Neuropsychological functioning after prolonged high altitude exposure in mountaineering

This prospective study examined the possibility of long lasting CNS sequelae of high altitude exposure in mountaineering. An extensive battery of neuropsychological and personality tests was given to 22 subjects before and after Himalayan climbs above 5334 m (17,500 ft). All subjects were at altitude for long periods without supplemental oxygen, but did not suffer other physical insults such as serious injury or food or water deprivation. Although several climbers experienced acute effects of mountain sickness while at altitude, their post-climb evaluations revealed no evidence of lasting cerebral dysfunction or psychological deficit. A few climbers' subjective ratings of mental functioning were worse after their expeditions, but these self-assessments were unsupported by their performances on the objective testing. It was concluded that in healthy people who do not suffer other physical insults as well, acute CNS effects of low oxygen tensions during high altitude climbs are reversible.