Pathological gambling in Parkinson's disease improves on chronic subthalamic nucleus stimulation

Dopamine and impulse control disorders in Parkinson's disease

There is an increasing awareness that impulse control disorders (ICDs), including compulsive gambling, buying, sexual behavior, and eating, can occur as a complication of Parkinson's disease (PD). In addition, other impulsive or compulsive disorders have been reported to occur, including dopamine dysregulation syndrome (DDS) and punding. Case reporting and prospective studies have reported an association between ICDs and the use of dopamine agonists (DAs), particularly at greater dosages, whereas dopamine dysregulation syndrome has been associated with greater dosages of levodopa or short-acting DAs. Data suggest that risk factors for an ICD may include male sex, younger age or younger age at PD onset, a pre-PD history of ICD symptoms, personal or family history of substance abuse or bipolar disorder, and a personality style characterized by impulsiveness. Although psychiatric medications are used clinically in the treatment of ICDs, there is no empiric evidence supporting their use in PD. Therefore, management for clinically significant ICD symptoms should consist of modifications to dopamine replacement therapy, particularly DAs, and there is emerging evidence that such management is associated with an overall improvement in ICD symptomatology. It is important that PD patients be aware that DA use may lead to the development of an ICD, and that clinicians monitor patients as part of routine clinical care. As empirically validated treatments for ICDs are emerging, it will be important to examine their efficacy and tolerability in individuals with cooccurring PD and ICDs.

Subthalamic nucleus stimulation in severe obsessive-compulsive disorder

BACKGROUND

Severe, refractory obsessive-compulsive disorder (OCD) is a disabling condition. Stimulation of the subthalamic nucleus, a procedure that is already validated for the treatment of movement disorders, has been proposed as a therapeutic option.

METHODS

In this 10-month, crossover, double-blind, multicenter study assessing the efficacy and safety of stimulation of the subthalamic nucleus, we randomly assigned eight patients with highly refractory OCD to undergo active stimulation of the subthalamic nucleus followed by sham stimulation and eight to undergo sham stimulation followed by active stimulation. The primary outcome measure was the severity of OCD, as assessed by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), at the end of two 3-month periods. General psychopathologic findings, functioning, and tolerance were assessed with the use of standardized psychiatric scales, the Global Assessment of Functioning (GAF) scale, and neuropsychological tests.

RESULTS

After active stimulation of the subthalamic nucleus, the Y-BOCS score (on a scale from 0 to 40, with lower scores indicating less severe symptoms) was significantly lower than the score after sham stimulation (mean [+/-SD], 19+/-8 vs. 28+/-7; P=0.01), and the GAF score (on a scale from 1 to 90, with higher scores indicating higher levels of functioning) was significantly higher (56+/-14 vs. 43+/-8, P=0.005). The ratings of neuropsychological measures, depression, and anxiety were not modified by stimulation. There were 15 serious adverse events overall, including 1 intracerebral hemorrhage and 2 infections; there were also 23 nonserious adverse events.

CONCLUSIONS

These preliminary findings suggest that stimulation of the subthalamic nucleus may reduce the symptoms of severe forms of OCD but is associated with a substantial risk of serious adverse events. (ClinicalTrials.gov number, NCT00169377.)

Antiparkinsonian medication and pathological gambling

Parkinson's disease is a common condition, usually treated by dopaminergic agents, both ergot and non-ergot. Many behavioural abnormalities are associated with such usage, including impulse control disorders (ICDs), dopamine dysregulation syndrome and 'punding'. Pathological gambling, a form of ICD, comprises persistent and maladaptive gambling of various types that disrupts personal, family or occupational activity. Pathological gambling may be associated with other abnormal actions such as pathological shopping, hoarding and hypersexuality. The incidence varies widely from study to study but may be up to 7% of users of dopaminergic agents. Recognition of this problem has led drug regulatory agencies to add precautions concerning pathological gambling to official drug information for the entire class of antiparkinsonian medications. The literature is not entirely consistent and opinions differ greatly, but pramipexole (a dopamine D2 and D3 agonist), and perhaps ropinirole (also a D2/D3 agonist), may be especially likely to be associated with pathological gambling, although the precise nature of the relationship is unclear. Treatment involves reducing the dose of the medication or switching to another medication; unfortunately, the Parkinson's disease may worsen. The mechanism of this adverse effect is believed to be excessive dopaminergic stimulation but probably not specifically involving D3 receptors. A parallel to addictive behaviour with stimulant drugs has been noted.

