title: Circadian and seasonal variation of migraine attacks in children.
abstract: OBJECTIVE
  To investigate the rhythmicity of migraine episodes without aura in a pediatric population.
  
  
  METHODS
  Time of occurrence of 2517 migraine attacks in 115 children was recorded, by means of a diary, both by hourly and monthly intervals.
  
  
  RESULTS
  A significant circadian variation, characterized by a peak in the afternoon (P < .001) and one in the early morning (P= .002) was found. A seasonal peak was also observed between November and January, while a nadir was observed in July.
  
  
  CONCLUSIONS
  The clustering of attacks in the morning and midday and in autumn-winter, with a minimum frequency in July, suggests that school activities may represent an important cause of migraine.
authors.affiliation: Department of Clinical and Experimental Medicine--Pediatrics, University of Ferrara, 44100 Ferrara, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Soriani
authors.forename: Elisa
authors.initials: E
authors.lastname: Fiumana
authors.forename: Roberto
authors.initials: R
authors.lastname: Manfredini
authors.forename: Benedetta
authors.initials: B
authors.lastname: Boari
authors.forename: Pier Antonio
authors.initials: PA
authors.lastname: Battistella
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Canetta
authors.forename: Stefania
authors.initials: S
authors.lastname: Pedretti
authors.forename: Caterina
authors.initials: C
authors.lastname: Borgna-Pignatti
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D020326:Migraine without Aura / Q000453:epidemiology* / Q000503:physiopathology*; D012621:Seasons