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

Mechanistic insights and therapeutic approaches in tic disorders: The distinctive role of ethnomedicine and modern medical interventions

Tic disorders (TDs) are a class of neurodevelopmental disorders that have received considerable scientific attention. The genesis of TDs is increasingly understood as a complex interplay of neurobiological, genetic, and immunological factors. Animal model studies have elucidated the pathophysiology of TDs, paving the way for innovative therapeutic approaches. This review provides a comprehensive analysis of the etiologic basis, experimental framework, and treatment strategies for TDs, highlighting the contributions of ethnomedicine and modern medicine. Our synthesis aims to deepen the understanding of the disease and spur the development of superior treatments. In addition, we present new insights and hypotheses for the future management of TDs, emphasizing the need for continued research into their etiology and progression, as well as the pursuit of more effective therapies. We advocate personalized, holistic care strategies that focus on symptom relief and improving patients' quality of life. Overall, this review provides a critical compendium for TD researchers and practitioners to help navigate the complexities of these disorders.

The Role of CBGTC Synaptic Neurotransmission in the Pathophysiology of Tics

The pathophysiology of tic disorders involves an alteration in the transmission of messages through the cortico-basal ganglia-thalamo-cortical circuit. A major requirement for the passage of a message through this circuit is an intact chemically mediated synaptic neurotransmitter system (ie, neurotransmitters and second messengers). This article reviews the scientific evidence supporting the involvement of a variety of neurotransmitters (ie, dopamine, glutamate, gamma-aminobutyric acid, serotonin, acetylcholine, and the opioid system). Although there are favored neurotransmitter abnormalities, their complex interactions suggest the likelihood that several are involved in the production of tics.

Pharmacotherapy for Tourette Syndrome

Tourette syndrome (TS) is associated with dysregulated cortico-striatal-thalamo-cortical neural circuitry, of which the primary implicated neurotransmitters include dopamine, glutamate, and gamma-aminobutyric acid. Pharmacologic intervention for tics should be considered when tics are causing psychological, functional, or physical impairment, and behavioral treatment is either inaccessible or ineffective. Only 3 medications have Food and Drug Administration approval for TS, including 2 typical antipsychotics (pimozide and haloperidol) and 1 atypical antipsychotic (aripiprazole). As such, off-label pharmacologic interventions are frequently used. Though there is no hierarchical recommendation for medication in the treatment of TS, common first-line approaches often include alphaagonists, followed by atypical antipsychotics, followed by typical antipsychotics. Pharmacological treatment options utilizing novel mechanisms of action are emerging.

Pharmacological Treatment of Tourette Disorder in Children

Background: Tourette disorder (TD) is a neurodevelopmental disorder characterized by childhood onset of tics lasting more than one year, with multiple motor tics and at least one phonic tic at some point during the course of the symptoms. Treatment of tics may include psychoeducation, non-pharmacologic treatment, or pharmacologic treatment. We review pharmacologic treatment here. Methods: We performed a literature review on pharmacologic treatments for TD. Results: There is no current evidence to suggest that medications impact the prognosis of tic disorders, so current clinical guidelines recommend reassurance of the patient and family and monitoring if there is no change in function or quality of life due to tics. If treatment is indicated, it must be chosen based on the needs of each individual patient. Comprehensive behavioral intervention for tics (CBIT) is considered first-line management for most individuals with bothersome tics, especially if they are mild to moderate in severity. Pharmacotherapy should be considered when tics are impairing daily functioning, causing social problems, accompanied by other neuropsychiatric symptoms, or when the patient is not likely to benefit from CBIT. Current recommended pharmacotherapy options include alpha-2 adrenergic agonists, dopamine modulators, GABAergic medications, dopamine depleters, and botulinum toxin injections. Additionally, there are other novel medications that are being studied in ongoing clinical trials. Conclusions: This review summarizes available pharmacotherapy options for TD in children. It provides an overview of new medications and offers guidance to physicians when selecting appropriate treatments. If medications are indicated for tic management, treatment should be chosen based on the needs of the individual patient.

