Intracranial vertebral artery disease in the New England Medical Center Posterior Circulation Registry.

We studied 75 patients with severe intracranial vertebral artery (ICVA) occlusive disease from the New England Medical Center Posterior Circulation Registry to learn the etiologies and locations of the vascular lesions, the location and patterns of related ischemia and infarctions, and the outcomes. All patients had neuroimaging and vascular studies. Thirty-nine percent of patients had bilateral ICVA lesions. Twenty-four percent also had basilar artery disease and 36% had associated extracranial disease. The most common site of lesions was the distal ICVA after the origin of the posterior inferior cerebellar artery (PICA). Twenty-five percent of patients had only proximal intracranial posterior circulation territory infarcts (medullary and PICA cerebellar); 32% had infarcts that involved other intracranial territories in addition to the proximal territory. We found more distal intracranial territory infarcts resulting mainly from embolism from ICVA lesions than reported previously; this occurred in 17% of all patients. The ICVA was a recipient site for emboli in 8% of patients. Thirteen percent of patients died during follow-up. The outcome was favorable in most surviving patients. Three-fourths of them had no deficit or only slight disability. The patients with distal territory infarcts due to emboli from the ICVA had the worst outcome.