The size of territorial brain infarction on CT relates to the degree of internal carotid artery obstruction.

We studied the relationship between infarct size and degree of internal carotid artery stenosis in 227 stroke patients without a source of embolism in the heart, who had a CT-verified territorial brain infarct. We used logistic regression analysis adjusting for differences between groups in co-associated variables such as age, sex, hypertension, diabetes mellitus, and a history of ischaemic heart disease. Ipsilateral carotid stenosis greater than 50% was more strongly associated with large than small infarcts; adjusted odds ration [(a)OR]: 4.56; 95% confidence interval (CI): 1.21-17.2; P = 0.02. For ipsilateral carotid occlusion the association was even stronger--(a)OR: 36.80; 95% CI: 2.54-533; P = 0.007. When large infarcts were compared with infarcts of small and moderate size together the ORs were 2.29, 95% CI 1.14-4.58 and 2.57, 95% CI 1.17-5.67 for carotid stenosis or occlusion, respectively. Our data show a relationship between greater than 50% carotid stenosis or occlusion and large brain infarcts. We suggest that haemodynamic impairment may contribute to infarct size in territorial infarcts of non-cardiac origin.