[A case of acute mountain sickness followed by globus pallidus syndrome]

A 71-year-old female was suffered from acute mountain sickness at an altitude of about 3,700 m. and became comatose. Although the patient recovered from the symptom after coming down from the mountain, family members and friends began to notice her personality changes in daily life. She became apathetic, uncommunicative, expressionless, less interested in hobbies and less sociable and was pointed it out by them. In neurological images, MRI revealed localized lesions at the globus pallidus, bilaterally. It was conjectured that pallidal lesions caused by hypobaric hypoxia at high elevation in the case induced neurobehavioral syndrome (globus pallidus syndrome) similar to the frontal lobe syndrome by way of the frontal-subcortical circuits. As, in recent years, the transportation to high ground has become relatively easy for the elderly, it is feared that the incidence of acute mountain sickness may increase. In acute mountain sickness, while neurological symptoms at the acute phase, such as headache, consciousness disturbances and ataxia, are emphasized, it is necessary, in examination of patients who recovered from acute symptoms, to recognize the presence of executive dysfunction as aftereffect, as seen in the present case.