title: Discriminating neurological from psychiatric hypersomnia using the forced awakening test.
abstract: BACKGROUND
  Sleep inertia refers to the inability to attain full alertness following awakening from sleep and is a major component of hypersomnia. As event-related potentials (ERPs) are correlated to the degree of consciousness, they allow exploring information processing in transitional states of vigilance. Their modifications during forced awakening (FA) context have been shown to reflect sleep inertia.
  
  
  OBJECTIVE
  To assess the diagnostic value of a FA test using an oddball stimulation protocol during a nap in a representative sample of patients with excessive daytime sleepiness (EDS).
  
  
  METHODS
  One hundred and seventy three patients [30 narcolepsy, 62 idiopathic hypersomnia, 33 sleep apnoea syndrome, and 48 other (mainly psychiatric) hypersomnia] performed an auditory target detection stimulation task during pre-, post-nap wakefulness, and during two successive intra-nap FA while the EEG was simultaneously recorded. Both the accuracy of target detection and the ERPs were evaluated. ERPs during forced awakening test were considered to reflect sleep inertia if they presented with a P300 delay and/or sleep negativities (N350/N550).
  
  
  RESULTS
  Pre-nap behavior and ERPs were normal in all patients. Behavioral results were significantly worse during FA than during wakefulness for all groups of patients. P300 latencies were significantly delayed on FA conditions in each group of patients except the psychiatric group. Sensitivity and specificity for detection of sleep inertia were 64% and 94%, respectively, with predictive values of 96% (positive) and 50% (negative).
  
  
  CONCLUSIONS
  Our results suggest that the FA test could be helpful as a diagnostic procedure for discriminating neurological from psychiatric hypersomnia.
authors.affiliation: Unité d'hypnologie, Service de Neurologie Fonctionnelle et d'Épileptologie, Hôpital Neurologique, Centre Hospitalier Est, 59, boulevard Pinel, 69677 Bron, France. laure.peter-derex@chu-lyon.fr
authors.forename: L
authors.initials: L
authors.lastname: Peter-Derex
authors.forename: F
authors.initials: F
authors.lastname: Perrin
authors.forename: T
authors.initials: T
authors.lastname: Petitjean
authors.forename: L
authors.initials: L
authors.lastname: Garcia-Larrea
authors.forename: H
authors.initials: H
authors.lastname: Bastuji
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001519:Behavior / Q000502:physiology; D003937:Diagnosis, Differential; D006970:Disorders of Excessive Somnolence / Q000175:diagnosis* / Q000523:psychology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis* / Q000523:psychology*; D008875:Middle Aged; D009290:Narcolepsy / Q000175:diagnosis / Q000523:psychology; D009422:Nervous System Diseases / Q000175:diagnosis* / Q000523:psychology*; D009460:Neurologic Examination; D011237:Predictive Value of Tests; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000523:psychology; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult
keywords: Event-related potentials; Hypersomnia; Hypersomnie; Inertie de sommeil; Potentiels évoqués; Sleep inertia