A case of moyamoya disease accompanied by an arteriovenous malformation.

It is well known that moyamoya disease sometimes is accompanied by cerebral aneurysm; however, no case of moyamoya disease with arteriovenous malformation has previously been published. We report such a case. A 33-year-old man suffered from transient left motor weakness and visual disturbance. Plain computed tomography (CT) showed a low density area in the left parietooccipital cortex. Enhanced CT revealed a ribbon-shaped enhanced area in the right temporooccipital cortex and a spotty enhanced area in the right frontal subcortex. Cerebral angiography revealed moyamoya disease. On the basis of Suzuki's angiographic classification, the patient was diagnosed as Stage III. Right carotid angiography revealed an arteriovenous malformation fed by basal moyamoya vessels and draining to the vein of Trolard and the sylvian vein of the right frontal lobe. This arteriovenous malformation consisted of feeders, the nidus, and drainers. Trolard's vein, which was one of the draining veins of the arteriovenous malformation, flowed to the moyamoya vessels of the right parietal vault.