Improvement of Tourette syndrome symptoms after intractable temporal lobe epileptic surgery: a case report

BACKGROUND

The comorbidities of either epilepsy or Tourette syndrome (TS) are heterogeneous. However, the co-occurrence of epilepsy and TS conditions is rarely encountered, let alone effective treatments that address both neurologic disorders at the same time.

METHODS

We report a 24-year-old female patient who was diagnosed with TLE and TS. She presented for seizure control. After evaluation with stereo-electroencephalography and electrocorticography monitoring, the patient underwent a resective surgery treatment and was followed for 9 months.

RESULTS

At the last follow-up, the patient remained seizure free and unexpectedly showed great improvement in TS symptoms and its psychiatric comorbidities.

CONCLUSION

This anecdotal case highlights the close association between TLE and TS and we suggest that epilepsy and TS share some common pathophysiologic mechanisms.

Successful Treatment of Tourette Syndrome With a Combination of Guanfacine and Aripiprazole: A Case Series

Tourette syndrome (TS) is a disorder of the nervous system that causes motor and vocal tics. Tics occur as sudden onset, rapid stereotyped purposeless movements or sounds. Combination therapies can be utilized for adequate control of motor and vocal tics. Patients diagnosed with TS and treated with aripiprazole and guanfacine from 2011-2022 at Saint Louis University Hospital were retrospectively surveyed. Three patients with TS treated with aripiprazole and guanfacine experienced significant improvement or complete resolution of their motor and vocal tics. In our cohort of three patients, the combination of guanfacine and aripiprazole significantly improved or resolved motor and vocal tics that were previously poorly controlled on other traditional medications.

Current and emerging pharmacotherapeutic strategies for Tourette syndrome

INTRODUCTION

Tourette syndrome (TS) is a chronic tic disorder characterized by both motor and vocal tics. The vast majority of patients present with co-morbid behavioral problems, especially tic-related obsessive-compulsive behaviors and attention-deficit and hyperactivity disorder. Evidence-based guidelines on the pharmacotherapy of TS have become available in recent years.

AREAS COVERED

The main purpose of this paper is to provide an overview of the current and emerging pharmacotherapeutic strategies for TS. A comprehensive search for the literature on the pharmacotherapy of tics was conducted using multiple databases (MEDLINE, Scopus, Web of Science, and Google Scholar), without date limits.

EXPERT OPINION

In consideration of the heterogeneity of the TS phenotypes, pharmacotherapy should be tailored to the individual patient. The choice of the pharmacological agent should take into account both the efficacy-to-tolerability ratio and the presence of co-morbid conditions. Evidence-based pharmacotherapy should aim at improving health-related quality life within a dynamic framework that typically requires active monitoring of the clinical presentation and reevaluation of the treatment intervention over time.

Fluphenazine decanoate-induced bradycardia: A case report

Sinus tachycardia and orthostatic hypotension have been so far reported among the negative cardiovascular complications of antipsychotic agents. This study aimed to report a case with bradycardia induced by fluphenazine decanoate administration. The patient was a 29‐year‐old man, admitted to the general teaching hospital in Sari, Iran, with a complaint of abdominal and gastric pain as well as weight loss following 7 months of fasting based on religious delusions. The patient developed bradycardia, 36 hours after fluphenazine decanoate administration. His pulse rate was also 46 beats per min (bpm). The antipsychotic medication was thus held and the patient did not take any drugs. On the 21st day after discontinuing this agent, the pulse rate reached 70 bpm. This case report notifies that much more attention should be paid to all patients before starting fluphenazine decanoate administration, and close cardiac monitoring must be done.

A 29‐year‐old single man showed bradycardia induced by fluphenazine decanoate. This case report notifies that much more attention should be paid to all patients before starting fluphenazine decanoate administration, and close cardiac monitoring must be done.

