Teaching neuroimages: carotid-cavernous fistula caused by fibromuscular dysplasia.

A 26-year-old woman developed headache, diplopia, and pulsatile tinnitus in 10 days. Neurologic examination revealed limitation of left eye movement, left dilated pupil with optic disc swelling and mild decreased vision, and a bruit over the left superior orbit. Her family history, laboratory data, and cerebral MRI showed normal findings. Cerebral CT angiography suggested left carotid-cavernous fistula (CCF). Follow-up angiography confirmed left CCF (figure 1). Nevertheless, multiple stenoses interspersed with aneurysmal dilation segments of carotid, vertebral, and renal arteries were found (figure 2). A diagnosis of fibromuscular dysplasia (FMD) was finally made. FMD is a rare cause of CCF.(1,2.)