Is incomplete circle of Willis associated with white matter lesion?

Objective: The pathogenesis of cerebral white matter lesion (WML) may be associated with chronic cerebral hypoperfusion. Incomplete circle of Willis (CoW) and cerebral artery stenosis (CAS) may contribute to chronic cerebral hypoperfusion. This study aimed to investigate whether incomplete CoW and CAS were associated with WML by a prospective study. Methods: 102 patients were enrolled in this study. The WML group included 52 patients who had level 2 or 3 WML according to Fazekas scale and no stroke history, and the control group included 50 patients who had normal cranial magnetic resonance images (MRI). All subjects underwent baseline examinations and completed MRI and contrast-enhanced cerebral CT angiography (CTA). CoW morphology was divided into complete and incomplete types according to the CTA results. The extent of CAS was calculated with reference to WASID method. Results: Hypertension, serum creatinine and homocysteine levels were higher in WML group than in control group (P<0.05). There were no significant differences of sex, age, smoking, diabetes, coronary artery disease, serum lipid, and blood glucose or alanine transaminase level between two groups (P>0.05). Although the percentage of CAS and incomplete CoW in WML group was higher than in control group, there was no significant difference between the two groups. Conclusions: CoW is the most important mechanism of cerebral collateral circulation. Incomplete CoW and CAS may impair self-regulation of cerebral blood flow and hemodynamic stability, but there is insufficient evidence to suggest that incomplete CoW and CAS are associated with WML in this study.