Impulse control disorders in Parkinson’s disease

Parkinson’s disease is a neurodegenerative disease characterised by typical motor symptoms and a range of non-motor symptoms, among which impulse control disorders, defined by an inability to resist temptations, impulses or urges, despite them being potentially harmful to the patient or caregivers, are gaining an increasing research interest. The most common compulsive activities include pathological gambling, hyper-sexuality, compulsive buying, and binge eating. The prevalence of impulse control disorders varies greatly depending on the country where the study was conducted, probably due to cultural and socioeconomic factors or the research methods used. Non-ergotamine dopamine agonists, and to a lesser extent highdose L-dopa and other antiparkinsonian drugs, are considered to be major risk factors for the development of impulse control disorders. Young age of patients, male gender, and early age of disease onset also increase the risk of developing this type of disorder. A probable cause of impulse control disorders is a state of dopaminergic overstimulation within the mesolimbic pathway and frontal-striatal circuit. The management of impulse control disorders is particularly challenging in view of the possible worsening of motor symptoms. The primary strategy remains dose reduction, discontinuation or switching from a dopamine agonist to another drug. If this type of intervention has failed, it is advisable to add atypical antipsychotics or antiepileptic drugs. Because of the low detection rate of impulse control disorders and their potentially devastating impact on patients’ personal and family lives, every clinician managing patients with Parkinson’s disease should be particularly vigilant for the presence of such disorders.