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Chen J, Liang S, Wei M, Ma Y, Bi T, Liu Z, Song Y, Chen H, Wang Y. Trace of delirium after robotic lower abdominal tumor resection at different end-tidal carbon dioxide: a RCT trial. BMC Anesthesiol 2024; 24:234. [PMID: 38997624 PMCID: PMC11241950 DOI: 10.1186/s12871-024-02617-3] [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: 09/22/2023] [Accepted: 07/01/2024] [Indexed: 07/14/2024] Open
Abstract
BACKGROUND Postoperative delirium (POD) often occurs in oncology patients, further increasing the medical and financial burden. Robotic technology in lower abdominal tumors resection reduces surgical trauma but increases risks such as carbon dioxide (CO2) absorption. This study aimed to investigate the differences in their occurrence of POD at different end-tidal CO2 levels. METHOD This study was approved by the Ethics Committee of Affiliated Hospital of He Bei University (HDFY-LL-2022-169). The study was registered with the Chinese Clinical Trials Registry on URL: http://www.chictr.org.cn , Registry Number: ChiCTR2200056019 (Registry Date: 27/08/2022). In patients scheduled robotic lower abdominal tumor resection from September 1, 2022 to December 31, 2022, a comprehensive delirium assessment was performed three days postoperatively using the CAM scale with clinical review records. Intraoperative administration of different etCO2 was performed depending on the randomized grouping after intubation. Group L received lower level etCO2 management (31-40mmHg), and Group H maintained the higher level(41-50mmHg) during pneumoperitoneum. Data were analyzed using Pearson Chi-Square or Wilcoxon Rank Sum tests and multiple logistic regression. Preoperative mental status score, alcohol impairment score, nicotine dependence score, history of hypertension and diabetes, duration of surgery and worst pain score were included in the regression model along with basic patient information for covariate correction analysis. RESULTS Among the 103 enrolled patients, 19 (18.4%) developed postoperative delirium. The incidence of delirium in different etCO2 groups was 21.6% in Group L and 15.4% in Group H, respectively, with no statistical differences. In adjusted multivariate analysis, age and during of surgery were statistically significant predictors of postoperative delirium. The breath-hold test was significantly lower postoperatively, but no statistical differences were found between two groups. CONCLUSION With robotic assistant, the incidence of postoperative delirium in patients undergoing lower abdominal tumor resection was not modified by different end-tidal carbon dioxide management, however, age and duration of surgery were positively associated risk factors.
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Affiliation(s)
- Jingwen Chen
- Department of Anesthesiology, Harbin Medical University Cancer Hospital, No. 150 Haping Rd., Nangang District, Harbin, 150081, China
| | - Si Liang
- Department of Anesthesiology, Affiliated Hospital of He Bei University, Baoding, 071000, China
- Clinical Medical College, Hebei University, Baoding, 071000, China
| | - Ming Wei
- Department of Anesthesiology, Harbin Medical University Cancer Hospital, No. 150 Haping Rd., Nangang District, Harbin, 150081, China
| | - Yue Ma
- Department of Anesthesiology, Harbin Medical University Cancer Hospital, No. 150 Haping Rd., Nangang District, Harbin, 150081, China
| | - Tianpeng Bi
- Department of Anesthesiology, Harbin Medical University Cancer Hospital, No. 150 Haping Rd., Nangang District, Harbin, 150081, China
| | - Zheng Liu
- Department of Anesthesiology, Harbin Medical University Cancer Hospital, No. 150 Haping Rd., Nangang District, Harbin, 150081, China
| | - Yang Song
- Department of Anesthesiology, Harbin Medical University Cancer Hospital, No. 150 Haping Rd., Nangang District, Harbin, 150081, China
| | - Hong Chen
- Department of Anesthesiology, Harbin Medical University Cancer Hospital, No. 150 Haping Rd., Nangang District, Harbin, 150081, China.
| | - Yu Wang
- Department of Anesthesiology, Harbin Medical University Cancer Hospital, No. 150 Haping Rd., Nangang District, Harbin, 150081, China.
