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Muth T, Schipke JD, Brebeck AK, Dreyer S. Assessing Critical Flicker Fusion Frequency: Which Confounders? A Narrative Review. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:medicina59040800. [PMID: 37109758 PMCID: PMC10141404 DOI: 10.3390/medicina59040800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/13/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023]
Abstract
The critical flicker fusion frequency (cFFF) refers to the frequency at which a regularly recurring change of light stimuli is perceived as steady. The cFFF threshold is often assessed in clinics to evaluate the temporal characteristics of the visual system, making it a common test for eye diseases. Additionally, it serves as a helpful diagnostic tool for various neurological and internal diseases. In the field of diving/hyperbaric medicine, cFFF has been utilized to determine alertness and cognitive functions. Changes in the cFFF threshold have been linked to the influence of increased respiratory gas partial pressures, although there exist inconsistent results regarding this effect. Moreover, the use of flicker devices has produced mixed outcomes in previous studies. This narrative review aims to explore confounding factors that may affect the accuracy of cFFF threshold measurements, particularly in open-field studies. We identify five broad categories of such factors, including (1) participant characteristics, (2) optical factors, (3) smoking/drug use, (4) environmental aspects, and (5) breathing gases and partial pressures. We also discuss the application of cFFF measurements in the field of diving and hyperbaric medicine. In addition, we provide recommendations for interpreting changes in the cFFF threshold and how they are reported in research studies.
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Affiliation(s)
- Thomas Muth
- Institute of Occupational, Social, Environmental Medicine, Faculty of Medicine, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany
| | - Jochen D Schipke
- Research Group Experimental Surgery, University Hospital Düsseldorf, 40225 Düsseldorf, Germany
| | | | - Sven Dreyer
- Hyperbaric Oxygen Therapy, University Hospital Düsseldorf, 40225 Düsseldorf, Germany
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Xu G, Fu J, Qi H, Li L, Chen W, Gao Y, Ma T, Ye Z, Li Z. The theory of critical flicker fusion frequency and its application in cataracts. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2023; 3:29-32. [PMID: 37846427 PMCID: PMC10577820 DOI: 10.1016/j.aopr.2022.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 10/05/2022] [Accepted: 10/09/2022] [Indexed: 10/18/2023]
Abstract
Background Due to media opacity, it is usually difficult to accurately evaluate the postoperative visual acuity in cataracts patients. As a small and portable tool, the critical flicker fusion frequency (CFF) device reflects the temporal resolution of visual function and has been widely used in clinical research. However, poor understanding of the technique and equipment limitations have restricted its clinical application in China. Main text There was a decrease in the CFF value in various ophthalmic diseases, indicating that the CFF is sensitive to detect visual functional changes. A number of studies have shown that the CFF test can accurately distinguish patients with simple cataracts from those with cataracts combined with fundus disease, and, as a visual test, it can more accurately predict postoperative visual acuity without being affected by media opacity. This study comprehensive reviews the basic principles of CFF and its application in ophthalmology, especially in cataracts. Conclusions As one of the tools for dynamic visual function detection, the CFF test could help doctors to assess the possible presence of fundus disease in cataracts patients, especially in eyes with dense cataracts, and more precisely provide a reasonable visual prognosis than other available visual tests.
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Affiliation(s)
- Guangcan Xu
- School of Medicine, Nankai University, Tianjin, China
- Department of Ophthalmology, The Third Medical Center, The Chinese People's Liberation Army General Hospital, Beijing, China
| | - Junxia Fu
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haolan Qi
- School of Medicine, Nankai University, Tianjin, China
- Department of Ophthalmology, The Third Medical Center, The Chinese People's Liberation Army General Hospital, Beijing, China
| | - Linyu Li
- School of Medicine, Nankai University, Tianjin, China
- Department of Ophthalmology, The Third Medical Center, The Chinese People's Liberation Army General Hospital, Beijing, China
| | - Wenqian Chen
- Department of Ophthalmology, The Third Medical Center, The Chinese People's Liberation Army General Hospital, Beijing, China
| | - Yi Gao
- Department of Ophthalmology, The Third Medical Center, The Chinese People's Liberation Army General Hospital, Beijing, China
| | - Tianju Ma
- Department of Ophthalmology, The Third Medical Center, The Chinese People's Liberation Army General Hospital, Beijing, China
| | - Zi Ye
- Department of Ophthalmology, The Third Medical Center, The Chinese People's Liberation Army General Hospital, Beijing, China
- The Chinese People's Liberation Army Medical School, Beijing, China
| | - Zhaohui Li
- School of Medicine, Nankai University, Tianjin, China
- Department of Ophthalmology, The Third Medical Center, The Chinese People's Liberation Army General Hospital, Beijing, China
- The Chinese People's Liberation Army Medical School, Beijing, China
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Vrijdag XCE, van Waart H, Sames C, Mitchell SJ, Sleigh JW. Does hyperbaric oxygen cause narcosis or hyperexcitability? A quantitative EEG analysis. Physiol Rep 2022; 10:e15386. [PMID: 35859332 PMCID: PMC9300958 DOI: 10.14814/phy2.15386] [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: 05/18/2022] [Revised: 06/21/2022] [Accepted: 06/24/2022] [Indexed: 11/24/2022] Open
