[A case of acute mountain sickness with bilateral lesion of pallidum]

The patient was 56-year-old female, who suffered from ataxia and then fell into coma on the next day after she had moved from the sea level to an altitude of 4,200 m. After she was brought to lower altitude, consciousness recovered within several hours. For about 2 days thereafter, disorientation was observed, and she was diagnosed as AMS (acute mountain sickness). Only insomnia continued in chronic stage. The results of X-ray computed tomography (CT) on 25th day after the onset of the disease revealed no abnormal finding except the slightly increasing uptake of contrast material. Symmetrical low density regions were seen in bilateral basal ganglia after one year, and the globus pallidus lesions were confirmed by magnetic resonance imaging. In the past, cerebral edema has been reported in most cases of AMS, and the neurotic symptoms of AMS have been attributed to cerebral edema, while the essential condition of this disease is not yet elucidated. In the present case, the globus pallidus lesions could be identified through the following-up of the central nervous system by X-ray CT and MRI as the first attempt for the case of AMS. There has been no report of globus pallidus lesions in the cases of AMS. Whereas low oxygen partial pressure is the primary cause of AMS, and it is highly probable that the disorders in globus pallidus as reported in the cases of carbon monoxide poisoning, anesthetic accident, etc. are related to the occurrence of AMS.