TREATMENT OF OBSTRUCTIVE SLEEP-APNEA IN ACHONDROPLASIA - EVALUATION OF SLEEP, BREATHING, AND SOMATOSENSORY-EVOKED POTENTIALS

The occurrence of obstructive sleep apnea (OSA) in achondroplasia has been linked to brain stem compression, Overnight sleep studies (11 sub jects) and somatosensory-evoked potentials (SEP's, 10 subjects) were r ecorded before and after conventional treatment of OSA in achondroplas ia, The two groups were derived from 30 subjects who underwent diagnos tic sleep studies and SEPs, including 15 females and 15 males with a m edian age 6.6 of years (range 1.0.47.6) at the time of the first study , In 30 initial studies there was no correlation between severity of O SA and abnormalities on SEP evaluation, Treatment of 17 subjects inclu ded adenotonsillectomy (n = 3), weight loss (n = 1), and nasal-mask co ntinuous positive airway pressure (CPAP) (n = 13), Sleep studies in 11 subjects after a delay of 8.8 +/- 2.8 months showed a reduction in re spiratory disturbance index (RDI) from 38.4 +/- 6.9 to 6.5 +/- 1.8 eve nts hr(-1) (p < 0.001) and movements/arousals fell from 10.4 +/- 2.2 t o 4.8 +/- 0.2 hr(-1) (p < 0.04), Obstructive events were reduced from 33.7 +/- 6.9 to 2.4 +/- 1.0 hr(-1) (p < 0.001), Improvement of respira tory indices was associated with an increased proportion of slow-wave sleep from 25.2 +/- 4.0% to 32.3 +/- 2.4% (p = 0.01), and decrease in stage 1-2 sleep from 59.3 +/- 5.8% to 46.6 +/- 1.9% (p = 0.03), There was no increase in the percentage of REM sleep (15.2% to 21.2%), Repea t SEP studies in 10 subjects, after clinically effective treatment of OSA, showed improvement of SEP score of at least 1 grade, in 5 of 7 (7 1%) with initially abnormal values, We conclude that treatment to reli eve upper airway obstruction improves OSA in achondroplasia, accompani ed by changes in sleep structure and, in some cases, improved studies of neurological function. (C) 1995 Wiley-Liss, Inc.