European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part III: pharmacological treatment

In 2011, the European Society for the Study of Tourette Syndrome (ESSTS) published the first European guidelines for Tourette Syndrome (TS). We now present an update of the part on pharmacological treatment, based on a review of new literature with special attention to other evidence-based guidelines, meta-analyses, and randomized double-blinded studies. Moreover, our revision took into consideration results of a recent survey on treatment preferences conducted among ESSTS experts. The first preference should be given to psychoeducation and to behavioral approaches, as it strengthens the patients' self-regulatory control and thus his/her autonomy. Because behavioral approaches are not effective, available, or feasible in all patients, in a substantial number of patients pharmacological treatment is indicated, alone or in combination with behavioral therapy. The largest amount of evidence supports the use of dopamine blocking agents, preferably aripiprazole because of a more favorable profile of adverse events than first- and second-generation antipsychotics. Other agents that can be considered include tiapride, risperidone, and especially in case of co-existing attention deficit hyperactivity disorder (ADHD), clonidine and guanfacine. This view is supported by the results of our survey on medication preference among members of ESSTS, in which aripiprazole was indicated as the drug of first choice both in children and adults. In treatment resistant cases, treatment with agents with either a limited evidence base or risk of extrapyramidal adverse effects might be considered, including pimozide, haloperidol, topiramate, cannabis-based agents, and botulinum toxin injections. Overall, treatment of TS should be individualized, and decisions based on the patient's needs and preferences, presence of co-existing conditions, latest scientific findings as well as on the physician's preferences, experience, and local regulatory requirements.

Metabolic events associated with the use of antipsychotics in children, adolescents and young adults: a multinational sequence symmetry study

It is known that younger patients treated with antipsychotics are at increased risk of metabolic events; however, it is unknown how this risk varies according to ethnicity, the class of antipsychotic and the specific product used, and by age group. We conducted a multinational sequence symmetry study in Asian populations (Hong Kong, Japan, Korea, Taiwan and Thailand) and non-Asian populations (Australia and Denmark) to evaluate the metabolic events associated with antipsychotics in both Asian and non-Asian populations, for typical and atypical antipsychotics, and by the subgroups of children and adolescents, and young adults. Patients aged 6-30 years newly initiating oral antipsychotic drugs were included. We defined a composite outcome for metabolic events which included dyslipidemia, hypertension and hyperglycemia. We calculated the sequence ratio (SR) by dividing the number of people for whom a medicine for one of the outcome events was initiated within a 12-month period after antipsychotic initiation by the number before antipsychotic initiation. This study included 346,904 antipsychotic initiators across seven countries. Antipsychotic use was associated with an increased risk of composite metabolic events with a pooled adjusted SR (ASR) of 1.22 (95% CI 1.00-1.50). Pooled ASRs were similar between Asian (ASR, 1.22; 95% CI 0.88-1.70) and non-Asian populations (ASR, 1.22; 95% CI 1.04-1.43). The pooled ASR for typical and atypical antipsychotics was 0.98 (95% CI 0.85-1.12) and 1.24 (95% CI 0.97-1.59), respectively. No difference was observed in the relative effect in children and adolescents compared to young adults. The risk of metabolic events associated with antipsychotics use was similar in magnitude in Asian and non-Asian populations despite the marked difference in drug utilization patterns.

Drug Repurposing for Glioblastoma and Current Advances in Drug Delivery-A Comprehensive Review of the Literature

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults with an extremely poor prognosis. There is a dire need to develop effective therapeutics to overcome the intrinsic and acquired resistance of GBM to current therapies. The process of developing novel anti-neoplastic drugs from bench to bedside can incur significant time and cost implications. Drug repurposing may help overcome that obstacle. A wide range of drugs that are already approved for clinical use for the treatment of other diseases have been found to target GBM-associated signaling pathways and are being repurposed for the treatment of GBM. While many of these drugs are undergoing pre-clinical testing, others are in the clinical trial phase. Since GBM stem cells (GSCs) have been found to be a main source of tumor recurrence after surgery, recent studies have also investigated whether repurposed drugs that target these pathways can be used to counteract tumor recurrence. While several repurposed drugs have shown significant efficacy against GBM cell lines, the blood–brain barrier (BBB) can limit the ability of many of these drugs to reach intratumoral therapeutic concentrations. Localized intracranial delivery may help to achieve therapeutic drug concentration at the site of tumor resection while simultaneously minimizing toxicity and side effects. These strategies can be considered while repurposing drugs for GBM.