Abstract
Divers breathe higher partial pressures of oxygen at depth than at the surface. The literature and diving community are divided on whether or not oxygen is narcotic. Conversely, hyperbaric oxygen may induce dose‐dependent cerebral hyperexcitability. This study evaluated whether hyperbaric oxygen causes similar narcotic effects to nitrogen, and investigated oxygen's hyperexcitability effect. Twelve human participants breathed “normobaric” air and 100% oxygen, and “hyperbaric” 100% oxygen at 142 and 284 kPa, while psychometric performance, electroencephalography (EEG), and task load perception were measured. EEG was analyzed with functional connectivity and temporal complexity algorithms. The spatial functional connectivity, estimated using mutual information, was summarized with the global efficiency network measure. Temporal complexity was calculated with a “default‐mode‐network (DMN) complexity” algorithm. Hyperbaric oxygen‐breathing caused no change in EEG global efficiency or in the psychometric test. However, oxygen caused a significant reduction of DMN complexity and a reduction in task load perception. Hyperbaric oxygen did not cause the same changes in EEG global efficiency seen with hyperbaric air, which likely related to a narcotic effect of nitrogen. Hyperbaric oxygen seemed to disturb the time evolution of EEG patterns that could be taken as evidence of early oxygen‐induced cortical hyperexcitability. These findings suggest that hyperbaric oxygen is not narcotic and will help inform divers' decisions on suitable gas mixtures.
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Affiliation(s)
- Xavier C E Vrijdag
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
| | - Hanna van Waart
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
| | - Chris Sames
- Slark Hyperbaric Unit, Waitemata District Health Board, Auckland, New Zealand
| | - Simon J Mitchell
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand.,Slark Hyperbaric Unit, Waitemata District Health Board, Auckland, New Zealand.,Department of Anaesthesia, Auckland City Hospital, Auckland, New Zealand
| | - Jamie W Sleigh
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand.,Department of Anaesthesia, Waikato Hospital, Hamilton, New Zealand
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Mankowska ND, Marcinkowska AB, Waskow M, Sharma RI, Kot J, Winklewski PJ. Reply to Vrijdag et al. Comment on “Mankowska et al. Critical Flicker Fusion Frequency: A Narrative Review. Medicina 2021, 57, 1096”. Medicina (B Aires) 2022; 58:medicina58060765. [PMID: 35744028 PMCID: PMC9228208 DOI: 10.3390/medicina58060765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 11/22/2022] Open
Affiliation(s)
- Natalia D. Mankowska
- Applied Cognitive Neuroscience Lab, Department of Human Physiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
- Correspondence: ; Tel./Fax: +48-58-3491515
| | - Anna B. Marcinkowska
- Applied Cognitive Neuroscience Lab, Department of Human Physiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
- 2nd Department of Radiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
- Institute of Health Sciences, Pomeranian University in Slupsk, 76-200 Slupsk, Poland;
| | - Monika Waskow
- Institute of Health Sciences, Pomeranian University in Slupsk, 76-200 Slupsk, Poland;
| | - Rita I. Sharma
- Department of Human Physiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
- Department of Anaesthesiology and Intensive Care, Medical University of Gdansk, 80-210 Gdansk, Poland
| | - Jacek Kot
- National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine in Gdynia, Medical University of Gdansk, 80-210 Gdansk, Poland;
| | - Pawel J. Winklewski
- 2nd Department of Radiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
- Institute of Health Sciences, Pomeranian University in Slupsk, 76-200 Slupsk, Poland;
- Department of Human Physiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
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Marcinkowska AB, Mankowska ND, Kot J, Winklewski PJ. Impact of Hyperbaric Oxygen Therapy on Cognitive Functions: a Systematic Review. Neuropsychol Rev 2022; 32:99-126. [PMID: 33847854 PMCID: PMC8888529 DOI: 10.1007/s11065-021-09500-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 03/07/2021] [Indexed: 12/13/2022]
Abstract
Hyperbaric oxygen therapy (HBOT) is a modality of treatment in which patients inhale 100% oxygen inside a hyperbaric chamber pressurised to greater than 1 atmosphere. The aim of this review is to discuss neuropsychological findings in various neurological disorders treated with HBOT and to open new perspectives for therapeutic improvement. A literature search was conducted in the MEDLINE (via PubMed) database from the inception up 10 May 2020. Eligibility criteria included original articles published in English. Case studies were excluded. Full-text articles were obtained from the selected studies and were reviewed on the following inclusion criteria (1) performed cognitive processes assessment (2) performed HBOT with described protocol. Two neuropsychologists independently reviewed titles, abstracts, full texts and extracted data. The initial search retrieved 1024 articles, and a total of 42 studies were finally included after applying inclusion and exclusion criteria. The search yielded controversial results with regard to the efficiency of HBOT in various neurological conditions with cognitive disturbance outcome. To the best of our knowledge this is the first state-of-the art, systematic review in the field. More objective and precise neuropsychological assessment methods are needed to exact evaluation of the efficacy of HBOT for neuropsychological deficits. Future studies should widen the assessment of HBOT effects on different cognitive domains because most of the existing studies have focussed on a single process. Finally, there is a need for further longitudinal studies.
