[Arteriovenous malformation of septum pellucidum in combination with persistent trigeminal neuralgia].

A 16-year-old boy with arteriovenous malformation (AVM) of septum pellucidum in combination with left side persistent trigeminal artery (PTA) is described. Presentation of AVM included severe intracranial hemorrhage and the lesion was removed surgically. The case deserves interest for two reasons. 1) The observation demonstrates the possibility of increased pressure in the afferent arteries of AVM. It was illustrated by distinctive displacement of the zones of the hemodynamical balance around the circle of Willis. The raised pressure in conditions of shunting can be explained using principles of the constant shear stress in the vascular system. 2) The observation of the features of venous system that may be causative for PTA. These features included presence of the large anastomotic vein between petrosal and cavernous sinuses, enlargement of petrosal sinuses and shrinking of transverse sinus ipsilateral to PTA.