Background Leukoaraiosis (LA) may reflect chronic small vessel ischaemia, but its underlying aetiology is uncertain. Possibilities include atheroma more proximally in the small cerebral vessels. In this case, LA would be expected to be associated with other risk factors for, and markers of, atherosclerosis. In light of conflicting results from previous studies, we investigated this association in a large cohort of well phenotyped patients with transient ischaemic attack (TIA) or minor stroke.

Methods Consecutive patients with TIA or minor stroke attending a TIA clinic were recruited and underwent routine MR-imaging and MR-angiography. LA was assessed by two independent observers using standard rating scales. A standardised clinical questionnaire was used to record data on major vascular risk factors.

Results 671 patients (mean (SD) age 71 (11), 56% men) with TIA (N=301) or minor stroke (N=370) attended the clinic. LA was independently associated with older age (p<0.0001), hypertension (p=0.001) and female sex (p<0.0001). The latter associations were still present after adjusting the analysis for age. However, LA was not associated with smoking, hypercholesterolaemia, ischaemic heart disease, peripheral vascular disease or diabetes, and it was unrelated to the severity of carotid disease.

Conclusion Leukoaraiosis was not associated with either carotid stenosis or risk factors for atherosclerosis, suggesting that its aetiology is independent of atherosclerotic disease.