Évaluation des troubles comportementaux hyper- et hypodopaminergiques dans la maladie de Parkinson

Résumé

Le stéréotype du patient parkinsonien dépressif, anxieux et apathique est actuellement bouleversé par la description récente de troubles comportementaux sévères et destructeurs comme le jeu pathologique ou l’hypersexualité, liés à une addiction dopaminergique. Cependant, des modifications comportementales peuvent survenir sans addiction dopaminergique. Elles sont nombreuses et variées, bénéfiques ou néfastes, bénignes ou sévères, et largement sous-évaluées car elles ne sont pas rapportées spontanément par les patients. Nous proposons une échelle d’évaluation comportementale, spécifiquement adaptée à la maladie de Parkinson. Elle est basée sur les concepts « d’hypodopaminergie » qui reflèterait l’hypofonctionnement dopaminergique et « d’hyperdopaminergie » lié à une sur-stimulation dopaminergique. Ainsi, des troubles psychiques et comportementaux aigus liés aux fluctuations hyper- ou hypodopaminergiques accompagnent fréquemment les fluctuations motrices. Cette échelle est construite en 18 items, regroupés en quatre parties : évaluation psychique générale, apathie, fluctuations non motrices et comportements hyperdopaminergiques. Une cotation en cinq points (0–4, d’absent à sévère) pour chaque item se fait au cours d’un entretien semi-structuré. Des questions ouvertes permettent au patient de s’exprimer le plus librement possible et des questions fermées précisent l’évaluation en termes de sévérité. Cet outil, utile dans la gestion du suivi thérapeutique des patients, peut s’intégrer à l’examen neuropsychologique au même titre que l’évaluation cognitive.

Abstract

The common perception that Parkinson's disease patients tend to be depressed, anxious, apathetic and harm-avoiding has currently been challenged by the recognition that they can also exhibit a hedonistic, novelty-seeking personality. Thus, Parkinson's disease patients may indulge in their passions in an irresponsible and disinhibited manner, and engage in repetitive, compulsive behaviors that may be harmful and destructive to their social or professional lives. The dopamine dysregulation syndrome includes hypersexuality, pathological gambling, and compulsive shopping; it is associated with addiction to dopaminergic medication. However, not all behavioral changes are necessarily accompanied by a dopaminergic addiction. After antiparkinson treatment is initiated, patients enter a ‘honeymoon period’ during which changes in mood and behavior reflect a return to the patients’ premorbid personality. The increased motivation and higher level of activity in professional as well as leisure activities are considered positive changes by both the patients and their relatives. With prolonged and increased dopaminergic treatment, these positive behavioral changes can become excessive and evolve into nocturnal hyperactivity and stereotyped, repetitive and time consuming behaviors which ultimately disorganize the patient's everyday routine and herald behavioral addictions. These drug-induced behavioral changes are under-appreciated by neurologists and under-reported by the patients who neither complain about the behaviors nor understand the relationship between motivated behavior and dopaminergic medication. For these reasons, we propose a new scale for the assessment of behavior and mood to quantify and track changes related to Parkinson's disease, to dopaminergic medication, and to non-motor fluctuations. This scale is based on the concept of hypo- and hyperdopaminergic mood and behavior. The scale consists of 18 items addressing non-motor symptoms, grouped in four parts: general psychological evaluation, apathy, non-motor fluctuations and hyperdopaminergic behaviors. The rating in five points (0–4 from absent to severe) is carried out during a semi-structured interview. Open-ended questions introduce each item, allowing patients to express themselves as freely as possible. Close-ended questions permit the rating of severity and intensity. This new instrument can be used by psychologists, psychiatrists or neurologists familiar with Parkinson's disease. Designed to detect changes in mood and behavior of Parkinson's disease patients resulting either from the disease or its treatment, this tool can be used in conjunction with the neurocognitive evaluation, to help tailor the treatment of motor and non-motor symptoms to each individual's needs.