title: Evidence for a vascular factor in migraine.
abstract: OBJECTIVE
  It has been suggested that migraine is caused by neural dysfunction without involvement of vasodilatation. Because dismissal of vascular mechanisms seemed premature, we examined diameter of extra- and intracranial vessels in migraine without aura patients.
  
  
  METHODS
  A novel high-resolution direct magnetic resonance angiography imaging technique was used to measure arterial circumference of the extracranial middle meningeal artery (MMA) and the intracranial middle cerebral artery (MCA). Data were obtained at baseline, during migraine attack, and after treatment with the migraine abortive drug sumatriptan (a 5-hydroxytryptamine agonist).
  
  
  RESULTS
  We found dilatation of both MMA and MCA during migraine attack (p = 0.001). Sumatriptan administration caused amelioration of headache (p < 0.001) and contraction of MMA (p < 0.001), but MCA remained unchanged (p = 0.16). Exploratory analysis revealed that in migraine attacks with half-sided headache, there was only dilatation on the headache side of MMA of 12.49% (95% confidence interval [CI], 4.16-20.83%) and of MCA of 12.88% (95% CI, 3.49-22.27%) and no dilatation on the non headache side of MMA (95% CI, -4.27 to 11.53%) and MCA (95% CI, -6.7 to 14.28%). In double-sided headache we found bilateral vasodilatation of both MMA and MCA (p < 0.001).
  
  
  CONCLUSIONS
  These data show that migraine without aura is associated with dilatation of extra- and intracerebral arteries and that the headache location is associated with the location of the vasodilatation. Furthermore, contraction of extracerebral and not intracerebral arteries is associated with amelioration of headache. Collectively, these data suggest that vasodilatation and perivascular release of vasoactive substances is an integral mechanism of migraine pathophysiology.
authors.affiliation: Danish Headache Center and Department of Neurology, Glostrup Hospital, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Mohammad S
authors.initials: MS
authors.lastname: Asghar
authors.forename: Adam E
authors.initials: AE
authors.lastname: Hansen
authors.forename: Faisal M
authors.initials: FM
authors.lastname: Amin
authors.forename: R J
authors.initials: RJ
authors.lastname: van der Geest
authors.forename: Patrick van der
authors.initials: Pv
authors.lastname: Koning
authors.forename: Henrik B W
authors.initials: HB
authors.lastname: Larsson
authors.forename: Jes
authors.initials: J
authors.lastname: Olesen
authors.forename: Messoud
authors.initials: M
authors.lastname: Ashina
mesh_terms: D000328:Adult; D001158:Arteries / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008578:Meninges / Q000098:blood supply*; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000503:physiopathology; D020326:Migraine without Aura / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology*; D018170:Sumatriptan / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects
chemical_list: D014662:Vasoconstrictor Agents; D018170:Sumatriptan