall of adaptation to rotation estimated by multilevel linear regression modeling. Additionally, adaptation, immediate recall, and correct test execution were evaluated. RESULTS Compared to 760m, assessments at 3100m with placebo revealed a mean (95%CI) increase in directional error during adaptation and immediate recall by 1.9° (0.2 to 3.5, p = 0.024) and 1.1° (0.4 to 1.8, p = 0.002), respectively. Post-sleep recall remained unchanged (p = NS), however post-sleep correct test execution was 14% less likely (9 to 19, p<0.001). Acetazolamide improved directional error during post-sleep recall by 5.6° (2.6 to 8.6, p<0.001) and post-sleep probability of correct test execution by 36% (30 to 42, p<0.001) compared to placebo. CONCLUSION In healthy individuals, 40y of age or older, altitude exposure impaired adaptation to and immediate recall and correct execution of a visuomotor task. Preventive acetazolamide treatment improved visuomotor performance after one night at altitude and increased the probability of correct test execution compared to placebo. CLINICALTRIALS.GOV IDENTIFIER ClinicalTrials.gov NCT03536520.
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Affiliation(s)
- Aurelia E. Reiser
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Michael Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Mona Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Aline Buergin
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Simon R. Schneider
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Paula Appenzeller
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Laura Mayer
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Lara Muralt
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Maamed Mademilov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Ainura Abdyraeva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Shoira Aidaralieva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Aibermet Muratbekova
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Azamat Akylbekov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Ulan Sheraliev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Saltanat Shabykeeva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Talant M. Sooronbaev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Konrad E. Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
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23
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Cognition and Neuropsychological Changes at Altitude-A Systematic Review of Literature. Brain Sci 2022; 12:brainsci12121736. [PMID: 36552195 PMCID: PMC9775937 DOI: 10.3390/brainsci12121736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/05/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
High-altitude (HA) exposure affects cognitive functions, but studies have found inconsistent results. The aim of this systematic review was to evaluate the effects of HA exposure on cognitive functions in healthy subjects. A structural overview of the applied neuropsychological tests was provided with a classification of superordinate cognitive domains. A literature search was performed using PubMed up to October 2021 according to PRISMA guidelines. Eligibility criteria included a healthy human cohort exposed to altitude in the field (at minimum 2440 m [8000 ft]) or in a hypoxic environment in a laboratory, and an assessment of cognitive domains. The literature search identified 52 studies (29 of these were field studies; altitude range: 2440 m-8848 m [8000-29,029 ft]). Researchers applied 112 different neuropsychological tests. Attentional capacity, concentration, and executive functions were the most frequently studied. In the laboratory, the ratio of altitude-induced impairments (64.7%) was twice as high compared to results showing no change or improved results (35.3%), but altitudes studied were similar in the chamber compared to field studies. In the field, the opposite results were found (66.4 % no change or improvements, 33.6% impairments). Since better acclimatization can be assumed in the field studies, the findings support the hypothesis that sufficient acclimatization has beneficial effects on cognitive functions at HA. However, it also becomes apparent that research in this area would benefit most if a consensus could be reached on a standardized framework of freely available neurocognitive tests.
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24
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Fabries P, Gomez-Merino D, Sauvet F, Malgoyre A, Koulmann N, Chennaoui M. Sleep loss effects on physiological and cognitive responses to systemic environmental hypoxia. Front Physiol 2022; 13:1046166. [PMID: 36579023 PMCID: PMC9792101 DOI: 10.3389/fphys.2022.1046166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/29/2022] [Indexed: 12/15/2022] Open
Abstract
In the course of their missions or training, alpinists, but also mountain combat forces and mountain security services, professional miners, aircrew, aircraft and glider pilots and helicopter crews are regularly exposed to altitude without oxygen supplementation. At altitude, humans are exposed to systemic environmental hypoxia induced by the decrease in barometric pressure (<1,013 hPa) which decreases the inspired partial pressure of oxygen (PIO2), while the oxygen fraction is constant (equal to approximately 20.9%). Effects of altitude on humans occur gradually and depend on the duration of exposure and the altitude level. From 1,500 m altitude (response threshold), several adaptive responses offset the effects of hypoxia, involving the respiratory and the cardiovascular systems, and the oxygen transport capacity of the blood. Fatigue and cognitive and sensory disorders are usually observed from 2,500 m (threshold of prolonged hypoxia). Above 3,500 m (the threshold for disorders), the effects are not completely compensated and maladaptive responses occur and individuals develop altitude headache or acute altitude illness [Acute Mountain Sickness (AMS)]. The magnitude of effects varies considerably between different physiological systems and exhibits significant inter-individual variability. In addition to comorbidities, the factors of vulnerability are still little known. They can be constitutive (genetic) or circumstantial (sleep deprivation, fatigue, speed of ascent.). In particular, sleep loss, a condition that is often encountered in real-life settings, could have an impact on the physiological and cognitive responses to hypoxia. In this review, we report the current state of knowledge on the impact of sleep loss on responses to environmental hypoxia in humans, with the aim of identifying possible consequences for AMS risk and cognition, as well as the value of behavioral and non-pharmacological countermeasures.
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Affiliation(s)
- Pierre Fabries
- REF-Aero Department, French Armed Forces Biomedical Research Institute—IRBA, Brétigny-sur-Orge, France,Laboratoire de Biologie de l’Exercice pour la Performance et la Santé (LBEPS), UMR, Université Paris-Saclay, IRBA, Evry-Courcouronnes, France,French Military Health Academy—Ecole du Val-de-Grâce, Place Alphonse Laveran, Paris, France,*Correspondence: Pierre Fabries,
| | - Danielle Gomez-Merino
- REF-Aero Department, French Armed Forces Biomedical Research Institute—IRBA, Brétigny-sur-Orge, France,Vigilance Fatigue Sommeil et Santé Publique (VIFASOM) URP 7330, Université de Paris Cité, Paris, France
| | - Fabien Sauvet
- REF-Aero Department, French Armed Forces Biomedical Research Institute—IRBA, Brétigny-sur-Orge, France,French Military Health Academy—Ecole du Val-de-Grâce, Place Alphonse Laveran, Paris, France,Vigilance Fatigue Sommeil et Santé Publique (VIFASOM) URP 7330, Université de Paris Cité, Paris, France
| | - Alexandra Malgoyre
- REF-Aero Department, French Armed Forces Biomedical Research Institute—IRBA, Brétigny-sur-Orge, France,Laboratoire de Biologie de l’Exercice pour la Performance et la Santé (LBEPS), UMR, Université Paris-Saclay, IRBA, Evry-Courcouronnes, France
| | - Nathalie Koulmann
- Laboratoire de Biologie de l’Exercice pour la Performance et la Santé (LBEPS), UMR, Université Paris-Saclay, IRBA, Evry-Courcouronnes, France,French Military Health Academy—Ecole du Val-de-Grâce, Place Alphonse Laveran, Paris, France
| | - Mounir Chennaoui
- REF-Aero Department, French Armed Forces Biomedical Research Institute—IRBA, Brétigny-sur-Orge, France,Vigilance Fatigue Sommeil et Santé Publique (VIFASOM) URP 7330, Université de Paris Cité, Paris, France
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25
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Zhang L, Meng J, Li H, Tang M, Zhou Z, Zhou X, Feng L, Li X, Guo Y, He Y, He W, Huang X. Hippocampal adaptation to high altitude: a neuroanatomic profile of hippocampal subfields in Tibetans and acclimatized Han Chinese residents. Front Neuroanat 2022; 16:999033. [DOI: 10.3389/fnana.2022.999033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 10/25/2022] [Indexed: 11/19/2022] Open
Abstract
The hippocampus is highly plastic and vulnerable to hypoxia. However, it is unknown whether and how it adapts to chronic hypobaric hypoxia in humans. With a unique sample of Tibetans and acclimatized Han Chinese individuals residing on the Tibetan plateau, we aimed to build a neuroanatomic profile of the altitude-adapted hippocampus by measuring the volumetric differences in the whole hippocampus and its subfields. High-resolution T1-weighted magnetic resonance imaging was performed in healthy Tibetans (TH, n = 72) and healthy Han Chinese individuals living at an altitude of more than 3,500 m (HH, n = 27). In addition, healthy Han Chinese individuals living on a plain (HP, n = 72) were recruited as a sea-level reference group. Whereas the total hippocampal volume did not show a significant difference across groups when corrected for age, sex, and total intracranial volume, subfield-level differences within the hippocampus were found. Post hoc analyses revealed that Tibetans had larger core hippocampal subfields (bilateral CA3, right CA4, right dentate gyrus); a larger right hippocampus–amygdala transition area; and smaller bilateral presubiculum, right subiculum, and bilateral fimbria, than Han Chinese subjects (HH and/or HP). The hippocampus and all its subfields were found to be slightly and non-significantly smaller in HH subjects than in HP subjects. As a primary explorational study, our data suggested that while the overall hippocampal volume did not change, the core hippocampus of Tibetans may have an effect of adaptation to chronic hypobaric hypoxia. However, this adaptation may have required generations rather than mere decades to accumulate in the population.
