Restless Leg Syndrome and Impulse-Control Disorders in Parkinson’s Disease: Observational study

Abstract

Background: Impulse-control disorders and related behaviors (ICD-RB) and restless leg syndrome (RLS) are common in Parkinson’s disease (PD) patients, but their relationship and independence from dopaminergic therapy are not well understood. This study aims to determine the correlation between ICD-RBs and RLS and the significant psycho-behavioral profile of RLS patients in the presence of ICD-RBs.Methods: The study screened PD patients visiting a neurology outpatient department for addictive behaviors, alcohol and substance abuse, and ICDs using the QUIP questionnaire. RLS was diagnosed based on the criteria set by the International RLS study group. The cohort was divided into groups based on the presence of ICDs and RLS.Results: 48.6% of the 72 PD patients in the study displayed at least one Impulse Control Disorder-Related Behavior (ICD-RB), with 57.1% showing compulsive medication use, 17.1% showing compulsive eating, 11.4% showing compulsive buying, 11.4% displaying gambling disorder, and 2.8% displaying hypersexuality. In addition, 26.3% of patients in the cohort had Restless Legs Syndrome (RLS), with 68.4% of these patients displaying at least one ICD-RB. Among patients with RLS and ICD-RBs, gambling was the most commonly observed behavior, displayed by 30.7% of patients, while 36.8% displayed co-occurring compulsive eating. Only one patient showed more than one ICD-RB, which included both gambling and compulsive medication use.Conclusion: The study concludes that 11% of PD patients can have co-occurrence of RLS and ICD-RBs, and this behavioral profile may be due to circadian fluctuation in dopamine release in a hyper-dopaminergic state. Long-term dopaminergic treatment or degenerative processes may be the cause of both RLS and ICD-RBs in PD patients.