INTRACRANIAL DURAL ARTERIOVENOUS-FISTULA WITH PERIMEDULLARY VENOUS DRAINAGE

Two cases of intracranial dural arterio-venous fistula (DAVF) with per imedullary venous drainage are reported. In both cases, MRI T2-weighte d (T2W) images showed an hypersignal within the cervical cord with spa ring of the thoracic cord. In one case perimedullary vessels were demo nstrated on TIW images after gadolinium i.v. administration. A complet e spinal angiogram did not show evidence of fistula but demonstrated t he lack of opacification of the conus medullaris venous drainage. Cere bral angiogram demonstrated in the first case a foramen magnum DAVF an d in the second case a petrous apex DAVF. Hypersignal limited to the c ervical cord at MRI on T2W images remain exceptionnal in case of intra cranial DAVF with perimedullary venous drainage. When neurological sym ptoms are suggestive, post gadolinium TIW sequences should be conducte d, followed by selective spinal angiogram. If normal venous drainage i s not objectivated (e.g. opacification of radiculo-medullary veins on the late phase), cerebral angiogram should be done to rule out an intr acranial DAVF.