ArticlePloS one2017
Caudwell Xtreme Everest: A prospective study of the effects of environmental hypoxia on cognitive functioning.
Article in PloS one, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 19 papers.
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Who cites it
19 citing papers in PubMed.
- Effect of acetazolamide on visuomotor performance at high altitude in healthy people 40 years of age or older-RCT.PloS one · 2023Trial
- High-altitude exposure alters the coupling among core large-scale brain networks: a multi-altitude rs-fMRI study.MedScience · 2026Article
- Cerebral oxygenation and cognitive performance under different acute normobaric hypoxic conditions: a fNIRS study.European journal of applied physiology · 2026Article
- Effect of Overdose-Induced Hypoxia on Neurocognitive Performance in Individuals With Opioid Dependence: A Prospective Multicenter Study.Alpha psychiatry · 2026Article
- Chronic high-altitude exposure is associated with an internally-directed perceptual shift: differential links with attention networks and autonomic regulation.Frontiers in neuroscience · 2026Article
- Microbiota-gut-brain axis imbalance: a promising therapeutic target for preserving brain health in high-altitude environment.Frontiers in neuroscience · 2026Review
- The Effects of Nocturnal Hypoxemia on Cognitive Performance in Andean Highlanders.High altitude medicine & biology · 2025Article
- Ventilatory response and delirium risk in hospitalised patients with acute hypoxia due to COVID-19.Scientific reports · 2025Article
- A review of methods for assessment of cognitive function in high-altitude hypoxic environments.Brain and behavior · 2024Review
- Cognitive Function among Young Women's Football Players in the Summer Heat.Translational sports medicine · 2023Article
- Cognition and Neuropsychological Changes at Altitude-A Systematic Review of Literature.Brain sciences · 2022Review
- Dietary Nitrate Supplementation Does Not Alter Exercise Efficiency at High Altitude - Further Results From the Xtreme Alps Study.Frontiers in physiology · 2022Article
- Impact of High Altitude on Cardiovascular Health: Current Perspectives.Vascular health and risk management · 2021Review
- Post-flight confusion: does flying affect the brain?BJPsych international · 2020Article
- Preservation of Neurovascular Coupling to Cognitive Activity in Anterior Cerebrovasculature During Incremental Ascent to High Altitude.High altitude medicine & biology · 2020Article
- Basic Biology of Hypoxic Responses Mediated by the Transcription Factor HIFs and its Implication for Medicine.Biomedicines · 2020Review
- Comparison of hypobaric hypoxia symptoms between a recalled exposure and a current exposure.PloS one · 2020Article
- Variation of Cognitive Function During a Short Stay at Hypobaric Hypoxia Chamber (Altitude: 3842 M).Frontiers in physiology · 2019Article
- The influence of hypoxia and prolonged exercise on attentional performance at high and extreme altitudes: A pilot study.PloS one · 2018Article
Corrections and comments
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Authors and funding
18 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe neuropsychological consequences of exposure to environmental hypobaric hypoxia (EHH) remain unclear. We thus investigated them in a large group of healthy volunteers who trekked to Mount Everest base camp (5,300 m).
methodsA neuropsychological (NP) test battery assessing memory, language, attention, and executive function was administered to 198 participants (age 44.5±13.7 years; 60% male). These were studied at baseline (sea level), 3,500 m (Namche Bazaar), 5,300 m (Everest Base Camp) and on return to 1,300 m (Kathmandu) (attrition rate 23.7%). A comparable control group (n = 25; age 44.5±14.1 years; 60% male) for comparison with trekkers was tested at/or near sea level over an equivalent timeframe so as to account for learning effects associated with repeat testing. The Reliable Change Index (RCI) was used to calculate changes in cognition and neuropsychological function during and after exposure to EHH relative to controls.
resultsOverall, attention, verbal ability and executive function declined in those exposed to EHH when the performance of the control group was taken into account (RCI .05 to -.95) with decline persisting at descent. Memory and psychomotor function showed decline at highest ascent only (RCI -.08 to -.56). However, there was inter-individual variability in response: whilst NP performance declined in most, this improved in some trekkers. Cognitive decline was greater amongst older people (r = .42; p < .0001), but was otherwise not consistently associated with socio-demographic, mood, or physiological variables.
conclusionsAfter correcting for learning effects, attention, verbal abilities and executive functioning declined with exposure to EHH. There was considerable individual variability in the response of brain function to sustained hypoxia with some participants not showing any effects of hypoxia. This might have implications for those facing sustained hypoxia as a result of any disease.
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