Impulse-control disorders in Parkinson's disease

Parkinson's disease is a neurodegenerative disorder characterized by bradykinesia, rigidity, postural instability, and resting tremor. Increasingly, Parkinson's disease has been associated with a broad spectrum of non-motor symptoms, such as olfactory loss, sleep disorders, autonomic dysfunction, cognitive impairment, psychosis, depression, anxiety, and apathy. In addition, a minority of Parkinson's disease patients develop compulsive behaviors while receiving dopamine-replacement therapy, including medication hoarding, pathological gambling, binge eating, hyperlibidinous behavior, compulsive shopping, and punding. These behaviors may result in psychosocial impairment for patients and therapeutic challenges for clinicians. This article reviews the anatomic substrates, behavioral spectrum, associated factors, and potential treatments for dopamine-replacement therapy-related compulsions in Parkinson's disease.

Long-term follow-up of impulse control disorders in Parkinson's disease

Recent studies have linked dopamine agonist (DA) usage with the development of impulse control disorders (ICDs) in Parkinson's disease (PD). Little is known about optimal management strategies or the long-term outcomes of affected patients. To report on the clinical interventions and long-term outcomes of PD patients who developed an ICD after DA initiation. Subjects contacted by telephone for a follow-up interview after a mean time period of 29.2 months. They were administered a modified Minnesota Impulse Disorder Interview for compulsive buying, gambling, and sexuality, and also self-rated changes in their ICD symptomatology. Baseline and follow-up dopamine replacement therapy use was recorded and verified by chart review. Of 18 subjects, 15 (83.3%) participated in the follow-up interview. At follow-up, patients were receiving a significantly lower DA levodopa equivalent daily dosage (LEDD) (Z = -3.1, P = 0.002) and a higher daily levodopa dosage (Z = -1.9, P = 0.05), but a similar total LEDD dosage (Z = -0.47, P = 0.64) with no changes in Unified Parkinson's Disease Rating Scale motor score (Z = -1.3, P = 0.19). As part of ICD management, 12 (80.0%) patients discontinued or significantly decreased DA treatment, all of whom experienced full or partial remission of ICD symptoms by self-report, and 10 (83.3%) of whom no longer met diagnostic criteria for an ICD. For PD patients who develop an ICD in the context of DA treatment, discontinuing or significantly decreasing DA exposure, even when offset by an increase in levodopa treatment, is associated with remission of or significant reduction in ICD behaviors without worsening in motor symptoms.

Deep brain stimulation for Parkinson's disease

The surgical treatment of Parkinson's disease has been through a revival phase over the last 20 years with the development of deep brain stimulation (DBS). Thalamic DBS was developed first and has proven to be a very effective treatment for tremor. The limitation is the lack of effect on other symptoms. Other targets were therefore investigated, and the procedure was applied to the subthalamic nucleus (STN) and the internal globus pallidus (GPi). STN stimulation can improve a wide range of symptoms and is currently the preferred target for many patients. Nevertheless, the morbidity seems higher than with other targets, and the selection criteria have to be quite strict. When STN DBS is not advised, thalamic DBS remains an option for patients with severe tremor, and GPi stimulation for those with severe dyskinesias. DBS remains a symptomatic treatment for a limited number of patients; it does not seem to alter the disease progression, and many patients are not suitable. There is, therefore, the need for further research into other targets and other approaches.

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.

Effects of chronic subthalamic stimulation on nonmotor fluctuations in Parkinson's disease

The aim of this study was to assess the outcome of nonmotor fluctuations (NMF) after chronic Subthalamic nucleus (STN) Deep Brain Stimulation (DBS) in Parkinson's disease(PD). Chronic stimulation of the STN has proved to be an effective treatment for advanced PD with motor complications. The outcome of NMF, which are also disabling, remains unknown. Forty-patients underwent bilateral STN stimulation. Each patient was interviewed before and after 1 yr of STN DBS with a structured questionnaire about their NMF. After 1 yr of chronic stimulation, the improvement in the motor score (UPDRS III) and dyskinesia amounted respectively to 67.4 and 76.3%. The decrease in motor fluctuations (MF) was 59% and 13 patients reported that their MF had disappeared. Comparatively, a reduction of the total number of NMF was also observed (mean number preoperatively: 15.6 per patient, postoperatively: 6.6). Most of the nonmotor fluctuating symptoms occurred in the "off" state preoperatively and no longer depended on the patient's motor state after surgery. The improvement in NMF was not identical for the different categories: pain/sensory fluctuations showed the best response to STN DBS (84.2%). Dysautonomic and cognitive fluctuations were also markedly improved (>60%) while psychic fluctuations remained the most frequent postoperative NMF observed. Some incapacitating manifestations such as drenching sweats and akathisia showed a remarkably good response to STN stimulation. In conclusion STN DBS alleviates NMF. It has strikingly successful effects on sensory, dysautonomic and cognitive fluctuations. However, psychic fluctuations respond less consistently to this treatment.