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Affiliation(s)
- Anna B Marcinkowska
- Applied Cognitive Neuroscience Lab, Department of Human Physiology, Medical University of Gdańsk, Tuwima Str. 15 80-210, Gdańsk, Poland.
- 2nd Department of Radiology, Medical University of Gdańsk, Gdańsk, Poland.
| | - Natalia D Mankowska
- Applied Cognitive Neuroscience Lab, Department of Human Physiology, Medical University of Gdańsk, Tuwima Str. 15 80-210, Gdańsk, Poland
| | - Jacek Kot
- National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine in Gdynia, Medical University of Gdansk, Gdańsk, Poland
| | - Pawel J Winklewski
- Applied Cognitive Neuroscience Lab, Department of Human Physiology, Medical University of Gdańsk, Tuwima Str. 15 80-210, Gdańsk, Poland
- 2nd Department of Radiology, Medical University of Gdańsk, Gdańsk, Poland
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Cannellotto M, Duarte M, Keller G, Larrea R, Cunto E, Chediack V, Mansur M, Brito DM, García E, Di Salvo HE, Verdini F, Domínguez C, Jorda-Vargas L, Roberti J, Di Girolamo G, Estrada E. Hyperbaric oxygen as an adjuvant treatment for patients with COVID-19 severe hypoxaemia: a randomised controlled trial. Emerg Med J 2021; 39:88-93. [PMID: 34907003 PMCID: PMC8678559 DOI: 10.1136/emermed-2021-211253] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 10/14/2021] [Indexed: 12/28/2022]
Abstract
Background Hyperbaric oxygen (HBO2) therapy has been proposed to treat hypoxaemia and reduce inflammation in COVID-19. Our objective was to analyse safety and efficacy of HBO2 in treatment of hypoxaemia in patients with COVID-19 and evaluate time to hypoxaemia correction. Methods This was a multicentre, open-label randomised controlled trial conducted in Buenos Aires, Argentina, between July and November 2020. Patients with COVID-19 and severe hypoxaemia (SpO2 ≤90% despite oxygen supplementation) were assigned to receive either HBO2 treatment or the standard treatment for respiratory symptoms for 7 days. HBO2 treatment was planned for ≥5 sessions (1 /day) for 90 min at 1.45 atmosphere absolute (ATA). Outcomes were time to normalise oxygen requirement to SpO2 ≥93%, need for mechanical respiratory assistance, development of acute respiratory distress syndrome and mortality within 30 days. A sample size of 80 patients was estimated, with a planned interim analysis after determining outcomes on 50% of patients. Results The trial was stopped after the interim analysis. 40 patients were randomised, 20 in each group, age was 55.2±9.2 years. At admission, frequent symptoms were dyspnoea, fever and odynophagia; SpO2 was 85.1%±4.3% for the whole group. Patients in the treatment group received an average of 6.2±1.2 HBO2 sessions. Time to correct hypoxaemia was shorter in treatment group versus control group; median 3 days (IQR 1.0–4.5) versus median 9 days (IQR 5.5–12.5), respectively (p<0.010). OR for recovery from hypoxaemia in the HBO2 group at day 3 compared with the control group was 23.2 (95% CI 1.6 to 329.6; p=0.001) Treatment had no statistically significant effect on acute respiratory distress syndrome, mechanical ventilation or death within 30 days after admission. Conclusion Our findings support the safety and efficacy of HBO2 in the treatment of COVID-19 and severe hypoxaemia. Trial registration number NCT04477954.
