SUBTHALAMIC nucleus (STN) activity patterns, captured using advanced recording techniques in patients with Parkinson’s disease (PD), reveal neurophysiological mechanisms underlying sleep fragmentation and offer potential biomarkers for therapeutic interventions.
Sleep fragmentation is a prevalent issue in Parkinson’s disease, significantly impacting quality of life and disease progression. However, the neurophysiological basis of this phenomenon has been unclear. This study used deep brain stimulation (DBS) technology to investigate the relationship between STN activity and sleep disturbances in PD, shedding light on potential biomarkers and therapeutic targets to address sleep dysfunction.
The study involved 13 patients with PD who underwent overnight polysomnography one month post-DBS surgery, before initiating stimulation programming. Subthalamic nucleus local field potentials (LFPs) were recorded wirelessly in real-time, correlating these signals with measures of sleep quality, including arousal and sleep fragmentation indices. The findings demonstrated that increased beta and low gamma oscillations during non-REM (NREM) sleep were associated with greater sleep disturbances (e.g., arousal index-betaNREM: r=0.9, p=0.0001; sleep fragmentation index-gammaNREM: r=0.6, p=0.0324). Additionally, the low-to-high power ratio (LHPR) of theta to beta/gamma oscillations was inversely related to sleep fragmentation (e.g., ArI-LHPRNREM: r=−0.8, p=0.0053). Notably, prolonged beta bursts (>0.25s) in NREM sleep were linked to transitions to more active cortical states (p<0.01) and showed a negative correlation with sleep spindle activity (β=−0.24, p<0.001). These insights highlight distinct and potentially actionable electrophysiological features within STN activity during sleep.
These findings enhance our understanding of the mechanisms driving sleep fragmentation in PD and underscore the potential of STN LFP features as biomarkers. From a clinical perspective, the results may inform the development of personalised closed-loop DBS systems that adjust in real time to mitigate sleep disturbances by targeting specific electrophysiological patterns. Future research should explore integrating these biomarkers into therapeutic strategies, with a focus on improving sleep quality and overall well-being in PD patients.
Reference
Zhang G et al. Neurophysiological features of STN LFP underlying sleep fragmentation in Parkinson’s disease. Journal of Neurology, Neurosurgery & Psychiatry. 2024;95:1112-22.
