[An aged case of bilateral ballistic movement which was thought to be exacerbated by respiratory insufficiency]

We report a 75-year-old man who had shown bilateral ballistic movements. He had suffered from pulmonary emphysema for about 35 years and was treated with oxygen therapy 3 years before. When he was 70 years old, involuntary movements appeared in bilateral limbs. His involuntary movements were ballistic, and become gradually worse. T2-weighted MRI after admission demonstrated high signal intensities in the bilateral pallidum, indicating multiple brain infarcts in the subcortical white matter. Ultrasonography showed 2 plaques in the left common carotid artery. Laboratory studies revealed blood coagulation abnormalities and hypoxia. Medication with clonazepam and tiapride together with oxygen therapy normalized blood gas levels and improved his involuntary movements. But after discharge, he stopped oxygen therapy and involuntary movement became worse again, associated with hypoxia demonstrated by his blood gas analysis. These findings suggest that not only cerebrovascular disease but hypoxia might play an important role in the appearance and exacerbation of involuntary movements.