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Affiliation(s)
- Mariana Cannellotto
- Research Department, Argentine Association of Hyperbaric Medicine and Research (AAMHEI), Buenos Aires, Argentina
| | - Mariano Duarte
- Laboratory of Arterial Hypertension, Cardiology Department, Hospital de Clinicas Jose de San Martin, Buenos Aires, Argentina.,Segunda Cátedra de Fisiología, Universidad de Buenos Aires Facultad de Medicina, Buenos Aires, Argentina
| | - Guillermo Keller
- Instituto Alberto C Taquini de Investigaciones en Medicina Traslacional - Facultad de Medicina, Universidad de Buenos Aires and CONICET, Buenos Aires, Argentina.,General Medicine, Hospital General de Agudos Donación Santojanni, Buenos Aires, Federal District, Argentina.,Tercera Cátedra de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ramiro Larrea
- General Medicine, Municipal Hospital of San Isidro, San Isidro, Argentina
| | - Eleonora Cunto
- Intensive Care Unit, Hospital de Infecciosas Dr Francisco Javier Muñiz, Buenos Aires, Argentina
| | - Viviana Chediack
- Intensive Care Unit, Hospital de Infecciosas Dr Francisco Javier Muñiz, Buenos Aires, Argentina
| | - Mariela Mansur
- General Medicine, Municipal Hospital of San Isidro, San Isidro, Argentina
| | - Daniela M Brito
- General Medicine, Municipal Hospital of San Isidro, San Isidro, Argentina
| | - Elizabeth García
- General Medicine, Hospital General de Agudos Donación Santojanni, Buenos Aires, Federal District, Argentina
| | - Héctor E Di Salvo
- General Medicine, Hospital General de Agudos Donación Santojanni, Buenos Aires, Federal District, Argentina
| | - Fabrizio Verdini
- Research Department, Argentine Association of Hyperbaric Medicine and Research (AAMHEI), Buenos Aires, Argentina
| | - Cecilia Domínguez
- Intensive Care Unit, Hospital de Infecciosas Dr Francisco Javier Muñiz, Buenos Aires, Argentina
| | - Liliana Jorda-Vargas
- Research Department, Argentine Association of Hyperbaric Medicine and Research (AAMHEI), Buenos Aires, Argentina
| | - Javier Roberti
- Qualitative Research in Health, Institute for Clinical Effectiveness and Health Policy, Buenos Aires, Argentina .,Centre for Research on Epidemiology and Public Health (CIESP), CONICET, Buenos Aires, Argentina
| | - Guillermo Di Girolamo
- Instituto Alberto C Taquini de Investigaciones en Medicina Traslacional - Facultad de Medicina, Universidad de Buenos Aires and CONICET, Buenos Aires, Argentina.,Tercera Cátedra de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Esteban Estrada
- Research Department, Argentine Association of Hyperbaric Medicine and Research (AAMHEI), Buenos Aires, Argentina.,Hyperbaric Medicine, Hospital Alta Complejidad JD Perón, Formosa, Argentina
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Mankowska ND, Marcinkowska AB, Waskow M, Sharma RI, Kot J, Winklewski PJ. Critical Flicker Fusion Frequency: A Narrative Review. MEDICINA (KAUNAS, LITHUANIA) 2021; 57:1096. [PMID: 34684133 PMCID: PMC8537539 DOI: 10.3390/medicina57101096] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 10/03/2021] [Accepted: 10/05/2021] [Indexed: 11/16/2022]
Abstract
This review presents the current knowledge of the usage of critical flicker fusion frequency (CFF) in human and animal model studies. CFF has a wide application in different fields, especially as an indicator of cortical arousal and visual processing. In medicine, CFF may be helpful for diagnostic purposes, for example in epilepsy or minimal hepatic encephalopathy. Given the environmental studies and a limited number of other methods, it is applicable in diving and hyperbaric medicine. Current research also shows the relationship between CFF and other electrophysiological methods, such as electroencephalography. The human eye can detect flicker at 50-90 Hz but reports are showing the possibility to distinguish between steady and modulated light up to 500 Hz. Future research with the use of CFF is needed to better understand its utility and application.
