Delayed-onset dystonia associated with corticospinal tract dysfunction.

We report a young man with delayed-onset dystonia secondary to a cerebral infarction. The infarction was caused by an embolic event at the age of 18 months. Delay to onset of dystonia was 16 years and, prior to the onset of dystonia, the patient had profound corticospinal tract dysfunction manifested by a severe hemiparesis. Computed tomography scan revealed infarction of the lentiform nucleus and precentral gyrus. The profound involvement of the corticospinal tract both clinically and radiologically are features not previously described in symptomatic dystonia and contradict the concept that sparing of the corticospinal tract is an essential feature for the onset of acquired dystonia.