Cognitive and Affective Theory of Mind Abilities in Parkinson's Disease Before and one Year After Subthalamic Deep Brain Stimulation

Anna Elsenbach^1*Melanie Astalosch¹Luísa Martins Ribeiro¹Elias Landfried¹Patricia Krause¹Gerd-Helge Schneider²Gregor A. Brandt¹Andrea A Kühn^1,3,4Dorothee Kübler-Weller¹

• ¹Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, and Humboldt-Universität zu Berlin, Berlin, Germany
• ²Charite - Universitatsmedizin Berlin Klinik fur Neurochirurgie mit Arbeitsbereich Padiatrische Neurochirurgie, Berlin, Germany
• ³Berlin School of Mind and Brain, Berlin, Germany
• ⁴Deutsches Zentrum fur Neurodegenerative Erkrankungen eV, Bonn, Germany

Background: Parkinson's Disease (PD) is associated with specific cognitive deficits and dysfunctions of Theory of Mind (ToM), which can impact patient's quality of life. ToM refers to the ability to infer the mental and emotional state of one's counterpart and involves the prefrontal cortex as well as the basal ganglia in its function. While bilateral Deep Brain Stimulation of the subthalamic nucleus (STN-DBS) in PD significantly improves motor symptoms, little is known on its effects on ToM. Methods: We prospectively applied an adapted version of the Yoni ToM paradigm, the Montréal Cognitive Assessment (MoCA) and an extensive tablet-based neurocognitive test set (CANTAB ConnectTM) prior to and one year after DBS surgery. Wilcoxon-signed-rank-tests were performed for comparisons of pre-and postoperative results and Spearman correlations assessed associations between parameters with consequent Bonferroni corrections for multiple comparisons. Results: 27 PD patients who received bilateral STN-DBS at Charité Universitätsmedizin Berlin between 06/2019 and 09/2021 were included in the study (21/77.8% male, age 58.7±10.1 years, disease duration 10.2±5.0 years). ToM abilities were stable one year after DBS surgery and associated with global cognition and a number of specific neuropsychological domains, namely reaction time, visual learning and multitasking performance. Conclusions: Our findings suggest that specific ToM abilities and global cognitive performance remain largely stable one year following STN-DBS. Performance in ToM tasks seems tied to individual cognitive profiles.