title: Clinical characteristics of migraine in a population-based twin sample: similarities and differences between migraine with and without aura.
abstract: OBJECTIVE
  To look into clinical differences between migraine with and without aura in a population-based sample of migraineurs.
  
  
  BACKGROUND
  Migraine presents in two major forms, migraine with and migraine without aura. With the exception of the aura phase, the clinical characteristics of these entities are very similar. Despite this, however, the recent epidemiological data underline differences between migraine with and without aura. We tried to examine whether other features besides the aura differ between these two major forms of migraine.
  
  
  METHODS
  We studied 321 twins suffering from migraine with aura and 166 twins with migraine without aura from the population-based Finnish Twin Cohort. Migraine was diagnosed according to the criteria of the International Headache Society (IHS). Analysis was based on the combination of a mailed questionnaire and a telephone interview by a neurologist. Special attention was paid to differences between migraine with and without aura.
  
  
  RESULTS
  Some qualities of headaches differed between IHS defined migraine with and without aura. Unilateral headache (Chi-squared p = 0.039) and photophobia (Chi-squared p = 0.010) were more typical for migraine with aura, while nausea was more typical for migraine without aura (Chi-squared p = 0.002). Duration of headache in migraine without aura was also longer than in migraine with aura (Mann-Whitney U-test 0.007).
  
  
  CONCLUSIONS
  There are clinical differences between IHS defined migraine with and without aura; even the headache phase between the two entities differs. It is worthwhile distinguishing between them when looking for the elusive genes for these more common forms of migraine.
authors.affiliation: Department of Neurology, University of Helsinki, Finland. mikko.kallela@pp.fimnet.fi
authors.forename: M
authors.initials: M
authors.lastname: Kallela
authors.forename: M
authors.initials: M
authors.lastname: Wessman
authors.forename: M
authors.initials: M
authors.lastname: Färkkilä
authors.forename: A
authors.initials: A
authors.lastname: Palotie
authors.forename: M
authors.initials: M
authors.lastname: Koskenvuo
authors.forename: M L
authors.initials: ML
authors.lastname: Honkasalo
authors.forename: J
authors.initials: J
authors.lastname: Kaprio
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000453:epidemiology* / Q000503:physiopathology; D011795:Surveys and Questionnaires