Effectiveness of aripiprazole in the treatment of adult Tourette patients up to 56 months

Pharmacological treatment for Tourette syndrome in children and adults: What is the quality of the evidence? A systematic review

BACKGROUND

Tourette syndrome (TS) is a neurodevelopmental disorder characterised by involuntary muscle movements manifesting as motor and vocal tics. In the majority, tics are manageable without medication. Where tics cause discomfort or impair function, behavioural or pharmaceutical treatments may be considered.

AIMS

To provide a meticulous examination of the quality of evidence for the current pharmacological treatments for TS.

METHODS

PubMed and Google Scholar were searched to identify randomised, placebo-controlled trials (RCTs) of aripiprazole, risperidone, clonidine, guanfacine, haloperidol, pimozide, tiapride and sulpiride for the treatment of tics in children and adults with TS. Quality of reporting and risk of bias were assessed against the CONSORT checklist and Cochrane risk of bias criteria, respectively.

RESULTS

Seventeen RCTs were identified. Response rates reached 88.6% for aripiprazole, 68.9% for clonidine, 62.5% for risperidone and 19% for guanfacine. Statistically significant improvements were reported for all medications compared to placebo in at least one study and for at least one measure of tic severity. Most studies predated the CONSORT and Cochrane criteria and did not score highly when assessed on these measures.

CONCLUSIONS

There are relatively few placebo-controlled trials of commonly prescribed medications. Studies are often of poor quality and short duration. There is evidence for the efficacy of each medication, but no drug is clearly superior. Clonidine and guanfacine are better tolerated than antipsychotics, but less effective. There is too little evidence to determine whether adults respond differently from children.

Aripiprazole for the treatment of Tourette syndrome

Introduction: Tourette syndrome (TS) is a neurodevelopmental disorder characterized by multiple tics which often persisting in forms of different severity throughout adult life. The prevalence of neuropsychiatric co-morbidity in patients with TS is high. Treatment of TS can involve pharmacological, behavioral, or, in rare cases, surgical therapies. Over the last two decades there has been growing interest in the use of aripiprazole, a novel partial dopamine receptor agonist, as a promising anti-tic agent.Areas covered: The authors reviewed the available literature evaluating the role of aripiprazole in the treatment of TS and other tic disorders in both children and adults. This includes data from five randomized controlled trials (RCTs) and eleven open-label studies.Expert opinion: There is moderate quality evidence supporting the use of aripiprazole in reducing tic severity in children and adolescents, however there is a lack of robust evidence evaluating its use in adults, despite expert consensus. Overall, it appears that aripiprazole is a safe and effective treatment for tics. Further large scale RCTs assessing the long-term efficacy and safety of aripiprazole in the treatment of tics are warranted, especially in adult populations with TS.

Pure delta-9-tetrahydrocannabinol and its combination with cannabidiol in treatment-resistant Tourette syndrome: A case report

OBJECTIVES

Anecdotal reports and preliminary studies suggest a therapeutic potential of cannabis in Tourette syndrome. We report the case of a female patient suffering from treatment-resistant Tourette syndrome.

METHODS

Guideline-directed antipsychotic treatment with risperidone and aripiprazole as well as pure delta-9-tetrahydrocannabinol had no significant effect on Tourette syndrome symptomatology.

RESULTS

Following administration of a daily dosage of 10 mg delta-9-tetrahydrocannabinol combined with 20 mg cannabidiol (CBD), the patient showed a rapid and highly significant improvement in the Yale Global Tic Severity Scale.

CONCLUSIONS

It can be speculated whether the beneficial effects may rely on the pharmacological properties of cannabidiol.