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Affiliation(s)
- Natalia D. Mankowska
- Applied Cognitive Neuroscience Lab, Department of Human Physiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
| | - Anna B. Marcinkowska
- Applied Cognitive Neuroscience Lab, Department of Human Physiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
- 2nd Department of Radiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
- Institute of Health Sciences, Pomeranian University in Slupsk, 76-200 Slupsk, Poland;
| | - Monika Waskow
- Institute of Health Sciences, Pomeranian University in Slupsk, 76-200 Slupsk, Poland;
| | - Rita I. Sharma
- Department of Human Physiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
- Department of Anaesthesiology and Intensive Care, Medical University of Gdansk, 80-210 Gdansk, Poland
| | - Jacek Kot
- National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine in Gdynia, Medical University of Gdansk, 80-210 Gdansk, Poland;
| | - Pawel J. Winklewski
- 2nd Department of Radiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
- Institute of Health Sciences, Pomeranian University in Slupsk, 76-200 Slupsk, Poland;
- Department of Human Physiology, Medical University of Gdansk, 80-210 Gdansk, Poland;
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Piispanen WW, Lundell RV, Tuominen LJ, Räisänen-Sokolowski AK. Assessment of Alertness and Cognitive Performance of Closed Circuit Rebreather Divers With the Critical Flicker Fusion Frequency Test in Arctic Diving Conditions. Front Physiol 2021; 12:722915. [PMID: 34447319 PMCID: PMC8384076 DOI: 10.3389/fphys.2021.722915] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 07/12/2021] [Indexed: 12/29/2022] Open
Abstract
Introduction: Cold water imposes many risks to the diver. These risks include decompression illness, physical and cognitive impairment, and hypothermia. Cognitive impairment can be estimated using a critical flicker fusion frequency (CFFF) test, but this method has only been used in a few studies conducted in an open water environment. We studied the effect of the cold and a helium-containing mixed breathing gas on the cognition of closed circuit rebreather (CCR) divers. Materials and Methods: Twenty-three divers performed an identical dive with controlled trimix gas with a CCR device in an ice-covered quarry. They assessed their thermal comfort at four time points during the dive. In addition, their skin temperature was measured at 5-min intervals throughout the dive. The divers performed the CFFF test before the dive, at target depth, and after the dive. Results: A statistically significant increase of 111.7% in CFFF values was recorded during the dive compared to the pre-dive values (p < 0.0001). The values returned to the baseline after surfacing. There was a significant drop in the divers’ skin temperature of 0.48°C every 10 min during the dive (p < 0.001). The divers’ subjectively assessed thermal comfort also decreased during the dive (p = 0.01). Conclusion: Our findings showed that neither extreme cold water nor helium-containing mixed breathing gas had any influence on the general CFFF profile described in the previous studies from warmer water and where divers used other breathing gases. We hypothesize that cold-water diving and helium-containing breathing gases do not in these diving conditions cause clinically relevant cerebral impairment. Therefore, we conclude that CCR diving in these conditions is safe from the perspective of alertness and cognitive performance.
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Affiliation(s)
- Wilhelm W Piispanen
- Faculty of Medicine, University of Turku, Turku, Finland.,DAN Europe Research Division, Finnish Branch, Helsinki, Finland
| | - Richard V Lundell
- The Centre for Military Medicine, The Finnish Defense Forces, Helsinki, Finland.,Department of Pathology, Helsinki University, Helsinki, Finland
| | - Laura J Tuominen
- Department of Pathology, Helsinki University, Helsinki, Finland.,Anesthesia and Intensive Care Unit, Tampere University Hospital, Tampere, Finland
| | - Anne K Räisänen-Sokolowski
- DAN Europe Research Division, Finnish Branch, Helsinki, Finland.,The Centre for Military Medicine, The Finnish Defense Forces, Helsinki, Finland.,Department of Pathology, Helsinki University and Helsinki University Hospital, Helsinki, Finland
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Kot J, Winklewski PJ. Commentary on using critical flicker fusion frequency to measure gas narcosis. Diving Hyperb Med 2021; 51:227-228. [PMID: 34157742 DOI: 10.28920/dhm51.2.227-228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 02/26/2021] [Indexed: 11/05/2022]
Affiliation(s)
- Jacek Kot
- National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine in Gdynia, Medical University of Gdansk, Poland.,Address for correspondence: Jacek Kot, National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine in Gdynia, Medical University of Gdansk, Poland,
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Vrijdag XC, van Waart H, Sleigh JW, Mitchell SJ. Reply: Commentary on using critical flicker fusion frequency to measure gas narcosis. Diving Hyperb Med 2021; 51:228-229. [PMID: 34157743 DOI: 10.28920/dhm51.2.228-229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 04/26/2021] [Indexed: 11/05/2022]
Affiliation(s)
- Xavier Ce Vrijdag
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand.,Address for correspondence: Xavier CE Vrijdag, Department of Anaesthesiology, School of Medicine, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand,
