Acute mountain sickness with reversible vasospasm.

A 32-year-old Japanese woman with headache, anorexia and malaise, just after travelling cities of the altitude of over 4000 m by a long-distance coach is described. Her magnetic resonance imaging (MRI) demonstrated strikingly increased T2 signal in the corpus callosum, particularly in the splenium, and MR angiography (MRA) revealed widespread vasospasm. These abnormalities resolved on subsequent MRI studies. We diagnosed her as high altitude cerebral edema (HACE), considered to be the end stage of acute mountain sickness (AMS).