Update on the Pharmacological Treatment of Tics with Dopamine-Modulating Agents

More than 40 years of research and clinical practice have proven the effectiveness of dopamine receptor antagonists in the pharmacological treatment of tics. A blockade of the striatal dopamine-D2 receptors is mainly responsible for their tic-reducing effect. A broad spectrum of dopamine-modulating agents, such as typical and atypical antipsychotics, but also dopamine receptor agonists are used with an immanent discord between experts about which of them should be considered as first choice. The present Review outlines the state of the art on pharmacological treatment of tics with dopamine-modulating agents by giving an systematic overview of studies on their effectiveness and a critical discussion of their specific adverse effects. It is considered as an update of a previous review of our research group published in 2013. The Review closes with a description of the current resulting treatment recommendations including the results of a first published revised survey on European expert's prescription preferences. Based on the enormously growing evidence on its effectiveness and safety, aripiprazole currently seems to be the most promising agent in the pharmacological treatment of tics. Furthermore, benzamides (especially tiapride), which are commonly used in Europe, have proven their excellent effectiveness-tolerability profile over decades in clinical practice and are therefore also highly recommended for the treatment of tics. Nevertheless, pharmacological treatment of tics remains an indiviual choice depending on each patient's own specific needs.

Management of Pediatric Movement Disorders: Present and Future

Management of movement disorders in children is an evolving field. This article outlines the major categories of treatment options for pediatric movement disorders and general guidelines for their use. We review the evidence for existing therapies, which continue to lack large-scale controlled trials to guide treatment decisions. The field continues to rely on extrapolations from adult studies and lower quality evidence such as case reports and case series to guide treatment guidelines and consensus statements. Developments in new pharmaceuticals for rare diseases have begun to provide hope for those cases in which a genetic diagnosis can be made. Advances in surgical therapies such as deep brain stimulation as well as new modes of treatment such as gene therapy, epigenetic modulation, and stem cell therapy hold promise for improving outcomes in both primary and secondary causes of movement disorders. There is a critical need for larger, multicenter, controlled clinical trials to fully evaluate treatments for pediatric movement disorders.

The Roles of Phasic and Tonic Dopamine in Tic Learning and Expression

Tourette syndrome (TS) prominently involves dopaminergic disturbances, but the precise nature of those disturbances has remained elusive. A substantial body of empirical work and recent computational models have characterized the specific roles of phasic and tonic dopamine (DA) in action learning and selection, respectively. Using insights from this work and models, we suggest that TS involves increases in both phasic and tonic DA, which produce increased propensities for tic learning and expression, respectively. We review the evidence from reinforcement-learning and habit-learning studies in TS, which supports the idea that TS involves increased phasic DA responses; we also review the evidence that tics engage the habit-learning circuitry. On the basis of these findings, we suggest that tics are exaggerated, maladaptive, and persistent motor habits reinforced by aberrant, increased phasic DA responses. Increased tonic DA amplifies the tendency to execute learned tics and also provides a fertile ground of motor hyperactivity for tic learning. We review evidence suggesting that antipsychotics may counter both the increased propensity for tic expression, by increasing excitability in the indirect pathway, and the increased propensity for tic learning, by shifting plasticity in the indirect pathway toward long-term potentiation (and possibly also through more complex mechanisms). Finally, we review evidence suggesting that low doses of DA agonists that effectively treat TS decrease both phasic and tonic DA, thereby also reducing the propensity for both tic learning and tic expression, respectively.

Specific effect of a dopamine partial agonist on counterfactual learning: evidence from Gilles de la Tourette syndrome

The dopamine partial agonist aripiprazole is increasingly used to treat pathologies for which other antipsychotics are indicated because it displays fewer side effects, such as sedation and depression-like symptoms, than other dopamine receptor antagonists. Previously, we showed that aripiprazole may protect motivational function by preserving reinforcement-related signals used to sustain reward-maximization. However, the effect of aripiprazole on more cognitive facets of human reinforcement learning, such as learning from the forgone outcomes of alternative courses of action (i.e., counterfactual learning), is unknown. To test the influence of aripiprazole on counterfactual learning, we administered a reinforcement learning task that involves both direct learning from obtained outcomes and indirect learning from forgone outcomes to two groups of Gilles de la Tourette (GTS) patients, one consisting of patients who were completely unmedicated and the other consisting of patients who were receiving aripiprazole monotherapy, and to healthy subjects. We found that whereas learning performance improved in the presence of counterfactual feedback in both healthy controls and unmedicated GTS patients, this was not the case in aripiprazole-medicated GTS patients. Our results suggest that whereas aripiprazole preserves direct learning of action-outcome associations, it may impair more complex inferential processes, such as counterfactual learning from forgone outcomes, in GTS patients treated with this medication.

