Vein of Galen Malformations: Part I Epidemiology, Clinical Presentation, and Radiologic Evaluation

Definition Situated in the quadrigeminal cistern, the vein of Galen or great cerebral vein arises as the confluence of two internal cerebral veins. Originating at the caudal tela choroidea, the vein then characteristically advances dorsally, passing between the splenium of the corpus callosum and pineal gland before emptying, along with the sagittal sinus, into the straight sinus. Vein of Galenmalformations (VGMs) are more accurately termed arteriovenous shunts, in that they are congenital vascular malformations stemming from a persistent embryonic channel, the median prosencephalic vein of Markowski, which normally participates in the formation of the vein of Galen. The anterior and posterior choroidal arteries, as well as the anterior cerebral artery, drain directly into the persistent prosencephalic vein, thus circumventing a capillary bed and contributing to the clinical manifestation of the disease.