NEUROPSYCHOLOGICAL EFFECTS AFTER CHRONIC SUBTHALAMIC STIMULATION AND THE TOPOGRAPHY OF THE NUCLEUS IN PARKINSON'S DISEASE

OBJECTIVE

The neuropsychological effects of chronic subthalamic nucleus (STN)-deep brain stimulation (DBS) as a treatment for Parkinson's disease are variable. Whether these side effects result from the target per se or current diffusion into neighboring structures is uncertain. In this study, the relationship between clinical outcomes and coordinates of active contact are analyzed and compared between patients with and without neuropsychological sequelae.

METHODS

Thirty-eight Parkinsonian patients who underwent bilateral STN-DBS were enrolled in this retrospective cohort study. They were followed for at least 12 months. During the follow-up period, they were divided into two groups for comparison; Group A included patients with neuropsychological side effects and Group B was composed of patients without neuropsychological side effects. The position of the active contact of the electrode was defined with postoperative magnetic resonance imaging scans according to the midcommissural line. Active contact coordinates and clinical outcomes were compared for the two groups.

RESULTS

Among the 38 Parkinsonian patients who underwent STN-DBS, eight patients who had neuropsychological side effects were assigned to Group A; the other 30 patients were assigned to Group B. In Groups A and B, the mean follow-up periods were 13.9 and 12.1 months, respectively, the Unified Parkinson's Disease Rating Scale motor score was improved by 53.4 and 45.2% (P = 0.24), respectively, and the levodopa equivalent daily dosage was decreased by 68.4 and 46.4% (P = 0.16), respectively. The mean coordinates of active contact in both Groups A and B were x = 10.1 and 10.5 mm, respectively, y = −2.8 and −3.9 mm, respectively, and z = −6.3 and −6.2 mm, respectively, relative to the midcommissural point. A significant difference was observed on the y axis (P = 0.01).

CONCLUSION

When taking spatial influence into consideration, the neuropsychological effects of chronic STN-DBS were related to a significant anteriorly located active contact within the ventral STN in this preliminary study. This might suggest the existence of topography of STN in patients with Parkinson's disease concerning limbic and associative circuits.

Medication-related impulse control and repetitive behaviors in Parkinson??s disease

PURPOSE OF REVIEW

A range of impulse control and repetitive behaviors presumed to be related to dopaminergic medications has been recognized in Parkinson's disease. These behaviors are linked by their incentive or reward-based and repetitive natures and overlap with addictions. The behaviors include pathological gambling, hypersexuality, compulsive shopping, and compulsive eating and are related to punding and compulsive medication use. In patients on dopamine agonists, these behaviors as a group are relatively common, can have potentially devastating psychosocial consequences and are commonly hidden.

RECENT FINDINGS

Recent studies have investigated prevalence rates and associated factors. The literature on these behaviors in Parkinson's disease, including definitions, epidemiology, pathophysiology and management, is reviewed. The relationship to medications, Parkinson's disease and individual susceptibility is examined.

SUMMARY

These behaviors can affect up to 14% of Parkinson's disease patients on dopamine agonists. Clinicians should warn patients prior to initiating dopamine agonists and enquire about these behaviors during follow up.

Intervening in the neuropsychiatric features of Parkinson's disease

Although Parkinson's disease is considered a movement disorder, it has a wide range and high prevalence of affective, psychotic, cognitive, behavioral and sleep-related features. To treat such features, agents including antidepressants, anxiolytics, antipsychotics and cognition-enhancing agents are commonly prescribed, although the targeted syndromes are often incompletely understood and controlled studies demonstrating a treatment's efficacy and tolerability in Parkinson's disease patients are often lacking. Nevertheless, the available information does suggest the outlines of management methods, pending expanded research to identify optimal strategies specific to Parkinson's disease.

