Persistent memory impairment after high altitude climbing.

High altitude climbing without supplementary oxygen is a common sporting practice and athletes have been extensively evaluated with respect to possible brain functional impairment during its performance. Little is known on the contrary about long-term effects of hypoxia on the central nervous system. We evaluated, at sea level, a group of 10 high-altitude climbers with a battery of neuropsychological tests before and 75 days after the ascent. Our results suggest the occurrence of an impairment of memory performance after return to sea-level at least in some subjects, while speech and certain practical abilities were unchanged.