Teaching Neuro Images : Dynamic vertebral artery insufficiency

Abstract

A 20-year-old healthy man presented with transient right upper monoparesis and brain MRI (figure, A) demonstrated left thalamic infarct. He presented 2 weeks later with left hemiparesis at basketball practice and right thalamic infarct (figure, B). Stroke risk factor workup was unrevealing. Conventional angiography demonstrated normal left vertebral artery course (figure, C and E), but dynamic left vertebral artery occlusion during 36° rightward head turn (figure, D and F). Bow hunter syndrome, first described in an archer,1 is eponymous for positional occlusion of the vertebral artery. This is associated with strokes from dynamic hypoperfusion. The patient remains symptom-free 1 month after microsurgical clip sacrifice of the left vertebral artery.