title: Hypnic headache.
abstract: BACKGROUND
  Hypnic headache (HH) is a rare primary headache characterized by strictly sleep-related headache attacks.
  
  
  METHODS
  This paper reviews the pertinent literature on HH.
  
  
  RESULTS
  Disease information is mainly based on case reports and small case series (around 250 cases) published since its first description in 1988 by Raskin. HH usually starts over the age of 50. Frequency of patients with HH among patients consulting tertiary headache care centers is estimated from 0.07% to 0.35%, but exact prevalence of HH is unknown. Diagnostic criteria were recently updated by the third edition of the International Classification of Headache Disorders beta version (ICHD-3). Recent data suggest a possible hypothalamic involvement.
  
  
  CONCLUSIONS
  Development of clinical research is needed to better understand the mechanisms of HH and to optimize treatment. Evidence for treatment data are missing, so treatment recommendations are based only on case reports or smaller open case series and reflect clinical experience. Caffeine can be used first line for acute treatment. Lithium and caffeine are possibly effective in prevention.
authors.affiliation: Département d'Evaluation et Traitement de la Douleur, Pôle Neurosciences Cliniques du CHU de Nice, Hôpital de Cimiez, Nice, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Lanteri-Minet
mesh_terms: D051270:Headache Disorders, Primary / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology; D006801:Humans
keywords: REM sleep; diagnostic classification; hypnic headache