0958 Effects of CPAP On EEG Delta Frequency In Patients with RBD: A Descriptive Case Series

Abstract

Obstructive sleep apnea (OSA) and idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) have been associated with increased risk for mild cognitive impairment (MCI) and dementia. We are interested in identifying the electroencephalographic (EEG) changes in patients with iRBD and OSA when they are treated with continuous positive airway pressure (CPAP). We hypothesized that there would be less delta activity in REM sleep with CPAP treatment. Our future goal is to identify the benefits of CPAP treatment in patients with iRBD and OSA and how this may help in the delay of onset or decrease progression of neurodegeneration. 3 patients diagnosed with iRBD and OSA based on the clinical history and nocturnal polysomnography findings, underwent CPAP titration. Six well-defined (without any artifact, arousals and respiratory events) REM sleep epochs (10 seconds each) were identified for each patient during the diagnostic and titration studies. The delta frequency band (0.4-3.6 Hz) in these portions was analyzed with spectral analysis. The discrete fast Fourier transform was used to calculate the EEG power spectrum. Spectral analysis showed a decrease in the mean delta power in two patients. In patient 1, mean Delta frequency decreased from 82.33 (95% CI: 76.69-87.97, SD: 9.9) to 72.66 (95% CI: 66.13-79.2; SD: 11.54). In patient 2, mean Delta frequency decreased from 72.41 (95% CI: 66.12-78.70, SD: 11.11) to 43.66 (95% CI: 36.87-50.45; SD: 11.99). Patient 3 has less delta activity at baseline {26.91 (95% CI: 20.6-33.23, SD 11.16)} and did not decrease with CPAP {41.25 (95% CI 30.83-51.66, SD 18.4)}. Our findings suggest that there are significant EEG changes in patients with IRBD and OSA with the treatment of CPAP. The overall increase in delta wave frequency in REM sleep stage might be indicative of encephalopathy with possible cognitive consequences in these patients. Subsequent decrease in delta frequency might be due to the beneficial effect of CPAP. Further studies with larger samples are required to validate the preliminary results presented here. None