An Aneurysm Associated with Moyamoya Disease

We recently experienced a case which had an aneurysm with Moyamoya disease. He developed by a sudden severe headach, vomitting and conscious disturbance. CT was performed, and it revealed hematoma having a diameter of 1. 0 cm adjacent to the anterior horn of the lateral ventricle in the head of the left caudate nucleus, and both lateral ventricles, 3rd ventricle, and 4th ventricle were found to be filled with clot. On the 17th day after onset, cerebral angiography was performed and it was found that both internal carotid arteries were strongly stenotic and Moyamoya vessels araised from bifurcation of each internal carotid artery. A spherical aneurysm 3 x 3 mm in size was seen in the periphery of the Moyamoya vessels, and its location was coincided with intracerebral hematoma on CT. This aneurysm were observed in enhanced CT, and became to smaller and smaller. We performed repeat cerebral angiography on 72nd day after onset, and found the aneurysm to be disappeared.