Safety and efficacy of aripiprazole for the treatment of pediatric Tourette syndrome and other chronic tic disorders

Tourette syndrome is a childhood-onset chronic tic disorder characterized by multiple motor and vocal tics and often accompanied by specific behavioral symptoms ranging from obsessionality to impulsivity. A considerable proportion of patients report significant impairment in health-related quality of life caused by the severity of their tics and behavioral symptoms and require medical intervention. The most commonly used medications are antidopaminergic agents, which have been consistently shown to be effective for tic control, but are also associated with poor tolerability because of their adverse effects. The newer antipsychotic medication aripiprazole is characterized by a unique mechanism of action (D2 partial agonism), and over the last decade has increasingly been used for the treatment of tics. We conducted a systematic literature review to assess the available evidence on the efficacy and safety of aripiprazole in pediatric patients with Tourette syndrome and other chronic tic disorders (age range: 4–18 years). Our search identified two randomized controlled trials (involving 60 and 61 participants) and ten open-label studies (involving between six and 81 participants). The majority of these studies used two validated clinician-rated instruments (Yale Global Tic Severity Scale and Clinical Global Impression scale) as primary outcome measures. The combined results from randomized controlled trials and open-label studies showed that aripiprazole is an effective, safe, and well-tolerated medication for the treatment of tics. Aripiprazole-related adverse effects (nausea, sedation, and weight gain) were less frequent compared to other antidopaminergic medications used for tic management and, when present, were mostly transient and mild. The reviewed studies were conducted on small samples and had relatively short follow-up periods, thus highlighting a need for further trials to assess the long-term use of aripiprazole in pediatric patients with Tourette syndrome and other chronic tic disorders with measurement of its efficacy using both clinician-rated and self-report scales.

Advances in management of movement disorders in children

Movement disorders in children are causally and clinically heterogeneous and present in a challenging developmental context. Treatment options are broad ranging, from pharmacotherapy to invasive neuromodulation and experimental gene and stem cell therapies. The clinical effects of these therapies are variable and often poorly sustained, and only a few of the management strategies used in paediatric populations have been tested in randomised controlled studies with age-appropriate cohorts. Identification of the most appropriate treatment is uniquely challenging in children because of the incomplete knowledge about the pathophysiology of movement disorders and their influence on normal motor development; thus, effective therapeutic options for these children remain an unmet need. It is vital to transfer the expanding knowledge of the movement disorders into the development of novel symptomatic or, ideally, disease-modifying treatments, and to assess these therapeutic strategies in appropriately designed and well done trials.

The role of atypical antipsychotics for treatment of Tourette's syndrome: an overview

Tourette's syndrome (TS) is a neuropsychiatric disorder of childhood onset characterized by multiple motor and phonic tics that fluctuate over time. Tic symptoms often improve by late adolescence, but some children and adults with TS may experience significant tic-related morbidity, including social and family problems, academic difficulties, and pain. When more conservative interventions are not successful, and when certain psychiatric co-morbidities further complicate the clinical profile, treating TS with an atypical antipsychotic medication may be a reasonable second-tier approach. However, the evidence supporting efficacy and safety of the atypical antipsychotics for treatment of tics is still very limited. The objective of this paper is to provide an updated overview of the role of atypical antipsychotics for treatment of TS, with evidence-based guidance on their use. Evidence for efficacy of different typical and atypical antipsychotics for treatment of tics was examined by conducting a systematic, keyword-related search of 'atypical antipsychotics' and 'Tourette's syndrome' in PubMed (National Library of Medicine, Washington, DC, USA). Four recent treatment consensus publications were also reviewed. This review focused on literature published from 2000 to 2013 and on available randomized controlled trials in TS. Evidence supporting the use of atypical antipsychotics for treatment of TS is limited. There are few randomized medication treatment trials in TS (i.e. risperidone, aripiprazole, ziprasidone), which employed varying methodologies, thereby restricting meaningful comparisons among studies. Future collaborations among clinical sites with TS expertise employing high-quality study design may better elucidate the role of atypical antipsychotics for treatment of TS.

