REM sleep behavior disorder is associated to increased risk of impulse control symptoms in patients with Parkinson’s disease

Abstract

REM sleep behavior disorder (RBD) affects about 50% of patients with Parkinson’s disease (PD) and is often associated to more severe both motor and non-motor impairment.However, it is unknown whether PD-RBD patients have an increased risk to develop impulse control disorders (ICDs) compared to PD-noRBD. We aimed to assess the frequency of ICD and related behaviors symptoms in PD with and without probable RBD. Two hundred and twenty consecutive patients with idiopathic PD (132 M, mean age: 66.6 ± 11.0 yrs.; mean duration of PD: 7.3 ± 4.7 yrs.; mean Hoen and Yahr score: 1.9 ± 0.7, mean Levo-dopa Equivalent Daily Dose: 731.8 ± 448.6 mg) filled out the RBD-Single question, the RBD Screening Questionnaire (RBDSQ) and the Questionnaire for Impulsive-Compulsive Disorders in Parkinson’s Disease’s (QUIP). Probable RBD was found in 99/220 (45%, 59 M) patients.One or more ICDs or related behaviors were found in 60/99 (60.6%) patients with PD-pRBD and in 46/121 (38.0%) PD-noRBD ( p = 0.001).PD-pRBD showed a higher QUIP score (1.5 ± 1.7 vs.0.8 ± 1.3; p = 0.009) and a higher number of ICD and related behaviors symptoms (1.5 ± 1.7 vs.0.9 ± 1.3; p = 0.001) compared to PD-noRBD. Furthermore, a significant positive correlation between RBDSQ and QUIP scores was observed in the whole group ( R = 0.269; p < 0.001).The frequencies of ICD symptoms in patients with PD-pRBD compared to PD-noRBD were as follows: compulsive gambling (9.1% vs.3.3%; p = 0.07), compulsive sexual behaviors (11.1%vs.6.6%; p = 0.23) compulsive shopping (14.4% vs.4.1%, p = 0.008) compulsive eating (18.2% vs.14.0%, p = 0.39), hobbyism (24.2% vs.13.2, p = 0.03), punding (19.2% vs.10.7%, p = 0.09), walkabout (6.1% vs.7.4%, p = 0.67), dopamine dysregulation syndrome (18.2% vs.5.0%, p = 0.002).A logistic regression model accounting for Center (Clermont-Ferrand/Turin), sex, age, PD duration, PD severity (H&Y score) and Levo-Dopa Equivalent Daily Dose, indicated that PD- pRBD have a twofold risk to develop any ICDs (RR: 2.1 (C.I. 1.31–3.60); p = 0.003) and a threefold risk to develop compulsive shopping (RR: 3.15 (1.11–8.9); p = 0.03 and Dopamine Dysregulation syndrome (RR: 3.15 (1.23–8.079; p = 0.017) compared to PD patients without RBD. This study showed for the first time that RBD is associated to an increased risk to develop ICD symptoms in PD, even after controlling for age, severity, duration of PD and dopaminergic treatment. Further studies are warranted to clarify the mechanism underlying this association. Authors are in debt with neuropsychologist Dr. Tiphaine Vidal and neurologists Drs. Ana-Raquel Marques, Bérangère Debilly, Philippe Derost, Miguel Ulla and Nicolas Vitello for their contribution in collecting clinical data and with biostatistician Bruno Pereira for helping in statistical analysis.