Background and Purpose: In patients with posterior inferior cerebellar artery infarction (PICAI) or lateral medullary infarction (LMI), the ipsilateral vertebral artery (VA) is often hypoplastic and therefore at an increased risk of ischemic stroke. We investigated the frequency and clinical significance of hypoplastic VA (HVA) in ischemic stroke patients with/without VA territory and normal healthy people.
Methods: Five hundred twenty-nine patients with ischemic stroke, including VA territory infarction (LMI/PICAI) were classified according to their stroke location [303 anterior (ACS) and 226 posterior circulation strokes (PCS)] by MRI. The frequency of HVA, defined as a diameter of ≤ 2 mm by MRA, was measured in comparison with 306 normal healthy people.
Results: One hundred eighty-five patients (35.2 %) from the cohort had HVA (3.4%, bilaterally). Patients with PCS showed a higher rate of HVA than those with ACS (45.6% versus 27.1%, P<0.001). The HVA frequency of the latter was similar to that of the normal group (26.5%). Of the 112 VA territory stroke patients, 58 (51.8%) showed HVA (bilateral HVA in 10), and all of 48 showed ipsilateral HVA territory stroke. In 102 VA territory stroke patients, classification of the ipsilateral VA as hypoplastic (versus dominant or symmetric) tended to predict the involvement of multiple and extensive lesions, and a higher incidence of steno-occlusion (P<0.001).
Conclusion: HVA is not rare in normal population, and rather frequent in patients with PCS. Those people with HVA may have a high probability of PCS with atherosclerotic susceptibility and ipsilateral lesions in the VA territory.
- ischemic stroke
- vertebral artery