Abstract
A case of fenestration of the middle cerebral artery (MCA) associated with an aneurysm arising from the distal bifurcation was reported.
A 65-year-old male was suddenly seized with severe headache followed by left hemiparesis. CT scan demonstrated a right temporal intracerebral hematoma and right carotid angiography showed an aneurysm arising from the bifurcation of the right MCA and a fenestration of the same artery proximal to the aneurysm. Neurological examination on admission revealed somnolence, nuchal stiffness, left spastic hemiparesis, and bilateral papilledema. At surgery the afferent and efferent arteries of the aneurysm showed marked arteriosclerosis. Eight cases with fenestration of the MCA confirmed by angiography or operation have been reported in the Japanese literature and concomitant aneurysms were detected in five of them. Fenestration might be a remnant of the primitive MCA from the fetal stage. The coexistence of fenestration and aneurysm in the present case seemed to indicate that congenital factors played a role in the pathogenesis of the aneurysm.