title: Is excessive daytime sleepiness characteristic of Prader-Willi syndrome? The effects of weight change.
abstract: OBJECTIVE
  To assess nighttime and daytime sleep patterns in patients with Prader-Willi syndrome and to examine the effects of weight change on excessive daytime sleepiness in patients with this disorder.
  
  
  METHODS
  Case series (within-subject design).
  
  
  METHODS
  A university sleep disorders center.
  
  
  METHODS
  Eight patients (5 males and 3 females), ranging in age from 5.5 to 21 years, who met the diagnostic criteria for Prader-Willi syndrome.
  
  
  METHODS
  Overnight sleep polysomnographic recording and daytime Multiple Sleep Latency Test. Four of the 8 patients were restudied after their weight had changed.
  
  
  METHODS
  Changes in the sleep disordered breathing rate and Multiple Sleep Latency Test measures.
  
  
  RESULTS
  Sleep-disordered breathing occurred in all patients and was principally characterized by obstructive hypoventilation or episodes of apnea that occurred primarily during rapid eye movement sleep. After weight reduction, 3 patients had respiratory values that were within the broad normal range (disordered breathing rate, < 15 breaths per hour). Statistically significant (P < .05) weight loss effects occurred during nonrapid eye movement sleep (decrease with weight loss, F = 6.243). Excessive daytime sleepiness was documented in 6 of 7 patients who completed the Multiple Sleep Latency Test. Excessive daytime sleepiness was not consistently correlated with body weight or any of the nocturnal sleep variables.
  
  
  CONCLUSIONS
  A sleep-related breathing disorder occurred during rapid eye movement and nonrapid eye movement sleep and improved with weight change in patients with Prader-Willi syndrome, emphasizing the importance of weight reduction in clinical management. However, excessive daytime sleepiness persisted despite a reduction in sleep-disordered breathing after weight loss, suggesting a primary disturbance of sleep. Our findings provide additional support for the view that primary hypersomnia is a characteristic feature of the Prader-Willi syndrome.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Md, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Harris
authors.forename: R P
authors.initials: RP
authors.lastname: Allen
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D002648:Child; D002675:Child, Preschool; D004038:Diet, Reducing; D006970:Disorders of Excessive Somnolence / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000150:complications* / Q000188:drug therapy; D017286:Polysomnography; D011218:Prader-Willi Syndrome / Q000150:complications*; D012044:Regression Analysis; D012891:Sleep Apnea Syndromes / Q000209:etiology*; D015431:Weight Loss