ABSTRACT
BACKGROUND AND PURPOSE: Impulse control disorders (ICDs) are frequent in Parkinson's disease (PD), with associated clinical and genetic risk factors. This study was aimed at analyzing the clinical features and the genetic background that underlie ICDs in PD. METHODS: We included 353 patients with PD in this study (58.9% men, mean age 62.4 ± 10.58 years, mean age at disease onset 52.71 ± 11.94 years). We used the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease for ICDs screening. Motor, nonmotor, and treatment-related features were evaluated according to the presence of ICDs. Twenty-one variants related to dopaminergic, serotonergic, glutamatergic, and opioid neurotransmitter systems were assessed. Association studies between polymorphisms and ICDs were performed. The combination of clinical and genetic variables was analyzed with receiver operating characteristic curves to assess the predictability of experiencing ICDs. RESULTS: Impulse control disorders appeared in 25.1% of the cases. Patients with ICDs were younger and presented a higher rate of anxiety. Treatment with dopamine agonists increased the risk of ICDs and it was dose dependent (P < 0.05). Genetic association studies showed that the DOPA decarboxylase gene (DDC), rs1451375, might modulate the risk of ICDs. Plotting the clinical-genetic model, the predictability of ICDs increased 11% (area under curve = 0.80; z = 3.22, P = 0.001) when adding the genotype data for single nucleotide polymorphisms. CONCLUSIONS: Polymorphisms in DDC might act as risk markers for ICDs in PD. The predictability of experiencing ICDs increased by adding genetic factors to clinical features. It is therefore important to assess the patient's genetic background to identify individuals at risk for ICDs.
Subject(s)
Disruptive, Impulse Control, and Conduct Disorders , Parkinson Disease , Aged , Disruptive, Impulse Control, and Conduct Disorders/epidemiology , Disruptive, Impulse Control, and Conduct Disorders/genetics , Dopamine , Dopamine Agonists , Female , Humans , Male , Middle Aged , Parkinson Disease/complications , Parkinson Disease/genetics , Polymorphism, Single NucleotideABSTRACT
The study was aimed at analysing the frequency of impulse control disorders (ICDs) and compulsive behaviours (CBs) in patients with Parkinson's disease (PD) and in control subjects (CS) as well as the relationship between ICDs/CBs and motor, nonmotor features and dopaminergic treatment in PD patients. Data came from COPPADIS-2015, an observational, descriptive, nationwide (Spain) study. We used the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) for ICD/CB screening. The association between demographic data and ICDs/CBs was analyzed in both groups. In PD, this relationship was evaluated using clinical features and treatment-related data. As result, 613 PD patients (mean age 62.47 ± 9.09 years, 59.87% men) and 179 CS (mean age 60.84 ± 8.33 years, 47.48% men) were included. ICDs and CBs were more frequent in PD (ICDs 12.7% vs. 1.6%, p < 0.001; CBs 7.18% vs. 1.67%, p = 0.01). PD patients had more frequent previous ICDs history, premorbid impulsive personality and antidepressant treatment (p < 0.05) compared with CS. In PD, patients with ICDs/CBs presented younger age at disease onset, more frequent history of previous ICDs and premorbid personality (p < 0.05), as well as higher comorbidity with nonmotor symptoms, including depression and poor quality of life. Treatment with dopamine agonists increased the risk of ICDs/CBs, being dose dependent (p < 0.05). As conclusions, ICDs and CBs were more frequent in patients with PD than in CS. More nonmotor symptoms were present in patients with PD who had ICDs/CBs compared with those without. Dopamine agonists have a prominent effect on ICDs/CBs, which could be influenced by dose.
