Lack of relation between severity of stroke and severity of extracranial internal carotid artery lesions in Taiwanese first-ever ischemic stroke patients

Background and Purpose. The authors attempt to determine whether hemodynami cally significant extracranial internal carotid artery (ICA) lesions correl ate with the severity of first-ever hemispheric ischemic stroke. Methods. C arotid duplex was used to evaluate carotid arteries. The National Institute s of Health Stroke Scale was used to describe the severity of the stroke an d was stratified as follows: 1-6 = mild, 7-15 = moderate, > 15 = severe. Du plex findings were categorized according to velocity criteria into < 50% st enosis if ICA peak systolic velocity (PSV) (cm/s) < 140 and > 50% stenosis if ICA PSV > 140 or ratio of ICA and common carotid artery in PSV >2. No de tectable flow at ICA was considered occlusion. Stroke subtype was classifie d according to TOAST criteria. Results. Two hundred nineteen consecutive pa tients were enrolled, including 127 with mild, 65 with moderate, and 27 wit h severe stroke. The prevalence of ICA stenosis > 50% in each group was 3.6 %, 1.4%, 0.9%, respectively. Two patients in the severe group had total ICA occlusion. The overall prevalence of significant ICA lesions was 6.8%. Con clusions. There is no positive correlation of stroke severity with the seve rity of duplex findings, which may be due to low prevalence of significant ICA lesions or other stroke mechanisms. Most of the patients had mild strok e, and the majority had ICA stenosis < 50%. Small-vessel occlusion tended t o have mild severity of stroke. Intracranial artery lesions or other factor s causing stroke in Taiwanese should be investigated. Given the low inciden ce of significant extracranial carotid disease in symptomatic Taiwanese str oke patients, routine screening of symptomatic Taiwanese for extracranial c arotid artery disease does not provide enough information to determine stro ke mechanism, and transcranial Doppler should be added to the screening tes ts.