Relationship between velocity of middle cerebral artery,severity of disease and watershed infarction in patients with extracranial internal carotid artery stenosis or occlusion

Objective To study the relationship between velocity of middle cerebral artery(MCA),severity of disease and watershed infarction(WSI) in patients with extracranial internal carotid artery(EICA) stenosis or occlusion.Methods Transcranial Doppler(TCD) was used to detect the mean velocity(MV) of MCA in 120 patients with EICA stenosis or occlusion.The National Institutes of Health Stroke Scale(NIHSS) was used to evaluated the patients′ condition.And CT or MRI was used to diagnosised the WSI.Results MV of MCA was severe reduced in 10 cases,middle reduced in 38 cases,and mild reduced in 42 cases,while there were 30 cases with normal MV.The scores of NIHSS in the four groups(12.5±4.7,3.9±4.8,3.2±4.7,2.4±4.9 respectively) had significant different(P0.01).The incidence of WSI in the four groups were 40%,63%,38%,27% respectively,the different was significant(P0.05).The incidence of WSI in the MV middle reduced group was significantly higher than those in the other groups.Conclusion The lower MV in MCA with severer EICA stenosis or occlusion,the disease condition is more severity,the incidence of WSI is also high.