Hyperkinetic movement disorders caused by corpus striatum infarcts: brain MRI/CT findings in three cases.

Three patients with hemichorea/hemiballismus/hemidystonia caused by discrete contralateral infarction of the corpus striatum are presented. The infarcts were all small on CT or MRI brain scan and were lacunar in type. Small discrete infarction of basal ganglionic structures allows such adventitious movements to be manifested. Involvement of contiguous areas, seen with larger infarcts, can suppress such movements. The infrequency of such hyperkinetic movement disorders, and the subtle infarct appearance on brain scan, can lead to a delay in the diagnosis.