title: Incomplete posterior circle of willis: a risk factor for migraine?
abstract: BACKGROUND
  Migraine is associated with vascular risk factors and white matter abnormalities (WMA). Cerebral hypoperfusion is known to be one mechanism underlying WMA and a few studies have shown that an incomplete circle of Willis (CW) may predispose to cerebral hypoperfusion. This study assessed the relationship between the morphologic characteristics of the CW and migraine.
  
  
  METHODS
  This case-control study was carried out in the Amiens University Hospital. Patients undergoing 3-dimensional time of flight magnetic resonance angiography of the CW from January 1 to June 30, 2006 were included (n = 124). A definitive diagnosis of migraine was established in 47 patients: 23 (48.9%) experienced migraine without aura and 24 (51.1%) migraine with aura. The remaining 77 patients with other neurologic disorders constituted the control group. The posterior CW was graded as complete when both posterior communicating arteries and the P1 segments of the posterior cerebral artery were present on visual examination and incomplete when one of these vessels was missing (interobserver agreement: K(total) = 0.746).
  
  
  RESULTS
  Incomplete posterior CW was significantly more common in migraineurs than in the control group (49% vs 18%; P < .001). On multivariate analysis, incomplete posterior CW was the sole independent factor associated with migraine (OR: 6.5; 95% CI: 2.6-16.2; P < .001). No difference was found between migraineurs with and without aura.
  
  
  CONCLUSIONS
  Despite some methodological limitations, our results showed that incomplete posterior CW was associated with migraine.
authors: Department of Neurology, Amiens University Hospital, Amiens, France.
authors: Jean-Marc
authors: JM
authors: Bugnicourt
authors: Pierre-Yves
authors: PY
authors: Garcia
authors: Johann
authors: J
authors: Peltier
authors: Bruno
authors: B
authors: Bonnaire
authors: Candice
authors: C
authors: Picard
authors: Olivier
authors: O
authors: Godefroy
mesh_terms: D000328:Adult; D002545:Brain Ischemia / Q000453:epidemiology / Q000503:physiopathology; D016022:Case-Control Studies; D015984:Causality; D020785:Central Nervous System Vascular Malformations / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology; D002536:Cerebral Arteries / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002941:Circle of Willis / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000453:epidemiology* / Q000503:physiopathology; D011237:Predictive Value of Tests; D015995:Prevalence; D011859:Radiography