Possible Morphological Pathomechanisms of Ischemic Stroke in the Posterior Circulation of Patients with Vertebral Artery Hypoplasia

ABSTRACT BACKGROUND The clinical significance of vertebral artery hypoplasia (VAH) and the possible pathomechanism of ischemic stroke in patients with VAH are still not completely clear. METHODS In a group of 80 posterior circulation strokes (PCS) patients, we compared the location of the ischemic areas in VAH (n = 26) and non‐VAH (n = 54) group. We assessed the side of VAH (diameter equal to or less than 2.5mm) with the stroke localization. RESULTS The possible morphological stroke pathomechanisms in the VAH group ‐ “blood flow reorganization” (n = 11) and “pathway liberation for embolization” (n = 10) ‐ were represented equally and may also act together (n = 3). In two cases, the stroke pathomechanism was unknown. The frequency of the presence of conventional risk factors ‐ hypertension (p = 1.0), diabetes mellitus (p = 0.62), hyperlipidemia (p= 1.0) and smoking (p = 1.0) ‐ and the stroke etiology ‐ cardioembolism (p = 0.80), atherosclerotic changes of large (p = 0.76) and small vessels (p = 0.79) ‐ did not differ between the two subgroups. CONCLUSION In patients with VAH, the combination of several pathomechanisms of ischemic stroke and the contribution of several risk factors can cause the clinical manifestation of PCS.