Punding and dyskinesias

Management of Impulse Control and Related Disorders in Parkinson's Disease: An Expert Consensus

BACKGROUND

Impulse-control and related behavioral disorders (ICBDs) significantly impact the lives of Parkinson's disease (PD) patients and caregivers, with lasting consequences if undiagnosed and untreated. While ICBD pathophysiology and risk factors are well-studied, a standardized severity definition and treatment evidence remain elusive.

OBJECTIVE

This work aimed to establish international expert consensus on ICBD treatment strategies. To comprehensively address diverse treatment availabilities, experts from various continents were included.

METHODS

From 2021 to 2023, global movement disorders specialists engaged in a Delphi process. A core expert group initiated surveys, involving a larger panel in three iterations, leading to refined severity definitions and treatment pathways.

RESULTS

Experts achieved consensus on defining ICBD severity, emphasizing regular PD patient screenings for early detection. General treatment recommendations focused on continuous monitoring, collaboration with significant others, and seeking specialist advice for legal or financial challenges. For mild to severe ICBDs, gradual reduction in dopamine agonists was endorsed, followed by reductions in other PD medications. Second-line treatment strategies included diverse approaches like reversing the last medication change, cognitive behavior therapy, subthalamic nucleus deep brain stimulation, and specific medications like quetiapine, clozapine, and antidepressants. The panel reached consensus on distinct treatment pathways for punding and dopamine dysregulation syndrome, formulating therapy recommendations. Comprehensive discussions addressed management strategies for the exacerbation of either motor or non-motor symptoms following the proposed treatments.

CONCLUSION

The consensus offers in-depth insights into ICBD management, presenting clear severity criteria and expert consensus treatment recommendations. The study highlights the critical need for further research to enhance ICBD management. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Course of Impulse Control Disorder Symptoms in Parkinson's Disease: Deep Brain Stimulation Versus Medications

Background

The effect of surgery on impulse control disorders (ICDs) remains unclear in Parkinson's disease (PD) patients undergoing deep brain stimulation (DBS).

Objective

To examine changes in ICD symptoms in PD patients undergoing DBS compared to a medication-only control group.

Methods

The study was a 2-center, 12-month, prospective, observational investigation of PD patients undergoing DBS and a control group matched on age, sex, dopamine agonist use, and baseline presence of ICDs. Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) and total levodopa equivalent daily dose (LEDD) were collected at baseline, 3, 6, and 12 months. Linear mixed-effects models assessed changes in mean QUIP-RS score (sum of buying, eating, gambling, and hypersexuality items).

Results

The cohort included 54 participants (DBS = 26, controls = 28), mean (SD) age 64.3 (8.1) and PD duration 8.0 (5.2) years. Mean baseline QUIP-RS was higher in the DBS group at baseline (8.6 (10.7) vs. 5.3 (6.9), P = 0.18). However, scores at 12 months follow-up were nearly identical (6.6 (7.3) vs. 6.0 (6.9) P = 0.79). Predictors of change in QUIP-RS score were baseline QUIP-RS score (β = 0.483, P < 0.001) and time-varying LEDD (β = 0.003, P = 0.02). Eight patients (four in each group) developed de novo ICD symptoms during follow-up, although none met diagnostic criteria for an impulse control disorder.

Conclusions

ICD symptoms (including de novo symptoms) at 12 months follow-up were similar between PD patients undergoing DBS and patients treated with pharmacological therapy only. Monitoring for emergence of ICD symptoms is important in both surgically- and medication-only-treated PD patients.

Neuropsychiatric Features of Punding and Hobbyism in Parkinson's Disease

BACKGROUND

Little is known about the cognitive and neuropsychiatric profile associated with punding and hobbyism in Parkinson's disease (PD).

OBJECTIVE

To compare the clinical and neuropsychological features of PD patients with punding and hobbyism to PD controls.

METHODS

The Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) was used as a screening tool, and a structured interview was used to diagnose punding/hobbyism. Clinical and neuropsychological assessment was conducted with validated questionnaires/scales.

RESULTS

Twenty-one patients with PD and punding (PD + pu) were compared to 26 with hobbyism (PD + h) and 25 PD controls. PD + pu patients showed higher levels of anxiety, non-motor symptoms and motor symptoms, and lower Frontal Assessment Battery scores. The PD + h group exhibited similar levels of anxiety and motor fluctuations to the PD + pu group.

CONCLUSION

PD + pu showed increased anxiety and frontal lobe dysfunction, similar to PD + h. Hobbyism could be a prodromal phase with increased risk of leading to punding.

Impulse Control Disorders and Levodopa-Induced Dyskinesias in Parkinson's Disease: Pulsatile versus Continuous Dopaminergic Stimulation

BACKGROUND

Dopaminergic medications in Parkinson's disease (PD) are usually associated with the development of both levodopa-induced dyskinesias (LID) and impulse control and repetitive behavior disorders (ICRB).

OBJECTIVE

To assess the prevalence and the severity of ICRB in a cohort of moderate and advanced PD patients and to investigate the potential interplay between ICRB, LID and dopaminergic therapies.

METHODS

117 PD patients were consecutively recruited. LID were assessed by using the Rush Dyskinesia Rating Scale (RDRS). ICRB were tested by means of Questionnaire for Impulsive Compulsive Disorders in Parkinson's Disease Rating Scale (QUIP-RS).

