Objective: To evaluate the effect of Deep Brain stimulation of the Subthalamic Nucleus (STN-DBS) on sense of agency in PD patients undergoing DBS; To look at differences in SoA between PD with and without ICB before and after DBS

Background: A key component of action experience is the sense of agency (SoA), the feeling of controlling one’s own actions, and the consequences of them. A recent study has showed that PD patients with impulsive-compulsive behaviours (ICB) have impaired sense of agency.

Method: Twenty-four PD patients performed an intentional binding paradigm, an index of SoA, where they judged the time of a voluntary action (pressing a button) and of an auditory effect (a tone) of the action. Patients were tested before DBS (ON medication) and one year after DBS (ON stimulation, both OFF and ON dopaminergic medication).
ICB were assessed by clinical interview and a validated questionnaire (Questionnaire for Impulsive-Compulsive Disorders in Parkinson’s Disease–Rating Scale) was employed to rate the severity of the disorder.

Results: There was no significant difference in action, tone and overall binding before and after DBS in the whole group of patients.
When comparing ICB patients to no-ICB patients, there was no difference in the binding task performance before DBS and no significant changes after DBS.
Considering the post-DBS assessment, repeated measure ANOVA with medication as within group factor (ON stimulation/OFF medication vs ON stimulation/ON medication) and presence of ICB as between group factor (ICB vs no-ICB) showed an effect of ICB (F_(1,23)=6.2, p=0.02) but no effect of medication (F_(1,23)=0.4, p=0.5) or interaction medication*ICB for overall binding. Indeed, post-hoc analysis showed that ICB patients had higher overall binding than no-ICB (p=0.02) OFF medication.
There was no significant association between clinical variables (age, disease duration, levodopa equivalent daily dose) and any score of the binding task before and after DBS.

Conclusion: STN-DBS does not change the action–effect binding in PD patients. However, PD with ICB differ from no-ICB when OFF medication with the DBS ON, showing higher action-effect binding.

References: Ricciardi L, Haggard P, de Boer L, Sorbera C, Stenner MP, Morgante F, Edwards MJ. Acting without being in control: Exploring volition in Parkinson’s disease with impulsive compulsive behaviours. Parkinsonism Relat Disord. 2017 Jul;40:51-57.

Moore JW, Schneider SA, Schwingenschuh P, Moretto G, Bhatia KP, Haggard P. Dopaminergic medication boosts action-effect binding in Parkinson’s disease. Neuropsychologia. 2010 Mar;48(4):1125-32

« Back to 2022 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/the-effect-of-deep-brain-stimulation-on-sense-of-agency-in-parkinsons-disease-patients-with-and-without-impulsive-compulsive-behaviours/