title: Anatomical variants of the circle of willis and brain lesions in migraineurs.
abstract: BACKGROUND
  Some reports demonstrated vascular alterations in brain magnetic resonance imaging (MRI) in migraineurs and a relationship between circle of Willis (Circle) variants and lacunar brain infarcts. We examined anomalies of the whole circle of Willis and their relationship with vascular brain lesions in migraineurs, to identify any possible vascular mechanism in migraine.
  
  
  METHODS
  We studied, with a cohort controlled study, the circle of Willis in migraineurs seen consecutively in our Headache Center, and in non-headache controls, using angio-MRI of the brain. Statistical analysis used ANOVA, Scheffè's criterion, t-student test.
  
  
  RESULTS
  We recruited 270 migraineurs (204 without aura (MWOA), 66 with aura (MWA) and 159 controls. Migraineurs presented an anatomical variant in 108 (40%) cases with 34 controls (21.4%) presenting a variant. We found a significant association between MWOA and variants (OR=2.4 CI95% [1.5 to 3.9]) and between MWA and variants (OR=3.2 CI95% [1.6 to 4.1]). Unilateral posterior variants with basilar hypoplasia are statistically associated only with MWA compared to controls (OR=9.2, CI95% [2.3 to 37.2]). Thirty-three percent of MWOA and 24% of MWA sufferers present some kind of brain lesion, included 2% of infra-tentorial lesions. We did not find any statistical association between the presence of Circle variants and ischemic lesions on MRI (OR=1.5 CI95% [0.68; 1.94]), or with infratentorial lacunar lesions (OR=1.58 CI95% [0.48 to 5.24]).
  
  
  CONCLUSIONS
  Anatomical variants of the Circle of Willis are significantly more frequent in migraineurs; posterior anomalies are more frequent in MWA, suggesting a vascular mechanism provoking changes in cerebral blood flow, thereby stimulating cortical spreading depression.
authors.affiliation: Department of Neurology, San Lazzaro Hospital, Alba, Italy. cicaves@alice.it
authors.forename: C
authors.initials: C
authors.lastname: Cavestro
authors.forename: L
authors.initials: L
authors.lastname: Richetta
authors.forename: M R
authors.initials: MR
authors.lastname: L'episcopo
authors.forename: E
authors.initials: E
authors.lastname: Pedemonte
authors.forename: S
authors.initials: S
authors.lastname: Duca
authors.forename: C
authors.initials: C
authors.lastname: Di Pietrantonj
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000473:pathology*; D002941:Circle of Willis / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000150:complications / Q000473:pathology*; D020325:Migraine with Aura / Q000473:pathology; D012189:Retrospective Studies; D055815:Young Adult