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26
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The effects of normobaric and hypobaric hypoxia on cognitive performance and physiological responses: A crossover study. PLoS One 2022; 17:e0277364. [DOI: 10.1371/journal.pone.0277364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 10/25/2022] [Indexed: 11/12/2022] Open
Abstract
This partially randomised controlled, crossover study sought to investigate the effects of normobaric hypoxia (NH) and hypobaric hypoxia (HH) on cognitive performance, the physiological response at rest and after a 3-min step-test. Twenty healthy participants (10 females and 10 males, 27.6±6.2yrs, 73.6±13.7kg, 175.3±8.9cm) completed a cognitive performance test, followed by the modified Harvard-step protocol, in four environments: normobaric normoxia (NN; PiO2: 146.0±1.5mmHg), NH (PiO2: 100.9±1.3mmHg), HH at the first day of ascent (HH1: PiO2 = 105.6±0.4mmHg) and HH after an overnight stay (HH2: PiO2 = 106.0±0.5mmHg). At rest and/or exercise, SpO2, NIRS, and cardiovascular and perceptual data were collected. The cerebral tissue oxygenation index and the cognitive performance (throughput, accuracy, and reaction time) were not different between the hypoxic conditions (all p>0.05). In NH, SpO2 was higher compared to HH1 (ΔSpO2 NH vs HH1: 1.7±0.5%, p = 0.003) whilst heart rate (ΔHR NH vs HH2: 5.8±2.6 bpm, p = 0.03) and sympathetic activation (ΔSNSi NH vs HH2: 0.8±0.4, p = 0.03) were lower in NH compared to HH2. Heart rate (ΔHR HH1 vs HH2: 6.9±2.6 bpm, p = 0.01) and sympathetic action (ΔSNSi HH1 vs HH2: 0.9±0.4, p = 0.02) were both lower in HH1 compared to HH2. In conclusion, cognitive performance and cerebral oxygenation didn’t differ between the hypoxic conditions. SpO2 was only higher in NH compared to HH1. In HH2, heart rate and sympathetic activation were higher compared to both NH and HH1. These conclusions account for a PiO2 between 100–106 mmHg.
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27
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Zhang X, Zhang J. The human brain in a high altitude natural environment: A review. Front Hum Neurosci 2022; 16:915995. [PMID: 36188182 PMCID: PMC9520777 DOI: 10.3389/fnhum.2022.915995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/25/2022] [Indexed: 12/04/2022] Open
Abstract
With the advancement of in vivo magnetic resonance imaging (MRI) technique, more detailed information about the human brain at high altitude (HA) has been revealed. The present review aimed to draw a conclusion regarding changes in the human brain in both unacclimatized and acclimatized states in a natural HA environment. Using multiple advanced analysis methods that based on MRI as well as electroencephalography, the modulations of brain gray and white matter morphology and the electrophysiological mechanisms underlying processing of cognitive activity have been explored in certain extent. The visual, motor and insular cortices are brain regions seen to be consistently affected in both HA immigrants and natives. Current findings regarding cortical electrophysiological and blood dynamic signals may be related to cardiovascular and respiratory regulations, and may clarify the mechanisms underlying some behaviors at HA. In general, in the past 10 years, researches on the brain at HA have gone beyond cognitive tests. Due to the sample size is not large enough, the current findings in HA brain are not very reliable, and thus much more researches are needed. Moreover, the histological and genetic bases of brain structures at HA are also needed to be elucidated.
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Affiliation(s)
- Xinjuan Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, China
- Department of Physiology, School of Medicine, Xiamen University, Xiamen, China
| | - Jiaxing Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, China
- Department of Physiology, School of Medicine, Xiamen University, Xiamen, China
- *Correspondence: Jiaxing Zhang,
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28
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Scheiwiller PM, Furian M, Buergin A, Mayer LC, Schneider SR, Mademilov M, Lichtblau M, Muralt L, Sheraliev U, Sooronbaev TM, Ulrich S, Bloch KE. Visuomotor performance at high altitude in COPD patients. Randomized placebo-controlled trial of acetazolamide. Front Physiol 2022; 13:980755. [PMID: 36160864 PMCID: PMC9493049 DOI: 10.3389/fphys.2022.980755] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/15/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction: We evaluated whether exposure to high altitude impairs visuomotor learning in lowlanders with chronic obstructive pulmonary disease (COPD) and whether this can be prevented by acetazolamide treatment. Methods: 45 patients with COPD, living <800 m, FEV1 ≥40 to <80%predicted, were randomized to acetazolamide (375 mg/d) or placebo, administered 24h before and during a 2-day stay in a clinic at 3100 m. Visuomotor performance was evaluated with a validated, computer-assisted test (Motor-Task-Manager) at 760 m above sea level (baseline, before starting the study drug), within 4h after arrival at 3100 m and in the morning after one night at 3100 m. Main outcome was the directional error (DE) of cursor movements controlled by the participant via mouse on a computer screen during a target tracking task. Effects of high altitude and acetazolamide on DE during an adaptation phase, immediate recall and post-sleep recall were evaluated by regression analyses. www.ClinicalTrials.gov NCT03165890. Results: In 22 patients receiving placebo, DE at 3100 m increased during adaptation by mean 2.5°, 95%CI 2.2° to 2.7° (p < 0.001), during immediate recall by 5.3°, 4.6° to 6.1° (p < 0.001), and post-sleep recall by 5.8°, 5.0 to 6.7° (p < 0.001), vs. corresponding values at 760 m. In 23 participants receiving acetazolamide, corresponding DE were reduced by -0.3° (-0.6° to 0.1°, p = 0.120), -2.7° (-3.7° to -1.6°, p < 0.001) and -3.1° (-4.3° to -2.0°, p < 0.001), compared to placebo at 3100 m. Conclusion: Lowlanders with COPD travelling to 3100 m experienced altitude-induced impairments in immediate and post-sleep recall of a visuomotor task. Preventive acetazolamide treatment mitigated these undesirable effects.
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Affiliation(s)
- P. M. Scheiwiller
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - M. Furian
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - A. Buergin
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - L. C. Mayer
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - S. R. Schneider
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - M. Mademilov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- National Center for Cardiology and Internal Medicine, Department of Respiratory Medicine, Bishkek, Kyrgyz Republic
| | - M. Lichtblau
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - L. Muralt
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - U. Sheraliev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- National Center for Cardiology and Internal Medicine, Department of Respiratory Medicine, Bishkek, Kyrgyz Republic
| | - T. M. Sooronbaev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- National Center for Cardiology and Internal Medicine, Department of Respiratory Medicine, Bishkek, Kyrgyz Republic
| | - S. Ulrich
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - K. E. Bloch
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
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29
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Chroboczek M, Kujach S, Łuszczyk M, Grzywacz T, Soya H, Laskowski R. Acute Normobaric Hypoxia Lowers Executive Functions among Young Men despite Increase of BDNF Concentration. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:10802. [PMID: 36078520 PMCID: PMC9518314 DOI: 10.3390/ijerph191710802] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/27/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Decreased SpO2 during hypoxia can cause cognitive function impairment, and the effects of acute hypoxia on high-order brain functions such as executive processing remain unclear. This study's goal was to examine the impact of an acute normobaric hypoxia breathing session on executive function and biological markers. METHODS Thirty-two healthy subjects participated in a blind study performing two sessions of single 30 min breathing bouts under two conditions (normoxia (NOR) and normobaric hypoxia (NH), FIO2 = 0.135). The Stroop test was applied to assess cognitive function. RESULTS No significant difference was observed in the Stroop interference in the "reading" part of the test in either condition; however, there was a significant increase in the "naming" part under NH conditions (p = 0.003), which corresponded to a significant decrease in SpO2 (p < 0.001). There was a significant increase (p < 0.013) in the brain-derived neurotrophic factor (BDNF) level after NH conditions compared to the baseline, which was not seen in NOR. In addition, a significant drop (p < 0.001) in cortisol levels in the NOR group and a slight elevation in the NH group was noticed. CONCLUSIONS According to these findings, acute hypoxia delayed cognitive processing for motor execution and reduced the neural activity in motor executive and inhibitory processing. We also noted that this negative effect was associated with decreased SpO2 irrespective of a rise in BDNF.
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Affiliation(s)
- Maciej Chroboczek
- Department of Physiology, Gdansk University of Physical Education and Sport, 80-336 Gdansk, Poland
| | - Sylwester Kujach
- Department of Physiology, Gdansk University of Physical Education and Sport, 80-336 Gdansk, Poland
| | - Marcin Łuszczyk
- Department of Physiology, Gdansk University of Physical Education and Sport, 80-336 Gdansk, Poland
| | - Tomasz Grzywacz
- Department of Sport, Institute of Physical Education, Kazimierz Wielki University, 85-064 Bydgoszcz, Poland
| | - Hideaki Soya
- Sports Neuroscience Division, Advanced Research Initiative for Human High Performance, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba 305-8574, Japan
| | - Radosław Laskowski
- Department of Physiology, Gdansk University of Physical Education and Sport, 80-336 Gdansk, Poland
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Department of Sports Neuroscience, Advanced Research Initiative for Human High Performance (ARIHHP), Faculty of Health and Sports Sciences, University of Tsukuba, Ibaraki 305-8577, Japan
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Pellegrini-Laplagne M, Dupuy O, Sosner P, Bosquet L. Effect of simultaneous exercise and cognitive training on executive functions, baroreflex sensitivity, and pre-frontal cortex oxygenation in healthy older adults: a pilot study. GeroScience 2022; 45:119-140. [PMID: 35881301 PMCID: PMC9315336 DOI: 10.1007/s11357-022-00595-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 05/20/2022] [Indexed: 02/02/2023] Open
Abstract
Aging is characterized by cognitive decline affecting daily functioning. To manage this socio-economic challenge, several non-pharmacological methods such as physical, cognitive, and combined training are proposed. Although there is an important interest in this subject, the literature is still heterogeneous. The superiority of simultaneous training compared to passive control and physical training alone seems clear but very few studies compared simultaneous training to cognitive training alone. The aim of this pilot study was to investigate the effect of simultaneous exercise and cognitive training on several cognitive domains in healthy older adults, in comparison with either training alone. Thirty-five healthy older adults were randomized into one of three experimental groups: exercise training, cognitive training, and simultaneous exercise and cognitive training. The protocol involved two 30-min sessions per week for 24 weeks. Cognitive performance in several domains, pre-frontal cortex oxygenation, and baroreflex sensitivity were assessed before and after the intervention. All groups improved executive performance, including flexibility or working memory. We found a group by time interaction for inhibition cost (F(2,28) = 6.44; p < 0.01) and baroreflex sensitivity during controlled breathing (F(2,25) = 4.22; p = 0.01), the magnitude of improvement of each variable being associated (r = -0.39; p = 0.03). We also found a decrease in left and right pre-frontal cortex oxygenation in all groups during the trail making test B. A simultaneous exercise and cognitive training are more efficient than either training alone to improve executive function and baroreflex sensitivity. The results of this study may have important clinical repercussions by allowing to optimize the interventions designed to maintain the physical and cognitive health of older adults.
