Bilateral occipital strokes from an atherosclerotic trigeminal artery.

A 58-year-old man with coronary disease presented with headache, confusion, and vision loss. On examination, he had retrograde and anterograde amnesia, superior homonymous quadrantanopias, and could not identify colors. MRI showed bilateral occipital infarcts involving the parahippocampal and lingual gyri (figure 1). CT angiography revealed a hypoplastic vertebrobasilar circulation, with a persistent right trigeminal artery supplying the rostral basilar artery (figure 2). Persistent fetal arteries may increase risk of atherogenesis due to increased turbulence. A rare cortical syndrome, new-onset achromatopsia with amnesia should provoke concern for top of the basilar syndrome. In this case, fetal artery intracranial atherosclerosis resulted in a “top of the trigeminal” syndrome.