Electrophysiological Correlates of Dynamic Cycling in Parkinson’s Disease

Objective Physical exercise, particularly tailored approaches like dynamic cycling, has shown promise in enhancing motor function in Parkinson’s disease (PD). We examined the underlying mechanisms of dynamic cycling in PD, emphasizing its impact on the activity of the subthalamic nucleus (STN), a pivotal region within the basal ganglia. Methods The investigation involved 77 dynamic cycling sessions conducted among seven PD individuals. Each participant underwent a maximum of 12 sessions over a four-week period. Local field potentials (LFPs) originating from the STN were recorded before and after dynamic cycling, utilizing DBS electrodes positioned within the nucleus. We evaluated both immediate and sustained impacts of dynamic cycling on LFP. The periodic LFP activity was assessed by determining the dominant spectral frequency and the power associated with that frequency. Aperiodic LFP activity was analyzed by calculating the 1/f exponent of the power spectrum. Results The comparison of LFP parameters immediately before and immediately after dynamic cycling did not reveal significant changes in the LFP characteristics. Long-term effects, over four weeks, however, revealed substantial alterations in power at the dominant frequency and 1/f exponent of the power spectrum. Changes were observed in both dorsal and ventral STN electrode contacts, with varied responses among participants. The comparison of parameters between hemispheres indicated a trend towards uniformity, implying a tendency for equalization in inter-hemispheric STN activity. Similar trends were also observed in the dorso-ventral parameter ratios, suggesting uniformity of neuronal activity across dorso-ventral axis of the STN in response to dynamic cycling. Conclusions These results highlight the impact of dynamic cycling on STN neuronal activity in PD. Prolonged interventions, even without immediate changes, bring about significant modifications, emphasizing the role of extended exercise in PD management and neuroplasticity. ### Competing Interest Statement Shaikh serves on speaker bureau for Acorda Pharmaceuticals, and Abbott Neuroscience. Angela Ridgel and Kenneth Loparo are co-inventors on two patents which are related to the device used in this study: ‘Bike System for Use in Rehabilitation of a Patient’, US 10,058,736. No royalties have been distributed from this patent. ### Clinical Trial NCT05298150 ### Funding Statement Shaikh was supported by the Career Development Grant from the American Academy of Neurology, George C. Cotzias Memorial Fellowship, Network Models in Dystonia grant from the Dystonia Medical Research Foundation, Department of VA Merit Review (I01RX003676), Care Source Ohio Community Partnership Grant, and philanthropic funds to the Department of Neurology at University Hospitals (Penni and Stephen Weinberg Chair in Brain Health). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: IRB of Kent State University gave ethical approval for this work I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Due to limitations from the IRB, the data is not available.