| | - Hanna van Waart
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
| | - Jamie W Sleigh
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand.,Department of Anaesthesia, Waikato Hospital, Hamilton, New Zealand
| | - Simon J Mitchell
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand.,Department of Anaesthesia, Auckland City Hospital, Auckland, New Zealand
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Vrijdag XC, van Waart H, Sleigh JW, Balestra C, Mitchell SJ. Investigating critical flicker fusion frequency for monitoring gas narcosis in divers. Diving Hyperb Med 2020; 50:377-385. [PMID: 33325019 PMCID: PMC7872789 DOI: 10.28920/dhm50.4.377-385] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Accepted: 07/28/2020] [Indexed: 01/14/2023]
Abstract
INTRODUCTION Critical flicker fusion frequency (CFFF) has been used in various studies to measure the cognitive effects of gas mixtures at depth, sometimes with conflicting or apparently paradoxical results. This study aimed to evaluate a novel automatic CFFF method and investigate whether CFFF can be used to monitor gas-induced narcosis in divers. METHODS Three hyperbaric chamber experiments were performed: 1) Automated and manual CFFF measurements during air breathing at 608 kPa (n = 16 subjects); 2) Manual CFFF measurements during air and heliox breathing at sea level (101.3 kPa) and 608 kPa (n = 12); 3) Manual CFFF measurements during oxygen breathing at sea level, 142 and 284 kPa (n = 10). All results were compared to breathing air at sea level. RESULTS Only breathing oxygen at sea level, and at 284 kPa, caused a significant decrease in CFFF (2.5% and 2.6% respectively compared to breathing air at sea level. None of the other conditions showed a difference with sea level air breathing. CONCLUSIONS CFFF did not significantly change in our experiments when breathing air at 608 kPa compared to air breathing at sea level pressure using both devices. Based on our results CFFF does not seem to be a sensitive tool for measuring gas narcosis in divers in our laboratory setting.
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Affiliation(s)
- Xavier Ce Vrijdag
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
- Deep Dive Dubai, Dubai, United Arab Emirates
- Corresponding author: Xavier Vrijdag, Department of Anaesthesiology, School of Medicine, University of Auckland, Private bag 92019, Auckland 1142, New Zealand,
| | - Hanna van Waart
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
| | - Jamie W Sleigh
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
- Department of Anaesthesia, Waikato Hospital, Hamilton, New Zealand
| | - Costantino Balestra
- Environmental, Occupational and Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), Brussels, Belgium
| | - Simon J Mitchell
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
- Department of Anaesthesia, Auckland City Hospital, Auckland, New Zealand
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Scholey AB, Benson S, Sela-Venter S, Mackus M, Moss MC. Oxygen Administration and Acute Human Cognitive Enhancement: Higher Cognitive Demand Leads to a More Rapid Decay of Transient Hyperoxia. JOURNAL OF COGNITIVE ENHANCEMENT 2019. [DOI: 10.1007/s41465-019-00145-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Lafère P, Hemelryck W, Germonpré P, Matity L, Guerrero F, Balestra C. Early detection of diving-related cognitive impairment of different nitrogen-oxygen gas mixtures using critical flicker fusion frequency. Diving Hyperb Med 2019; 49:119-126. [PMID: 31177518 DOI: 10.28920/dhm49.2.119-126] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 03/08/2019] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Cognitive impairment related to inert gas narcosis (IGN) is a threat to diving safety and operations at depth that might be reduced by using enriched air nitrox (EANx) mixtures. Using critical flicker fusion frequency (CFFF), a possible early detection of cognitive abilities/cerebral arousal impairment when breathing different oxygen (O2) fractions was investigated. METHODS Eight male volunteers performed, in random order, two dry chamber dives breathing either air or EANx40 (40% O₂-60% nitrogen) for 20 minutes (min) at 0.4 MPa. Cognition and arousal were assessed before the dive; upon arrival at 0.4 MPa; after 15 min exposure at 0.4 MPa; on surfacing and 30 min post-dive using behavioural computer-based testing psychology experiment building language (PEBL) and by CFFF while continuously recording brain oxygenation with near-infrared spectroscopy. RESULTS In both breathing conditions, CFFF and PEBL demonstrated a significant inverse correlation (Pearson r of -0.90, P < 0.0001), improved cognitive abilities/cerebral arousal occurred upon arrival at 0.4 MPa followed by a progressive deterioration. Initial brain activation was associated with a significant increase in oxyhaemoglobin (HbO2) and a simultaneous decrease of deoxyhaemoglobin (HHb). The magnitude of the changes was significantly greater under EANx (P = 0.038). CONCLUSIONS Since changes were not related to haemodynamic variables, HbO₂ and HHb values indicate a significant, O₂-dependent activation in the prefrontal cortex. Owing to the correlation with some tests from the PEBL, CFFF could be a convenient measure of cognitive performance/ability in extreme environments, likely under the direct influence of oxygen partial pressure, a potent modulator of IGN symptoms.
