Polysomnographic features associated with clonazepam and melatonin treatment in isolated REM sleep behavior disorder: Time for new therapeutic approaches?

AIMS

Although clonazepam (CLO) and melatonin (MLT) are the most frequently used treatments for REM sleep behavior disorder, the polysomnographic features associated with their use are little known. The aim of this study was to evaluate polysomnographic and clinical parameters of patients with idiopathic/isolated REM sleep behavior disorder (iRBD) treated chronically with CLO, sustained-release MLT, alone or in combination, and in a group of drug-free iRBD patients.

METHODS

A total of 96 patients were enrolled: 43 drug-free, 21 with CLO (0.5-2 mg), 20 with sustained-release MLT (1-4 mg), and 12 taking a combination of them (same doses). Clinical variables and polysomnography were collected.

RESULTS

Although clinical improvement was reported in all groups, MLT impacted sleep architecture more than the other treatments, with significant and large increase in N3 stage, moderate reduction in N2 and REM sleep, and moderate increase in REM latency. CLO moderately increased the percentage of both REM sleep and especially N2, while reducing N1 and wakefulness. Patients treated with both CLO and MLT did not show major changes in sleep architecture.

CONCLUSION

These results suggest that the administration of MLT or CLO impacts (positively) on sleep parameters of iRBD patients. However, there is a need to better stratify patients, in order to treat them in a targeted manner, depending on the patient's individual sleep architecture and expected differential effects of these agents.

The Associations between Polysomnographic Parameters and Memory Impairment among Patients with Obstructive Sleep Apnea: A 10-Year Hospital-Based Longitudinal Study

Obstructive sleep apnea (OSA) has been associated with cognitive decline via several mechanisms, including intermittent hypoxemia, sleep fragmentation, and neuroinflammation. The neurological consequences of OSA have evolved into a major biopsychosocial concern in the elderly, especially memory impairment. We aimed to identify the polysomnographic (PSG) parameters capable of predicting memory impairment among OSA patients at or over age 50 with OSA. We reviewed the 10-year electronic medical records of OSA patients and compared the initial PSG parameters between those presenting and not presenting self-reported memory impairment. We conducted subgroup analyses based on OSA severity and performed multivariate analysis to correlate PSG parameters with memory impairment. The result showed that 25 out of the 156 (16%) investigated patients experienced self-reported memory impairment during follow-up. As compared to OSA patients without self-reported memory impairment, those reported with self-reported memory impairment had a higher oxygen desaturation index (ODI) (23.9 ± 17.8 versus 18.2 ± 12.0, p = 0.048). Regarding the associations between apnea-hypopnea index (AHI) as well as ODI and self-reported memory impairment among OSA subgroups classified by severity, the associations were only evident in the severe OSA subgroup in both univariate (p < 0.001; p = 0.005) and multivariate analyses (p = 0.014; p = 0.018). We concluded that AHI and ODI are the most relevant PSG parameters in predicting memory impairment in severe OSA patients.

Which is more important: the number or duration of respiratory events to determine the severity of obstructive sleep apnea?

Aim: Apnea-hypopnea index (AHI) take account only the number of apnea and hypopnea regardless of their duration and morphology. The aim of this study was to compare the mean obstructive apnea duration (MOAD), mean mixed apnea duration (MMAD), mean central apnea duration (MCAD), mean total apnea duration (MTAD) and mean hypopnea duration (MHD) with the demographic parameters, blood oxygenation and other polysomnographic sleep parameters in patients diagnosed with severe obstructive sleep apnea (OSA).Materials and methods: A retrospective study included 121 patients who had a diagnosis of severe OSA. The correlations between the MOAD, MMAD, MCAD, MTAD, MHD and patient demographic parameters, blood oxygenation and other polysomnographic sleep parameters were analyzed.Results: Severe OSA patients with longer MOAD and MTAD had shorter Stage N3. Longer MOAD, MMAD, MCAD, MTAD, MHD were related to lower mean oxygen saturation. Longer MOAD and MTAD were associated with higher oxygen desaturation index. MOAD, MMAD, MTAD were positively associated with a duration below oxygen saturation 85%.Conclusions: Respiratory events can have different characteristics even though the average number of events per hour would be similar. Novel parameters like MOAD, MMAD, MCAD, MTAD, MHD could enhance the evaluation and classification of OSA in addition to AHI.