Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

Circle of Willis Variations, Migraine, and Stroke

Brain Behav; ePub 2019 Feb 16; Hamming, et al

In a recent study, researchers found no significant difference in the completeness of the circle of Willis (CoW) in acute stroke patients with migraine compared to those without. Participants were recruited from a prospective acute stroke study. All underwent CT angiography on admission. Lifetime migraine history was assessed with a screening questionnaire and confirmed by an interview based on International Classification of Headache Disorders criteria. The CoW was assessed for incompleteness/hypoplasia (any segment <1 mm), for anterior cerebral artery asymmetry (difference >1/3), and for posterior communicating artery (Pcom) dominance (Pcom–P1 difference >1/3). They found:

  • Included were 646 participants with stroke, of whom 52 had a history of migraine.
  • Of these, 45 (87%) had an incomplete or hypoplastic CoW vs 506 (85%) of the 594 participants without migraine (adjusted odds ratio [aOR]:1.47).
  • There were no differences between participants with and without migraine in variations of the anterior or posterior CoW, anterior cerebral artery asymmetry (aOR 0.86), or Pcom dominance (aOR:0.64).
  • There were no differences in CoW variations between migraine patients with or without aura.


Hamming AM, van Walderveen MAA, Mulder IA, et al. Circle of Willis variations in migraine patients with ischemic stroke. [Published online ahead of print February 16, 2019]. Brain Behav. doi:10.1002/brb3.1223.