Motor events during REM sleep are associated with occipital lobe activity in Parkinson's disease

Study objectives: Abnormal motor events during REM sleep are common in Parkinson's disease (PD), but few studies have evaluated motor events comprehensively. This study aimed to categorize different types of motor events and explore their relationships with clinical symptoms, sleep structure and cortical electrophysiological characteristics. Methods: 116 PD patients (49 women and 67 men) underwent a clinical assessment and video-polysomnography. REM sleep-related motor events were classified into elementary motor events and complex motor events. Patients were categorized into three groups: PD-non motor events (PD-nME), PD-elementary motor events (PD-eME), and PD-complex motor events (PD-cME). Receiver operating characteristic (ROC) curves were used to calculate the predictive value of PSG-EEG for motor events during REM sleep. Results: PD-cME group showed prolonged total sleep time, increased REM sleep percentage, and shortened REM latency compared to other groups. Both PD-eME and PD-cME groups exhibited higher theta relative power and lower beta relative power across extensive cortical regions compared to PD-nME group. Additionally, PD-cME group showed reduced alpha relative power in the left occipital lobe compared to other groups. The theta/ beta ratio (TBR) in the right occipital lobe demonstrated significant predictive value for both elementary and complex motor events during REM sleep. Conclusion: Both elementary and complex motor events during REM sleep in PD patients were associated with abnormal cortical activation. The occipital cortex may potentially constitute a component of the neural circuitry underlying REM sleep.