Dual origin of the left vertebral artery: extracranial MRA and CTA findings.

Abstract

A 48-year-old man presented with a posterior circulation stroke secondary to left lateral medullary infarction. Contrast-enhanced magnetic resonance angiography (CEMRA) revealed 40-45% intracranial left vertebral artery stenosis, likely atherosclerotic in nature. CEMRA and subsequent computed tomography angiography also identified a duplicate origin of the left vertebral artery. The importance of recognition of this rare anatomical variant, its potential contribution to stroke aetiology, and the advantage of non-invasive vascular imaging prior to catheter angiography is emphasised.