A preliminary quantitative analysis of REM sleep chin EMG in Parkinson's disease with or without REM sleep behavior disorder.

OBJECTIVES: To compare REM sleep chin EMG quantitative features between Parkinson's disease (PD) patients with or without REM sleep behavior disorder (RBD). SUBJECTS AND METHODS: Twenty-seven consecutive PD patients (mean age 67.9 years) and 19 normal controls (mean age 67.5 years) were enrolled. Detailed clinical, laboratory, and polysomnographic studies were obtained in all participants and characteristics of chin electromyographic amplitude during rapid eye movements sleep were analyzed by means of an automatic quantitative approach (Atonia Index). RESULTS: Sixteen of the 27 patients were affected by RBD. An Atonia Index below 0.90 showed high sensitivity (0.938) and specificity (0.909) for the diagnosis of RBD within the group of PD patients. CONCLUSION: This study recommends the Atonia Index as an objective measure to support and aid the diagnosis of RBD in PD.