High leg motor activity in sleep apnea hypopnea patients: efficacy of clonazepam combined with nasal CPAP on polysomnographic variables

The association of sleep apnea hypopnea syndrome (SAHS) with high leg activity in the same patient is a dilemma for the physician, as clonazepam, used to treat periodic leg movement syndrome (PLMS) can aggravate apneas, while nasal continuous positive airway pressure (nCPAP) can exacerbate PLMS. The present study aimed to compare nCPAP alone (n), nCPAP combined with clonazepam (n+c) and clonazepam alone (c) in patients with mild to moderate SAHS associated with high leg activity. Fourteen patients with an apnea hypopnea index (AHI) between 10 and 50 h(-1) and a leg movement index with regard to time in bed [LMI (TIB)] > 15 h(-1) on baseline polysomnography (b) were recorded on three consecutive nights with n, n+c and c, respectively. Leg movements were detected, using actigraphy, and were subsequently categorized into periodic, apnea- or hypopnea-related and nonperiodic movements (defined as neither periodic nor related to a respiratory event). The three treatments were successful in improving breathing [AHI b 26.1 (3.2) n 11.8 (2.4) n+c 5.0 (0.7) c 14.9 (1.8) h(-1)], leg activity [LMI (TIB) b 391 (4.8) n 22.5 (4.4) n+c 23.9 (3.9) c 22.6 (3.7) h(-1)] and sleep fragmentation [stage shift index b 373 (2.6) n 28.6 (1.6) n+c 25.6 (1.8) c 26.6 (1.6) h(-1)]. All types of movements were reduced, the effect being significant for respiratory events related and nonperiodic movements. Combination therapy was more effective than nCPAP alone in reducing the AHI and in improving sleep efficiency. We conclude that in patients with mild to moderate SASH associated with high leg activity, nCPAP improves nocturnal breathing and clonazepam reduces leg activity. More unexpectedly nCPAP is beneficial on leg activity and clonazepam on breathing, probably through a decrease in sleep fragmentation. The best results are obtained with combination therapy.