title: Long-term study of the sleep of insomnia patients with sleep state misperception and other insomnia patients.
abstract: OBJECTIVE
  The objectives were 1) to investigate differences among patients with subjective insomnia (sleep state misperception), patients with objective findings of insomnia, and normal volunteers and 2) to assess the consistency of the sleep findings during a 2-month period.
  
  
  METHODS
  Twenty-one subjects were studied. Subjects with sleep state misperception (N = 7) had insomnia complaints for more than 1 year, no objective sleep disturbance, and sleep efficiency of 90% or greater (on the diagnostic screening sleep recording), while subjectively estimating that sleep time was less than 6.5 hours. Subjects with objective insomnia (N = 7) met the same subjective criteria, but objectively sleep efficiency was 85% or less. Normal subjects (N = 7) had no insomnia complaints and objective sleep efficiency of 90% or greater. All subjects were recorded on 2 consecutive nights three times with a 3-week period between each pair of nights (6 standard all-night polysomnographic sessions of 8 hours). A subjective sleep questionnaire was administered after each sleep recording night.
  
  
  RESULTS
  Sleep stage variables (percentages) were similar between the two insomnia groups, and both were different from the normal subjects. Sleep continuity variables were disturbed in the objective insomnia group, but they were similar in the sleep state misperception and normal groups. Both insomnia groups rated their sleep as inadequate on the questionnaires and differed from the normal subjects. The distinct sleep patterns of each of the three groups did not vary over the 6 nights of assessment.
  
  
  CONCLUSIONS
  Sleep state misperception may be a prodromic or transitional state of sleep dysfunction between normal sleep and the sleep pattern of objective insomnia.
authors.affiliation: Sleep Disorders Center, Henry Ford Hospital, Detroit, MI 48202-2689.
authors.forename: R J
authors.initials: RJ
authors.lastname: Salin-Pascual
authors.forename: T A
authors.initials: TA
authors.lastname: Roehrs
authors.forename: L A
authors.initials: LA
authors.lastname: Merlotti
authors.forename: F
authors.initials: F
authors.lastname: Zorick
authors.forename: T
authors.initials: T
authors.lastname: Roth
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008950:MMPI; D008297:Male; D008875:Middle Aged; D012890:Sleep / Q000502:physiology; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D012894:Sleep Stages / Q000502:physiology; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D012895:Sleep, REM / Q000502:physiology; D013998:Time Perception