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Affiliation(s)
- Manon Pellegrini-Laplagne
- grid.11166.310000 0001 2160 6368Laboratoire MOVE (EA6314), Faculté des sciences du sport, Université de Poitiers, 8 allée Jean Monnet – TSA 31113 – 96073 Poitiers cedex 9, Poitiers, France
| | - Olivier Dupuy
- Laboratoire MOVE (EA6314), Faculté des sciences du sport, Université de Poitiers, 8 allée Jean Monnet - TSA 31113 - 96073 Poitiers cedex 9, Poitiers, France. .,School of Kinesiology and Physical Activity Sciences (EKSAP), Faculty of Medicine, University of Montreal, Montreal, Canada.
| | - Phillipe Sosner
- grid.11166.310000 0001 2160 6368Laboratoire MOVE (EA6314), Faculté des sciences du sport, Université de Poitiers, 8 allée Jean Monnet – TSA 31113 – 96073 Poitiers cedex 9, Poitiers, France ,Mon Stade, Paris, France
| | - Laurent Bosquet
- grid.11166.310000 0001 2160 6368Laboratoire MOVE (EA6314), Faculté des sciences du sport, Université de Poitiers, 8 allée Jean Monnet – TSA 31113 – 96073 Poitiers cedex 9, Poitiers, France ,grid.14848.310000 0001 2292 3357School of Kinesiology and Physical Activity Sciences (EKSAP), Faculty of Medicine, University of Montreal, Montreal, Canada
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Varis N, Leinonen A, Parkkola K, Leino TK. Hyperventilation and Hypoxia Hangover During Normobaric Hypoxia Training in Hawk Simulator. Front Physiol 2022; 13:942249. [PMID: 35910556 PMCID: PMC9326353 DOI: 10.3389/fphys.2022.942249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/24/2022] [Indexed: 11/25/2022] Open
Abstract
Introduction: In military aviation during high-altitude operations, an oxygen or cabin pressure emergency can impair brain function and performance. There are variations in individuals’ physiological responses to low partial pressure of oxygen and hypoxia symptoms can vary from one exposure to another. The aim of this study was to evaluate how normobaric hypoxia (NH) affects pilots’ minute ventilation and 10 min afterwards on Instrument Landing System (ILS) flight performance in Hawk simulator during a tactical flight sortie. Methods: Fifteen volunteer fighter pilots from the Finnish Air Force participated in this double blinded, placebo controlled and randomized study. The subjects performed three flights in a tactical Hawk simulator in a randomized order with full flight gear, regulators and masks on. In the middle of the flight without the subjects’ knowledge, 21% (control), 8% or 6% oxygen in nitrogen was turned on. Minute ventilation (VE) was measured before, during NH and after NH. Forehead peripheral oxygen saturation (SpO2), wireless ECG and subjective symptoms were documented. The flights were conducted so that both subjects and flight instructors were blinded to the gas mixture. The pilots performed tactical maneuvers at simulated altitude of 20,000 ft or 26,000 ft until they recognized the symptoms of hypoxia. Thereafter they performed hypoxia emergency procedures with 100% oxygen and returned to base (RTB). During the ILS approach, flight performance was evaluated. Results: The mean VE increased during NH from 12.9 L/min (21% O2 on the control flight) to 17.8 L/min with 8% oxygen (p < 0.01), and to 21.0 L/min with 6% oxygen (p < 0.01). Ten minutes after combined hyperventilation and hypoxia, the ILS flight performance decreased from 4.4 (control flight) to 4.0 with 8% oxygen (p = 0.16) and to 3.2 with 6% oxygen (p < 0.01). A significant correlation (r = -0.472) was found between the subjects’ VE during 6% oxygen exposure and the ILS flight performance. Discussion: Hyperventilation during NH has a long-lasting and dose-dependent effect on the pilot’s ILS flight performance, even though the hypoxia emergency procedures are executed 10 min earlier. Hyperventilation leads to body loss of carbon dioxide and hypocapnia which may even worsen the hypoxia hangover.
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Affiliation(s)
- Nikke Varis
- Faculty of Medicine and Health Technology Tampere University, Tampere, Finland
- *Correspondence: Nikke Varis,
| | - Antti Leinonen
- School of Medicine University of Eastern Finland, Kuopio, Finland
| | - Kai Parkkola
- Faculty of Medicine and Health Technology Tampere University, Tampere, Finland
- National Defense University, Helsinki, Finland
| | - Tuomo K. Leino
- National Defense University, Helsinki, Finland
- Aeromedical Centre Centre for Military Medicine, Helsinki, Finland
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Guicciardi M, Pazzona R, Manca A, Monni A, Scalas LF, Perra F, Leban B, Roberto S, Mulliri G, Ghiani G, Doneddu A, Crisafulli A. Executive Functions and Mood States in Athletes Performing Exercise Under Hypoxia. Front Psychol 2022; 13:906336. [PMID: 35712141 PMCID: PMC9196732 DOI: 10.3389/fpsyg.2022.906336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/09/2022] [Indexed: 11/13/2022] Open
Abstract
Hypoxia can impair cognitive performance, whereas exercise can enhance it. The effects of hypoxia on cognitive performance during exercise appear to be moderated by exercise duration and intensity and by severity and duration of hypoxia and cognitive task. In normal individuals, exercise under hypoxia can evoke adverse post-exercise mood states, such as tension and fatigue. However, little is known about the effects of hypoxia during exercise in trained athletes. The purpose of this study was to investigate how hypoxia affected executive functions and mood states, assessed, respectively, during and post-exercise and to explore the role of motivation moderators, such as inhibition and activation systems (BIS-BAS). Two different sessions of exercise in normoxia and hypoxia (FiO2 13%), each lasting 18 min, were randomly assigned in a counterbalanced order and administered to seventeen male athletes. During exercise bouts, participants performed a mental task (BST) aimed to produce cognitive interference and suppression. Reaction times and accuracy of responses were recorded. After 5 min, all participants completed two questionnaires assessing mood states (ITAMS) and incidence of symptoms potentially related to hypoxia (AMS-C). The results show that hypoxia impairs cognitive performance in terms of slower reaction times, but a high BAS attenuates this effect. Participants with high BAS show an equivalent cognitive performance under hypoxia and normoxia conditions. No effects were found on mood states. Further research is required to investigate the role of BAS, cognitive abilities, and mood states in prolonged hypoxic conditions.
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Affiliation(s)
- Marco Guicciardi
- Department of Education, Psychology, Philosophy, Faculty of Humanities, University of Cagliari, Cagliari, Italy
| | - Riccardo Pazzona
- Department of Education, Psychology, Philosophy, Faculty of Humanities, University of Cagliari, Cagliari, Italy
| | - Andrea Manca
- Department of Education, Psychology, Philosophy, Faculty of Humanities, University of Cagliari, Cagliari, Italy
| | - Alessandra Monni
- Department of Education, Psychology, Philosophy, Faculty of Humanities, University of Cagliari, Cagliari, Italy
| | - Laura Francesca Scalas
- Department of Education, Psychology, Philosophy, Faculty of Humanities, University of Cagliari, Cagliari, Italy
| | - Federica Perra
- Department of Education, Psychology, Philosophy, Faculty of Humanities, University of Cagliari, Cagliari, Italy
| | - Bruno Leban
- Department of Mechanical, Chemical and Materials Engineering, Faculty of Engineering and Architecture, University of Cagliari, Cagliari, Italy
| | - Silvana Roberto
- Sports Physiology Lab, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Gabriele Mulliri
- Sports Physiology Lab, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Giovanna Ghiani
- Sports Physiology Lab, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Azzurra Doneddu
- Sports Physiology Lab, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Antonio Crisafulli
- Sports Physiology Lab, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
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Intensity-dependent acute aerobic exercise: Effect on reactive control of attentional functions in acclimatized lowlanders at high altitude. Physiol Behav 2022; 250:113785. [PMID: 35346735 DOI: 10.1016/j.physbeh.2022.113785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/22/2022] [Accepted: 03/22/2022] [Indexed: 11/21/2022]
Abstract
Human attentional function is sensitive to hypoxia. However, little is known about whether and how attentional function is altered after acute aerobic exercise at high altitude, especially for acclimatized lowlanders. In this study, we used the Attention Network Test (ANT) to measure alerting, orienting, and executive control functions and the Stroop Color and Word Test (SCWT) with a different proportion of incongruent trials to investigate proactive and reactive control of executive function. We randomly divided the sample of 160 Tibetan lowlanders who had lived in the highlands for more than two years into four groups. Each of three groups performed 20 min of low-, moderate-, or high-intensity acute aerobic exercise, separately, and a control group watched a 20-min documentary. The ANT and SCWT were conducted before and after exercise or watching the documentary. The results indicated that the executive control effects of the three experimental groups significantly decreased and, in the posttest, the executive control effects of the high-intensity group were lower than those of the low-intensity group. Furthermore, the accuracy of the moderate- and high-intensity groups was increased significantly in the blocks containing 25% incongruent trials of SCWT task. These results suggest that the acute aerobic exercise at high altitude will improve the reactive control of attentional functions in acclimatized lowlanders, and the intensity may play an important role in the exercise-cognition interaction at high altitude.