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Alexander M, Machado L. Chronic exercise and neuropsychological function in healthy young adults: a randomised controlled trial investigating a running intervention. Cogn Process 2024; 25:241-258. [PMID: 38421460 PMCID: PMC11106121 DOI: 10.1007/s10339-024-01177-1] [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: 12/07/2022] [Accepted: 01/23/2024] [Indexed: 03/02/2024]
Abstract
Despite the well-known physical and mental health benefits of regular exercise, many of the world's population, including healthy young adults, grossly undershoot recommended physical activity levels. Chronic exercise has potential to improve cognitive performance and affect in most age groups. However, there is currently a poverty of relevant research in young adults, especially randomised controlled trials. To address this, the current research investigated the effects of a running intervention on neuropsychological function (cognition and affect) in young adults. We predicted that following a running intervention, neuropsychological performance would improve alongside increases in aerobic fitness. Thirty-two healthy young adult university students were randomised (using a 3:1 ratio) into an intervention or control group, with the intervention group (n = 24) asked to run for 30 min three times a week over a 6-week period and the control group (n = 8) asked to maintain their current level of exercise over a 6-week period. We assessed fitness, cognitive performance, affect and running enjoyment at baseline and follow-up, and runners recorded the environmental conditions of their runs. Repeated measures ANCOVAs failed to find any significant effects of the running intervention on fitness or the neuropsychological measures. Anecdotal evidence supported running environment and enjoyment as potentially relevant factors. The failure to find any fitness improvements, which likely underpins the lack of neuropsychological improvements, highlights the importance of monitoring exercise sessions. Coupled with other insights gained from this trial, this article may prove useful towards future endeavours to develop exercise interventions beneficial to young adults.TRN: ACTRN12621000242820, Date of registration: 08/03/2021.
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Affiliation(s)
- Mhairi Alexander
- Department of Psychology, University of Otago, William James Building, 275 Leith Walk, Dunedin, 9054, New Zealand
- Brain Research New Zealand, Auckland, New Zealand
| | - Liana Machado
- Department of Psychology, University of Otago, William James Building, 275 Leith Walk, Dunedin, 9054, New Zealand.
- Brain Research New Zealand, Auckland, New Zealand.
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3
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Carr JMJR, Hoiland RL, Fernandes IA, Schrage WG, Ainslie PN. Recent insights into mechanisms of hypoxia-induced vasodilatation in the human brain. J Physiol 2023. [PMID: 37655827 DOI: 10.1113/jp284608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/07/2023] [Indexed: 09/02/2023] Open
Abstract
The cerebral vasculature manages oxygen delivery by adjusting arterial blood in-flow in the face of reductions in oxygen availability. Hypoxic cerebral vasodilatation, and the associated hypoxic cerebral blood flow reactivity, involve many vascular, erythrocytic and cerebral tissue mechanisms that mediate elevations in cerebral blood flow via micro- and macrovascular dilatation. This contemporary review focuses on in vivo human work - with reference to seminal preclinical work where necessary - on hypoxic cerebrovascular reactivity, particularly where recent advancements have been made. We provide updates with the following information: in humans, hypoxic cerebral vasodilatation is partially mediated via a - likely non-obligatory - combination of: (1) nitric oxide synthases, (2) deoxygenation-coupled S-nitrosothiols, (3) potassium channel-related vascular smooth muscle hyperpolarization, and (4) prostaglandin mechanisms with some contribution from an interrelationship with reactive oxygen species. And finally, we discuss the fact that, due to the engagement of deoxyhaemoglobin-related mechanisms, reductions in O2 content via haemoglobin per se seem to account for ∼50% of that seen with hypoxic cerebral vasodilatation during hypoxaemia. We further highlight the issue that methodological impediments challenge the complete elucidation of hypoxic cerebral reactivity mechanisms in vivo in healthy humans. Future research is needed to confirm recent advancements and to reconcile human and animal findings. Further investigations are also required to extend these findings to address questions of sex-, heredity-, age-, and disease-related differences. The final step is to then ultimately translate understanding of these mechanisms into actionable, targetable pathways for the prevention and treatment of cerebral vascular dysfunction and cerebral hypoxic brain injury.
