title: Subarachnoid hemorrhage of unexplained cause.
abstract: During a 7-year period, we observed 58 patients with signs and symptoms of subarachnoid hemorrhage (SAH) in whom clinical and neuroradiological investigations failed to reveal a reasonable cause of the bleeding. Repeat panangiography was negative in the 2 patients with spasm. Rebleeding episodes soon after admission were rare, and the overall rebleeding rate was 3.4% (equivalent to an annual recurrence of 0.6%). In 1 case, a second extensive angiographic evaluation showed a small cerebral arteriovenous malformation, which was successfully treated surgically. On follow-up, 89% of the patients experienced a good outcome, with return to normal activities. This study confirms a good prognosis for patients with SAH of unknown cause. The necessity of performing a second angiographic study and the role of small infundibular dilations of the cerebral arteries are discussed.
authors.affiliation: Division of Neurosurgery, Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Giombini
authors.forename: M G
authors.initials: MG
authors.lastname: Bruzzone
authors.forename: F
authors.initials: F
authors.lastname: Pluchino
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D000368:Aged; D002533:Cerebral Angiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000209:etiology* / Q000628:therapy