Periodic limb movements of sleep (PLMS) is a common sleep disorder and can occur concomitantly with obstructive sleep apnea (OSA).The effect of nasal continuous positive airway pressure (nCPAP) on PLMS has been shown to be variable. We intended to study this effect in patients with OSA.
We retrospectively reviewed the baseline and nCPAP polysomnograms of 146 consecutive patients that presented for nCPAP after initial diagnosis of sleep disordered breathing. The periodic limb movement index (PLMI), the periodic limb movement arousal index (PLMAI), and the apnea hypopnea index (AHI) were noted before and after nCPAP .
7 patients (4.8%) had a PLMAI ≥ 5 at baseline. The PLMAI normalized (< 5) in 6 of those patients (86 %) with nCPAP (mean baseline AHI=22.4, mean nCPAPAHI=8.6). 139 patients (95.2 %) had a PLMAI < 5 at baseline. After nCPAP (mean baseline AHI= 32.7, mean nCPAPAHI =3.9), the PLMAI increased to > 5 in 11 of those patients (7.9 %), and remained < 5 in 128 (92.1 %). 7 of these 11 patients (63.6 %) and 44 of the 128 patients (34.4 %) had a PLMI > 5 at baseline
Effective nCPAP tended to eliminate preexisting arousing PLMS, while it increased them in a percentage of patients who did not have them at baseline. The presence of non-arousing PLMS at baseline did not predict the appearance of arousing PLMS with treatment of sleep disordered breathing.
In patients with OSA, the diagnosis of PLMS cannot be made or excluded until the OSA is eliminated because they may appear or disappear with treatment.
Z.C. Boujaoude, None.