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Affiliation(s)
- Jay M J R Carr
- Centre for Heart, Lung and Vascular Health, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Ryan L Hoiland
- Department of Anesthesiology, Pharmacology and Therapeutics, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Collaborative Entity for Researching Brain Ischemia (CEREBRI), University of British Columbia, Vancouver, British Columbia, Canada
| | - Igor A Fernandes
- Department of Health and Kinesiology, Purdue University, Indiana, USA
| | - William G Schrage
- Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
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Zhang Q, Haselden WD, Charpak S, Drew PJ. Could respiration-driven blood oxygen changes modulate neural activity? Pflugers Arch 2023; 475:37-48. [PMID: 35761104 PMCID: PMC9794637 DOI: 10.1007/s00424-022-02721-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 05/26/2022] [Accepted: 06/16/2022] [Indexed: 01/31/2023]
Abstract
Oxygen is critical for neural metabolism, but under most physiological conditions, oxygen levels in the brain are far more than are required. Oxygen levels can be dynamically increased by increases in respiration rate that are tied to the arousal state of the brain and cognition, and not necessarily linked to exertion by the body. Why these changes in respiration occur when oxygen is already adequate has been a long-standing puzzle. In humans, performance on cognitive tasks can be affected by very high or very low oxygen levels, but whether the physiological changes in blood oxygenation produced by respiration have an appreciable effect is an open question. Oxygen has direct effects on potassium channels, increases the degradation rate of nitric oxide, and is rate limiting for the synthesis of some neuromodulators. We discuss whether oxygenation changes due to respiration contribute to neural dynamics associated with attention and arousal.
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Affiliation(s)
- Qingguang Zhang
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - William D Haselden
- Medical Scientist Training Program, College of Medicine, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Serge Charpak
- Institut de La Vision, INSERM, CNRS, Sorbonne Université, Paris, France
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Patrick J Drew
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA.
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
- Department of Neurosurgery, The Pennsylvania State University, University Park, PA, 16802, USA.
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Drew PJ. Neurovascular coupling: motive unknown. Trends Neurosci 2022; 45:809-819. [PMID: 35995628 PMCID: PMC9768528 DOI: 10.1016/j.tins.2022.08.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/01/2022] [Accepted: 08/05/2022] [Indexed: 12/13/2022]
Abstract
In the brain, increases in neural activity drive changes in local blood flow via neurovascular coupling. The common explanation for increased blood flow (known as functional hyperemia) is that it supplies the metabolic needs of active neurons. However, there is a large body of evidence that is inconsistent with this idea. Baseline blood flow is adequate to supply oxygen needs even with elevated neural activity. Neurovascular coupling is irregular, absent, or inverted in many brain regions, behavioral states, and conditions. Increases in respiration can increase brain oxygenation without flow changes. Simulations show that given the architecture of the brain vasculature, areas of low blood flow are inescapable and cannot be removed by functional hyperemia. As discussed in this article, potential alternative functions of neurovascular coupling include supplying oxygen for neuromodulator synthesis, brain temperature regulation, signaling to neurons, stabilizing and optimizing the cerebral vascular structure, accommodating the non-Newtonian nature of blood, and driving the production and circulation of cerebrospinal fluid (CSF).
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Affiliation(s)
- Patrick J Drew
- Center for Neural Engineering, Departments of Engineering Science and Mechanics, Neurosurgery, Biology, and Biomedical Engineering, The Pennsylvania State University, W-317 Millennium Science Complex, University Park, PA 16802, USA.
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Effect of a speed ascent to the top of Europe on cognitive function in elite climbers. Eur J Appl Physiol 2022; 122:635-649. [PMID: 34993575 DOI: 10.1007/s00421-021-04855-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 11/19/2021] [Indexed: 11/03/2022]
Abstract
PURPOSE The combined effects of acute hypoxia and exercise on cognition remain to be clarified. We investigated the effect of speed climbing to high altitude on reactivity and inhibitory control in elite climbers. METHODS Eleven elite climbers performed a speed ascent of the Mont-Blanc (4810 m) and were evaluated pre- (at 1000 m) and immediately post-ascent (at 3835 m). In both conditions, a Simon task was done at rest (single-task session, ST) and during a low-intensity exercise (dual-task session, DT). Prefrontal cortex (PFC) oxygenation and middle cerebral artery velocity (MCAv) were monitored using near-infrared spectroscopy and transcranial Doppler, respectively, during the cognitive task. Self-perceived mental fatigue and difficulty to perform the cognitive tests were estimated using a visual analog scale. Heart rate and pulse oxygenation (SpO2) were monitored during the speed ascent. RESULTS Elite climbers performed an intense (~ 50% of the time ≥ 80% of maximal heart rate) and prolonged (8h58 ± 6 min) exercise in hypoxia (minimal SpO2 at 4810 m: 78 ± 4%). Reaction time and accuracy during the Simon task were similar pre- and post-ascent (374 ± 28 ms vs. 385 ± 39 ms and 6 ± 4% vs. 5 ± 4%, respectively; p > 0.05), despite a reported higher mental fatigue and difficulty to perform the Simon task post-ascent (all p < 0.05). The magnitude of the Simon effect was unaltered (p > 0.05), suggesting a preserved cognitive control post-ascent. Pattern of PFC oxygenation and MCAv differed between pre- and post-ascent as well as between ST and DT conditions. CONCLUSIONS Cognitive control is not altered in elite climbers after a speed ascent to high-altitude despite substantial cerebral deoxygenation and fatigue perception.