RESULTS

55 patients were affected by LID. Among them, 37 were treated only by oral therapy, OT (LID/OT), while 18 were on treatment with jejunal levodopa infusion, JLI (LID/JLI). 62 patients were not affected by LID (NLID) and all of them were on therapy only with oral drugs. The overall prevalence of clinically significant ICRB was 34% (95% CI = 26% to 43%) and the mean value (±SD) of QUIP-RS total score was 5.4±8.5. Prevalence of clinically significant ICRB, as well as severity of ICRB, was higher in patients with LID compared to NLID patients (p = 0.016 and p < 0.001, respectively). When considering LID/JLI, LID/OT and NLID groups, QUIP-RS total score was significantly higher in LID/OT patients compared to LID/JLI (10.4±11.8 vs. 4.9±6.0, p = 0.019) and NLID (10.4±11.8 vs. 2.5±4.8, p < 0.001) groups.

CONCLUSION

PD patients with LID show ICRB more frequently and more severely than patients without LID. Among LID patients, those treated by JLI showed a lower severity of ICRB than those on OT, suggesting a potential protective effect of JLI on ICRB.

Further characterisation of psychosis-like behaviours induced by L-DOPA in the MPTP-lesioned marmoset

Parkinson's disease (PD) psychosis afflicts over half of patients and poses a significant burden on quality of life. The aetiology of PD psychosis is multifactorial and likely arises from the complex interaction between dopamine replacement therapy and disease state. The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned common marmoset is a validated model to predict the efficacy of therapeutic compounds for treatment-related complications, including PD psychosis. In this model, psychosis-like behaviours (PLBs) encompass stereotypies that are idiosyncratic in nature and reproducible with each L-3,4-dihydroxyphenylanaline (L-DOPA) administration. In the present study, we sought to expand upon the existing repertoire of PLBs through the characterisation of novel stereotypical behaviours that appear dependent on the environment. We then discuss our findings in the context of clinical reports on stereotypical behaviours termed "punding" in subjects with PD, which consists of stereotypical repetitive and senseless behaviours. The poor understanding of the pathophysiology governing punding and consequent lack of effective therapies stand to benefit from enhanced characterisation of these stereotypical behaviours in a validated pre-clinical model. We hope that further characterisation of PLBs in the MPTP-lesioned marmoset will be helpful in the evaluation of interventions that seek to alleviate PD psychosis symptoms.

Medical Management and Prevention of Motor Complications in Parkinson's Disease

Levodopa is the most effective medication for the treatment of the motor symptoms of Parkinson's disease. However, over time, the clinical response to levodopa becomes complicated by a reduction in the duration and reliability of motor improvement (motor fluctuations) and the emergence of involuntary movements (levodopa-induced dyskinesia). Strategies that have been attempted in an effort to delay the development of these motor complications include levodopa sparing and continuous dopaminergic therapy. Once motor complications occur, a wide array of medical treatments is available to maximize motor function through the day while limiting dyskinesia. Here, we review the clinical features, epidemiology, and risk factors for the development of motor complications, as well as strategies for their prevention and medical management.

The role of dopamine pharmacotherapy and addiction-like behaviors in Parkinson's disease

Addictions involve a spectrum of behaviors that encompass features of impulsivity and compulsivity, herein referred to as impulsive-compulsive spectrum disorders (ICSDs). The etiology of ICSDs likely involves a complex interplay among neurobiological, psychological and social risk factors. Neurobiological risk factors include the status of the neuroanatomical circuits that govern ICSDs. These circuits can be altered by disease, as well as exogenous influences such as centrally-acting pharmacologics. The 'poster child' for this scenario is Parkinson's disease (PD) medically managed by pharmacological treatments. PD is a progressive neurodegenerative disease that involves a gradual loss of dopaminergic neurons largely within nigrostriatal projections. Replacement therapy includes dopamine receptor agonists that directly activate postsynaptic dopamine receptors (bypassing the requirement for functioning presynaptic terminals). Some clinically useful dopamine agonists, e.g., pramipexole and ropinirole, exhibit high affinity for the D2/D3 receptor subtypes. These agonists provide excellent relief from PD motor symptoms, but some patients exhibit debilitating ICSD. Teasing out the neuropsychiatric contribution of PD-associated pathology from the drugs used to treat PD motor symptoms is challenging. In this review, we posit that modern clinical and preclinical research converge on the conclusion that dopamine replacement therapy can mediate addictions in PD and other neurological disorders. We provide five categories of evidences that align with this position: (i) ICSD prevalence is greater with D2/D3 receptor agonist therapy vs PD alone. (ii) Capacity of dopamine replacement therapy to produce addiction-like behaviors is independent of disease for which the therapy is being provided. (iii) ICSD-like behaviors are recapitulated in laboratory rats with and without PD-like pathology. (iv) Behavioral pathology co-varies with drug exposure. (v) ICSD Features of ICSDs are consistent with agonist pharmacology and neuroanatomical substrates of addictions. Considering the underpinnings of ICSDs in PD should not only help therapeutic decision-making in neurological disorders, but also apprise ICSDs in general.