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Geng YN, Zhao M, Yang JL, Cheng X, Han Y, Wang CB, Jiang XF, Fan M, Zhu LL. GP-14 protects against severe hypoxia-induced neuronal injury through the AKT and ERK pathways and its induced transcriptome profiling alteration. Toxicol Appl Pharmacol 2022; 448:116092. [PMID: 35654276 DOI: 10.1016/j.taap.2022.116092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 05/21/2022] [Accepted: 05/24/2022] [Indexed: 10/18/2022]
Abstract
Gypenosides are major bioactive ingredients of G. pentaphyllum. In our previous study, we found that gypenosides had neuroprotective effects against hypoxia-induced injury. In the current study, we focused on the protective effects of gypenoside-14 (GP-14), which is one of the newly identified bioactive components, on neuronal injury caused by severe hypoxia (0.3% O2). The results showed that GP-14 pretreatment alleviated the cell viability damage and apoptosis induced by hypoxia in PC12 cells. Moreover, GP-14 pretreatment also attenuated primary neuron injuries under hypoxic conditions. Additionally, GP-14 pretreatment significantly ameliorated neuronal damage in the hippocampal region induced by high-altitude cerebral edema (HACE). At the molecular level, GP-14 pretreatment reversed the decreased activities of the AKT and ERK signaling pathways caused by hypoxia in PC12 cells and primary neurons. To comprehensively explore the possible mechanisms, transcriptome sequencing was conducted, and these results indicated that GP-14 could alter the transcriptional profiles of primary neuron. Taken together, our results suggest that GP-14 acts as a neuroprotective agent to protect against neuronal damage induced by severe hypoxia and it is a promising compound for the development of neuroprotective drugs.
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Affiliation(s)
- Ya-Nan Geng
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China; Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Ming Zhao
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Jun-Li Yang
- CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Xiang Cheng
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Ying Han
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Cheng-Bo Wang
- CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Xiu-Fang Jiang
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Ming Fan
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing 100069, China; Beijing Institute of Basic Medical Sciences, Beijing 100850, China; School of information Science & Engineering, Lanzhou University, Lanzhou 730000, China.
| | - Ling-Ling Zhu
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226019, China; College of Life Sciences, Anhui Medical University, Hefei 230032, China; Hengyang Medical School, University of South China, Hengyang 421001, China.
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35
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Ylikoski J, Lehtimäki J, Pääkkönen R, Mäkitie A. Prevention and Treatment of Life-Threatening COVID-19 May Be Possible with Oxygen Treatment. Life (Basel) 2022; 12:754. [PMID: 35629421 PMCID: PMC9142938 DOI: 10.3390/life12050754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 04/22/2022] [Accepted: 05/12/2022] [Indexed: 01/08/2023] Open
Abstract
Most SARS CoV-2 infections probably occur unnoticed or cause only cause a mild common cold that does not require medical intervention. A significant proportion of more severe cases is characterized by early neurological symptoms such as headache, fatigue, and impaired consciousness, including respiratory distress. These symptoms suggest hypoxia, specifically affecting the brain. The condition is best explained by primary replication of the virus in the nasal respiratory and/or the olfactory epithelia, followed by an invasion of the virus into the central nervous system, including the respiratory centers, either along a transneural route, through disruption of the blood-brain barrier, or both. In patients, presenting with early dyspnea, the primary goal of therapy should be the reversal of brain hypoxia as efficiently as possible. The first approach should be intermittent treatment with 100% oxygen using a tight oronasal mask or a hood. If this does not help within a few hours, an enclosure is needed to increase the ambient pressure. This management approach is well established in the hypoxia-related diseases in diving and aerospace medicine and preserves the patient's spontaneous breathing. Preliminary research evidence indicates that even a small elevation of the ambient pressure might be lifesaving. Other neurological symptoms, presenting particularly in long COVID-19, suggest imbalance of the autonomous nervous system, i.e., dysautonomia. These patients could benefit from vagal nerve stimulation.
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Affiliation(s)
- Jukka Ylikoski
- Department of Otorhinolaryngology—Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland; (J.Y.); (R.P.)
- Helsinki Ear Institute, 00420 Helsinki, Finland;
- Salustim Group Inc., 90440 Kempele, Finland
| | - Jarmo Lehtimäki
- Helsinki Ear Institute, 00420 Helsinki, Finland;
- Salustim Group Inc., 90440 Kempele, Finland
| | - Rauno Pääkkönen
- Department of Otorhinolaryngology—Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland; (J.Y.); (R.P.)
| | - Antti Mäkitie
- Department of Otorhinolaryngology—Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland; (J.Y.); (R.P.)
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Tobita K, Mekjavic IB, McDonnell AC. Individual Variation Exists Within the Psychological Response to Hypoxic Bed Rest: A Retrospective Analysis. Front Physiol 2022; 13:810055. [PMID: 35222078 PMCID: PMC8870828 DOI: 10.3389/fphys.2022.810055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 01/17/2022] [Indexed: 11/13/2022] Open
Abstract
Individual variation is of interest to Space Agency's, which cannot be explored with astronauts due to anonymity. We retrospectively analysed data collected throughout three projects (LunHab: 10-day male, PlanHab: 21-day male, and FemHab: 10-day female) to elucidate the potentially masked individual variation in the psychological responses to bed rest. The Profile of Mood State (POMS) and Positive and Negative Affect Schedule (PANAS) - instruments used to asses psychological state - and Lake Louise Mountain Sickness (LLMS) scores were collected prior to, following and throughout three interventions: 1: normoxic bed rest 2: hypoxic bed rest and 3: hypoxic ambulatory confinement. Total Mood Disturbance (TMD) was calculated from the POMS results, positive affect (PA), and negative affect (NA) from PANAS. The three instruments were included in a latent class mixed model. TMD, NA, and LLMS were included in a four-class model, with each class representing a specific type of response (Class 1: descending, Class 2: flat, Class 3: somewhat flat, Class 4: ascending). Responses for PA were assigned to only two classes (Classes 1 and 2). 54.55% or 24 participants were included in Class 2 (TMD, NA, and LLMS), where the responses did not change and neither hypoxia or activity level had a significant effect on emotional state. The remaining participants were allotted to Class 1, 3, or 4, where hypoxia was a significant covariate, while activity (bed rest) was significant only for class 3. For PA, 84.09% or 37 participants were assigned to class 2 indicating a significant effect of hypoxia on the participants responses with no effect of physical activity. Class 1 participants (n = 7) were not affected by hypoxia, however, physical activity improved their PA. Participants undergoing confinement, hypoxia and bed rest do not exhibit a uniform emotional response and may be categorised into 2-4 distinct classes. These results indicate significant individual emotional responses, that may be masked and underreported by traditional statistical approaches like means ± SD. The emotional state of our participants is a complex construct likely influenced by past experiences and different coping mechanisms which allowed some to adapt to the experimental environment more readily.
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Affiliation(s)
- Kunihito Tobita
- Department of Sustainable System Sciences, Osaka Prefecture University, Sakai, Japan
| | - Igor B. Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Adam C. McDonnell
- Department of Automation, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
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Figueiredo PS, Sils IV, Staab JE, Fulco CS, Muza SR, Beidleman BA. Acute mountain sickness and sleep disturbances differentially influence cognition and mood during rapid ascent to 3000 and 4050 m. Physiol Rep 2022; 10:e15175. [PMID: 35133088 PMCID: PMC8822873 DOI: 10.14814/phy2.15175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 12/04/2022] Open
Abstract
The impact of acute mountain sickness (AMS) and sleep disturbances on mood and cognition at two altitudes relevant to the working and tourist population is unknown. Twenty unacclimatized lowlanders were exposed to either 3000 m (n = 10; 526 mmHg) or 4050 m (n = 10; 460 mmHg) for 20 h in a hypobaric chamber. AMS prevalence and severity was assessed using the Environmental Symptoms Questionnaire (ESQ) and an AMS‐C score ≥ 0.7 indicated sickness. While sleeping for one night both at sea level (SL) and high altitude (HA), a wrist motion detector was used to measure awakenings (Awak, events/h) and sleep efficiency (Eff, %). If Eff was ≥85%, individuals were considered a good sleeper (Sleep+). Mood and cognition were assessed using the Automated Neuropsychological Assessment Metric and Mood Scale (ANAM‐MS). The ESQ and ANAM‐MS were administered in the morning both at SL and after 20 h at HA. AMS severity (mean ± SE; 1.82 ± 0.27 vs. 0.20 ± 0.27), AMS prevalence (90% vs. 10%), depression (0.63 ± 0.23 vs. 0.00 ± 0.24) Awak (15.6 ± 1.6 vs. 10.1 ± 1.6 events/h), and DeSHr (38.5 ± 6.3 vs. 13.3 ± 6.3 events/h) were greater (p < 0.05) and Eff was lower (69.9 ± 5.3% vs. 87.0 ± 5.3%) at 4050 m compared to 3000 m, respectively. AMS presence did not impact cognition but fatigue (2.17 ± 0.37 vs. 0.58 ± 0.39), anger (0.65 ± 0.25 vs. 0.02 ± 0.26), depression (0.63 ± 0.23 vs. 0.00 ± 0.24) and sleepiness (4.8 ± 0.4 vs. 2.7 ± 0.5) were greater (p < 0.05) in the AMS+ group. The Sleep− group, compared to the Sleep+ group, had lower (p < 0.05) working memory scores (50 ± 7 vs. 78 ± 9) assessed by the Sternberg 6‐letter memory task, and lower reaction time fatigue scores (157 ± 17 vs. 221 ± 22), assessed by the repeated reaction time test. Overall, AMS, depression, DeSHr, and Awak were increased (p < 0.05) at 4050 m compared to 3000 m. In addition, AMS presence impacted mood while poor sleep impacted cognition which may deteriorate teamwork and/or increase errors in judgement at HA.
