Intrinsic brain connectivity predicts impulse control disorders in patients with Parkinson's disease

Background: Impulse control disorders can be triggered by dopamine replacement therapies in patients with PD. Using resting‐state functional MRI, we investigated the intrinsic brain network connectivity at baseline in a cohort of drug‐naive PD patients who successively developed impulse control disorders over a 36‐month follow‐up period compared with patients who did not. Methods: Baseline 3‐Tesla MRI images of 30 drug‐naive PD patients and 20 matched healthy controls were analyzed. The impulse control disorders' presence and severity at follow‐up were assessed by the Questionnaire for Impulsive‐Compulsive Disorders in Parkinson's Disease Rating Scale. Single‐subject and group‐level independent component analysis was used to investigate functional connectivity differences within the major resting‐state networks. We also compared internetwork connectivity between patients. Finally, a multivariate Cox regression model was used to investigate baseline predictors of impulse control disorder development. Results: At baseline, decreased connectivity in the default‐mode and right central executive networks and increased connectivity in the salience network were detected in PD patients with impulse control disorders at follow‐up compared with those without. Increased default‐mode/central executive internetwork connectivity was significantly associated with impulse control disorders development (P < 0.05). Conclusions: Our findings demonstrated that abnormal brain connectivity in the three large‐scale networks characterizes drug‐naive PD patients who will eventually develop impulse control disorders while on dopaminergic treatment. We hypothesize that these divergent cognitive and limbic network connectivity changes could represent a potential biomarker and an additional risk factor for the emergence of impulse control disorders. © 2017 International Parkinson and Movement Disorder Society