title: From wakefulness to sleep: migraine and hypnic headache association in a series of 23 patients.
abstract: OBJECTIVE
  We analyzed characteristics of hypnic headache (HH), migraine and the relationship between both headaches in 23 patients. HH is an uncommon primary headache characterized by exclusively sleep-related attacks. Concurrence of other headaches, mainly migraine, has been reported, but relationship between both syndromes has rarely been considered.
  
  
  METHODS
  We prospectively collected data in a headache outpatient office from January 2008 to September 2013. Demographic data and migraine and hypnic headache mean features were assessed.
  
  
  RESULTS
  Twenty-three out of 2500 (0.92%) were diagnosed with HH or probable HH, and 16 of them (69.5%) had a history of migraine. Mean age at onset of HH and migraine was 56.2 ± 9.3 and 24.6 ± 12.2 years, respectively. In 12 cases, migraine attacks disappeared at 56.7 ± 9.8 years old. Regarding the relationship between both syndromes, in 10 patients, migraine disappeared and HH began immediately after. In 1 case there was a pain-free period, and in 5 an overlap between both headaches was registered.
  
  
  CONCLUSIONS
  A history of migraine is common in HH patients in our series. Most frequent transition pattern was an immediate change between both syndromes. Hypnic headache and migraine might share a common pathophysiological predisposition.
authors.affiliation: Neurology Department, Hospital Clínico Universitario, Valladolid, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Ruiz
authors.forename: Patricia
authors.initials: P
authors.lastname: Mulero
authors.forename: María Isabel
authors.initials: MI
authors.lastname: Pedraza
authors.forename: Carolina
authors.initials: C
authors.lastname: de la Cruz
authors.forename: Cristina
authors.initials: C
authors.lastname: Rodríguez
authors.forename: Irene
authors.initials: I
authors.lastname: Muñoz
authors.forename: Johanna
authors.initials: J
authors.lastname: Barón
authors.forename: Angel Luis
authors.initials: AL
authors.lastname: Guerrero
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D051270:Headache Disorders, Primary / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000150:complications*; D011446:Prospective Studies; D012189:Retrospective Studies; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*
keywords: chronic migraine; hypnic headache; migraine; overlap syndrome; transition pattern