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Affiliation(s)
- Peter S. Figueiredo
- Biophysics and Biomedical Modeling Division U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
| | - Ingrid V. Sils
- Thermal and Mountain Medicine Division U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
| | - Janet E. Staab
- Military Performance Division U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
| | - Charles S. Fulco
- Thermal and Mountain Medicine Division U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
| | - Stephen R. Muza
- Strategic Science and Development Office U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
| | - Beth A. Beidleman
- Biophysics and Biomedical Modeling Division U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
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Committeri G, Bondi D, Sestieri C, Di Matteo G, Piervincenzi C, Doria C, Ruffini R, Baldassarre A, Pietrangelo T, Sepe R, Navarra R, Chiacchiaretta P, Ferretti A, Verratti V. Neuropsychological and Neuroimaging Correlates of High-Altitude Hypoxia Trekking During the "Gokyo Khumbu/Ama Dablam" Expedition. High Alt Med Biol 2022; 23:57-68. [PMID: 35104160 DOI: 10.1089/ham.2021.0029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Committeri Giorgia, Danilo Bondi, Carlo Sestieri, Ginevra Di Matteo, Claudia Piervincenzi, Christian Doria, Roberto Ruffini, Antonello Baldassarre, Tiziana Pietrangelo, Rosamaria Sepe, Riccardo Navarra, Piero Chiacchiaretta, Antonio Ferretti, and Vittore Verratti. Neuropsychological and neuroimaging correlates of high-altitude hypoxia trekking during the "Gokyo Khumbu/Ama Dablam" expedition. High Alt Med Biol 00:000-000, 2021. Background: Altitude hypoxia exposure may produce cognitive detrimental adaptations and damage to the brain. We aimed at investigating the effects of trekking and hypoxia on neuropsychological and neuroimaging measures. Methods: We recruited two balanced groups of healthy adults, trekkers (n = 12, 6 F and 6 M, trekking in altitude hypoxia) and controls (gender- and age-matched), who were tested before (baseline), during (5,000 m, after 9 days of trekking), and after the expedition for state anxiety, depression, verbal fluency, verbal short-term memory, and working memory. Personality and trait anxiety were also assessed at a baseline level. Neuroimaging measures of cerebral perfusion (arterial spin labeling), white-matter microstructural integrity (diffusion tensor imaging), and resting-state functional connectivity (functional magnetic resonance imaging) were assessed before and after the expedition in the group of trekkers. Results: At baseline, the trekkers showed lower trait anxiety (p = 0.003) and conscientiousness (p = 0.03) than the control group. State anxiety was lower in the trekkers throughout the study (p < 0.001), and state anxiety and depression decreased at the end of the study in both groups (p = 0.043 and p = 0.007, respectively). Verbal fluency increased at the end of the study in both groups (p < 0.001), whereas verbal short-term memory and working memory performance did not change. No significant differences between before and after the expedition were found for neuroimaging measures. Conclusions: We argue that the observed differences in the neuropsychological measures mainly reflect aspecific familiarity and learning effects due to the repeated execution of the same questionnaires and task. The present results thus suggest that detrimental effects on neuropsychological and neuroimaging measures do not necessarily occur as a consequence of short-term exposure to altitude hypoxia up to 5,000 m, especially in the absence of altitude sickness.
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Affiliation(s)
- Giorgia Committeri
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Danilo Bondi
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Carlo Sestieri
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Ginevra Di Matteo
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | | | - Christian Doria
- Department of Biomedical Sciences for Health, Università Degli Studi di Milano, Milan, Italy
| | - Roberto Ruffini
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Antonello Baldassarre
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Tiziana Pietrangelo
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | | | - Riccardo Navarra
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Piero Chiacchiaretta
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Antonio Ferretti
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Vittore Verratti
- Department of Psychological, Health and Territorial Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
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39
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Bao H, He X, Wang F, Kang D. Study of Brain Structure and Function in Chronic Mountain Sickness Based on fMRI. Front Neurol 2022; 12:763835. [PMID: 35069409 PMCID: PMC8777079 DOI: 10.3389/fneur.2021.763835] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 12/08/2021] [Indexed: 12/21/2022] Open
Abstract
Objective: Headache and memory impairment are the primary clinical symptoms of chronic mountain sickness (CMS). In this study, we used voxel-based morphometry (VBM) and the amplitude of the low-frequency fluctuation method (ALFF) based on blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI) to identify changes in the brain structure and function caused by CMS. Materials and Methods: T1W anatomical images and a resting-state functional MRI (fMRI) of the whole brain were performed in 24 patients diagnosed with CMS and 25 normal controls matched for age, sex, years of education, and living altitude. MRI images were acquired, followed by VBM and ALFF data analyses. Results: Compared with the control group, the CMS group had increased gray matter volume in the left cerebellum crus II area, left inferior temporal gyrus, right middle temporal gyrus, right insula, right caudate nucleus, and bilateral lentiform nucleus along with decreased gray matter volume in the left middle occipital gyrus and left middle temporal gyrus. White matter was decreased in the bilateral middle temporal gyrus and increased in the right Heschl's gyrus. Resting-state fMRI in patients with CMS showed increased spontaneous brain activity in the left supramarginal gyrus, left parahippocampal gyrus, and left middle temporal gyrus along with decreased spontaneous brain activity in the right cerebellum crus I area and right supplementary motor area. Conclusion: Patients with CMS had differences in gray and white matter volume and abnormal spontaneous brain activity in multiple brain regions compared to the controls. This suggests that long-term chronic hypoxia may induce changes in brain structure and function, resulting in CMS.
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Affiliation(s)
- Haihua Bao
- Department of Medical Imaging Center, Qinghai University Affiliated Hospital, Xining, China
| | - Xin He
- Department of Medical Imaging Center, Qinghai University Affiliated Hospital, Xining, China
| | - Fangfang Wang
- Department of Medical Imaging Center, Qinghai University Affiliated Hospital, Xining, China
| | - Dongjie Kang
- Department of Medical Imaging Center, Qinghai University Affiliated Hospital, Xining, China
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40
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Semenov DG, Belyakov AV, Rybnikova EA. Experimental Modeling of Damaging and Protective Hypoxia of the Mammalian Brain. J EVOL BIOCHEM PHYS+ 2022; 58:2021-2034. [PMID: 36573160 PMCID: PMC9773672 DOI: 10.1134/s0022093022060291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/07/2022] [Accepted: 11/07/2022] [Indexed: 12/24/2022]
Abstract
Currently, there is a new surge of interest in the problem of hypoxia, almost lost in recent decades. Due to the fact that the circle of competent specialists in this field has significantly narrowed, it is necessary to carry out an intensive exchange of knowledge. In order to inform a wide range of interested researchers and doctors, this review summarizes the current understanding of hypoxia, its pathogenic and adaptogenic consequences, as well as key physiological and molecular mechanisms that implement the response to hypoxia at various levels-from cellular to organismic. The review presents a modern classification of forms of hypoxia, the understanding of which is necessary for the formation of a scientifically based approach to experimental modeling of hypoxic states. An analysis of the literature covering the history and current level of hypoxia modeling in mammals and human experiments, including methods for creating moderate hypoxia used to increase the resistance of the nervous system to severe forms of hypoxia and other extreme factors, is carried out. Special attention is paid to the discussion of the features and limitations of various approaches to the creation of hypoxia, as well as the disclosure of the potential for the practical application of moderate hypoxic effects in medicine.