Deep Brain Stimulation in Moroccan Patients With Parkinson's Disease: The Experience of Neurology Department of Rabat

Introduction: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is known as a therapy of choice of advanced Parkinson's disease. The present study aimed to assess the beneficial and side effects of STN DBS in Moroccan Parkinsonian patients. Material and Methods: Thirty five patients underwent bilateral STN DBS from 2008 to 2016 in the Rabat University Hospital. Patients were assessed preoperatively and followed up for 6 to 12 months using the Unified Parkinson's Disease Rating Scale in four conditions (stimulation OFF and ON and medication OFF and ON), the levodopa-equivalent daily dose (LEDD), dyskinesia and fluctuation scores and PDQ39 scale for quality of life (QOL). Postoperative side effects were also recorded. Results: The mean age at disease onset was 42.31 ± 7.29 years [28-58] and the mean age at surgery was 54.66 ± 8.51 years [34-70]. The median disease duration was 11.95 ± 4.28 years [5-22]. Sixty-three percentage of patients were male. 11.4% of patients were tremor dominant while 45.71 showed akinetic-rigid form and 42.90 were classified as mixed phenotype. The LEDD before surgery was 1200 mg/day [800-1500]. All patients had motor fluctuations whereas non-motor fluctuations were present in 61.80% of cases. STN DBS decreased the LEDD by 51.72%, as the mean LEDD post-surgery was 450 [188-800]. The UPDRS-III was improved by 52.27%, dyskinesia score by 66.70% and motor fluctuations by 50%, whereas QOL improved by 27.12%. Post-operative side effects were hypophonia (2 cases), infection (3 cases), and pneumocephalus (2 cases). Conclusion: Our results showed that STN DBS is an effective treatment in Moroccan Parkinsonian patients leading to a major improvement of the most disabling symptoms (dyskinesia, motor fluctuation) and a better QOL.

Management of impulse control disorders with deep brain stimulation: A double-edged sword

Deep brain stimulation (DBS) is a surgical option for advanced Parkinson's disease. Although DBS is used to treat motor fluctuation, DBS may affect non-motor symptoms including mood disorders, cognitive dysfunction, and behavior problems. Impulse control disorders (ICDs) are abnormal behaviors with various manifestations such as pathological gambling, hypersexuality, compulsive shopping, and binge eating, which can affect the quality of life in patients with Parkinson's disease. The effect of DBS on ICD is controversial. Reducing medication by DBS may improve ICDs, however, worsening or even developing new ICDs after DBS can occur. We will review the impact of DBS on ICDs and reveal factors associated with a good response to DBS as well as risk factors for developing ICDs after DBS. We also propose a strategy to manage preexisting ICD and prevent postoperative de novo ICDs.

Apathy and Impulse Control Disorders: Yin & Yang of Dopamine Dependent Behaviors

Neuropsychiatric symptoms are common non-motor symptoms in Parkinson's disease (PD). Apathy and impulse control disorders (ICD) are two opposite motivational expressions of a continuous behavioural spectrum involving hypo- and hyperdopaminergia. Both syndromes share pathological (decreased vs increased) dopamine receptor stimulation states. Apathy belongs to the spectrum of hypodopaminergic symptoms together with anhedonia, anxiety and depression. Apathy is a key symptom of PD which worsens with disease progression. Animal models, imaging and pharmacological studies concur in pointing out dopaminergic denervation in the aetiology of parkinsonian apathy with a cardinal role of decreased tonic D2/D3 receptor stimulation. ICDs are part of the hyperdopaminergic behavioural spectrum, which also includes punding, and dopamine dysregulation syndrome (DDS), which are all related to non-physiological dopaminergic stimulation induced by antiparkinsonian drugs. According to clinical data tonic D2/D3 receptor stimulation can be sufficient to induce ICDs. Clinical observations in drug addiction and PD as well as data from studies in dopamine depleted rodents provide hints allowing to argue that both pulsatile D1 and D2 receptor stimulation and the severity of dopaminergic denervation are risk factors to develop punding behavior and DDS. Imaging studies have shown that the brain structures involved in drug addiction are also involved in hyperdopaminergic behaviours with increase of bottom-up appetitive drive and decrease in prefrontal top down behavioural control.

Dyskinesias and impulse control disorders in Parkinson's disease: From pathogenesis to potential therapeutic approaches

Dopaminergic treatment in Parkinson's disease (PD) reduces the severity of motor symptoms of the disease. However, its chronic use is associated with disabling motor and behavioral side effects, among which levodopa-induced dyskinesias (LID) and impulse control disorders (ICD) are the most common. The underlying mechanisms and pathological substrate of these dopaminergic complications are not fully understood. Recently, the refinement of imaging techniques and the study of the genetics and molecular bases of LID and ICD indicate that, although different, they could share some features. In addition, animal models of parkinsonism with LID have provided important knowledge about mechanisms underlying such complications. In contrast, animal models of parkinsonism and abnormal impulsivity, although useful regarding some aspects of human ICD, do not fully resemble the clinical phenotype of ICD in patients with PD, and until now have provided limited information. Studies on animal models of addiction could complement the previous models and provide some insights into the background of these behavioral complications given that ICD are regarded as behavioral addictions. Here we review the most relevant advances in relation to imaging, genetics, biochemistry and pharmacological interventions to treat LID and ICD in patients with PD and in animal models with a view to better understand the overlapping and unique maladaptations to dopaminergic therapy that are associated with LID and ICD.

