Cortical thickness and cognitive decline in Parkinson patients with deep brain stimulation in the MARK-PD study

Advanced Parkinsons disease (PD) and deep brain stimulation (DBS) are associated with cognitive impairment. We aimed to evaluate whether regional cortical thickness is associated with cognitive decline in patients with advanced PD treated with DBS. From the MARK-PD study, 32 patients with DBS implantation were included. Cortical thickness of 148 brain areas and cognitive function were assessed with MRI data using the FreeSurfer pipeline and Montreal Cognitive Assessment at baseline and follow-up (median 17 months), respectively. Adjusted linear and Cox regression models were calculated. Thinner orbitofrontal, cingulate, and occipito-temporal cortices as well as cuneus is related to significant cognitive decline. Moreover, lower thickness of these cortices is also associated with faster cognitive decline. Our study suggests that PD patients treated with DBS and lower cortical thickness in multiple brain regions develop at stronger and faster cognitive decline during the later course of the disease. ### Competing Interest Statement RS, MU and JGP have nothing to declare. MPN received lecture fees from Abbvie, Abbott and Boston scientific and served as consultant for Medtronic, Boston scientific, Licher, Zambon and Abbvie. CB served on scientific advisory boards for Bial, Desitin, Kyowa Kirin, Merz, STADA Pharm and Zambon and received honoraria for lectures from Abbvie, Bial, Desitin, TAD Pharma, UCB Pharma and Zambon. CG reports personal fees from AMGEN, personal fees from Boehringer Ingelheim, Novartis, Daiichi Sankyo, Abbott, Prediction Biosciences and Bayer. CUC reports personal fees from Pfizer and Zambon. ### Funding Statement CUC and RS are supported by an Else Kroener Exzellenzstipendium from the Else Kroener-Fresenius-Stiftung (grant numbers 2018\_EKES.04 to CUC, 2020\_EKES.16 to RS). ### 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: The study protocol was approved by the local ethics committee (PV5298) of the Chamber of Physicians Hamburg. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the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