title: The Prevalence and Characteristics of Primary Headache and Dream-Enacting Behaviour in Japanese Patients with Narcolepsy or Idiopathic Hypersomnia: A Multi-Centre Cross-Sectional Study.
abstract: BACKGROUND
  Because the prevalence and characteristics of primary headache have yet to be thoroughly studied in patients with hypersomnia disorders, including narcolepsy and idiopathic hypersomnia, we examined these parameters in the Japanese population.
  
  
  METHODS
  In a multicentre cross-sectional survey, among 576 consecutive outpatients with sleep disorders, 68 narcolepsy patients and 35 idiopathic hypersomnia patients were included. Additionally, 61 healthy control subjects participated. Semi-structured headache questionnaires were administered to all participants.
  
  
  RESULTS
  The patients with narcolepsy (52.9%) and idiopathic hypersomnia (77.1%) more frequently experienced headache than the healthy controls (24.6%; p<0.0001). The prevalence rates were 23.5%, 41.2% and 4.9% for migraine (p<0.0001) and 16.2%, 23.5% and 14.8% (p = 0.58) for tension-type headache among the narcolepsy patients, the idiopathic hypersomnia patients and the control subjects, respectively. Those who experienced migraine more frequently experienced excessive daytime sleepiness, defined as an Epworth Sleepiness Scale score of ≥10, than those who did not experience headache among the patients with narcolepsy (93.8% vs. 65.6%, p = 0.040) and idiopathic hypersomnia (86.7% vs. 37.5%, p = 0.026). Dream-enacting behaviour (DEB), as evaluated by the rapid eye movement sleep disorders questionnaire, was more frequently observed in the narcolepsy patients than in the idiopathic hypersomnia patients and the control subjects. An increased DEB frequency was observed in the narcolepsy patients with migraines compared to those without headache.
  
  
  CONCLUSIONS
  Migraines were frequently observed in patients with narcolepsy and idiopathic hypersomnia. DEB is a characteristic of narcolepsy patients. Further studies are required to assess the factors that contribute to migraines in narcolepsy and idiopathic hypersomnia patients.
authors.affiliation: Department of Neurology, Dokkyo Medical University, Tochigi, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: School of Nursing, Dokkyo Medical University, Tochigi, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyamoto
authors.affiliation: Department of Neurology, Dokkyo Medical University Koshigaya Hospital, Saitama, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Miyamoto
authors.affiliation: Yoyogi Sleep Disorder Centre, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Inoue
authors.affiliation: Yoyogi Sleep Disorder Centre, Tokyo, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Matsui
authors.affiliation: Yoyogi Sleep Disorder Centre, Tokyo, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Nishida
authors.affiliation: Sleep & Stress Clinic, Tokyo, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Hayashida
authors.affiliation: Yoyogi Sleep Disorder Centre, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Usui
authors.affiliation: Sleep & Stress Clinic, Tokyo, Japan.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Ueki
authors.affiliation: Yoyogi Sleep Disorder Centre, Tokyo, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Kokubunji Sakura Clinic, Tochigi, Japan.
authors.forename: Momoyo
authors.initials: M
authors.lastname: Murata
authors.affiliation: Department of Neurology, Dokkyo Medical University, Tochigi, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Numao
authors.affiliation: Department of Neurology, Dokkyo Medical University, Tochigi, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: Department of Neurology, Dokkyo Medical University, Tochigi, Japan.
authors.forename: Shiho
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Department of Neurology, Dokkyo Medical University, Tochigi, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Hirata
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data; D015897:Comorbidity; D003430:Cross-Sectional Studies; D006970:Disorders of Excessive Somnolence / Q000453:epidemiology* / Q000208:ethnology; D005260:Female; D006261:Headache / Q000453:epidemiology* / Q000208:ethnology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000453:epidemiology / Q000208:ethnology; D009290:Narcolepsy / Q000453:epidemiology* / Q000208:ethnology; D010045:Outpatients / Q000706:statistics & numerical data; D017286:Polysomnography; D015995:Prevalence; D020187:REM Sleep Behavior Disorder / Q000453:epidemiology* / Q000208:ethnology; D011795:Surveys and Questionnaires; D055815:Young Adult