Choreoathetosis in Moyamoya Disease

Moyamoya disease is a cerebral angiopathy characterized by bilateral progressive narrowing of internal carotid arteries, developing collateral vessels with the aspect of a “puff of smoke.” The presentation with movement disorders is extremely rare. We present the case of an 11-year-old girl with low academic performance who complained of involuntary movements starting in her right hand. Neurologic examination showed preserved muscle strength and right hemichoreoathetosis. Neuroimaging showed left hemisphere hypoperfusion and a hypertrophic distal lenticulostriate artery. The symptoms were controlled with medications, and cerebral revascularization was performed. Although movement disorders are usually related to cerebral lesions or hypoperfusion, cases without these etiologies were described. Thus the finding of asymmetric lenticulostriate arteries improving after asymmetry reduction suggests a possible role in the pathogenesis. Further studies are needed to fully elucidate the mechanisms between moyamoya disease and movement disorders.