Cerebral arteriovenous malformations and movement disorders.

A series of six patients with movement disorders associated with cerebral arteriovenous malformations (AVM) is reported. The AVMs were classified according to the Spetzler-Martin classification as grade V (one patient), grade IV (four patients), and as grade III (one patient). One patient had action-induced hemidystonia caused by a contralateral frontoparietal AVM which compressed the putamen and was supplied partially by enlarged lenticulostriate arteries. Two patients presented with unilateral cortical tremor associated with contralateral high-frontal cortical/subcortical AVMs sparing the basal ganglia. Another patient developed hemidystonia and hemichorea-hemiballism after bleeding of a contralateral temporooccipital AVM and subsequent ischemia. Two patients had focal dystonia after thalamic and basal ganglia hemorrhage from AVMs. Five patients were operated on. The movement disorder was abolished in one patient postoperatively. Different mechanisms were identified that are relevant for the development of AVM-related movement disorders: mass effect, diaschisis, local parenchymal altered cerebral blood flow, and hemorrhagic or ischemic structural lesions.