“Basilar Web” Causing Basilar Branch Infarction

We present a young patient with no vascular risk factors with a basilar branch infarction secondary to a shelf-like filling defect of the basilar artery. This defect was present and unchanged on repeat imaging and determined to be most consistent with a basilar web. Similar to carotid webs, a basilar web is believed to be an area of focal intimal fibroplasia that increases the risk of brainstem infarction. Focal fibroplasia of the posterior circulation should be considered when evaluating young adults with posterior circulation strokes of otherwise undetermined cause.