Unexpected movement disorders in neurosurgical practice: report of three cases.

Hyperkinetic movement disorders may develop as a complication of stereotactic thalamotomy or pallidotomy. However, such movement disorders are uncommon after nonsterotactic intracranial operations. The authors report three cases of involuntary movement disorders unexpectedly developing after intracranial operations. The patients had undergone clipping of an internal carotid aneurysm, removal of an intracerebral hematoma, and resection of a tentorial meningioma. Two patients developed choreic movements and a dystonic posture of the unilateral upper extremity. One patient showed a tremor that had features of both parkinsonism and essential tremor. The symptoms of these patients were medically uncontrollable, and they were successfully treated with stereotactic ventrolateral thalamotomy.