title: Hallucinations and sleep disorders in PD: six-year prospective longitudinal study.
abstract: OBJECTIVE
  To prospectively assess the relationship of hallucinations to sleep disorders in patients with Parkinson disease (PD) over 6 years.
  
  
  BACKGROUND
  Several studies suggest an association between hallucinations and sleep disruption, but no longitudinal study has examined their progression and relationship, nor whether sleep alterations predict future hallucinations.
  
  
  METHODS
  Eighty-nine PD patients were recruited to fill cells of normal sleep without hallucinations (n = 20); sleep fragmentation only (n = 20); vivid dreams/nightmares (n = 20); hallucinations with insight (n = 20); hallucinations without insight (n = 9). At baseline, 6 months, 18 months, 4 years, and 6 years, sleep disorders and hallucinations were assessed by standardized scales with the longitudinal data analyzed by generalized estimating equations and other nonparametric tests.
  
  
  RESULTS
  At 6 years, we could account for all subjects (49 interviewed, 40 deceased or too ill for interview). Hallucination prevalence and severity increased over time (p < 0.0001). The odds of being a hallucinator increased by a factor of 1.39 at each successive time point. Sleep disorders, however, fluctuated widely among patients and time points, with no evidence of progression in severity (p = 0.73). The prevalence of sleep fragmentation did not differ between subjects with vs without hallucinations (OR = 1.43, p = 0.13). The presence of vivid dreams/nightmares, however, was highly correlated with the concurrent presence (OR = 2.32) and severity of hallucinations (OR = 3.02, both p < 0.0001). Vivid dreams/nightmares among non-hallucinators did not predict future development of hallucinations (OR = 0.94, p = 0.51).
  
  
  CONCLUSIONS
  Hallucinations and global sleep disorders follow different patterns of progression in Parkinson disease and are separate behavioral abnormalities. Sleep alterations are not necessarily harbingers of hallucinations.
authors.affiliation: Department of Neurological Sciences, Rush Medical College, Rush University, Chicago, IL, USA. cgoetz@rush.edu
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Goetz
authors.forename: Joanne
authors.initials: J
authors.lastname: Wuu
authors.forename: Linda M
authors.initials: LM
authors.lastname: Curgian
authors.forename: Sue
authors.initials: S
authors.lastname: Leurgans
mesh_terms: D000368:Aged; D005260:Female; D006212:Hallucinations / Q000453:epidemiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009735:Nursing Homes; D010300:Parkinson Disease / Q000401:mortality / Q000473:pathology*; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012893:Sleep Wake Disorders / Q000453:epidemiology*; D013995:Time