Underlying venous pathology causing perimesencephalic subarachnoid hemorrhage.
BACKGROUND
Perimesencephalic subarachnoid hemorrhage (PSH) is a relatively benign clinical entity with a low risk of recurrent bleeding. The precise etiology of PSH has not yet been determined. We report here three cases of PSH with clinical and radiological features that support a venous system as a cause.


METHODS
The first patient, a 72-year-old woman, had PSH and venous hemorrhagic infarct in the left thalamus on non-contrast CT. Subsequent cerebral angiography revealed widespread thrombosis in the cerebral venous system, a potential cause for reflux overflow hemorrhage. The second patient, a 55-year-old man with an established diagnosis of neuro-Behçet's disease, a well-known cause for cerebral venulitis, presented with PSH one year later. The third patient, a 39-year-old female, with incomplete Behçet's disease was admitted with PSH.


CONCLUSIONS
Current concepts on the anatomic origin and the possible pathophysiologic mechanism leading to PSH are discussed. The underlying pathological conditions in the venous system in our cases provide theoretical clues to the anatomic origin of PSH in general.
Lee
Jaejoon
J
Department of Medicine, Samsung Medical Centre, Seoul, Republic of Korea.
Koh
Eun-Mi
EM
Chung
Chin-Sang
CS
Hong
Seung-Chul
SC
Kim
Yong-Bum
YB
Chung
Pil-Wook
PW
Suh
Bum-Chun
BC
Moon
Heui-Soo
HS
D000328:Adult; D000368:Aged; D002533:Cerebral Angiography / Q000379:methods; D002550:Cerebral Veins / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008636:Mesencephalon / Q000473:pathology*; D008875:Middle Aged; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000209:etiology*; D014057:Tomography, X-Ray Computed / Q000379:methods; D014652:Vascular Diseases / Q000150:complications* / Q000000981:diagnostic imaging*