Background: Subthalamic nucleus deep brain stimulation (STN-DBS) improves motor symptoms of Parkinson's disease (PD) and motor complications of dopaminergic treatment. Whether STN-DBS should be considered when PD patients experience neuropsychiatric symptoms is controversial. Lack of systematic behavioral evaluation at baseline hampers the understanding of postoperative neuropsychiatric outcomes.
Objective: This study compares the behavioral profile of a surgical population to that in general PD.
Methods: Single center data from 234 PD surgical candidates were compared to data from 260 non-demented PD patients consulting in 13 PD expert centers at different stages of disease. The latter were considered representative of the general PD population. Neuropsychiatric symptoms were assessed using the Ardouin Scale of Behavior in PD, a guided interview quantifying changes in severity of 21 neuropsychiatric symptoms, classified into psychic non-motor fluctuations, hypo- and hyperdopaminergic behaviors. Multivariate analyses were performed to study differences in behavioral items between the two groups.
Results: Surgical candidates were younger, had longer disease duration and used significantly higher doses of dopaminergic drugs. After adjustment for covariates, dopaminergic addiction (OR 10.83; p = 0.002), nocturnal hyperactivity (OR 1.87; p = 0.04), excessive hobbyism (OR 2.37; p = 0.008), "excess in motivation" (OR 4.02; p < .001), psychic OFF (2.87; p < 0.001) and psychic ON (2.10; p = 0.001) fluctuations were more frequent in the surgical candidates. Depressed mood prevailed in the general PD population (OR 0.53; p = 0.045).
Conclusion: Behavioral complications of dopaminergic treatment are frequent in PD patients candidates for STN-DBS. They cannot be considered as contraindications for STN-DBS but must be taken into account in postoperative management.
Keywords: Parkinson disease; deep brain stimulation; dopamine; impulse control disorders; subthalamic nucleus.