To highlight a rare case of left transverse sinus dural arteriovenous fistula (D-AVF) with bilateral thalamic hyper-intensity. The imaging findings and the role of angiography in diagnosis, evaluation and management of D-AVF are discussed.

A 66-year-old man, with chronic kidney disease (CKD), type 2 diabetes mellitus (DM) and long standing hypertension presented to the emergency department with 2 episodes of focal motor seizures involving the right upper limb, each episode lasting 15 seconds with an interval of 2 hours. Upon arrival, his blood pressure was 210/120 mm Hg and neurological examination revealed mild confusion with dysarthria, and a NIH stroke scale (NIHSS) of 6. His basic metabolic panel showed elevated blood urea nitrogen (BUN) of 86mg/dl, creatinine of 5.1mg/dl and blood glucose of 206 mg/dl. Other investigations including coagulation profile and serum electrolytes were normal. MRI revealed symmetrical enlargement of thalamus with diffuse signal alteration on T2 and FLAIR sequences. MR angiography was suggestive of prominent straight sinus along with multiple pontine vessels involving the left temporo-occipital lobe. Left transverse sinus showed saturation signals on TOF MRA sequences.  Four-vessel angiogram revealed left transverse sinus D-AVF with feeders from left meningeal artery, left occipital artery and left posterior meningeal artery. Endovascular embolization of D-AVF was done and post procedure angiogram revealed minimal residual fistula. Post-operative NIHSS was 1 and the patient was discharged in a stable neurological condition.

D-AVF with retrograde flow into cortical veins poses a high threat of neurological complications. Hence, prompt diagnosis and treatment help avoid neurological sequelae. Long term follow up with angiography is recommended due to risk of recanalization of D-AVF.