engleski

Impact of carotid disease on posterior circulation in patients with vertebral artery occlusion – a functional transcranial Doppler study

Almost one quarter of all ischemic strokes occur in posterior circulation. Approximately 20% of posterior circulation strokes evolve as a result of vertebral artery (VA) disease. Significantly higher rate of TIA in vertebrobasilar system occurred in patients with combined carotid and vertebral artery disease. Transcranial Doppler (TCD) recording during visual stimulation represents a reliable method for cerebral vasoreactivity testing of posterior circulation. The aim of present study is to evaluate the visually evoked responses in the posterior cerebral artery (PCA) by means of TCD in patients with isolated VA occlusion and in patients with VA occlusion and carotid disease. The study included adult patients with isolated extracranial or intracranial vertebral artery occlusion ; patients with extracranial or intracranial vertebral artery occlusion and unilateral significant carotid stenosis or occlusion and healthy individuals. Recording of mean blood flow velocities (MBFV) in PCAs during examinee’s eyes closed and during looking at white light was performed. Significantly larger increase of MBFV in both PCAs in control group then in patients with isolated VA occlusion was detected. Comparing to control group, in patients with combined VA occlusion and carotid disease the increase of MBFV in PCA was even lower. We recorded weaker visually evoked response in the group of patients with VA occlusion and carotid disease than in patients with isolated VA occlusion. Our results indicate that carotid disease aggravates the impact of VA occlusion on posterior circulation and impairment of cerebral vasoreactivity in posterior circulation.

carotid artery ; vertebral artery

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