Comparison of oscillatory activity in substantia nigra pars reticulata between Parkinson’s disease and dystonia

Parkinson's disease (PD) is associated with disrupted neural activity in the substantia nigra, but its electrophysiological changes remain underexplored. This study investigates the oscillatory patterns of substantia nigra pars reticulata (SNr) in PD, compared to dystonia (DT). Intraoperative recordings of the SNr were obtained from 20 PD and 16 DT patients during DBS surgery. Spectral power, neuronal firing rate, beta burst dynamics, and correlation analysis of the SNr signal were analyzed. PD patients exhibited increased alpha and beta power, elevated firing rates, and reduced aperiodic exponent values in SNr compared to DT. PD beta bursts showed prolonged durations and fewer short bursts. Beta power negatively correlated with motor symptom improvement rates in PD but not in DT patients. These findings highlight pathological beta power in SNr of PD, which indicates that SNr-DBS may offer a future therapeutic avenue for PD.