Dynamical Analysis of Abnormal Oscillatory Activity in the BG and PPN Associated with Sleep-Related Alterations in Parkinson’s Disease and Its Modulation by DBS

Background: Parkinson’s disease (PD) is a common neurodegenerative disorder in which over 80% of patients experience severe sleep disorders. Understanding the neural dynamical mechanisms underlying these sleep disturbances is essential for developing targeted therapeutic strategies. Methods: We construct a basal ganglia–thalamocortical–pedunculopontine nucleus (BGTC–PPN) network model by combining Hodgkin–Huxley and Izhikevich neuron models to simulate both healthy and PD network dynamics. We systematically compare the discharge patterns, synchronization indices and power spectral densities of key nuclei between healthy and PD conditions. In addition, we use coherence analysis to characterize the frequency-dependent coupling between the PPN and basal ganglia nuclei, and investigate deep brain stimulation (DBS) modulation effects on the PD network using rectangular-wave stimulation at three target nuclei. Results: Under the PD condition, neuronal activity in the GPi and STN is increased but synchronization in the GPe and PPN is enhanced. β band oscillations are increased, and low-frequency activity in the PPN is disrupted. Coherence analysis reveals frequency-dependent coupling between the PPN and basal ganglia during PD-related network states. Comparison of different DBS targets demonstrates distinct effects. Within our 5-Hz-resolution frequency sweep, STN-DBS broadly suppresses β oscillations and, at approximately 70 Hz, minimizes the deviation of both the δ and β bands from the healthy reference; PPN-DBS enhances δ band activity at low stimulation frequencies or suppresses β synchronization at high frequencies, but these two effects do not co-occur within a single frequency window; GPi-DBS yields a larger increase in δ band power relative to the PD baseline near 55 Hz and suppresses β power in the GPi and PPN, yet the STN β deviation remains elevated across the scanned frequencies. Conclusions: PD-related pathological changes extend beyond motor circuitry and alter BGTC–PPN network dynamics that may be relevant to sleep. The target-dependent and frequency-dependent effects of DBS indicate that STN-DBS at approximately 70 Hz concurrently minimizes the deviation of both the δ and β bands from the healthy reference, whereas GPi-DBS and PPN-DBS modulate the two bands in a frequency-decoupled manner within our 5 Hz resolution frequency sweep. These findings provide a computational framework for optimizing DBS intervention strategies for PD-related sleep dysfunction.