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Pearson AG, Miller KB, Corkery AT, Eisenmann NA, Howery AJ, Carl AE, Eldridge MW, Barnes JN. Impact of age and cyclooxygenase inhibition on the hemodynamic response to acute cognitive challenges. Am J Physiol Regul Integr Comp Physiol 2021; 321:R208-R219. [PMID: 34161746 DOI: 10.1152/ajpregu.00048.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Structural and functional changes in the cerebral vasculature occur with advancing age, which may lead to impaired neurovascular coupling (NVC) and cognitive decline. Cyclooxygenase (COX) inhibition abolishes age-related differences in cerebrovascular reactivity, but it is unclear if COX inhibition impacts NVC. The purpose of this study was to examine the influence of aging on NVC before and after COX inhibition. Twenty-three young (age = 25 ± 4 yr) and 21 older (age = 64 ± 5 yr) adults completed two levels of difficulty of the Stroop and n-back tests before and after COX inhibition. Middle cerebral artery blood velocity (MCAv) was measured using transcranial Doppler ultrasound and mean arterial blood pressure (MAP) was measured using a finger cuff. Hemodynamic variables were measured at rest and in response to cognitive challenges. During the Stroop test, older adults demonstrated a greater increase in MCAv (young: 2.2 ± 6.8% vs. older: 5.9 ± 5.8%; P = 0.030) and MAP (young: 2.0 ± 4.9% vs. older: 4.8 ± 4.9%; P = 0.036) compared with young adults. There were no age-related differences during the n-back test. COX inhibition reduced MCAv by 30% in young and 26% in older adults (P < 0.001 for both). During COX inhibition, there were no age-related differences in the percent change in MCAv or MAP in response to the cognitive tests. Our results show that older adults require greater increases in MCAv and MAP during a test of executive function compared with young adults and that any age-related differences in NVC were abolished during COX inhibition. Collectively, this suggests that aging is associated with greater NVC necessary to accomplish a cognitive task.
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Affiliation(s)
- Andrew G Pearson
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Kathleen B Miller
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Adam T Corkery
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Nicole A Eisenmann
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Anna J Howery
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Alexandra E Carl
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Marlowe W Eldridge
- Division of Critical Care, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.,John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Jill N Barnes
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin.,Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
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8
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Burtscher J, Millet GP, Place N, Kayser B, Zanou N. The Muscle-Brain Axis and Neurodegenerative Diseases: The Key Role of Mitochondria in Exercise-Induced Neuroprotection. Int J Mol Sci 2021; 22:6479. [PMID: 34204228 PMCID: PMC8235687 DOI: 10.3390/ijms22126479] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/13/2021] [Accepted: 06/15/2021] [Indexed: 12/12/2022] Open
Abstract
Regular exercise is associated with pronounced health benefits. The molecular processes involved in physiological adaptations to exercise are best understood in skeletal muscle. Enhanced mitochondrial functions in muscle are central to exercise-induced adaptations. However, regular exercise also benefits the brain and is a major protective factor against neurodegenerative diseases, such as the most common age-related form of dementia, Alzheimer's disease, or the most common neurodegenerative motor disorder, Parkinson's disease. While there is evidence that exercise induces signalling from skeletal muscle to the brain, the mechanistic understanding of the crosstalk along the muscle-brain axis is incompletely understood. Mitochondria in both organs, however, seem to be central players. Here, we provide an overview on the central role of mitochondria in exercise-induced communication routes from muscle to the brain. These routes include circulating factors, such as myokines, the release of which often depends on mitochondria, and possibly direct mitochondrial transfer. On this basis, we examine the reported effects of different modes of exercise on mitochondrial features and highlight their expected benefits with regard to neurodegeneration prevention or mitigation. In addition, knowledge gaps in our current understanding related to the muscle-brain axis in neurodegenerative diseases are outlined.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, University of Lausanne, CH-1015 Lausanne, Switzerland; (G.P.M.); (N.P.); (B.K.); (N.Z.)