Stimulation of subterritories of the subthalamic nucleus reveals its role in the integration of the emotional and motor aspects of behavior

Two parkinsonian patients who experienced transient hypomanic states when the subthalamic nucleus (STN) was stimulated during postoperative adjustment of the electrical parameters for antiparkinsonian therapy agreed to have the mood disorder reproduced, in conjunction with motor, cognitive, and behavioral evaluations and concomitant functional neuroimaging. During the experiment, STN stimulation again induced a hypomanic state concomitant with activation of cortical and thalamic regions known to process limbic and associative information. This observation suggests that the STN plays a role in the control of a complex behavior that includes emotional as well as cognitive and motor components. The localization of the four contacts of the quadripolar electrode was determined precisely with an interactive brain atlas. The results showed that (i) the hypomanic state was caused only by stimulation through one contact localized in the anteromedial STN; (ii) both this contact and the contact immediately dorsal to it improved the parkinsonian motor state; (iii) the most dorsal and ventral contacts, located at the boundaries of the STN, neither induced the behavioral disorder nor improved motor performance. Detailed analysis of these data led us to consider a model in which the three functional modalities, emotional, cognitive, and motor, are not processed in a segregated manner but can be subtly combined in the small volume of the STN. This nucleus would thus serve as a nexus that integrates the motor, cognitive, and emotional components of behavior and might consequently be an effective target for the treatment of behavioral disorders that combine emotional, cognitive, and motor impairment.

Management of impulse control disorders in Parkinson’s disease

Impulse control disorders (ICDs) are a set of behaviors, including pathologic gambling, hypersexuality, compulsive shopping, compulsive eating, and punding, which are now recognized to occur in a subset of patients with Parkinson's disease (PD). Although the underlying pathophysiology of these behaviors is poorly understood, they appear to be associated with the use, and sometimes overuse, of dopaminergic agents prescribed for the treatment of the motor symptoms of PD. At present, there are limited data to support any particular therapeutic strategy. Approaches worth considering in the management of the PD patient with an ICD include reduction or discontinuation of dopamine agonist therapy, trials of various pharmacologic agents, psychosocial interventions, and deep brain stimulation of the subthalamic nucleus. However, the management of each patient must be tailored for the particular clinical setting, and the development of evidence-based treatment strategies awaits future prospective studies and randomized controlled trials.

Pathological gambling after bilateral subthalamic nucleus stimulation in Parkinson disease

We describe a patient with advanced Parkinson's disease who developed pathological gambling within a month after successful bilateral subthalamic nucleus (STN) stimulation. There was no history of gambling. On neuropsychological testing, slight cognitive decline was evident 1 year after surgery. Stimulation of the most dorsal contact with and without medication induced worse performances on decision making tests compared with the more ventral contact. Pathological gambling disappeared after discontinuation of pergolide and changing the stimulation parameters. Pathological gambling does not seem to be associated with decision making but appears to be related to a combination of bilateral STN stimulation and treatment with dopamine agonists.

Pathological gambling in Parkinson's disease: Risk factors and differences from dopamine dysregulation. An analysis of published case series

Pathological gambling (PG) has been reported as a complication of the treatment of Parkinson's disease (PD). We examined all published cases of PG for prevalence and risk factors of this complication, the relationship of PG and use of dopamine agonists (DA), and the relationship of PG to the dopamine dysregulation syndrome (DDS). The prevalence of PG in prospective studies of PD patients using DA has been reported between 2.3 and 8%, compared to approximately 1% in the general population. As in the general population, PD patients with this complication are often young, male and have psychiatric co-morbidity. The vast majority are on DA, often at maximum dose or above. Differences between oral DA failed to reach significance. PG associated with levodopa monotherapy is uncommon, but in the majority of cases levodopa is co-prescribed, suggesting possible cross-sensitization of brain systems mediating reward. PG can occur with DDS but often occurs in isolation. In contrast to DDS, escalation and self regulation of anti-parkinsonian medication are not usually seen. PG in patients with PD using DA is higher than PG reported in the general population, but shares similar characteristics and risk factors. PG is predominantly associated with oral DA. It often occurs in isolation and may not be associated with DDS, which typically occurs on treatment with levodopa or subcutaneous apomorphine.