Ischemic stroke in the vertebrobasilar system. Risk factors, etiology, and localization.

OBJECTIVE To investigate and determine the clinical findings, lesions, risk factors, and variety of etiology in Turkish patients suffering from vertebrobasilar ischemia. METHODS The clinical, radiological, and prognostic features of patients with ischemic stroke in the vertebrobasilar system (VBS) are not homogeneous. The mechanism, localization, and severity of the vascular lesions and the presence of coexisting vascular risk factors influence the prognosis. The study included 134 patients with ischemic strokes in the VBS that were evaluated according to age, gender, clinical findings, risk factors, lesion localization, echocardiography, Doppler sonography, and cervical magnetic resonance angiography at Haydarpasa Numune Education and Research Hospital, Istanbul, Turkey between 1998-2002. RESULTS Hypertension, heart disease, smoking, diabetes mellitus, and hyperlipidemia were the most commonly observed risk factors. While infratentorial involvement was seen at a higher ratio (75.4%), acute multi-infarcts appearing simultaneously were mostly localized in the thalamus and the brain stem (18.7%). Large and small vessel disease incidences have been found in 32.8% and 20.1% of the patients. Cardioembolism with an incidence rate of 41.8% was the most frequent etiological cause in VBS ischemia. No significant meaning has been developed with age and gender as compared to the relationship between localization and etiological subgroups. CONCLUSION The most common risk factors were hypertension and cardiac diseases, and the most common localization of the infarcts was the infratentorial region. The cerebellum was seen as the most coexisting localization with all multiple infarcts. Cardioembolism accounted for the largest etiological group in all localizations and in multiple infarcts.