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland
| | - Grégoire P. Millet
- Institute of Sport Sciences, University of Lausanne, CH-1015 Lausanne, Switzerland; (G.P.M.); (N.P.); (B.K.); (N.Z.)
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland
| | - Nicolas Place
- Institute of Sport Sciences, University of Lausanne, CH-1015 Lausanne, Switzerland; (G.P.M.); (N.P.); (B.K.); (N.Z.)
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland
| | - Bengt Kayser
- Institute of Sport Sciences, University of Lausanne, CH-1015 Lausanne, Switzerland; (G.P.M.); (N.P.); (B.K.); (N.Z.)
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland
| | - Nadège Zanou
- Institute of Sport Sciences, University of Lausanne, CH-1015 Lausanne, Switzerland; (G.P.M.); (N.P.); (B.K.); (N.Z.)
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland
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Carr JMJR, Caldwell HG, Ainslie PN. Cerebral blood flow, cerebrovascular reactivity and their influence on ventilatory sensitivity. Exp Physiol 2021; 106:1425-1448. [PMID: 33932955 DOI: 10.1113/ep089446] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 04/26/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the topic of this review? Cerebrovascular reactivity to CO2 , which is a principal factor in determining ventilatory responses to CO2 through the role reactivity plays in determining cerebral extra- and intracellular pH. What advances does it highlight? Recent animal evidence suggests central chemoreceptor vasculature may demonstrate regionally heterogeneous cerebrovascular reactivity to CO2 , potentially as a protective mechanism against excessive CO2 washout from the central chemoreceptors, thereby allowing ventilation to reflect the systemic acid-base balance needs (respiratory changes in P aC O 2 ) rather than solely the cerebral needs. Ventilation per se does not influence cerebrovascular reactivity independent of changes in P aC O 2 . ABSTRACT Alveolar ventilation and cerebral blood flow are both predominantly regulated by arterial blood gases, especially arterial P C O 2 , and so are intricately entwined. In this review, the fundamental mechanisms underlying cerebrovascular reactivity and central chemoreceptor control of breathing are covered. We discuss the interaction of cerebral blood flow and its reactivity with the control of ventilation and ventilatory responsiveness to changes in P C O 2 , as well as the lack of influence of ventilation itself on cerebrovascular reactivity. We briefly summarize the effects of arterial hypoxaemia on the relationship between ventilatory and cerebrovascular response to both P C O 2 and P O 2 . We then highlight key methodological considerations regarding the interaction of reactivity and ventilatory sensitivity, including the following: regional heterogeneity of cerebrovascular reactivity; a pharmacological approach for the reduction of cerebral blood flow; reactivity assessment techniques; the influence of mean arterial blood pressure; and sex-related differences. Finally, we discuss ventilatory and cerebrovascular control in the context of high altitude and congestive heart failure. Future research directions and pertinent questions of interest are highlighted throughout.
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Affiliation(s)
- Jay M J R Carr
- Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan Campus, British Columbia, Canada
| | - Hannah G Caldwell
- Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan Campus, British Columbia, Canada
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan Campus, British Columbia, Canada
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White N, Kouwenhoven M, Machado L. Short-Term Retest Performance in Young versus Older Adults: Consideration of Integrated Speed-Accuracy Measures. Exp Aging Res 2021; 48:68-85. [PMID: 33993852 DOI: 10.1080/0361073x.2021.1919475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Objectives: The current research addressed gaps in the literature regarding short-term computerized cognitive retest performance in young and older adults using two integrated speed-accuracy metrics. The aims were: (a) to advance the aging literature on short-term retest performance using a computerized cognitive battery and a retest schedule that included both within- and between-day time points, and (b) to assess the test-retest reliability of two integrated speed-accuracy metrics, inverse efficiency scores (IES) and balanced integration scores (BIS).Method: Twenty young (18-23 years) and thirty older (65-71 years) men completed a battery measuring a range of cognitive functions, six times over three testing days, each 1 week apart.Results: Compared to young adults, older adults exhibited steeper within- and between-day performance gains in IES and BIS, which may reflect a combination of lower initial cognitive ability and familiarity, indicating that older adults may require more familiarization on computerized tests. Relative to unadjusted reaction times, IES reliability appeared comparable in older adults, but slightly lower among young adults. The reliability of BIS was lower than unadjusted reaction times and IES in both age groups.Discussion: Our findings provide guidance for researchers wanting to combine speed and accuracy into a single performance metric in repeated testing contexts.
