[A case of acute subdural hematoma associated with convexity meningioma]

A 61-year-old normotensive woman was admitted to our hospital with complaints of severe headache and nausea. She has had a limp due to the poliomyelitis in her childhood. Three days before admission, she had a headache without unconsciousness. On admission, she was almost alert. Her vital signs were normal. A mild monoparesis of the atrophic right lower extremity was evident. This impairment was due to her past poliomyelitis. There were no other motor palsy, sensory loss, nuchal rigidity, and papilledema. A plain CT scan showed a crescent high density zone adjacent to a round high density mass in the left convexity. A cerebral angiogram showed a vascular left temporoparietal mass supplied by a middle meningeal artery. A craniotomy was then immediately performed. The well encapsulated tumor was totally resected, and the adjacent subdural hematoma was also evacuated. Histologically, the tumor was transitional meningioma with areas containing thin-walled vessels and focal necrosis. Postoperative course was uneventful. The origin of hemorrhage in this case would seem to be the thin-walled blood vessel with loss of vessel support. The clinical significance and the mechanism of the hemorrhage from the meningioma were discussed.