Difference in infarct volume and patterns between cardioembolism and internal carotid artery disease: focus on the degree of cardioembolic risk and carotid stenosis

Background and objective: Infarct volume and patterns may vary according to the stroke subtype. Within each stroke subtype, however, it is not clear if the infarct volume and patterns are affected by the risk of cardioembolism (CE) and the degree of arterial stenosis.

Patients and methods: We included consecutive patients with acute symptomatic ischemic lesions on diffusion-weighted imaging (DWI) performed within 48 h of symptom onset who had CE or internal carotid artery disease (ICAD). CE was divided into high-risk and medium-risk groups, and ICAD was divided into ICA occlusion (ICAO) and ICA stenosis (ICAS > or =50%) groups. DWI lesion patterns were classified as single versus multiple, and as large territorial versus perforating artery (large > or =2 cm, small <2 cm) versus pial artery versus border zone infarct. Infarct volumes and National Institutes of Health Stroke Scale (NIHSS) scores were obtained.

Results: Of the 167 patients included, 120 had CE (98 high-risk, 22 medium-risk) and 47 had ICAD (25 ICAO, 22 ICAS). The infarct volume was largest in the high-risk CE group, followed by the ICAO group. The infarct volumes in the medium-risk CE and ICAS groups were similar. Infarct volumes correlated with NIHSS scores. Single and large territorial infarcts were more common in the high-risk CE group, while multiple lesions as well as pial and border zone infarcts were more frequent in the ICAD subgroups. The lesion patterns of the medium-risk CE and ICAD groups were relatively similar.

Conclusions: CE and ICAD have heterogeneous radiologic characteristics depending on the risk of embolism and the degree of carotid stenosis.