Fibromuscular dysplasia with carotid artery dissection presenting as an isolated hemianopsia

Internal carotid artery (ICA) dissection is a well-known cause of anterior circulation stroke, but its association with posterior circulation stroke has been less commonly reported. The latter situation can arise when there is persistent fetal circulation of the posterior cerebral artery and has, to our knowledge, never been reported in the setting of fibromuscular dysplasia (FMD) involving the ICA.

A 52-year-old man awoke with severe headache and noted visual loss. Examination confirmed a congruous left homonymous hemianopsia. A head computed tomography scan revealed an acute right posterior parietal infarct. Carotid ultrasonography demonstrated complete occlusion of the right ICA. Conventional angiography confirmed this and was diagnostic of FMD with dissection. A right-sided persistent fetal circulation was also noted. Magnetic resonance imaging revealed right parietal and right occipital infarctions.

The patient received ASA and clopidogrel and his visual deficit resolved within days. One year later, he remained asymptomatic and there was no suggestion of FMD in other vascular beds.

Although infrequently reported, carotid disease, including dissection, can be responsible for posterior circulation infarcts. Cervical artery dissection can be related to underlying arteriopathies such as FMD, which must be differentiated from vasculitis and vasospasm.