Hyperglycemia-induced hemichoreoathetosis: the presenting manifestation of a vascular malformation of the lenticular nucleus.

A 72-year-old diabetic woman developed paroxysmal hemichoreoathetosis during an episode of nonketotic hyperglycemia. The movement disorder abated as the blood glucose normalized. A computed tomographic scan revealed a vascular malformation involving the lenticular nucleus on the side contralateral to the dyskinesia. Hyperglycemia has rarely been reported to cause episodic dyskinesias, but there have been no prior reports of patients with striatal vascular abnormalities in whom hyperglycemia seemingly caused a transient movement disorder.