Objective:

To demonstrate an uncommon mimic of idiopathic intracranial hypertension (IIH).

Background:

Common precipitating factors of IIH include sudden weight change, uremia, and usage of steroids, vitamin A, and tetracycline. Secondary causes of increased intracranial pressure include infection, brain mass, and cerebral venous thrombosis. This case presents a rare arteriovenous malformation (AVM) as a rare mimic of IIH. 

Design/Methods:

A 49-year-old female presented with 6 months of intermittent vision loss and right>left sided recurring, pulsating headaches. An 80 pound weight gain was endorsed, but denied vitamin A use. Ophthalmoscopic exam demonstrated bilateral grade 5 disc edema, retinal nerve fiber layer whitening with associated disc heme, and obstruction of multiple vessels. Visual fields and acuity were intact, although patient complained of a subjective left field cut. Lumbar puncture revealed an elevated opening pressure of 35 cm H2O; cerebrospinal fluid demonstrated 2 nucleated cells, 1 red blood cell, glucose 59 mg/dl and protein 24 mg/dL. Initial imaging showed protrusion of the right>left optic nerves and severe stenosis of the right>left transverse sinus. No brain mass, cerebral venous thrombus, or enhancement was seen. Findings were concerning for IIH. Patient was started on acetazolamide with no benefit; stenting of transverse sinus was considered.

Results:

Cerebral angiogram for pre-operative stent evaluation revealed a right occipital unruptured AVM in addition to the transverse sinus stenosis. A partial endovascular embolization of the AVM followed by sub-occipital craniotomy and resection of the right AVM nidus as well as right transverse stent for definitive management. Patient had significantly improved disc edema, headaches, and visual field at the 3-month follow-up. 

Conclusions: