Management of impulse control disorders in Parkinson’s disease

A survey of impulse control disorders in Parkinson's disease patients in Shanghai area and literature review

Background

Levodopa and dopamine agonists are the main treatments for Parkinson’s disease (PD) in recent years. Increased drug dosages are linked to some severe side effects, one of which is impulse control disorders (ICD). Many studies have reported the related risk factors of ICDs, such as dopamine agonist, male sex, younger age, earlier age of onset and so on. This study aims to investigate the incidence of ICD in Chinese PD patients from Shanghai area, explore the association of ICD with dopamine replacement therapy (DRT).

Methods

Two hundred seventeen PD patients were consecutively recruited from the Movement Disorder Clinic of Ruijin Hospital from March to October 2013. Minnesota Impulsive Disorders Interview was used to assess the PD patients. PD patients with possible ICD would undergo a further interview by a movement disorder specialist to confirm the diagnosis. Clinical information was also collected.

Results

Nine PD patients (4.15 %) showed ICD behaviors as follows: hypersexuality (4, 1.84 %), pathological gambling (3, 1.38 %), binge eating (1, 0.46 %), compulsive shopping (1, 0.46 %). Compared with the non-ICD PD group, ICD PD group took more dopamine agonists (LED 119.4 ± 86.4 mg/d vs 60.5 ± 80.5 mg/d, P = 0.019), had higher total levodopa equivalent dosage (TLED 912.81 ± 878.73 mg/d vs 503.78 ± 359.14 mg/d, P = 0.031), and had higher H&Y stage (2.33 ± 0.87 vs 1.41 ± 0.52, p = 0.013). However, logistic regression analysis didn’t reveal the above factors as independent risk factors of ICD behaviors in our study.

Conclusion

The incidence of ICDs behaviors in PD patients in our study is much lower than in western countries. ICD-PD group took higher dopamine agonists and higher total levodopa equivalent dosage, even though logistic regression analysis didn’t reveal them as independent risk factors.

Neuropsychiatric Behaviors in the MPTP Marmoset Model of Parkinson’s Disease

Objectives:

Neuropsychiatric symptoms are increasingly recognised as a significant problem in patients with Parkinson's disease (PD). These symptoms may be due to ‘sensitisation’ following repeated levodopa treatment or a direct effect of dopamine on the disease state. The levodopa-treated MPTP-lesioned marmoset was used as a model of neuropsychiatric symptoms in PD patients. Here we compare the time course of levodopa-induced motor fluctuations and neuropsychiatric-like behaviors to determine the relationship between duration of treatment and onset of symptoms.

Methods:

Marmosets were administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (2.0 mg/kg s.c.) for five days, resulting in stable parkinsonism. Levodopa (15 mg/kg and benserazide, 3.75 mg/kg) p.o. b.i.d. was administered for 30 days. Animals were evaluated for parkinsonian disability, dyskinesia and on-time (motor fluctuations) and neuropsychiatric-like behaviors on Day 0 (prior to levodopa) and on Days 1, 7, 13, 27 and 30 of treatment using post hoc DVD analysis by a trained rater, blind to the treatment day.

Results:

The neuropsychiatric-like behavior rating scale demonstrated high interrater reliability between three trained raters of differing professional backgrounds. As anticipated, animals exhibited a progressive increase in levodopa-induced motor fluctuations, dyskinesia and wearing-off, that correlated with the duration of levodopa therapy. In contrast, levodopa-induced neuropsychiatric-like behaviors were present on Day 1 of levodopa treatment and their severity did not correlate with duration of treatment.

Conclusions:

The data suggest that neuropsychiatric disorders in PD are more likely an interaction between levodopa and the disease state than a consequence of sensitisation to repeated dopaminergic therapy.

Gambling disorder during dopamine replacement treatment in Parkinson's disease: a comprehensive review

Gambling Disorder (GD) is characterized by “the failure to resist gambling impulses despite severe personal, family or occupational consequences”. In the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V), GD replaces the DSM-IV diagnosis of Pathological Gambling (PG). GD estimated prevalence ranges between 0.4% and 3.4% within the adult population and it seems to be more common in patients with Parkinson's disease (PD). In this population, GD recently has become more widely recognized as a possible complication of dopamine agonist (DA) therapy. This association has aroused great interest for the dramatic impact GD has on patients' quality of life. Management of PG in patients with PD could be demanding. It is based on patient and caregiver education, modification of dopamine replacement therapy, and in some cases psychoactive drug administration. In this review article, the authors provide an overview of GD pathogenesis during DA therapy as well as a summary of available treatment options.

Diagnosis and treatment of impulse control disorders in patients with movement disorders

Impulse control disorders are a psychiatric condition characterized by the failure to resist an impulsive act or behavior that may be harmful to self or others. In movement disorders, impulse control disorders are associated with dopaminergic treatment, notably dopamine agonists (DAs). Impulse control disorders have been studied extensively in Parkinson's disease, but are also recognized in restless leg syndrome and atypical Parkinsonian syndromes. Epidemiological studies suggest younger age, male sex, greater novelty seeking, impulsivity, depression and premorbid impulse control disorders as the most consistent risk factors. Such patients may warrant special monitoring after starting treatment with a DA. Various individual screening tools are available for people without Parkinson's disease. The Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease has been developed specifically for Parkinson's disease. The best treatment for impulse control disorders is prevention. However, after the development of impulse control disorders, the mainstay intervention is to reduce or discontinue the offending anti-Parkinsonian medication. In refractory cases, other pharmacological interventions are available, including neuroleptics, antiepileptics, amantadine, antiandrogens, lithium and opioid antagonists. Unfortunately, their use is only supported by case reports, small case series or open-label clinical studies. Prospective, controlled studies are warranted. Ongoing investigations include naltrexone and nicotine.

Nonmotor symptoms in Parkinson's disease

The recognition and treatment of nonmotor symptoms are increasingly emphasized in the care of Parkinson's disease (PD) patients. This manuscript will review signs and symptoms localized, generally, to the cortex, basal ganglia, brainstem, spinal cord, and peripheral nervous system. Cortical manifestations include dementia, mild cognitive impairment, and psychosis. Apathy, restlessness (akathisia), and impulse control disorders will be linked as basal ganglia symptoms. Symptoms attributed to the brainstem comprise depression, anxiety, and sleep disorders. Peripheral nervous system disturbances may lead to orthostatic hypotension, constipation, pain, and sensory disturbances.

Perceptions of cause and control of impulse control behaviours in people with Parkinson's disease

OBJECTIVES

 Impulse control behaviours (ICBs) have been a recent focus of research in people with Parkinson's disease (PD). However, the current literature is largely limited to a biomedical understanding and gaps remain in our understanding of the perceived cause of these behaviours and how people themselves experience them. Consequently, this study sought to investigate how people with PD perceive the cause and controllability of their ICB.

DESIGN

 The study utilized qualitative methodology involving semi-structured interviews. Interpretative phenomenological analysis (IPA) allowed an in-depth exploration of the subjective experience of ICBs.

METHODS

 Ten people with idiopathic PD and current or recent history of ICBs were recruited from an existing research participant pool.

RESULTS

 The themes that arose from the participants' accounts were 'Conflicting views on causality', 'Impulse control behaviours as a coping strategy', and 'The relationship between causal attribution and perceived controllability'.

CONCLUSION

 Participants' beliefs about the cause of ICBs varied from externalized cause (medication) to internalized (coping with the impact of PD). These causal attributions were fundamental to the perceived controllability of the behaviours and psychological benefits. Further research is warranted to explore a psychosocial viewpoint of this feature of PD and to provide appropriate and effective biopsychosocial interventions.

Impulse control disorders in Parkinson's disease: seeking a roadmap toward a better understanding

The development of an impulse control disorder (ICD) is now recognized as a potential nonmotor adverse effect of dopamine replacement therapy in Parkinson's disease (PD). Here, recent epidemiological, neurophysiological and genetic advances are summarized to outline potential mechanisms involved. It is safe to say that dopaminergic drugs, particularly dopamine agonists, are able to induce ICDs only in a minority of patients, while the majority are somehow protected from this adverse effect. While it seems clear that men with early-onset PD are more vulnerable, other predisposing factors, such as various current or pre-PD personality traits, are a matter of debate. In terms of neurophysiological advances, one may find striking analogies to the addiction literature suggesting a causal chain beginning with certain predisposing conditions of striatal dopamine synapses, an "unnatural" increase of dopamine stimulation and a characteristic pattern of resulting functional changes in remote networks of appetitive drive and impulse control. Future prospects include potential add-on medications and the possible identification of genetic predispositions at a genome-wide scale. Functional imaging of pharmacogenetic interactions (imaging pharmacogenomics) may be an important tool on that road.

Evaluation and management of the non-motor features of Parkinson's disease

Parkinson's disease (PD) is traditionally viewed as a motor disorder with a characteristic triad of tremor, rigidity and bradykinesia. There is now increasing awareness that PD is a complex systemic disorder with many nonmotor symptoms (NMS) which include autonomic dysfunction, sleep disorders, sensory and neuropsychiatric features. NMS become more common in severity and frequency with advancing disease when neuropsychiatric features such as cognitive impairment and psychosis dominate the clinical picture. NMS are strongly correlated with quality of life for patients and their families as well as institutional care placement. Despite their importance, NMS are poorly recognized by clinicians and often undeclared by patients. Use of a validated screening tool NMSQuest followed by specific symptom assessment instruments strengthens the recognition and holistic management of NMS in PD. Some NMS such as mood disturbance, anxiety, pain and insomnia may be improved by optimization of dopaminergic therapy. Conversely, psychosis, excess daytime somnolence or impulse control disorder (ICD) may be triggered by dopaminergic drugs. Other NMS such as dementia and severe depression may be unresponsive to dopaminergic treatment and may reflect perturbations in cholinergic, serotonergic or noradrenergic neurotransmitter function. These symptoms are more challenging to manage but may be ameliorated to some extent by agents such as acetylcholinesterase inhibitor or antidepressant drugs. This contribution reviews the evidence for the evaluation and management of key NMS in PD (apathy, anxiety, depression, psychosis, dementia, ICD, sleep disturbance, autonomic dysfunction, pain) and highlights the urgent need for both novel therapies and more controlled trials for current therapeutic strategies.

Impulse control disorders in patients with Parkinson's disease receiving dopamine replacement therapy: evidence and implications for the addictions field

AIMS

To describe the prevalence, phenomenology and correlates of 'impulse control disorders' (ICDs) in patients with Parkinson's disease (PD) treated with dopamine replacement therapy (DRT); to assess the strength of the evidence that DRT plays a contributory causal role in these disorders; and to highlight the implications of these disorders for research in the addiction field.

METHODS

PubMed and Web of Science databases were searched and the reference lists of papers examined.

RESULTS

The prevalence of ICDs in Parkinson's patients using DRT varied between 3.5% and 13.6%, depending on the severity and range of disorders assessed. PD patients with ICDs were: generally younger; had an earlier onset of PD; had a personal or family history of substance abuse or an ICD; and were more likely to be treated with dopamine receptor agonists (DA agonists) than levodopa (l-dopa). There is reasonable evidence that dopaminergic medications play a causal role in ICDs in that they occur at a higher rate in an otherwise low-risk population of adults, begin after initiation of DA agonist therapy and cease upon its discontinuation. A causal relationship is biologically plausible, but the role of other factors (such as concurrent mood disorders) remain to be clarified by better-controlled studies.

CONCLUSIONS

Impulse control disorders among patients with Parkinson's disease receiving dopamine replacement therapy may provide a unique opportunity for addiction researchers to study the neurobiology of impulsive forms of behaviour (such as problem gambling) that appear to be caused, in part, by the therapeutic use of dopamine receptor agonists.

Dopamine agonists diminish value sensitivity of the orbitofrontal cortex: a trigger for pathological gambling in Parkinson's disease?

The neurobehavioral underpinnings of pathological gambling are not well understood. Insight might be gained by understanding pharmacological effects on the reward system in patients with Parkinson's disease (PD). Treatment with dopamine agonists (DAs) has been associated with pathological gambling in PD patients. However, how DAs are involved in the development of this form of addiction is unknown. We tested the hypothesis that tonic stimulation of dopamine receptors specifically desensitizes the dopaminergic reward system by preventing decreases in dopaminergic transmission that occurs with negative feedback. Using functional magnetic resonance imaging, we studied PD patients during three sessions of a probabilistic reward task in random order: off medication, after levodopa (LD) treatment, and after an equivalent dose of DA (pramipexole). For each trial, a reward prediction error value was computed using outcome, stake, and probability. Pramipexole specifically changed activity of the orbitofrontal cortex (OFC) in two ways that were both associated with increased risk taking in an out-of-magnet task. Outcome-induced activations were generally higher with pramipexole compared with LD or off medication. In addition, only pramipexole greatly diminished trial-by-trial correlation with reward prediction error values. Further analysis yielded that this resulted mainly from impaired deactivation in trials with negative errors in reward prediction. We propose that DAs prevent pauses in dopamine transmission and thereby impair the negative reinforcing effect of losing. Our findings raise the question of whether pathological gambling may in part stem from an impaired capacity of the OFC to guide behavior when facing negative consequences.

Medical treatment of Parkinson disease

The cardinal characteristics of Parkinson disease (PD) include resting tremor, rigidity, and bradykinesia. Patients may also develop autonomic dysfunction, cognitive changes, psychiatric symptoms, sensory complaints, and sleep disturbances. The treatment of motor and non-motor symptoms of Parkinson disease is addressed in this article.

Impulse control disorders in Parkinson's disease

Since the original descriptions of hedonistic homeostatic dysregulation syndrome and pathological gambling in Parkinson's disease, impulse control disorders, such as compulsive spending, punding, or binge eating, are increasingly recognized. Although the term hedonistic homeostatic dysregulation syndrome has been supplanted by the concept of the dopamine dysregulation syndrome, the features of severe dyskinesias, cyclical mood disorder with hypomania or manic psychosis, and impairment of social and occupational functioning in the setting of increased intake of antiparkinson therapy remain. At this time, impulse control disorder is defined as maladaptive behaviors that emerge with disease progression and increasing antiparkinson medications. These behaviors may be disruptive, such as punding, or destructive, such as compulsive spending, gambling, binge eating, or hypersexuality.

Current status of symptomatic medical therapy in Parkinson's disease

Symptomatic medical therapies for Parkinson's disease (PD) have been disease modifying and have led to improvement in daily function, quality of life, and survival. For 40 years, these therapies have been primarily dopaminergic, and currently include the dopamine (DA) precursor levodopa (LD), DA agonists, catechol-O-methyltransferase (COMT) inhibitors, and monoamine oxidase (MAO) inhibitors. The roles of all these classes of agents have evolved, with significant changes occurring since the early 2000s. This article reviews the current literature for each of these classes of drugs, with a focus on efficacy and place in the therapeutic scheme. Levodopa is no longer considered to be toxic and, thus, its early use is not only appropriate but recommended. Ergot agonists are no longer in use, and new agents administered in patch form or subcutaneous injections have been approved. The COMT inhibitor tolcapone, with its significant efficacy, has been reintroduced, and two new MAO inhibitors have been approved. Selected safety issues are discussed, including the incidence of melanoma in relation to LD; pathological gambling and DA agonists; hepatic toxicity of tolcapone; and the tyramine or so-called cheese reaction with MAO B inhibitors. The article closes with a discussion of future directions and new drugs under development.

Drug Insight: impulse control disorders and dopamine therapies in Parkinson's disease

Impulse control disorders (ICDs) constitute a group of relatively common psychiatric conditions. ICDs typically involve pleasurable or hedonic behaviors (e.g. gambling, shopping or sex) that are performed repetitively, excessively or compulsively, to an extent that interferes in major areas of life functioning. Over the past decade, case reports, case studies and controlled examinations have reported ICDs in neurological patients, particularly those with Parkinson's disease (PD). A relationship between dopamine agonist treatment and ICDs was initially suggested on the basis of clinical observations, and subsequent systematic studies have provided more-substantial support for this association. Ongoing studies of the clinical characteristics of individuals with PD with and without ICDs suggest that certain individuals might be at increased risk of developing ICDs during PD treatment. Emerging data suggest that the association between dopamine agonists and ICDs extends into other neurological patient populations in which these agents are employed, such as those with restless legs syndrome. In this article, we summarize current knowledge regarding ICDs, review their relationships with PD and its treatments, provide practical clinical recommendations based on existing data, and suggest avenues for future research directed at advancing clinical care strategies.