High-altitude cerebral edema (HACE): the Denver/Front Range experience.

High-altitude cerebral edema (HACE) is a potentially fatal metabolic encephalopathy associated with a time-dependent exposure to the hypobaric hypoxia of altitude. Symptoms commonly are headache, ataxia, and confusion progressing to stupor and coma. HACE is often preceded by symptoms of acute mountain sickness and coupled, in its severe form, with high-altitude pulmonary edema.