Brainstem congestion as the initial presentation of cavernous sinus dural arteriovenous fistula without ocular symptoms.

Background: Cavernous sinus dural arteriovenous fistula (CSDAVF) is an abnormal arteriovenous connection involving the dura mater within or adjacent to the wall of the cavernous sinus. While cases with superior ophthalmic vein drainage and ocular symptoms are typical, we report a rare case of CSDAVF draining into the perimedullary vein of the medulla oblongata and spinal cord and causing cerebellar ataxia and myelopathy as the initial presentation.

Case Description: A 73-year-old man presented with vertigo and rapidly progressing gait disturbance. Digital subtraction angiography revealed a left CSDAVF draining only into the spinal perimedullary veins, which was classified as Cognard type V. We performed a transvenous embolization through the occluded left inferior petrosal sinus and achieved a super-selective shunt occlusion using three platinum coils. The postoperative course was uneventful with immediate improvement of symptoms.

Conclusion: CSDAVF should be considered as a differential diagnosis in a patient with venous congestion in the brainstem.