Association between waking EEG slowing and REM sleep behavior disorder in PD without dementia.

Abstract

To compare nondemented patients with Parkinson's disease (PD) with and without REM sleep behavior disorder (RBD) to healthy controls on quantitative EEG characteristics for both wakefulness and REM sleep. Fifteen patients with PD (7 patients with polysomnographic-confirmed RBD [PD-RBD] and 8 patients without RBD [PD-NRBD]) and 15 healthy control subjects were studied. Each subject underwent a quantitative EEG analysis of both wakefulness and REM sleep. During wakefulness, patients with PD-RBD showed a higher theta power in frontal, parietal, temporal, and occipital regions in comparison to patients with PD-NRBD and control subjects. Moreover, a slowing of the dominant occipital frequency was observed only in patients with PD-RBD (p < 0.02). Patients with PD-NRBD did not present any slowing of the EEG. No between-group difference in quantitative REM sleep EEG was observed. This study demonstrates that the EEG slowing reported during wakefulness in nondemented patients with PD is strongly related to the presence of RBD.