Subdural hematoma as a cause of contralateral dystonia.

A 72-year-old patient was operated on for a right-sided chronic subdural hematoma. After removal of the drain he became somnolent and developed dystonia of the left arm. Computerised tomography demonstrated a new right-sided subdural hematoma with compression of the right hemisphere and a midline shift to the contralateral side. Within hours after evacuation of the recurrent hematoma the dystonia disappeared. Rapid development and reversal is unusual in secondary dystonia. Mechanical compression, altered vascular supply, and metabolic changes may underlie the pathophysiology of this rare symptomatic movement disorder.