Isolated intracranial fibromuscular dysplasia of the posterior cerebral artery.

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory arterial disease that most commonly affects the renal and internal carotid arteries, but intracranial FMD is very rare. We report a patient with FMD involving the posterior cerebral arteries (PCAs). A 24year old female was presented with a 4day history of right homonymous hemianopsia with throbbing headache in the left temporo-occipital area. The brain magnetic resonance imaging (MRI) revealed an acute ischemic stroke in the left PCA territory, while the Time of Flight (TOF) magnetic resonance angiogram (MRA) showed segmental luminal irregularities in the left proximal PCA. The conventional angiogram revealed the "string of beads" appearance, a characteristic that is pathognomonic for FMD. The patient's inhospital clinical course was stable, while there was no recurrence of stroke. This is the second report of FMD of the PCA. Notwithstanding incredibly rare incidences of isolated intracranial FMD and nonspecific findings of MRA, such a pathophysiology should be considered as the cause for a stroke in young patients, especially those with no cardiovascular risk factor.