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Affiliation(s)
- D. G. Semenov
- Pavlov Institute of Physiology of Russian Academy of Sciences, St. Petersburg, Russia
| | - A. V. Belyakov
- Pavlov Institute of Physiology of Russian Academy of Sciences, St. Petersburg, Russia
| | - E. A. Rybnikova
- Pavlov Institute of Physiology of Russian Academy of Sciences, St. Petersburg, Russia
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41
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Wang X, Cui L, Ji X. Cognitive impairment caused by hypoxia: from clinical evidences to molecular mechanisms. Metab Brain Dis 2022; 37:51-66. [PMID: 34618295 DOI: 10.1007/s11011-021-00796-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/09/2021] [Indexed: 12/23/2022]
Abstract
Hypoxia is a state of reduced oxygen supply and excessive oxygen consumption. According to the duration of hypoxic period, it can be classified as acute and chronic hypoxia. Both acute and chronic hypoxia could induce abundant neurological deficits. Although there have been significant advances in the pathophysiological injuries, few studies have focused on the cognitive dysfunction. In this review, we focused on the clinical evidences and molecular mechanisms of cognitive impairment under acute and chronic hypoxia. Hypoxia can impair several cognitive domains such as attention, learning and memory, procession speed and executive function, which are similar in acute and chronic hypoxia. The severity of cognitive deficit correlates with the duration and degree of hypoxia. Recovery can be achieved after acute hypoxia, while sequelae or even dementia can be observed after chronic hypoxia, perhaps due to the different molecular mechanisms. Cardiopulmonary compensatory response, glycolysis, oxidative stress, calcium overload, adenosine, mitochondrial disruption, inflammation and excitotoxicity contribute to the molecular mechanisms of cognitive deficit after acute hypoxia. During the chronic stage of hypoxia, different adaptive responses, impaired neurovascular coupling, apoptosis, transcription factors-mediated inflammation, as well as Aβ accumulation and tau phosphorylation account for the neurocognitive deficit. Moreover, brain structural changes with hippocampus and cortex atrophy, ventricle enlargement, senile plaque and neurofibrillary tangle deposition can be observed under chronic hypoxia rather than acute hypoxia.
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Affiliation(s)
- Xiaoyin Wang
- Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Lili Cui
- Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Xunming Ji
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.
- Department of Neurosurgery, Xuanwu Hospital of Capital Medical University, No 45, Changchun Street, Beijing, 100053, Xicheng District, China.
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42
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O'Keeffe K, Dean J, Hodder S, Lloyd A. Self-Selected Motivational Music Enhances Physical Performance in Normoxia and Hypoxia in Young Healthy Males. Front Psychol 2021; 12:787496. [PMID: 34956012 PMCID: PMC8702523 DOI: 10.3389/fpsyg.2021.787496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/18/2021] [Indexed: 11/13/2022] Open
Abstract
Humans exposed to hypoxia are susceptible to physiological and psychological impairment. Music has ergogenic effects through enhancing psychological factors such as mood, emotion, and cognition. This study aimed to investigate music as a tool for mitigating the performance decrements observed in hypoxia. Thirteen males (mean ± SD; 24 ± 4 years) completed one familiarization session and four experimental trials; (1) normoxia (sea level, 0.209 FiO2) and no music; (2) normoxia (0.209 FiO2) with music; (3) normobaric hypoxia (∼3800 m, 0.13 FiO2) and no music; and (4) normobaric hypoxia (0.13 FiO2) with music. Experimental trials were completed at 21°C with 50% relative humidity. Music was self-selected prior to the familiarization session. Each experimental trial included a 15-min time trial on an arm bike, followed by a 60-s isometric maximal voluntary contraction (MVC) of the biceps brachii. Supramaximal nerve stimulation quantified central and peripheral fatigue with voluntary activation (VA%) calculated using the doublet interpolation method. Average power output (W) was reduced with a main effect of hypoxia (p = 0.02) and significantly increased with a main effect of music (p = 0.001). When combined the interaction was additive (p = 0.87). Average MVC force (N) was reduced in hypoxia (p = 0.03) but VA% of the biceps brachii was increased with music (p = 0.02). Music reduced subjective scores of mental effort, breathing discomfort, and arm discomfort in hypoxia (p < 0.001). Music increased maximal physical exertion through enhancing neural drive and diminishing detrimental mental processes, enhancing performance in normoxia (6.3%) and hypoxia (6.4%).
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Affiliation(s)
- Kate O'Keeffe
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - Jacob Dean
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - Simon Hodder
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - Alex Lloyd
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
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43
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Bullock T, Giesbrecht B, Beaudin AE, Goodyear BG, Poulin MJ. Effects of changes in end-tidal PO 2 and PCO 2 on neural responses during rest and sustained attention. Physiol Rep 2021; 9:e15106. [PMID: 34755481 PMCID: PMC8578925 DOI: 10.14814/phy2.15106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/08/2021] [Accepted: 10/10/2021] [Indexed: 01/23/2023] Open
Abstract
Impairments of cognitive function during alterations in arterial blood gases (e.g., high-altitude hypoxia) may result from the disruption of neurovascular coupling; however, the link between changes in arterial blood gases, cognition, and cerebral blood flow (CBF) is poorly understood. To interrogate this link, we developed a multimodal empirical strategy capable of monitoring neural correlates of cognition and CBF simultaneously. Human participants performed a sustained attention task during hypoxia, hypercapnia, hypocapnia, and normoxia while electroencephalographic (EEG) activity and CBF (middle and posterior cerebral arteries; transcranial Doppler ultrasound) were simultaneously measured. The protocol alternated between rest and engaging in a visual target detection task that required participants to monitor a sequence of brief-duration colored circles and detect infrequent, longer duration circles (targets). The target detection task was overlaid on a large, circular checkerboard that provided robust visual stimulation. Spectral decomposition and event-related potential (ERP) analyses were applied to the EEG data to investigate spontaneous and task-specific fluctuations in neural activity. There were three main sets of findings: (1) spontaneous alpha oscillatory activity was modulated as a function of arterial CO2 (hypocapnia and hypercapnia), (2) task-related neurovascular coupling was disrupted by all arterial blood gas manipulations, and (3) changes in task-related alpha and theta band activity and attenuation of the P3 ERP component amplitude were observed during hypocapnia. Since alpha and theta are linked with suppression of visual processing and executive control and P3 amplitude with task difficulty, these data suggest that transient arterial blood gas changes can modulate multiple stages of cognitive information processing.
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Affiliation(s)
- Tom Bullock
- Department of Psychological and Brain SciencesUniversity of CaliforniaSanta BarbaraCaliforniaUSA
- Institute for Collaborative BiotechnologiesUniversity of CaliforniaSanta BarbaraCaliforniaUSA
| | - Barry Giesbrecht
- Department of Psychological and Brain SciencesUniversity of CaliforniaSanta BarbaraCaliforniaUSA
- Institute for Collaborative BiotechnologiesUniversity of CaliforniaSanta BarbaraCaliforniaUSA
- Interdepartmental Graduate Program in Dynamical NeuroscienceUniversity of CaliforniaSanta BarbaraCaliforniaUSA
| | - Andrew E. Beaudin
- Department of Physiology & PharmacologyUniversity of CalgaryCalgaryAlbertaCanada
- Hotchkiss Brain InstituteCumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada
| | - Bradley G. Goodyear
- Hotchkiss Brain InstituteCumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada
- Department of Clinical NeurosciencesUniversity of CalgaryCalgaryAlbertaCanada
- Department of RadiologyUniversity of CalgaryCalgaryAlbertaCanada
| | - Marc J. Poulin
- Department of Physiology & PharmacologyUniversity of CalgaryCalgaryAlbertaCanada
- Hotchkiss Brain InstituteCumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada
- Department of Clinical NeurosciencesUniversity of CalgaryCalgaryAlbertaCanada
- O’Brien Institute for Public HealthUniversity of CalgaryCalgaryAlbertaCanada
- Libin Cardiovascular Institute of AlbertaUniversity of CalgaryCalgaryAlbertaCanada
- Faculty of KinesiologyUniversity of CalgaryCalgaryAlbertaCanada
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44
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Muñoz S, Nazzal C, Jimenez D, Frenz P, Flores P, Alcantara-Zapata D, Marchetti N. Health Effects of Chronic Intermittent Hypoxia at a High Altitude among Chilean Miners: Rationale, Design, and Baseline Results of a Longitudinal Study. Ann Work Expo Health 2021; 65:908-918. [PMID: 34435202 DOI: 10.1093/annweh/wxab029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/09/2021] [Accepted: 03/31/2021] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES This study aims to assess the health effects on mining workers of exposure to chronic intermittent hypoxia (CIH) at high- and very high-altitude mining compared with similar work at lower altitudes in Chile, and it also aims to constitute the baseline of a 5-year follow-up study. METHODS We designed a cross-sectional study to assess health conditions in 483 miners working at 2 levels of altitude exposure: 336 working at a very high or high altitude (HA; 247 above 3900-4400 m, and 89 at 3000-3900 m), and 147 below 2400 m. Subjects were randomly selected in two stages. First, a selection of mines from a census of mines in each altitude stratum was made. Secondly, workers with less than 2 years of employment at each of the selected mines were recruited. The main outcomes measured at the baseline were mountain sickness, sleep alterations, hypertension, body mass index, and neurocognitive functions. RESULTS Prevalence of acute mountain sickness (AMS) was 28.4% in the very high-altitude stratum (P = 0.0001 compared with the low stratum), and 71.7% experienced sleep disturbance (P = 0.02). The adjusted odds ratio for AMS was 9.2 (95% confidence interval: 5.2-16.3) when compared with the very high- and low-altitude groups. Motor processing speed and spatial working memory score were lower for the high-altitude group. Hypertension was lower in the highest-altitude subjects, which may be attributed to preoccupational screening even though this was not statistically significant. CONCLUSIONS Despite longer periods of acclimatization to CIH, subjects continue to present AMS and sleep disturbance. Compromise of executive functions was detected, including working memory at HA. Further rigorous research is warranted to understand long-term health impacts of high-altitude mining, and to provide evidence-based policy recommendations.