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Affiliation(s)
- Pierre Lafère
- DAN Europe Research Division, Roseto, Italy.,Laboratoire ORPHY, EA 4324, UFR sciences et techniques, Université de Bretagne Occidentale, Brest, France.,Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), Brussels, Belgium.,Corresponding author: Pierre Lafère, Laboratoire ORPHY, EA 4324, UFR sciences et techniques, Université de Bretagne Occidentale, 6 Avenue Le Gorgeu - CS 93837, 29238 Brest Cedex 3, France,
| | - Walter Hemelryck
- DAN Europe Research Division, Roseto, Italy.,Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), Brussels, Belgium
| | - Peter Germonpré
- DAN Europe Research Division, Roseto, Italy.,Centre for Hyperbaric Oxygen Therapy, Military Hospital 'Queen Astrid', Brussels
| | | | - François Guerrero
- DAN Europe Research Division, Roseto, Italy.,Laboratoire ORPHY, EA 4324, UFR sciences et techniques, Université de Bretagne Occidentale, Brest, France
| | - Costantino Balestra
- DAN Europe Research Division, Roseto, Italy.,Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), Brussels, Belgium.,Anatomical Research and Clinical Studies (ARCS), Vrije Universiteit Brussel (V.U.B.), Brussels.,Anatomical Research Training and Education (ARTE), Vrije Universiteit Brussel (V.U.B.).,Motor Sciences, Université Libre De Bruxelles (U.L.B.), Brussels
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Rocco M, Pelaia P, Di Benedetto P, Conte G, Maggi L, Fiorelli S, Mercieri M, Balestra C, De Blasi RA. Inert gas narcosis in scuba diving, different gases different reactions. Eur J Appl Physiol 2018; 119:247-255. [PMID: 30350155 DOI: 10.1007/s00421-018-4020-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 10/13/2018] [Indexed: 12/25/2022]
Abstract
PURPOSE Underwater divers face several potential neurological hazards when breathing compressed gas mixtures including nitrogen narcosis which can impact diver's safety. Various human studies have clearly demonstrated brain impairment due to nitrogen narcosis in divers at 4 ATA using critical flicker fusion frequency (CFFF) as a cortical performance indicator. However, recently some authors have proposed a probable adaptive phenomenon during repetitive exposure to high nitrogen pressure in rats, where they found a reversal effect on dopamine release. METHODS Sixty experienced divers breathing Air, Trimix or Heliox, were studied during an open water dive to a depth of 6 ATA with a square profile testing CFFF measurement before (T0), during the dive upon arriving at the bottom (6 ATA) (T1), 20 min of bottom time (T2), and at 5 m (1.5 ATA) (T3). RESULTS CFFF results showed a slight increase in alertness and arousal during the deep dive regardless of the gas mixture breathed. The percent change in CFFF values at T1 and T2 differed among the three groups being lower in the air group than in the other groups. All CFFF values returned to basal values 5 min before the final ascent at 5 m (T3), but the Trimix measurements were still slightly better than those at T0. CONCLUSIONS Our results highlight that nitrogen and oxygen alone and in combination can produce neuronal excitability or depression in a dose-related response.
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Affiliation(s)
- Monica Rocco
- Department of Surgical and Medical Science and Translational Medicine, Anesthesia and Intensive Care, Sapienza University, Rome, Italy.
| | - P Pelaia
- Department of Biomedical Sciences and Public Health, Anesthesia and Intensive Care, Università Politecnica delle Marche Torrette, Ancona, Italy
| | - P Di Benedetto
- Azienda Ospedaliero, Universitaria Sant'Andrea, Rome, Italy
| | - G Conte
- Department of Informatics Engineering, University Politecnica delle Marche, Ancona, Italy
| | - L Maggi
- Anesthesia and Intensive Care, Università Campus Biomedico, Rome, Italy
| | - S Fiorelli
- Department of Surgical and Medical Science and Translational Medicine, Anesthesia and Intensive Care, Sapienza University, Rome, Italy
| | - M Mercieri
- Department of Surgical and Medical Science and Translational Medicine, Anesthesia and Intensive Care, Sapienza University, Rome, Italy
| | - C Balestra
- Environmental, Occupational and Ageing (Integrative) Physiology Lab, Haute Ecole Bruxelles-Brabant (HE2B), Brussels, Belgium
| | - R A De Blasi
- Department of Surgical and Medical Science and Translational Medicine, Anesthesia and Intensive Care, Sapienza University, Rome, Italy
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15
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Jensen BH, Bram T, Kappelgaard P, Arvidsson H, Loskutova E, Munch IC, Larsen M. Visual function and retinal vessel diameters during hyperthermia in man. Acta Ophthalmol 2017; 95:690-696. [PMID: 28000983 DOI: 10.1111/aos.13361] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 11/07/2016] [Indexed: 11/29/2022]
Abstract
