SLEEP AND BREATHING PATTERNS IN PATIENTS WITH PRADER-WILLI-SYNDROME (PWS) - EFFECTS OF AGE AND GENDER

Patients with Prader Willi syndrome (PWS) often complain of daytime hy persomnolence. Because of reported daytime sleepiness and high prevale nce of morbid obesity, these patients have been considered at risk for sleep related disordered breathing, but polysomnographic studies have been limited. We evaluated sleep and breathing polysomnographically i n 24 PWS patients including 15 adults and 9 children. All adult patien ts completed MSLT testing on the day following the nocturnal sleep stu dy. Both adult and children groups showed little or no sleep apnea, bu t REM related oxygen desaturation was quite common, its severity signi ficantly correlated with increased obesity. Sleep patterns in both gro ups showed abnormal REM sleep cycles with variable REM latency (at tim es significantly shortened) and fragmented REM sleep with multiple bri ef REM periods. REM sleep abnormalities were still present in some pat ients without REM related desaturation. As a group, patients with PWS demonstrated pathological somnolence as measured by MSLT, which correl ated with nocturnal sleep efficiency but not with nocturnal REM latenc y. It is hypothesized that the abnormal sleep findings in PWS reflect an underlying hypothalamic dysfunction characteristic of this syndrome .