Perimesencephalic subarachnoid hemorrhage: Etiologies, risk factors, and necessity of the second angiogram

Abstract

Aim:In this paper, we aim to present our experience with a series of patients with PMSAH. In addition, the clinical course of perimesencephalic subarachnoid hemorrgade (PMSAH) is discussed with an evaluation of etiologies, risk factors, and the necessity for a second angiogram on follow-up.Materials and Methods:The data for this study were obtained retrospectively from patients who were treated at the Uludag University, School of Medicine, Department of Neurosurgery, Division of Neurovascular Surgery's clinic with a diagnosis of PMSAH between January 1980 and March 2002.Results:We identified a total of 24 patients, 12 male. The mean age at the time of hemorrhage was 53 ± 12 years. In all patients, the onset was typical with a sudden severe headache. Five of the patients were Hunt-Hess Grade I, 15 were Grade II, and 4 were Grade III. The initial 4-vessel angiography was normal in 23 cases. Twenty-two had a second 4-vessel angiography, and all were normal. We observed acute hydrocephalus in 5 patients (20.8%). We did not observe re-bleeding during the follow-up of our patients.Conclusion:Patients with PMSAH have a particularly excellent outcome, and there is no need to evaluate these patients with repeat angiography.

Perimesencephalic nonaneurysmal subarachnoid hemorrhage caused by transverse sinus thrombosis

“…While arterial and venous origins have already been both postulated as the source of perimesencephalic subarachnoid hemorrhage, [ 7 , 23 , 24 ] the precise etiology and anatomical source of PNSAH still remain enigmatic despite recent advances in the association between venous drainage pattern of the basal vein of Rosenthal and PNSAH. [ 7 , 12 – 14 ] The most common hypothesis is that PNSAH is venous in origin due to the invariably mild initial presentation, its benign clinical course, limited extension of hemorrhage, low incidence of rebleeding and vasospasm.…”

Clinical Policy: Critical Issues in the Evaluation and Management of Adult Patients Presenting to the Emergency Department With Acute Headache

“…This entity has normal cerebral angiography testing results (CTA, DSA, or MRA) with no established vascular cause for the bleeding. 73,74 The cause for perimesencephalic SAH is not entirely understood and may represent many different etiologies such as venous bleeding, vasospasm, capillary telangiectasia, or perforating artery bleeding. 74,75 The prognosis for perimesencephalic SAH is thought to be benign in almost all cases and no neurosurgical interventions are indicated.…”

“…73,74 The cause for perimesencephalic SAH is not entirely understood and may represent many different etiologies such as venous bleeding, vasospasm, capillary telangiectasia, or perforating artery bleeding. 74,75 The prognosis for perimesencephalic SAH is thought to be benign in almost all cases and no neurosurgical interventions are indicated. 76 The strategy of CT/LP requires further angiography (CTA, DSA, or MRA) in this small group of patients to delineate operative versus nonoperative causes.…”

Atypical case of perimesencephalic subarachnoid hemorrhage

“…PM-SAH accounts for two-thirds of all SAH cases of unclear etiology, and is associated with an excellent clinical outcome. 2 The pathogenesis may be related to a pre-pontine venous or capillary lesion resulting in leakage or rupture at the level of the tentorial hiatus. 3 To our knowledge, no prior cases have been reported of PM-SAH related to probable CAA-RI.…”