December 1996

Is Excessive Daytime Sleepiness Characteristic of Prader-Willi Syndrome?The Effects of Weight Change

Author Affiliations

From The Developmental Neuropsychiatry Program, Division of Child and Adolescent Psychiatry, Department of Psychiatry and Behavioral Sciences (Dr Harris), and The Johns Hopkins Sleep Disorder Center, Department of Neurology (Dr Allen), The Johns Hopkins University School of Medicine, Baltimore, Md.

Arch Pediatr Adolesc Med. 1996;150(12):1288-1293. doi:10.1001/archpedi.1996.02170370066011

Objectives:  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.

Design:  Case series (within-subject design).

Setting:  A university sleep disorders center.

Patients:  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.

Interventions:  Overnight sleep polysomnographic recording and daytime Multiple Sleep Latency Test. Four of the 8 patients were restudied after their weight had changed.

Main Outcome Measure:  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.Arch Pediatr Adolesc Med. 1996;150:1288-1293