Presentation
Altered conscious state, headache
Patient Data
Bilateral thalamic hypodensity with mass effect. A tubular ectatic structure is shown connecting the vein of Galen to the right cerebello-pontine cistern. No intraparenchymal hemorrhage, no venous sinus or internal cerebral vein hyperdensity.
Post contrast images reveal the abnormal vessel in the right perimesencephalic cistern to be an enlarged vein with venous varix. The internal cerebral veins opacify poorly. Findings consistent with deep venous thrombosis, venous "infarction" with the associated dilated vein indicating a dural arteriovenous fistula-confirmed on subsequent DSA.
Bilateral thalamic hyperintensity, heterogenous areas of restricted diffusion (see ADC). No opacification of internal cerebral veins. Local veins suggesting DAVF.
Meningeal supply from both cavernous ICA and external carotid branches fills a DAVF, with drainage to the basal vein of rosenthal, vein of galen and contralateral transverse sinus. There is no opacificatoin of the internal cerebral veins, in particular on the normal venous phase of either internal carotid or vertebral injections.
Case Discussion
The pattern of bilateral thalamic low density strongly suggests internal cerebral vein thrombosis. This may be apparent on non contrast enhanced CT as increased density. MRI or CTA/CTV can confirm the diagnosis. In this case there is a complex DAVF, with the presentation precipitated by internal cerebral vein thrombosis, confirmed by the lack of opacification on venous phase of bilateral carotid and vertebral angiography. More commonly deep venous "infarction" follows spontaneous internal cerebral vein thrombosis.