[Recurrent unipolar depression with 48-hour cycle and the state--dependent abnormal involuntary movements following right thalamic hemorrhage].

A 70-year-old woman was admitted because of depression and abnormal involuntary movements of her left extremities. Six months before the admission, she developed left hemiparesis caused by right thalamic hemorrhage. On neurological examination, she had mild motor and sensory hemiparesis on the left side. She showed recurrent depression each other days with a 48-hour cycle, and hemichorea-hemiballism appeared in her left upper and lower extremities exclusively on the days with depressive phase. Her depressive symptoms were characterized by psychomotor retardation but not by feeling of suicide or guilty. She was then diagnosed as having a rapid cycler following the right thalamic hemorrhage. To our knowledge, it is extremely rare to see the state-dependent involuntary movements in patients with rapid cycler. The coexistence of post-stroke depression and hemichorea-hemiballism in the present patient may suggest that both disorders appear on the basis of the common pathophysiological mechanism such as dysfunction on frontal cortico-basal ganglia-thalamo-cortical loops.