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Affiliation(s)
- Sergio Muñoz
- Department of Public Health-CIGES, Faculty of Medicine, Universidad de La Frontera, 01145 Av. Francisco Salazar, Casilla 54-D, Temuco, Chile
| | - Carolina Nazzal
- Program of Occupational Health, School of Public Health, Faculty of Medicine, University of Chile, 939 Av. Independencia, Santiago, Chile
| | - Daniel Jimenez
- Program of Occupational Health, School of Public Health, Faculty of Medicine, University of Chile, 939 Av. Independencia, Santiago, Chile
| | - Patricia Frenz
- Program of Occupational Health, School of Public Health, Faculty of Medicine, University of Chile, 939 Av. Independencia, Santiago, Chile
| | - Patricia Flores
- Faculty of Medicine, Psychiatry Department, Catholic University of Chile, 12351 Camino El Alba, Las Condes, Santiago, Chile.,Servicio de Neurología, Departamento de Medicina, Clínica Alemana-Universidad del Desarrollo, Avenida Vitacura 5951, Región Metropolitana de Santiago, Santiago de Chile, Chile
| | - Diana Alcantara-Zapata
- Program of Occupational Health, School of Public Health, Faculty of Medicine, University of Chile, 939 Av. Independencia, Santiago, Chile
| | - Nella Marchetti
- Program of Occupational Health, School of Public Health, Faculty of Medicine, University of Chile, 939 Av. Independencia, Santiago, Chile
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45
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Cai J, Ruan J, Shao X, Ding Y, Xie K, Tang C, Yan Z, Luo E, Jing D. Oxygen Enrichment Mitigates High-Altitude Hypoxia-Induced Hippocampal Neurodegeneration and Memory Dysfunction Associated with Attenuated Tau Phosphorylation. High Alt Med Biol 2021; 22:274-284. [PMID: 34348049 DOI: 10.1089/ham.2020.0218] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Cai, Jing, Junyong Ruan, Xi Shao, Yuanjun Ding, Kangning Xie, Chi Tang, Zedong Yan, Erping Luo, and Da Jing. Oxygen enrichment mitigates high-altitude hypoxia-induced hippocampal neurodegeneration and memory dysfunction associated with attenuated tau phosphorylation. High Alt Med Biol 00:000-000, 2021. Background: Brain is predominantly vulnerable to high-altitude hypoxia (HAH), resulting in neurodegeneration and cognitive impairment. The technology of oxygen enrichment has proven effective to decrease the heart rate and improve the arterial oxygen saturation by reducing the equivalent altitude. However, the efficacy of oxygen enrichment on HAH-induced cognitive impairments remains controversial based on the results of neuropsychological tests, and its role in HAH-induced hippocampal morphological and molecular changes remains unknown. Therefore, this study aims to systematically investigate the effects of oxygen enrichment on the memory dysfunction and hippocampal neurodegeneration caused by HAH. Materials and Methods: Fifty-one male Sprague-Dawley rats were equally assigned to three groups: normal control, HAH, and HAH with oxygen enrichment (HAHO). Rats in the HAH and HAHO groups were exposed to hypoxia for 3 days in a hypobaric hypoxia chamber at a simulated altitude of 6,000 m. Rats in the HAHO group were supplemented with oxygen-enriched air, with 12 hours/day in the hypobaric hypoxia chamber. Results: Our results showed that oxygen enrichment improved the locomotor activity of HAH-exposed rats. The Morris water maze test revealed that oxygen enrichment significantly ameliorated HAH-induced spatial memory deficits. Oxygen enrichment also improved morphological alterations of pyramidal cells and the ultrastructure of neurons in the hippocampal CA1 region in rats exposed to acute HAH. Tau hyperphosphorylation at Ser396, Ser262, Thr231, and Thr181 was also significantly attenuated by oxygen enrichment in HAH-exposed rats. Conclusions: Together, our study reveals that oxygen enrichment can ameliorate HAH-induced cognitive impairments associated with improved hippocampal morphology and molecular expression, and highlights that oxygen enrichment may become a promising alternative treatment against neurodegeneration for humans ascending to the plateau.
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Affiliation(s)
- Jing Cai
- Department of Clinical Diagnostics, College of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang, China.,Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Junyong Ruan
- Medical Engineering Department, Qingdao Special Servicemen Recuperation Center of PLA Navy, Qingdao, China
| | - Xi Shao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Yuanjun Ding
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Kangning Xie
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Chi Tang
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Zedong Yan
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Erping Luo
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Da Jing
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
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46
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Shaw DM, Cabre G, Gant N. Hypoxic Hypoxia and Brain Function in Military Aviation: Basic Physiology and Applied Perspectives. Front Physiol 2021; 12:665821. [PMID: 34093227 PMCID: PMC8171399 DOI: 10.3389/fphys.2021.665821] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/22/2021] [Indexed: 01/04/2023] Open
Abstract
Acute hypobaric hypoxia (HH) is a major physiological threat during high-altitude flight and operations. In military aviation, although hypoxia-related fatalities are rare, incidences are common and are likely underreported. Hypoxia is a reduction in oxygen availability, which can impair brain function and performance of operational and safety-critical tasks. HH occurs at high altitude, due to the reduction in atmospheric oxygen pressure. This physiological state is also partially simulated in normobaric environments for training and research, by reducing the fraction of inspired oxygen to achieve comparable tissue oxygen saturation [normobaric hypoxia (NH)]. Hypoxia can occur in susceptible individuals below 10,000 ft (3,048 m) in unpressurised aircrafts and at higher altitudes in pressurised environments when life support systems malfunction or due to improper equipment use. Between 10,000 ft and 15,000 ft (4,572 m), brain function is mildly impaired and hypoxic symptoms are common, although both are often difficult to accurately quantify, which may partly be due to the effects of hypocapnia. Above 15,000 ft, brain function exponentially deteriorates with increasing altitude until loss of consciousness. The period of effective and safe performance of operational tasks following exposure to hypoxia is termed the time-of-useful-consciousness (TUC). Recovery of brain function following hypoxia may also lag beyond arterial reoxygenation and could be exacerbated by repeated hypoxic exposures or hyperoxic recovery. This review provides an overview of the basic physiology and implications of hypoxia for military aviation and discusses the utility of hypoxia recognition training.
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Affiliation(s)
- David M Shaw
- Aviation Medicine Unit, Royal New Zealand Air Force Base Auckland, Auckland, New Zealand.,School of Sport, Exercise and Nutrition, Massey University, Auckland, New Zealand
| | - Gus Cabre
- Aviation Medicine Unit, Royal New Zealand Air Force Base Auckland, Auckland, New Zealand
| | - Nicholas Gant
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand
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47
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Frost S, E Orr J, Oeung B, Puvvula N, Pham K, Brena R, DeYoung P, Jain S, Sun S, Malhotra A, Heinrich EC. Improvements in sleep-disordered breathing during acclimatization to 3800 m and the impact on cognitive function. Physiol Rep 2021; 9:e14827. [PMID: 33991443 PMCID: PMC8123551 DOI: 10.14814/phy2.14827] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 03/10/2021] [Indexed: 11/25/2022] Open
Abstract
Sojourners to high altitude often experience poor sleep quality due to sleep‐disordered breathing. Additionally, multiple aspects of cognitive function are impaired at high altitude. However, the impact of acclimatization on sleep‐disordered breathing and whether poor sleep is a major contributor to cognitive impairments at high altitude remains uncertain. We conducted nocturnal actigraphy and polygraphy, as well as daytime cognitive function tests, in 15 participants (33% women) at sea level and over 3 days of partial acclimatization to high altitude (3800 m). Our goal was to determine if sleep‐disordered breathing improved over time and if sleep‐disordered breathing was associated with cognitive function. The apnea–hypopnea index and oxygen desaturation index increased on night 1 (adj. p = 0.026 and adj. p = 0.026, respectively), but both improved over the subsequent 2 nights. These measures were matched by poorer self‐reported sleep quality on the Stanford Sleepiness Scale and PROMIS questionnaires following 1 night at high altitude (adj. p = 0.027 and adj. p = 0.022, respectively). The reaction time on the psychomotor vigilance task was slower at high altitude and did not improve (SL: 199 ± 27, ALT1: 224 ± 33, ALT2: 216 ± 41, ALT3: 212 ± 27 ms). The reaction times on the balloon analog risk task decreased at high altitude (SL: 474 ± 235, ALT1: 375 ± 159, ALT2: 291 ± 102, ALT3: 267 ± 90 ms), perhaps indicating increased risk‐taking behavior. Finally, multiple cognitive function measures were associated with sleep‐disordered breathing and measures of subjective sleep quality, rather than low daytime arterial oxygen saturation. These data indicate that sleep‐disordered breathing at moderately high altitude improves with partial acclimatization and that some aspects of cognitive performance in unacclimatized sojourners may be impacted by poor sleep rather than hypoxemia alone.
