Superior anastomotic vein hypoplasia as a unique predisposing factor for cerebral venous hypertension and atraumatic non-aneurysmal subarachnoid hemorrhage: A case report

Subarachnoid hemorrhage (SAH) is a major cause of hemorrhagic stroke with substantial morbidity and mortality. Cerebral venous and/or sinus thrombosis can result in SAH in rare occasions, representing a mechanism for atraumatic, non-aneurysmal SAH that does not have another clear physical mechanism. A 54 year-old female with acute thunderclap headache presented to the emergency department with right sylvian fissure SAH. DSA revealed right cavernous sinus thrombosis, bilateral hypoplastic veins of Trolard, and an engorged right superficial middle temporal vein. Hypercoagulable work-up revealed an elevation of Factor VIII. We propose a unique mechanism for a case of atraumatic, non-aneurysmal SAH, in which we infer that bilateral hypoplasia of the superior anastomotic veins (of Trolard) resulted in a predisposition toward cerebral venous hypertension, resulting in SAH due to venous rupture.