Resting State Network alterations during Deep Brain Stimulation in Parkinson's Disease

Background: Current treatment strategies for Parkinson's disease (PD) include medication and deep brain stimulation (DBS). While these treatment options are effective, their exact mechanisms remain elusive. Objectives: We aim at identifying alterations in whole-brain electrophysiological resting state networks (RSNs) due to DBS and medication with the objective to gain insights into neural correlates of DBS and medication. Methods: We recorded 18 PD patients with DBS at rest in the magnetoencephalogram (MEG) in 4 conditions: medication off - stimulation off, medication off - stimulation on, medication on - stimulation off, and medication on - stimulation on. We derived RSNs and determined 4 consistent networks across conditions: visual, frontal auditory, and SMN (sensorimotor network). Result: In the SMN, medication had a suppressing effect on functional connectivity. Surprisingly, we could not find a significant change due to DBS. Both medication and stimulation increased functional connectivity in the frontal network. In the auditory network, stimulation decreased functional connectivity while medication both decreased and increased functional connectivity in some parts of the network. Finally, medication and stimulation had opposing effects on the visual network: medication suppressed while DBS increased functional connectivity. Conclusion: Overall, our findings reveal that DBS and medication have differential effects on various RSNs, which is relevant for understanding not only their complementary treatment effects but also the side effects. ### Competing Interest Statement Alfons Schnitzler received consultant and speaker fees from Medtronic Inc., Boston Scientific and Abbott. ### Funding Statement Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Project-ID 424778381 - TRR 295. EF gratefully acknowledges support from the Volkswagen Foundation (Lichtenberg program 89387). ### 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: Ethics committee of the medical faculty, Heinrich-Heine University Duesseldorf, study number 5608R 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 All data produced in the present study are available upon reasonable request to the authors