Pathophysiology of L-dopa-induced motor and non-motor complications in Parkinson's disease

Involuntary movements, or dyskinesia, represent a debilitating complication of levodopa (L-dopa) therapy for Parkinson's disease (PD). L-dopa-induced dyskinesia (LID) are ultimately experienced by the vast majority of patients. In addition, psychiatric conditions often manifested as compulsive behaviours, are emerging as a serious problem in the management of L-dopa therapy. The present review attempts to provide an overview of our current understanding of dyskinesia and other L-dopa-induced dysfunctions, a field that dramatically evolved in the past twenty years. In view of the extensive literature on LID, there appeared a critical need to re-frame the concepts, to highlight the most suitable models, to review the central nervous system (CNS) circuitry that may be involved, and to propose a pathophysiological framework was timely and necessary. An updated review to clarify our understanding of LID and other L-dopa-related side effects was therefore timely and necessary. This review should help in the development of novel therapeutic strategies aimed at preventing the generation of dyskinetic symptoms.

The subthalamic nucleus, oscillations, and conflict

The subthalamic nucleus (STN), which is currently the most common target for deep brain stimulation (DBS) for Parkinson's disease (PD), has received increased attention over the past few years for the roles it may play in functions beyond simple motor control. In this article, we highlight several of the theoretical, interventional, and electrophysiological studies that have implicated the STN in response inhibition. Most influential among this evidence has been the reported effect of STN DBS in increasing impulsive responses in the laboratory setting. Yet, how this relates to pathological impulsivity in patients' everyday lives remains uncertain.

Behavioral effects of levodopa

In recent years, levodopa-induced behavioral changes have received increased attention in the medical literature and in clinical practice. The spectrum of these symptoms includes non-motor fluctuations with neuropsychiatric symptoms, compulsive behaviors such as punding, dopamine dysregulation syndrome, and impulse control disorders, psychosis and hallucinations, as well as hypomania and mania. Despite knowledge of the clinical features associated with these behaviors, many of them are probably underdiagnosed. Although the mechanisms underlying behavioral symptoms are still incompletely understood, recent data from imaging and pathological studies have increased our understanding and guided new treatment strategies. Appropriate management remains challenging, because reduction of levodopa (l-dopa) and dopaminergic treatment is often recommended; however, doses required for control of motor symptoms may still induce behavioral changes. Newer modes of delivery of dopaminergic treatment, deep brain stimulation, and nondopaminergic agents may either provide alternatives for treatment of these behavioral problems or permit treatment of parkinsonism with less risk of these behavioral disorders.

Impulsive and compulsive behaviors in Parkinson's disease

BACKGROUND

Impulsive and compulsive behaviors (ICBs) are a heterogeneous group of conditions that may be caused by long-term dopaminergic replacement therapy (DRT) of Parkinson's disease (PD). The spectrum of ICBs includes dopamine dysregulation syndrome (DDS), punding, and impulse control disorders (ICDs).

CONTENTS

We made a detailed review regarding the epidemiology, pathology, clinical characteristics, risk factors, diagnosis as well as treatment of ICBs.

RESULTS

The prevalence of ICBs in PD patients is approximately 3-4% for DDS, 0.34-4.2% for punding, and 6-14% for ICDs, with higher prevalence in Western populations than in Asian. Those who take high dose of levodopa are more prone to have DDS, whereas, ICDs are markedly associated with dopamine agonists. Different subtypes of ICBs share many risk factors such as male gender, higher levodopa equivalent daily dose, younger age at PD onset, history of alcoholism, impulsive, or novelty-seeking personality. The Questionnaire for Impulsive-Compulsive Disorder in Parkinson's Disease-Rating Scale seems to be a rather efficacious instrument to obtain relevant information from patients and caregivers. Treatment of ICBs is still a great challenge for clinicians. Readjustment of DRT remains the primary method. Atypical antipsychotics, antidepressants, amantadine, and psychosocial interventions are also prescribed in controlling episodes of psychosis caused by compulsive DRT, but attention should be drawn to balance ICBs symptoms and motor disorders. Moreover, deep brain stimulation of the subthalamic nucleus might be a potential method in controlling ICBs.

CONCLUSION

The exact pathophysiological mechanisms of ICBs in PD remains poorly understood. Further researches are needed not only to study the pathogenesis, prevalence, features, and risk factors of ICBs, but to find efficacious therapy for patients with these devastating consequences.

Impulse control disorders in Parkinson's disease: an overview from neurobiology to treatment

Parkinson's disease (PD) is the second most common neurodegenerative brain disorder and is characterized by motor symptoms such as tremor, bradykinesia, rigidity and postural instability. A majority of the patients also develop non-motor symptoms. Impulse control disorders (ICD) are behavioural changes that often fail to be detected in clinical practice. The prevalence of ICD in PD varies widely from 6.1 to 31.2 % and treatment with dopaminergic medication is considered to be the greatest risk factor. Management consists mainly of reducing dopaminergic medication. In our experience, ICD has a tremendous impact on the quality of life of the patients and their families and should therefore not be disregarded. Studies addressing the role of ICD in PD caregiver strain are imperative. We attempt to give a comprehensive overview of the literature on the complicated neurobiology of ICD and discuss risk factors, genetic susceptibility, screening modalities and management.

A conditioned response as a measure of impulsive-compulsive behaviours in Parkinson's disease

Objectives

Parkinson's Disease patients wore a device on the wrist that gave reminders to take levodopa and also measured bradykinesia and dyskinesia. Consumption of medications was acknowledged by placing the thumb on the device. Some patients performed this acknowledgement repeatedly and unconsciously. This study examines whether this behaviour reflected increased impulsivity.

Methods and Results

Twenty five participants were selected because they had i) excess acknowledgements described above or ii) Impulsive-Compulsive Behaviours or iii) neither of these. A blinded assessor applied clinical scales to measure Impulsive-Compulsive Behaviours, cognition, depression, anxiety and apathy. A Response Ratio, representing the number of acknowledgements/number of doses (expressed as a percentage) was tightly correlated with ratings of Impulsive-Compulsive Behaviours (r² = 0.79) in 19/25 subjects. Some of these patients had dyskinesia, which was higher with extraneous responses than with response indicating medication consumption. Six of the 25 subjects had high Impulsive-Compulsive Behaviour Scores, higher apathy scores, low levels of dyskinesia and normal Response Ratios. Patients without ICB (low RR) also had low dyskinesia levels regardless of the relevance of the response.

Conclusion

An elevated Response Ratio is a specific measure of a type of ICB where increased incentive salience is attributed to cues by the presence of high striatal dopamine levels, manifested by high levels of dyskinesia. This study also points to a second form of ICBs which occur in the absence of dyskinesia, has normal Response Ratios and higher apathy scores, and may represent prefrontal pathology.

Amantadine and cognitive flexibility: decision making in Parkinson's patients with severe pathological gambling and other impulse control disorders

INTRODUCTION

Dopamine replacement therapy for Parkinson's disease (PD) was recently linked to the development of impulse control disorders such as pathological gambling (PG), hypersexuality, compulsive shopping, and binge or compulsive eating. Antiglutamatergic agents including amantadine (Ama) reduce these behaviors in PD and non-PD patients. The aim of our study is to evaluate the changes in executive functions, emotions, and reward/loss processing during Ama treatment in PD patients.

METHODS

Thirty-three patients affected by idiopathic PD were selected from a cohort of 1,096 PD patients and categorized in three different groups: ten affected by PG (PD-PG); nine PD patients with other impulse control disorder (PD-ICD); and 14 PD patient without any psychiatric disorder (PD-CTR-controls). For the neuropsychological evaluation, the following behavioral tasks where administered: the Stroop, the emotional Stroop, and the monetary reward/loss risk-taking tasks.

RESULTS

During Ama treatment, PD-PGs showed a decrease in risky choices and an increase in non-risky choices (t(9)=-2.40, P<0.05 and t(9)=2,67, P<0.05 uncorrected, respectively). Between-group comparison showed a significant decrease in risky choices for PD-PG with respect to PD-CTR (t(22)=-4.16, P<0.01), and a decreased accuracy for positive words in comparison between PD-PG and PD-ICD (t(17)=-7,49, P<0.01) and PD-PG and PD-CTR (t(22)=-4.29, P<0.01). No within- and between-group differences were observed for Stroop task.

DISCUSSION

Our data showed that Ama add-on therapy reduces hypersensitivity to reward and sustains activation toward uncertainty in PD-PG patients. These finding might explain the behavioral mechanism underlying the effect of antiglutamatergic drugs.

Impulsive and compulsive behaviors in Parkinson's disease

Impulsive-compulsive behaviors (ICBs) in Parkinson's disease (PD) are a common and devastating side effect of dopamine replacement therapy. In this review we describe the phenomenology, prevalence, and risk factors of patients with PD. Results of behavioral studies assessing the neuropsychological profile of patients with PD emphasize that the ICBs, which are behavioral addictions, are not hedonically motivated. Rather, other factors such as the inability to cope with uncertainty may be triggering ICBs. New insights from functional imaging studies, strengthening the incentive salience hypothesis, are discussed, and therapeutic guidelines for the management of ICBs in PD are given.

Repetitive transcranial magnetic stimulation transiently reduces punding in Parkinson's disease: a preliminary study

Amongst the impulse-control disorders (ICDs) associated with dopamine-replacement therapy in patients with Parkinson's disease (PD) is a repetitive, complex, stereotyped behaviour called punding. Disruption of the reciprocal loops between the striatum and structures in the prefrontal cortex (PFC) following dopamine depletion may predispose patients with PD to these behavioural disorders. The purpose of the present study was to assess the effects of repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral PFC (DLPFC) on punding in PD. We used low-frequency (LF) rTMS in four PD patients presenting with punding. Punding was transiently reversed by LF-rTMS over the DLPFC without enhancing motor impairment. The effect was more sustained after right DLPFC rTMS. Therefore, LF-rTMS produced a transient beneficial effect in PD patients with punding, similar to that reported in PD patients with levodopa-induced dyskinesias. rTMS might have therapeutic potential for the treatment of punding and perhaps other ICDs in PD.

[Severe punding in Parkinson's disease]

BACKGROUND

Punding is a stereotypical behavior characterized by an intense fascination with repetitive handling and examining of mechanical devices or arranging common objects. This condition, which is different from both obsessive-compulsive disorder and mania, is still underestimated in patients with Parkinson's disease and may have deleterious social consequences on patients and their families.

CASE REPORT

We report the case of severe punding in a 23-year-old parkinsonian woman, who presented, a few days following a rise in the dose of pergolide up to 2,5 mg/(d), frequent and daily unusual repetitive behavior, characterized by ceaseless sewing, disassembly and reassembly of phones, and coloring of drawings. These behaviors were associated with a common peak of dose dyskinesia and were responsible for a considerable reduction in duration of sleep with negative impact on the quality of life of her parents. These symptoms significantly improved immediately after switching pergolide to an equivalent dose of ropinirole (12 mg/(d).

DISCUSSION

Punding has only recently come to the attention of physicians through the first report in a parkinsonian patient, triggered by dopaminergic replacement therapy. The phenomenon was thought to be related to excessive dopaminergic stimulation of the limbic and associative pathways. The current mainstay of treatment is the reduction in the dose of dopaminergic medication or changing the presumed responsible drug, often a dopaminergic agonist. In this article, the authors review the epidemiology, pathophysiology and management of this curious phenomenon.

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.

[Repetitive impulse-associated behavioral disorders in Parkinson's disease]

Parkinson's disease (PD) is associated with a number of behavioral disorders which may cause considerable social, professional or financial problems. Impulse control disorders (ICDs), such as pathological gambling, binge eating, compulsive shopping and hypersexuality occur in approximately 13-14% of PD patients. Further behavioral disorders are the dopamine dysregulation syndrome (DDS), a substance dependence characterized by craving for dopaminergic substances and punding (prolonged repetitive activities which are not goal-oriented).Treatment-related risk factors are dopamine agonists for ICDs and a high total dopaminergic dose for DDS and punding. Shared risk factors are young age at onset, impulsive personality traits, depression and possibly dyskinesia. At the neuronal level these behavioral disorders seem to be associated with changes in the reward system and dysfunction of the orbitofrontal cortex. The evidence level for management strategies is at present insufficient. For ICDs current clinical practice consists of discontinuation or reduction of dopamine agonists.

The prevalence and clinical characteristics of punding in Parkinson's disease

BACKGROUND

Punding (the display of stereotyped, repetitive behaviors) is a relatively recently discovered feature of Parkinson's disease (PD). Little is known about the prevalence and clinical characteristics of punding in PD.

METHODS

In this review, four large scientific databases were comprehensively searched for literature in relation to punding prevalence and clinical correlates in the context of PD.

RESULTS

Prevalence was found to vary greatly (between 0.34 to 14%), although there were large disparities in study populations, assessment methods, and criteria. We observed an association between punding, dopaminergic medications, and impulse control disorder. Other characteristics, which may be more common among punders, include a higher severity of dyskinesia, younger age of disease onset, longer disease duration, and male gender.

DISCUSSION

More research in large clinical datasets is required in many areas before conclusions are drawn. The pathophysiology behind the punding phenomenon is also poorly understood at present, rendering it difficult to develop targeted therapy. The current mainstay of treatment is the reduction in the dose of dopaminergic medications, the evidence for other suggested therapies being purely empirical.

Impulse control disorders in Parkinson's disease: recent advances

PURPOSE OF REVIEW

The aim is to review the recent advances in the epidemiology and pathophysiology of impulse control disorders (ICDs) in Parkinson's disease.

RECENT FINDINGS

Large cross-sectional and case-control multicentre studies show that ICDs in Parkinson's disease are common, with a frequency of 13.6%. These behaviours are associated with impaired functioning and with depressive, anxiety and obsessive symptoms, novelty seeking and impulsivity. Behavioural subtypes demonstrate differences in novelty seeking and impulsivity, suggesting pathophysiological differences. Observational and neurophysiological studies point towards a potential mechanistic overlap between behavioural (ICDs) and motor (dyskinesias) dopaminergic sequelae. Converging data suggest dopamine agonists in ICDs appear to enhance learning from rewarding outcomes and impulsive choice. ICD patients also have enhanced risk preference and impaired working memory. Neuroimaging data point towards enhanced bottom-up ventral striatal dopamine release to incentive cues, gambling tasks and reward prediction, and possible inhibition of top-down orbitofrontal influences. Dopamine agonist-related ventral striatal hypoactivity to risk is consistent with impaired risk evaluation.

SUMMARY

Recent large-scale studies and converging findings are beginning to provide an understanding of mechanisms underlying ICDs in Parkinson's disease, which can guide prevention of these behaviours and optimize therapeutic approaches.

Dopamine receptors and Parkinson's disease

Parkinson's disease (PD) is a progressive extrapyramidal motor disorder. Pathologically, this disease is characterized by the selective dopaminergic (DAergic) neuronal degeneration in the substantia nigra. Correcting the DA deficiency in PD with levodopa (L-dopa) significantly attenuates the motor symptoms; however, its effectiveness often declines, and L-dopa-related adverse effects emerge after long-term treatment. Nowadays, DA receptor agonists are useful medication even regarded as first choice to delay the starting of L-dopa therapy. In advanced stage of PD, they are also used as adjunct therapy together with L-dopa. DA receptor agonists act by stimulation of presynaptic and postsynaptic DA receptors. Despite the usefulness, they could be causative drugs for valvulopathy and nonmotor complication such as DA dysregulation syndrome (DDS). In this paper, physiological characteristics of DA receptor familyare discussed. We also discuss the validity, benefits, and specific adverse effects of pharmaceutical DA receptor agonist.

Dopamine-induced nonmotor symptoms of Parkinson's disease

Nonmotor symptoms of Parkinson's disease (PD) may emerge secondary to the underlying pathogenesis of the disease, while others are recognized side effects of treatment. Inevitably, there is an overlap as the disease advances and patients require higher dosages and more complex medical regimens. The non-motor symptoms that emerge secondary to dopaminergic therapy encompass several domains, including neuropsychiatric, autonomic, and sleep. These are detailed in the paper. Neuropsychiatric complications include hallucinations and psychosis. In addition, compulsive behaviors, such as pathological gambling, hypersexuality, shopping, binge eating, and punding, have been shown to have a clear association with dopaminergic medications. Dopamine dysregulation syndrome (DDS) is a compulsive behavior that is typically viewed through the lens of addiction, with patients needing escalating dosages of dopamine replacement therapy. Treatment side effects on the autonomic system include nausea, orthostatic hypotension, and constipation. Sleep disturbances include fragmented sleep, nighttime sleep problems, daytime sleepiness, and sleep attacks. Recognizing the non-motor symptoms that can arise specifically from dopamine therapy is useful to help optimize treatment regimens for this complex disease.

Management of punding in Parkinson's disease: an open-label prospective study

Punding, a peculiar stereotyped behavior characterized by intense fascination with complex, excessive, non-goal-oriented, repetitive activities, is a quite rare condition complicating Parkinson's disease (PD). It is triggered by dopaminergic therapy and could have a strong impact on patient quality of life. No study has specifically investigated medical management of this condition, and only a few anecdotal reports have provided therapeutic hints. Given the suggested similarities to drug-induced dyskinesias, we have previously suggested a multistep algorithm for management of punding. We conducted a prospective open-label study on ten PD punders aimed at testing its validity. In two cases, reduction of levodopa therapy was efficacious; amantadine was effective in controlling punding in four cases; in the remaining cases, quetiapine was employed, with mild efficacy in two cases.

Insights into pathophysiology of punding reveal possible treatment strategies

Punding is a stereotyped behavior characterized by an intense fascination with a complex, excessive, nongoal oriented, repetitive activity. Men tend to repetitively tinker with technical equipment such as radio sets, clocks, watches and car engines, the parts of which may be analyzed, arranged, sorted and cataloged but rarely put back together. Women, in contrast, incessantly sort through their handbags, tidy continuously, brush their hair or polish their nails. Punders are normally aware of the inapposite and obtuse nature of the behavior; however, despite the consequent self-injury, they do not stop such behavior. The most common causes of punding are dopaminergic replacement therapy in patients affected by Parkinson's disease (PD) and cocaine and amphetamine use in addicts. The vast majority of information about punding comes from PD cases. A critical review of these cases shows that almost all afflicted patients (90%) were on treatment with drugs acting mainly on dopamine receptors D1 and D2, whereas only three cases were reported in association with selective D2 and D3 agonists. Epidemiological considerations and available data from animal models suggest that punding, drug-induced stereotypies, addiction and dyskinesias all share a common pathophysiological process. Punding may be related to plastic changes in the ventral and dorsal striatal structures, including the nucleus accumbens, and linked to psychomotor stimulation and reward mechanisms. Possible management guidelines are proposed.

Volitional disorders: a proposal for DSM-V

In the DSM-IV-TR, specific impulse control disorders not elsewhere classified (ICD) have been designated following four principles: (1) through the addition of an adjective that emphasizes the aberrant character of an otherwise normal behaviour (e.g., pathological gambling); (2) by means of metaphors (such as in intermittent explosive disorder); (3) according to the presumably quintessential nature of their main signs and symptoms, such as impulsive (e.g., impulse control disorders not elsewhere classified), compulsive (e.g., compulsive shopping), or addictive (e.g., internet addiction); or (4) using Greek suffix mania (e.g., kleptomania, pyromania, and trichotillomania). Given this flagrant inconsistency, we argue that time has come to adopt a less arbitrary way of describing these disorders, at least until it becomes clearer whether they are really impulsive, compulsive or addictive or if the preoccupation with this distinction is valid. In keeping with DSM's emphasis on descriptive phenomenology rather than on unsupported theory, a less biased terminology is in order. Therefore, we would like to suggest: (1) the substitution of the term ICD by the more neutral expression 'volitional disorders not elsewhere classified'; (2) the use of the classical Greek suffix mania, already present in some DSM-IV-TR ICDs, as the main naming principle to be adopted in the DSM-V; and (3) the creation of compulsive, impulsive, and mixed subtypes of the 'volitional disorders not elsewhere classified', since they are beginning to be validated by treatment trials.

Dopamine dysregulation syndrome: an overview of its epidemiology, mechanisms and management

Dopamine dysregulation syndrome (DDS) is a relatively recently described iatrogenic disturbance that may complicate long-term symptomatic therapy of Parkinson's disease. Patients with DDS develop an addictive pattern of dopamine replacement therapy (DRT) use, administering doses in excess of those required to control their motor symptoms. The prevalence of DDS in patients attending specialist Parkinson's disease centres is 3-4%. Amongst the behavioural disturbances associated with DDS are punding, which is a complex stereotyped behaviour, and impulse control disorders (ICDs), such as pathological gambling, hypersexuality, compulsive shopping and compulsive eating. We review the risk factors and potential mechanisms for the development of DDS, including personality traits, potential genetic influences and Parkinson's disease-related cognitive deficits. Impulsive personality traits are prominent in patients developing DDS, and have been previously associated with the development of substance dependence. Candidate genes affecting the dopamine 'D(2)-like' receptor family have been associated with impulsive personality traits in addition to drug and nondrug addictions. Impaired decision making is implicated in addictive behaviours, and decision-making abilities can be influenced by dopaminergic medications. In Parkinson's disease, disruption of the reciprocal loops between the striatum and structures in the prefrontal cortex following dopamine depletion may predispose to DDS. The role of DRT in DDS is discussed, with particular reference to models of addiction, suggesting that compulsive drug use is due to progressive neuroadaptations in dopamine projections to the accumbens-related circuitry. Evidence for neuroadaptations and sensitization occurring in DDS include enhanced levodopa-induced ventral striatal dopamine release. Levodopa is still considered the most potent trigger for DDS in Parkinson's disease, but subcutaneous apomorphine and oral dopamine agonists may also be responsible. In the management of DDS, further research is needed to identify at-risk groups, thereby facilitating more effective early intervention. Therefore, an increased awareness of the syndrome amongst treating physicians is vital. Medication reduction strategies are employed, particularly with regard to avoiding rapidly acting 'booster' DRT formulations. Psychosocial treatments, including cognitive-behavioural therapy, have been beneficial in treating substance use disorders and ICDs in non-Parkinson's disease patients, but there are currently no published trials of psychological interventions in DDS. Further studies are also required to identify factors that can predict those patients with DDS or ICDs who will derive benefit from surgical interventions such as deep brain stimulation.

Intermittent Dopaminergic stimulation causes behavioral sensitization in the addicted brain and parkinsonism

The gold standard therapy for Parkinson's disease (PD) consists in chronic administration of pulses of the dopamine (DA) precursor l-dihydroxyphenylalanine (l-DOPA). Although the main brain area which is DA-deficient is the dorsal striatum (more the putamen than the caudate nucleus), other DA-innervated brain regions (i.e., the ventral striatum and other limbic areas) are affected by systemic administration of l-DOPA. While such a therapy produces an increase in synaptic and nonsynaptic DA, which replace the neurotransmitter deficiency, peaks of extracellular DA in the course of disease progression produce abnormal involuntary movements related to behavioral sensitization. Methamphetamine (METH), a widely abused drug, is known to produce behavioral sensitization, related to DA release (more in the ventral than dorsal striatum as well as other limbic regions). The present review discusses the overlapping between these treatments, based on pulses of DA stimulation with an emphasis on the class of DA receptors; signal transduction pathways; rearranged expression of neurotransmitters, cotransmitters, and their receptors coupled with ultrastructural changes. In fact, all these levels of synaptic plasticity show a surprising homology following these treatments, posing the mechanisms of behavioral sensitization during DA-replacement therapy in PD very close to the neurobiological mechanisms operating during METH abuse. In line with this view is the growing evidence of addictive behaviors in PD patients during the course of DA-replacement therapy.

Parkinson's disease-related disorders in the impulsive-compulsive spectrum

In Parkinson's disease (PD), there is increasing evidence for disorders in the impulsive-compulsive spectrum, related to the disease itself, to the pharmacological management of this disease or to both. These disorders comprise dopamine deficiency syndrome (with immediate reward seeking behaviour), dopamine dependency syndrome (with addictive behaviour), dopamine dysregulation syndrome (with both addictive behaviour and stereotyped behaviour) and impulse control disorders (such as pathological gambling, compulsive shopping, binge eating and hypersexuality). These disorders are especially seen in PD patients with young age of onset, higher doses of antiparkinsonian drugs, pre-existent or current depression, pre-existing recreational drug or alcohol use, and high novelty seeking personality traits.Dopamine is not only implicated in voluntary movement control but also plays a significant role in the brain's reward system and the modulation of behaviours. Therefore, most if not all drugnaïve PD patients will suffer dysphoria, leading to mild immediate reward seeking behaviour as a consequence of the striatal dopaminergic denervation. In some of these patients, during treatment, this may even lead to the intake of increasing quantities of levodopa, above those required to adequately treat motor parkinsonism, with all characteristics of a dopamine dependence syndrome. These patients may develop plastic changes in the striatal matrix leading to hyperkinesia, caused by extracellular striatal dopaminergic fluctuations due to pulsatile dopamine replacement therapy. As soon as these changes are also seen in the striatal striosomes, in the framework of a dopamine dysregulation syndrome, stereotyped behaviours (punding) may occur (supposedly due to dorsal versus ventral striatal overactivity). Finally, impulse control disorders are suggested as being pure adverse side-effects of dopamine replacement therapy. Obsessive-compulsive behaviour (caused by ventral to dorsal overactivity) so far has not been described in PD patients.Treatment of impulse control disorders is related to the underlying pathology. In the case of an intrinsic dopamine deficiency syndrome, treatment with dopamine replacement therapy, especially levodopa, will help. In the multifactorial (intrinsic and extrinsic) dopamine dependency and dysregulation syndromes, addictive behaviour might best be helped by psychosocial strategies, and punding by continuous dopaminergic receptor stimulation (or amantadine), hypothesized to reduce the plastic changes-induced hypersensitization. The extrinsic impulse control disorders might be best treated by reducing or replacing dopamine receptor agonists.

Pediatric movement disorders: an update

PURPOSE OF REVIEW

Pediatric movement disorders the represent a broad range of disorders, the majority of which are intermittent and hyperkinetic. The goal of this review is to discuss recent findings in several under-recognized conditions (motor stereotypy disorder, restless legs syndrome, and infantile masturbation) as well as the area of autoimmune movement disorders [Sydenham's chorea and PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection)].

RECENT FINDINGS

Advances to be discussed include clarification of symptoms, diagnostic clues, epidemiology, pathogenesis, and treatment.

SUMMARY

Significant progress has been made in the study of several paroxysmal movement disorders. Motor stereotypies can occur in typical children and persist over time. Infantile masturbation is often misdiagnosed for seizures or dystonia. Restless leg syndrome is a relatively common problem in children and established criteria are available. Advances have been made in the hallmark autoimmune disorder Sydenham's chorea, but PANDAS remains controversial.