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Affiliation(s)
- Naomi White
- Department of Psychology, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand, Auckland, New Zealand
| | | | - Liana Machado
- Department of Psychology, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand, Auckland, New Zealand
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Burley CV, Francis ST, Thomas KN, Whittaker AC, Lucas SJE, Mullinger KJ. Contrasting Measures of Cerebrovascular Reactivity Between MRI and Doppler: A Cross-Sectional Study of Younger and Older Healthy Individuals. Front Physiol 2021; 12:656746. [PMID: 33912073 PMCID: PMC8072486 DOI: 10.3389/fphys.2021.656746] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/10/2021] [Indexed: 12/12/2022] Open
Abstract
Cerebrovascular reactivity (CVR) is used as an outcome measure of brain health. Traditionally, lower CVR is associated with ageing, poor fitness and brain-related conditions (e.g. stroke, dementia). Indeed, CVR is suggested as a biomarker for disease risk. However, recent findings report conflicting associations between ageing or fitness and CVR measures. Inconsistent findings may relate to different neuroimaging modalities used, which include transcranial Doppler (TCD) and blood-oxygen-level-dependant (BOLD) contrast magnetic resonance imaging (MRI). We assessed the relationship between CVR metrics derived from two common imaging modalities, TCD and BOLD MRI, within the same individuals and with expected significant differences (i.e., younger vs. older) to maximise the expected spread in measures. We conducted two serial studies using TCD- and MRI-derived measures of CVR (via inspired 5% CO2 in air). Study 1 compared 20 younger (24 ± 7 years) with 15 older (66 ± 7 years) participants, Study 2 compared 10 younger (22 ± 2 years) with 10 older (72 ± 4 years) participants. Combining the main measures across studies, no significant correlation (r = 0.15, p = 0.36) was observed between individual participant TCD- and BOLD-CVR measures. Further, these measures showed differential effects between age groups; with TCD-CVR higher in the older compared to younger group (4 ± 1 vs. 3 ± 1 %MCAv/mmHg P ET CO2; p < 0.05, Hedges' g = 0.75), whereas BOLD-CVR showed no difference (p = 0.104, Hedges' g = 0.38). In Study 2 additional measures were obtained to understand the origin of the discrepancy: phase contrast angiography (PCA) MRI of the middle cerebral artery, showed a significantly lower blood flow (but not velocity) CVR response in older compared with younger participants (p > 0.05, Hedges' g = 1.08). The PCA CVR metrics did not significantly correlate with the BOLD- or TCD-CVR measures. The differing CVR observations between imaging modalities were despite expected, correlated (r = 0.62-0.82), age-related differences in resting CBF measures across modalities. Taken together, findings across both studies show no clear relationship between TCD- and BOLD-CVR measures. We hypothesize that CVR differences between imaging modalities are in part due to the aspects of the vascular tree that are assessed (TCD:arteries; BOLD:venules/veins). Further work is needed to understand the between-modality CVR response differences, but caution is needed when comparing CVR metrics derived from different imaging modalities.
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Affiliation(s)
- Claire V. Burley
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
- Dementia Centre for Research Collaboration, School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - Susan T. Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - Kate N. Thomas
- Department of Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Anna C. Whittaker
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom
| | - Samuel J. E. Lucas
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
| | - Karen J. Mullinger
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
- School of Psychology, University of Birmingham, Birmingham, United Kingdom
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Griffiths TD, Talbot JS, Douglas AJM, Richards CT, Lord RN. Exercised state of mind: A perspective on ageing, cerebral blood flow and cognition. J Physiol 2021; 599:2523-2524. [PMID: 33644861 DOI: 10.1113/jp281368] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 02/23/2021] [Indexed: 11/08/2022] Open
Affiliation(s)
- Thomas D Griffiths
- School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
| | - Jack S Talbot
- School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
| | - Andrew J M Douglas
- School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
| | - Cory T Richards
- School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
| | - Rachel N Lord
- School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
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Ibrahim NA, Badour MI, Stone RM, Shepley BR. The enigma of cerebral blood flow and cognition. J Physiol 2021; 599:1739-1741. [PMID: 33442911 DOI: 10.1113/jp281175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 01/04/2021] [Indexed: 11/08/2022] Open
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