title: Misdiagnosis of narcolepsy.
abstract: BACKGROUND
  Narcolepsy is a chronic primary sleep disorder, characterized by excessive daytime sleepiness and sleep dysfunction with or without cataplexy. Narcolepsy is uncommon, with a low prevalence rate which makes it difficult to diagnose definitively without a complex series of tests and a detailed history. The aim of this study was to review patients referred to a tertiary sleep centre who had been labelled with a diagnosis of narcolepsy prior to referral in order to assess if the diagnosis was accurate, and if not, to determine the cause of diagnostic misattribution.
  
  
  METHODS
  All patients seen at a sleep centre from 2007-2013 (n = 551) who underwent detailed objective testing including an MSLT PSG, as well as wearing an actigraphy watch and completing a sleep diary for 2 weeks, were assessed for a pre-referral and final diagnosis of narcolepsy.
  
  
  RESULTS
  Of the 41 directly referred patients with a diagnostic label of narcolepsy, 19 (46 %) were subsequently confirmed to have narcolepsy on objective testing and assessment by a sleep physician using ICSD-2 criteria.
  
  
  CONCLUSIONS
  The diagnosis of narcolepsy was incorrectly attributed to almost 50 % of patients labelled with a diagnosis of narcolepsy who were referred for further opinion by a variety of specialists and generalists. Accurate diagnosis of narcolepsy is critical for many reasons, such as the impact it has on quality of life, driving, employment, insurance and pregnancy in women as well as medication management.
authors.affiliation: Sleep Research Unit, Department of Sleep Medicine, University of Edinburgh, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK.
authors.forename: Laura
authors.initials: L
authors.lastname: Dunne
authors.affiliation: Department of Neurology, University of Dundee, Ninewells Hospital, Dundee, DD1 9SY, UK.
authors.forename: Pallavi
authors.initials: P
authors.lastname: Patel
authors.affiliation: Sleep Research Unit, Department of Sleep Medicine, University of Edinburgh, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK.
authors.forename: Emily L
authors.initials: EL
authors.lastname: Maschauer
authors.affiliation: Sleep Research Unit, Department of Sleep Medicine, University of Edinburgh, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK.|Department of Neurology, University of Dundee, Ninewells Hospital, Dundee, DD1 9SY, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Morrison
authors.affiliation: Sleep Research Unit, Department of Sleep Medicine, University of Edinburgh, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK. rlriha@hotmail.com.
authors.forename: Renata L
authors.initials: RL
authors.lastname: Riha
mesh_terms: D000328:Adult; D000368:Aged; D002375:Catalepsy / Q000175:diagnosis / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009290:Narcolepsy / Q000175:diagnosis* / Q000453:epidemiology; D017286:Polysomnography; D012017:Referral and Consultation; D012737:Sex Factors; D000074361:Sleep Latency; D055815:Young Adult
keywords: Cataplexy; Diagnosis; MSLT; Misdiagnosis; Narcolepsy