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Affiliation(s)
- Shyleen Frost
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Jeremy E Orr
- Division of Pulmonary, Critical Care, Sleep Medicine and Physiology, School of Medicine, University of California, San Diego, CA, USA
| | - Britney Oeung
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Nikhil Puvvula
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Kathy Pham
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Rebbecca Brena
- Division of Pulmonary, Critical Care, Sleep Medicine and Physiology, School of Medicine, University of California, San Diego, CA, USA
| | - Pamela DeYoung
- Division of Pulmonary, Critical Care, Sleep Medicine and Physiology, School of Medicine, University of California, San Diego, CA, USA
| | - Sonia Jain
- Biostatistics Research Center, Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, CA, USA
| | - Shelly Sun
- Biostatistics Research Center, Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, CA, USA
| | - Atul Malhotra
- Division of Pulmonary, Critical Care, Sleep Medicine and Physiology, School of Medicine, University of California, San Diego, CA, USA
| | - Erica C Heinrich
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
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48
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Effect of Acute Normobaric Hypoxia Exposure on Executive Functions among Young Physically Active Males. J Clin Med 2021; 10:jcm10081560. [PMID: 33917691 PMCID: PMC8068023 DOI: 10.3390/jcm10081560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 03/31/2021] [Accepted: 04/04/2021] [Indexed: 12/15/2022] Open
Abstract
Background: On the one hand, hypoxic exposure may result in progressive brain metabolism disturbance, causing subsequent cognitive impairments. On the other hand, it might also enhance neurogenesis and brain vascularization as well as accelerate cerebral blood flow, leading to cognitive function improvement. The aim of this study was to investigate whether progressive stages of normobaric hypoxia (NH) (FIO2 = 13%, FIO2 = 12%, and FIO2 = 11%) differentially affect post-exposure cognitive performance. Methods: Fifteen physically active men (age = 23.1 ± 2.1) participated in the study. The Stroop test (ST) was applied to assess cognitive function. To generate NH conditions, a hypoxic normobaric air generator was used. Results: We observed an executive function impairment (“naming” interference p < 0.05) after NH exposure (FIO2 = 13%). After exposure at FIO2 = 12% and FIO2 = 11%, no changes were observed in the Stroop test. Also, changes in SpO2 during subsequent NH exposure were observed. Conclusions: The current investigation shows that executive functions deteriorate after acute NH exposure and this post-exposure deterioration is not proportional to the normobaric hypoxia stages among young physically active males.
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49
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Frontera JA, Melmed K, Fang T, Granger A, Lin J, Yaghi S, Zhou T, Lewis A, Kurz S, Kahn DE, de Havenon A, Huang J, Czeisler BM, Lord A, Meropol SB, Troxel AB, Wisniewski T, Balcer L, Galetta S. Toxic Metabolic Encephalopathy in Hospitalized Patients with COVID-19. Neurocrit Care 2021; 35:693-706. [PMID: 33725290 PMCID: PMC7962078 DOI: 10.1007/s12028-021-01220-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/20/2021] [Indexed: 12/15/2022]
Abstract
Background Toxic metabolic encephalopathy (TME) has been reported in 7–31% of hospitalized patients with coronavirus disease 2019 (COVID-19); however, some reports include sedation-related delirium and few data exist on the etiology of TME. We aimed to identify the prevalence, etiologies, and mortality rates associated with TME in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive patients. Methods We conducted a retrospective, multicenter, observational cohort study among patients with reverse transcriptase–polymerase chain reaction-confirmed SARS-CoV-2 infection hospitalized at four New York City hospitals in the same health network between March 1, 2020, and May 20, 2020. TME was diagnosed in patients with altered mental status off sedation or after an adequate sedation washout. Patients with structural brain disease, seizures, or primary neurological diagnoses were excluded. The coprimary outcomes were the prevalence of TME stratified by etiology and in-hospital mortality (excluding comfort care only patients) assessed by using a multivariable time-dependent Cox proportional hazards models with adjustment for age, race, sex, intubation, intensive care unit requirement, Sequential Organ Failure Assessment scores, hospital location, and date of admission. Results Among 4491 patients with COVID-19, 559 (12%) were diagnosed with TME, of whom 435 of 559 (78%) developed encephalopathy immediately prior to hospital admission. The most common etiologies were septic encephalopathy (n = 247 of 559 [62%]), hypoxic-ischemic encephalopathy (HIE) (n = 331 of 559 [59%]), and uremia (n = 156 of 559 [28%]). Multiple etiologies were present in 435 (78%) patients. Compared with those without TME (n = 3932), patients with TME were older (76 vs. 62 years), had dementia (27% vs. 3%) or psychiatric history (20% vs. 10%), were more often intubated (37% vs. 20%), had a longer hospital length of stay (7.9 vs. 6.0 days), and were less often discharged home (25% vs. 66% [all P < 0.001]). Excluding comfort care patients (n = 267 of 4491 [6%]) and after adjustment for confounders, TME remained associated with increased risk of in-hospital death (n = 128 of 425 [30%] patients with TME died, compared with n = 600 of 3799 [16%] patients without TME; adjusted hazard ratio [aHR] 1.24, 95% confidence interval [CI] 1.02–1.52, P = 0.031), and TME due to hypoxemia conferred the highest risk (n = 97 of 233 [42%] patients with HIE died, compared with n = 631 of 3991 [16%] patients without HIE; aHR 1.56, 95% CI 1.21–2.00, P = 0.001). Conclusions TME occurred in one in eight hospitalized patients with COVID-19, was typically multifactorial, and was most often due to hypoxemia, sepsis, and uremia. After we adjustment for confounding factors, TME was associated with a 24% increased risk of in-hospital mortality. Supplementary Information The online version contains supplementary material available at 10.1007/s12028-021-01220-5.
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Affiliation(s)
- Jennifer A Frontera
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA.
| | - Kara Melmed
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Taolin Fang
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Andre Granger
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Jessica Lin
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Shadi Yaghi
- Brown University School of Medicine, Providence, RI, USA
| | - Ting Zhou
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Ariane Lewis
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Sebastian Kurz
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - D Ethan Kahn
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Adam de Havenon
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Joshua Huang
- New York University Langone Hospitals, New York, NY, USA
| | - Barry M Czeisler
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Aaron Lord
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Sharon B Meropol
- Department of Population Health, New York University Grossman School of Medicine, New York, NY, USA
| | - Andrea B Troxel
- Department of Population Health, New York University Grossman School of Medicine, New York, NY, USA
| | - Thomas Wisniewski
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Laura Balcer
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Steven Galetta
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
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Bondi D, Verratti V, Nori R, Piccardi L, Prete G, Pietrangelo T, Tommasi L. Spatial Abilities at High Altitude: Exploring the Role of Cultural Strategies and Hypoxia. High Alt Med Biol 2021; 22:157-165. [PMID: 33416426 DOI: 10.1089/ham.2020.0115] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bondi, Danilo, Vittore Verratti, Raffaella Nori, Laura Piccardi, Giulia Prete, Tiziana Pietrangelo, and Luca Tommasi. Spatial abilities at high altitude: Exploring the role of cultural strategies and hypoxia. High Alt Med Biol. 22: 157-165, 2021. Background: Over the past couple of decades, the number of people of different cultures traveling to places of high altitude (HA) increased. At HA, a decline in cognitive abilities has been described, including spatial skills. However, it is still unknown whether people accustomed to hypobaric hypoxia are less susceptible to cognitive decline. Method: We aimed to determine if three ethnic groups would show any difference in the performance of spatial abilities. Italian trekkers (46.20 ± 15.83 years), Nepalese porters (30.33 ± 8.55 years), and lowlander and highlander Sherpas (30.33 ± 8.55 and 37.00 ± 16.51 years) were tested with a building photograph recognition, a map orienting, and a mental rotation task during a Himalayan expedition. Accuracy and response times were collected at low altitude (LA) and HA. Results: Nepalese performed the worst (photograph task: p = 0.015, η2p = 0.36; map task: p = 0.016, η2p = 0.36), but the difference was mitigated after correcting for length of schooling. Participants took more time to respond at LA than in HA condition (photograph task: 24.0 ± 15.3 seconds vs. 12.7 ± 6.3 seconds, p = 0.008, η2p = 0.57; map task: 12.5 ± 1.8 seconds vs. 7.8 ± 0.6 seconds, p = 0.038, η2p = 0.40). In the map task, participants performed with greater accuracy at LA (5.1 ± 0.4 vs. 4.4 ± 0.4 number of correct responses, p = 0.006, η2p = 0.59). Conclusions: Altitude hypoxia elicited impairments in cognitive spatial tasks. This may be due to the inability to acquire new unfamiliar patterns, and to the difficulty in managing a high cognitive workload. The ethnic differences were ascribed to schooling, even we consider the different system of reference usually exploited in each culture (egocentric: dependent, or allocentric: independent from the personal viewpoint), and that Westerners are more likely to focus on specific details of the scene. Further studies should investigate the diverse strategies to complete spatial tasks.
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Affiliation(s)
- Danilo Bondi
- Department of Neuroscience, Imaging and Clinical Sciences and Health and Territorial Sciences, University "G. d'Annunzio" of Chieti - Pescara, Chieti, Italy
| | - Vittore Verratti
- Department of Psychological, Health and Territorial Sciences, University "G. d'Annunzio" of Chieti - Pescara, Chieti, Italy
| | - Raffaella Nori
- Department of Psychology, University of Bologna, Bologna, Italy
| | - Laura Piccardi
- Department of Psychology, Sapienza University of Rome, Rome, Italy.,Cognitive and Motor Rehabilitation Unit, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Giulia Prete
- Department of Psychological, Health and Territorial Sciences, University "G. d'Annunzio" of Chieti - Pescara, Chieti, Italy
| | - Tiziana Pietrangelo
- Department of Neuroscience, Imaging and Clinical Sciences and Health and Territorial Sciences, University "G. d'Annunzio" of Chieti - Pescara, Chieti, Italy
| | - Luca Tommasi
- Department of Psychological, Health and Territorial Sciences, University "G. d'Annunzio" of Chieti - Pescara, Chieti, Italy
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