Updates in medical and surgical therapies for Tourette syndrome

Tourette syndrome is a complex neurobehavioral disorder defined by multiple motor and at least 1 vocal tic, persisting over 1 year, waxing and waning in severity, and not explained by another condition. The condition may range from mild nuisance to debilitating and disabling in severity. Management includes counseling and reassurance, behavioral interventions, pharmacologic, and rarely, surgical interventions. Traditionally, alpha-2 agonists and dopamine receptor antagonists have been utilized. In addition, a number of different pharmacotherapies have been implemented in the search for improved management of tics with better tolerability. In rare, severely disabling cases, neuromodulation with deep brain stimulation may be indicated. Optimal brain targets and candidate selection are still in evolution. This article will review the evidence for current medical and surgical therapies with a focus on recent updates.

Imaging the where and when of tic generation and resting state networks in adult Tourette patients

Introduction: Tourette syndrome (TS) is a neuropsychiatric disorder with the core phenomenon of tics, whose origin and temporal pattern are unclear. We investigated the When and Where of tic generation and resting state networks (RSNs) via functional magnetic resonance imaging (fMRI).

Methods: Tic-related activity and the underlying RSNs in adult TS were studied within one fMRI session. Participants were instructed to lie in the scanner and to let tics occur freely. Tic onset times, as determined by video-observance were used as regressors and added to preceding time-bins of 1 s duration each to detect prior activation. RSN were identified by independent component analysis (ICA) and correlated to disease severity by the means of dual regression.

Results: Two seconds before a tic, the supplementary motor area (SMA), ventral primary motor cortex, primary sensorimotor cortex and parietal operculum exhibited activation; 1 s before a tic, the anterior cingulate, putamen, insula, amygdala, cerebellum and the extrastriatal-visual cortex exhibited activation; with tic-onset, the thalamus, central operculum, primary motor and somatosensory cortices exhibited activation. Analysis of resting state data resulted in 21 components including the so-called default-mode network. Network strength in those regions in SMA of two premotor ICA maps that were also active prior to tic occurrence, correlated significantly with disease severity according to the Yale Global Tic Severity Scale (YGTTS) scores.

Discussion: We demonstrate that the temporal pattern of tic generation follows the cortico-striato-thalamo-cortical circuit, and that cortical structures precede subcortical activation. The analysis of spontaneous fluctuations highlights the role of cortical premotor structures. Our study corroborates the notion of TS as a network disorder in which abnormal RSN activity might contribute to the generation of tics in SMA.

Fine motor skills in adult Tourette patients are task-dependent

Background

Tourette syndrome is a neuropsychiatric disorder characterized by motor and phonic tics. Deficient motor inhibition underlying tics is one of the main hypotheses in its pathophysiology. Therefore the question arises whether this supposed deficient motor inhibition affects also voluntary movements. Despite severe motor tics, different personalities who suffer from Tourette perform successfully as neurosurgeon, pilot or professional basketball player.

Methods

For the investigation of fine motor skills we conducted a motor performance test battery in an adult Tourette sample and an age matched group of healthy controls.

Results

The Tourette patients showed a significant lower performance in the categories steadiness of both hands and aiming of the right hand in comparison to the healthy controls. A comparison of patients’ subgroup without comorbidities or medication and healthy controls revealed a significant difference in the category steadiness of the right hand.

Conclusions

Our results show that steadiness and visuomotor integration of fine motor skills are altered in our adult sample but not precision and speed of movements. This alteration pattern might be the clinical vignette of complex adaptations in the excitability of the motor system on the basis of altered cortical and subcortical components. The structurally and functionally altered neuronal components could encompass orbitofrontal, ventrolateral prefrontal and parietal cortices, the anterior cingulate, amygdala, primary motor and sensorimotor areas including altered corticospinal projections, the corpus callosum and the basal ganglia.