A Prospective Evaluation of the Acute Effects of High Altitude on Cognitive and Physiological Functions in Lowlanders

Abstract

Cognitive function impairment due to high altitude exposure has been reported with some contradictory results regarding the possible selective cognitive domain involvement. We prospectively evaluated in 36 lowlanders, exposed for 3 consecutive days to an altitude of 3,269 m, specific cognitive abilities (attention, processing speed, and decision-making) required to safely explore the mountains, as well as to work at altitude. We simultaneously monitored the physiological parameters. Our study provides evidence of a reduced processing speed in lowlanders when exposed to altitude in the first 24 h. There was a fairly quick recovery since this impairment was no more detectable after 36 h of exposure. There were no clinically relevant effects on decision-making, while psychomotor vigilance was unaffected at altitude except for individuals with poor sleep. Significant changes were seen in physiological parameters (increased heart rate and reduced peripheral oxygen saturation). Our results may have practical implications, suggesting that individuals should practice prudence with higher ascent when performing risky activities in the first 24–36 h, even at altitudes below 3,500 m, due to an impairment of the cognitive performance that could worsen and lead to accidents.

Hypoxia and risk preferences: Mild hypoxia impacts choices for low-probability high-payoff bets

“…However, little is known about the effects of mild hypoxia on higher-order cognitive abilities such as decision making and reasoning (e.g., Green and Morgan, 1985 ; Legg et al, 2014 ). Although the impact of mild hypoxia is not particularly striking in field studies and/or after acclimatization ( Niedermeier et al, 2017 ; Falla et al, 2021 ), laboratory findings are in line with those concerning the effect of acute stressors on decisions (for a review, see Morgado et al 2015 ; Starcke and Brand, 2016 ). They suggest that a mild oxygen depletion (equal to what is experienced at an altitude of 3,000m/9,842 ft) promotes risk-taking behavior (see also Pighin et al, 2020 ).…”

Recommendations for traveling to altitude with neurological disorders

“… 152 Several studies have investigated the acute and chronic effect of HA exposure on cognition in healthy subjects, and it is still not clear whether there is a selective or a general impairment of tasks investigating both central executive (working memory set-shifting, updating, monitoring, inhibition, and planning) and non-executive (perception, attention, and short term memory) functions. 153 - 155 Two cases of secondary subcortical dementia with neuropsychiatric symptoms, due to lesion in the globus pallidus bilaterally, following HACE at HA (3500 m) have been reported. 24 Due to the potential deleterious effect exerts by hypoxia on cognitive functions it is not advisable to allow patients with any type of dementia to go to altitude and this could be applied also to MCI patients.…”

Cardiac Adaptation to Prolonged High Altitude Migration Assessed by Speckle Tracking Echocardiography

“…There are many factors that affect cardiac adaptation to high altitude dwelling, including altitude level, exposure time, and racial differences. Cardiac responses to acute hypoxic exposure in people normally living at low altitudes (lowlanders) have been studied extensively ( 2 , 3 ). Conventional echocardiographic studies show that in healthy subjects exposed to acute hypoxic conditions of high altitude, the systolic function of both ventricles is preserved, but there is impaired diastolic function ( 4 ).…”