Intracranial Hemorrhage Secondary to Infra-orbital External Carotid Artery to Basal Veins Fistulas

Abstract

Background— The etiology of mesencephalic subarachnoid hemorrhage or isolated intraventricular hemorrhage
remains unknown in many patients.
Case Description— We report two cases of intracranial hemorrhage caused by venous hypertension secondary to
filling of basal venous system from facial and sphenopalatine branches of external carotid artery via fistulas located
in the infraorbital region. We noted an abnormal pathway of intracranial venous drainage and believe that it led to
venous bleeding in these patients. This pathway was successfully closed after combination of endovascular coil
placement and particulate embolization of arteriovenous fistulas.
Conclusion— Venous hypertension in basal venous plexus through extracranial arterial contribution may be con
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sidered in patients with mesencephalic subarachnoid hemorrhage or isolated intraventricular hemorrhage.