[Middle cerebral artery occlusion with Moyamoya phenomenon.--2nd report: report of an autopsy case].

About the middle cerebral artery occlusion with moyamoya phenomenon, we have reported the clinical and angiographical study of 10 cases. Now we present an autopsy case. A 53-year-old female was admitted to our hospital on May, 22, 1978, two hours after an apparent subarachnoid hemorrhage. Neurological examination revealed drowsiness, nuchal rigidity right hemiparesis and motor aphasia. Left carotid angiogram showed an occlusion of the left middle cerebral artery at its origin with moyamoya phenomenon, but did not demonstrate an occlusion and/or stenosis of the intracranial internal carotid artery. Furthermore right carotid and bilateral vertebral angiograms were normal. The hospital course was progressively uphill, and she did not have any focal neurological deficits at discharge. But she committed suicide with a poison (Paraquat) on August, 19, 1978. Histopathologic examination of the left middle cerebral artery revealed a stenosis, with a maximum diameter of 900 microns. In this portion the lumen was not be occluded, and arteriosclerotic and inframatric exchanges were not present. The elastica interna was reduplicated, frayed and at times discontinuous. The tunica media was very thin or disappeared. On the other hand, moyamoya vessels were found between distal and peripheral portion of the stenotic middle cerebral artery as a collateral circulation. These findings suggested that the stenotic arterial wall of the left middle cerebral artery might be a congenital hypoplasia.