PURPOSE To assess the effect of elevated core body temperature on temporal and spatial contrast sensitivity and retinal vessel diameters. METHODS The study included 13 healthy volunteers aged 20-37 years. Core body temperature elevation (target +1.1°C) was induced by wrapping the participants in cling film, tinfoil and warming blankets. Subsequent cooling was achieved by undressing. Flicker sensitivity (critical flicker fusion frequency) was chosen to assess temporal resolution, while the Freiburg Vision Test was used to determine spatial contrast sensitivity at 1.5 cycles per degree. Scanning laser ophthalmoscopy was used to measure retinal trunk vessel diameters. Assessment was made at baseline, during hyperthermia and after cooling. RESULTS The induction of a mean increase in core body temperature of 1.02°C was associated with a 7.15-mmHg mean reduction in systolic blood pressure (p < 0.01), a 10.6-mmHg mean reduction in diastolic blood pressure (p < 0.01), a mean increase in pulse rate of 36.3 bpm (p < 0.0001), a 2.66% improvement in flicker sensitivity (CI95 1.37-3.94, p < 0.001), a 2.80% increase in retinal artery diameters (CI95 1.09-4.51, p < 0.01) and a 2.95% increase in retinal vein diameters (CI95 0.96-4.94, p < 0.01). There was no detectable effect of temperature on spatial contrast sensitivity. All ocular test parameters returned to baseline levels after cooling. CONCLUSION Increased core body temperature was accompanied by improved temporal visual resolution and retinal trunk vessel dilation. The results suggest that hyperthermia is associated with enhanced retinal function and increased retinal metabolism.
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Affiliation(s)
- Bettina Hagström Jensen
- Faculty of Health and Medical Science; University of Copenhagen; Copenhagen Denmark
- Department of Ophthalmology; Rigshospitalet; Glostrup Denmark
| | - Thue Bram
- Faculty of Health and Medical Science; University of Copenhagen; Copenhagen Denmark
- Department of Ophthalmology; Rigshospitalet; Glostrup Denmark
| | - Per Kappelgaard
- Faculty of Health and Medical Science; University of Copenhagen; Copenhagen Denmark
- Department of Ophthalmology; Rigshospitalet; Glostrup Denmark
| | | | - Ekaterina Loskutova
- Department of Ophthalmology; Rigshospitalet; Glostrup Denmark
- Department of Chemical and Life Sciences; Waterford Institute of Technology; MPRG: Macular Pigment Research Group; Waterford Ireland
| | - Inger Christine Munch
- Faculty of Health and Medical Science; University of Copenhagen; Copenhagen Denmark
- Department of Ophthalmology; Roskilde Hospital; Roskilde Denmark
| | - Michael Larsen
- Faculty of Health and Medical Science; University of Copenhagen; Copenhagen Denmark
- Department of Ophthalmology; Rigshospitalet; Glostrup Denmark
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Beckhauser TF, Francis-Oliveira J, De Pasquale R. Reactive Oxygen Species: Physiological and Physiopathological Effects on Synaptic Plasticity. J Exp Neurosci 2016; 10:23-48. [PMID: 27625575 PMCID: PMC5012454 DOI: 10.4137/jen.s39887] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 08/09/2016] [Accepted: 08/13/2016] [Indexed: 12/18/2022] Open
Abstract
In the mammalian central nervous system, reactive oxygen species (ROS) generation is counterbalanced by antioxidant defenses. When large amounts of ROS accumulate, antioxidant mechanisms become overwhelmed and oxidative cellular stress may occur. Therefore, ROS are typically characterized as toxic molecules, oxidizing membrane lipids, changing the conformation of proteins, damaging nucleic acids, and causing deficits in synaptic plasticity. High ROS concentrations are associated with a decline in cognitive functions, as observed in some neurodegenerative disorders and age-dependent decay of neuroplasticity. Nevertheless, controlled ROS production provides the optimal redox state for the activation of transductional pathways involved in synaptic changes. Since ROS may regulate neuronal activity and elicit negative effects at the same time, the distinction between beneficial and deleterious consequences is unclear. In this regard, this review assesses current research and describes the main sources of ROS in neurons, specifying their involvement in synaptic plasticity and distinguishing between physiological and pathological processes implicated.
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Affiliation(s)
- Thiago Fernando Beckhauser
- Physiology and Biophysics Department, Biomedical Sciences Institute, Sao Paulo University (USP), Butanta, Sao Paulo, Brazil
| | - José Francis-Oliveira
- Physiology and Biophysics Department, Biomedical Sciences Institute, Sao Paulo University (USP), Butanta, Sao Paulo, Brazil
| | - Roberto De Pasquale
- Physiology and Biophysics Department, Biomedical Sciences Institute, Sao Paulo University (USP), Butanta, Sao Paulo, Brazil
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