Tourette syndrome in children: An update

Tourette syndrome (TS) causes academic, social, emotional, physical, and functional problems. Most TS patients also have comorbid neuropsychological conditions. The purpose of this review is to provide updated information to the clinician about phenomenology, epidemiology, comorbidities, pathophysiology and management strategies for tics (a hallmark of TS) and TS. Recent findings suggest that TS is likely due to a combination of several different genes and environmental factors, with possible involvement of the cortical-basal ganglia-thalamocortical circuit and related multiple neurotransmitters. First-line management includes psychoeducation for families, patients, and school personnel, as well as behavioral therapy. Non-medicine treatment for tics is advancing to include younger children and increase access via remote service applications. Pharmacotherapy is used if appropriate and several new medicines are under investigation (e.g., Tetrabenazine, valbenazine, deutetrabenazine, ecopipam, cannabinoids). Deep brain stimulation and Mouthguard therapy can be used for children with intractable illness.

Swearing and coprophenomena - A multidimensional approach

Swearing, cursing, expletives - all these terms are used to describe the utterance of taboo words. Studies show that swearing makes up around 0.5 % of the daily spoken content, however, the inter-individual variability is very high. One kind of pathologic swearing is coprolalia in Tourette syndrome (TS), which describes the involuntary outburst of taboo words. Coprolalia occurs in approximately 20-30 % of all patients with TS. This review compares swearing in healthy people and coprolalia in people with TS and is the first one to develop a multidimensional framework to account for both phenomena from a similar perspective. Different research findings are embedded in one theoretical framework consisting of reasons, targets, functions/effects and influencing factors for swearing and coprolalia. Furthermore, the very limited research investigating obscene gestures and copropraxia, compulsive obscene gestures, is summarized. New research questions and gaps are brought up for swearing, obscene gestures and coprophenomena.

Use of Tic-Suppressing Medication and Other Psychotropic Drugs in Children and Adolescents with Newly Diagnosed Tic Disorders in Denmark

Objective: Only few psychotropic drugs are approved to treat tic disorders. The aim was to describe use of tic-suppressing medication and other psychotropic drugs in children with tics. Methods: Using nationwide registries, we identified children receiving a tic diagnosis in Denmark during 2006-2017 and extracted data on tic-suppressing medication and other psychotropic drugs. Results: Antipsychotics were used by 12%. Use of tic-suppressing medication increased with age and varied according to sex. Over time less children with tics were medicated (from 44% to 38% in the total use of psychotropic drugs) mainly due to decreased use of antipsychotics (from 18% to 6.4%). In recent years, use of aripiprazole exceeded that of risperidone (38% vs. 35%), although risperidone was most often first choice (34%) followed by aripiprazole (22%). Most children stayed on their initial treatment. Attention-deficit/hyperactivity disorder medication (27%) was the most common additional psychotropic drug class used. Regional variations were found in the treatment of tics. Hospital specialists were mainly responsible for treatment. Conclusions: Most children with tics do not use tic-suppressing or other psychotropic drugs. The use of aripiprazole superseded risperidone, however risperidone remains the most common first-choice treatment. Treatment was mainly handled by specialists, which is reassuring given the lack of national guidelines, however, regional variations merit further attention as do the variation in treatment between young girls and boys.

Use of Complementary and Alternative Medicine in Children With Tourette Syndrome

INTRODUCTION

Tourette syndrome is a neuropsychiatric condition defined by motor and phonic tics with onset in childhood. Many families have concerns regarding potential side effects of pharmacologic treatments, and often have difficulty accessing comprehensive behavioral intervention for tics. Patients and caregivers may turn to complementary and alternative medicine (CAM) as they perceive these as "natural" and therefore "safe." Although there are anecdotal reports of an increased use of CAM in Tourette syndrome patients, the exact prevalence is unknown.

