Background: Impulse-control disorders (ICDs) occur in patients with Parkinson disease (PD), especially in younger patients on dopamine therapies.
Objective: To assess the prevalence of ICD symptoms and its pharmacological correlations in a sample of French patients with PD and without PD (poststroke).
Methods: Outpatients with PD and without PD (poststroke) were screened for compulsive behaviors related to hypersexuality, compulsive shopping, pathological gambling, or compulsive eating by means of the Questionnaire for Impulse-Control Disorders--short version. Full medical history and Unified Parkinson's Disease Rating Scale scores were also recorded. Dose of dopamine agonists were converted to defined daily doses (DDDs), according to the World Health Organization Anatomical Therapeutic Chemical classification system classification system.
Results: Two hundred three patients with PD and 52 patients without PD were recruited (mean ± SD age, 67 ± 1 vs 69 ± 2, P= 0.4; males: 62% vs 55% P= 0.2). Symptoms of ICDs were reported by 0% of poststroke patients and 25% of the patients with PD (P < 0.001). Hypersexuality was reported by 10% of the patients with PD, compulsive shopping by 6%, pathological gambling by 3%, and compulsive eating by 14%. A logistic regression analysis found that age younger than 68 years (odds ratio [OR], 3.3; 95% confidence interval, 1.6-6.6) and exposure to dopamine agonists (OR, 20.3; 95% confidence interval, 2.7-65.0) or monoaminooxidase-B inhibitor (OR, 3.7; 95% confidence interval, 1.1-12.6) were significant factors associated with increased ICD frequency. Patients with ICD symptoms were exposed to higher dopamine doses than those without them (1.6 ± 0.1 vs 1.0 ± 0.1 daily-defined doses; P < 0.001). A dose-response pharmacodynamic model disclosed a significant nonlinear dose-response relationship between dopamine agonists and frequency of ICD symptoms (P < 0.01).
Conclusions: Impulse-control disorder symptoms were more frequent in the patients with PD than in the poststroke patients with PD. Impulse-control disorder symptoms were related to younger age and exposure to monoaminooxidase-B inhibitors, and showed a nonlinear dose-response relationship with dopamine agonists.