White matter disease and an incomplete circle of Willis

IntroductionWhite matter disease occurs as a consequence of small vessel disease; however, hypoperfusion may also play a role. We investigated whether patients with less cerebral vessel anastomosis may develop more white matter disease.MethodsMagnetic resonance imaging (1.5t) with intracranial magnetic resonance angiography data was collected on a convenience sample between July 2008 and January 2009. All patients were independently assessed for circle of Willis variants by two researchers and categorized into two groups: those with a complete circle of Willis and those with an incomplete circle of Willis (absent vessels). The complete group was sub-divided into a classical group (entirely normal circle of Willis) and a hypoplastic group (hypoplasia but no absent vessels). White matter disease assessment was conducted for these groups, by two researchers blind to magnetic resonance angiography findings, on all patients over 50 years old.ResultsThe circle of Willis was characterized in 163 patients, while ...