OBJECTIVE

The purpose of this study was to identify commonly used CAM therapies for children with Tourette syndrome at Penn State Hershey Medical Center.

METHODS

A questionnaire was administered to the caregivers of children (<18 years old) via telephone. The data pertaining to demographics, type of CAM use, duration of use, adverse effects, and caregiver's perception of the effectiveness were collected.

RESULTS

A total of 110 patients participated in this survey. When inquired about the different CAM methods, 69.1% of the participants reported using 1 or more CAM therapies, and 58% of those who used CAM informed the doctor about their use. Ninety-three percent of those who used CAM therapy reported a decrease in tic frequency. The most commonly used CAM therapies were stress management (44.6%), herbal medicine (18.2%), homeopathy (12.7%), and meditation (9.1%). In total, 46% of the participants said that CAM helped more than medication.

CONCLUSION

The majority of patients interviewed were using CAM therapies, and a significant portion reported benefit greater than medication. More than half of all participants discussed CAM therapies with their physicians, and 63% of participants felt that their physicians would support their use of CAM therapies.

The Pathophysiology of Tics; An Evolving Story

Background:

Tics, defined as quick, rapid, sudden, recurrent, non-rhythmic motor movements or vocalizations are required components of Tourette Syndrome (TS) - a complex disorder characterized by the presence of fluctuating, chronic motor and vocal tics, and the presence of co-existing neuropsychological problems. Despite many advances, the underlying pathophysiology of tics/TS remains unknown.

Objective:

To address a variety of controversies surrounding the pathophysiology of TS. More specifically: 1) the configuration of circuits likely involved; 2) the role of inhibitory influences on motor control; 3) the classification of tics as either goal-directed or habitual behaviors; 4) the potential anatomical site of origin, e.g. cortex, striatum, thalamus, cerebellum, or other(s); and 5) the role of specific neurotransmitters (dopamine, glutamate, GABA, and others) as possible mechanisms (Abstract figure).

Methods:

Existing evidence from current clinical, basic science, and animal model studies are reviewed to provide: 1) an expanded understanding of individual components and the complex integration of the Cortico-Basal Ganglia-Thalamo-Cortical (CBGTC) circuit - the pathway involved with motor control; and 2) scientific data directly addressing each of the aforementioned controversies regarding pathways, inhibition, classification, anatomy, and neurotransmitters.

Conclusion:

Until a definitive pathophysiological mechanism is identified, one functional approach is to consider that a disruption anywhere within CBGTC circuitry, or a brain region inputting to the motor circuit, can lead to an aberrant message arriving at the primary motor cortex and enabling a tic. Pharmacologic modulation may be therapeutically beneficial, even though it might not be directed toward the primary abnormality.

Tourette's disorder in children and adolescents

Tourette's disorder (TD) is one of the five American Psychiatric Association's 2013 Diagnostic and Statistical Manual of Mental Disorders (DSM-5) classifications of tic disorders. Eponymously linked with the noted 19th century French physician, Gilles de la Tourette [1857-1904], this disorder is identified in 0.3% to 0.7% of the population. It is characterized as a familial neuropsychiatric condition with multiple motor tics and vocal tics (one or more) present for more than 1 year with varying severity. The underlying pathophysiology involves dysfunctional activity of the basal ganglia and circuitry of the frontal cortex as well as dorsolateral striatum deficits. Contributory factors include genetic features interacting with milieu influences. A number of comorbid disorders are seen including obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder (ADHD). Concepts of management are considered including behavioral therapy and pharmacologic approaches with alpha-adrenoceptor agonists, atypical antipsychotics (AAs), haloperidol, pimozide and others. Other management includes botulinum injections and deep brain stimulation in adults.

Tics and Tourette Syndrome

PURPOSE OF REVIEW

The purpose of this article is to present current information on the phenomenology, epidemiology, comorbidities, and pathophysiology of tic disorders and discuss therapy options. It is hoped that a greater understanding of each of these components will provide clinicians with the necessary information to deliver thoughtful and optimal care to affected individuals.

