|Curved reformat of the normal-caliber right vertebral artery showing all 4 segments of the artery.|
|Curved reformat of the left vertebral artery shows diffuse, small caliber of the artery.|
- Operational definitions are either 1) asymmetrical ratio of or greater than 1:1.7, or 2) discrepancy of greater than 2 mm diameter
- Prevalence 2%-6% of population (from autopsy and angiographic series)
- Posterior circulation ischemia: hypoplasia leads to reduction of posterior circulation blood flow velocity therefore has a negative role in occlusion of major cerebral arteries
- Migraine with aura and vestibular neuronitis: hypoplasia is believed to be associated with regional hypo perfusion and complex neurovascular consequences
Chuang YM, Chan L, Wu HM, et al. The clinical relevance of vertebral artery hypoplasia. Acta Neurol Taiwan 2012;21:1-7.