RECENT FINDINGS

Recent advances include the finding that Tourette syndrome is likely due to a combination of several different genes, both low-effect and larger-effect variants, plus environmental factors. Pathophysiologically, increasing evidence supports involvement of the cortical-basal ganglia-thalamocortical circuit; however, the primary location and neurotransmitter remain controversial. Behavioral therapy is first-line treatment, and pharmacotherapy is based on tic severity. Several newer therapeutic agents are under investigation (eg, valbenazine, deutetrabenazine, cannabinoids), and deep brain stimulation is a promising therapy.

SUMMARY

Tics, defined as sudden, rapid, recurrent, nonrhythmic motor movements or vocalizations, are essential components of Tourette syndrome. Although some tics may be mild, others can cause significant psychosocial, physical, and functional difficulties that affect daily activities. In addition to tics, most affected individuals have coexisting neuropsychological difficulties (attention deficit hyperactivity disorder, obsessive-compulsive disorder, anxiety, mood disorder, disruptive behaviors, schizotypal traits, suicidal behavior, personality disorder, antisocial activities, and sleep disorders) that can further impact social and academic activities or employment.

Evidence-based treatment of Tourette's disorder and chronic tic disorders

Introduction: Chronic Tic Disorders and Tourette's Disorder (collectively referred to as TD) are characterized by sudden, rapid, and repetitive motor movements or vocalizations called tics. Children, adolescents, and adults with TD often experience co-occurring psychiatric symptoms and impairments in multiple domains. As a result of tics and other symptoms, patients with TD can develop negative self-views, require considerable accommodations, and experience a poor quality of life. Therefore, the efficient and effective management of TD bears considerable importance. Areas covered: This expert review evaluated the empirical support for behavioral and pharmacological interventions based on the results of randomized controlled trials (RCTs). Behavioral interventions evaluated include habit reversal training (HRT), comprehensive behavioral intervention for tics (CBIT), and exposure response prevention (ERP). Reviewed pharmacological interventions included alpha-2 agonists, antipsychotics, and anticonvulsants. Expert opinion: This review identified several efficacious behavioral and pharmacological interventions for TD. However, several gaps in the management of TD include: (1) the access/availability of behavioral interventions, (2) novel and more efficacious treatment approaches, and (3) the development of more comprehensive interventions to manage TD. In order to advance the treatment of TD, additional research is necessary to efficiently, effectively, and comprehensively develop and evaluate new treatments for patients with TD.

Merging the Pathophysiology and Pharmacotherapy of Tics

Background

Anatomically, cortical-basal ganglia-thalamo-cortical (CBGTC) circuits have an essential role in the expression of tics. At the biochemical level, the proper conveyance of messages through these circuits requires several functionally integrated neurotransmitter systems. In this manuscript, evidence supporting proposed pathophysiological abnormalities, both anatomical and chemical is reviewed. In addition, the results of standard and emerging tic-suppressing therapies affecting nine separate neurotransmitter systems are discussed. The goal of this review is to integrate our current understanding of the pathophysiology of Tourette syndrome (TS) with present and proposed pharmacotherapies for tic suppression.

Methods

For this manuscript, literature searches were conducted for both current basic science and clinical information in PubMed, Google-Scholar, and other scholarly journals to September 2018.

Results

The precise primary site of abnormality for tics remains undetermined. Although many pathophysiologic hypotheses favor a specific abnormality of the cortex, striatum, or globus pallidus, others recognize essential influences from regions such as the thalamus, cerebellum, brainstem, and ventral striatum. Some prefer an alteration within direct and indirect pathways, whereas others believe this fails to recognize the multiple interactions within and between CBGTC circuits. Although research and clinical evidence supports involvement of the dopaminergic system, additional data emphasizes the potential roles for several other neurotransmitter systems.

Discussion

A greater understanding of the primary neurochemical defect in TS would be extremely valuable for the development of new tic-suppressing therapies. Nevertheless, recognizing the varied and complex interactions that exist in a multi-neurotransmitter system, successful therapy may not require direct targeting of the primary abnormality.