European clinical guidelines for Tourette syndrome and other tic disorders: summary statement

Chemical Probes for Investigating the Endocannabinoid System

Cannabis sativa has been used therapeutically since early civilizations, with key cannabinoids Δ9-tetrahydrocannabinol (THC) 3.1 and cannabidiol characterized in the 1960s, leading to the discovery of cannabinoid receptors type 1 (CB1R) and type 2 (CB2R) and the endocannabinoid system (ECS) in the 1990s. The ECS, involving endogenous ligands like 2-arachidonoylglycerol (2-AG) 1.1, anandamide (N-arachidonoylethanolamine (AEA)) 1.2, and various proteins, regulates vital processes such as sleep, appetite, and memory, and holds significant therapeutic potential, especially for neurological disorders. Small molecule-derived pharmacological tools, or chemical probes, target key components of the ECS and are crucial for target validation, mechanistic studies, pathway elucidation, phenotypic screening, and drug discovery. These probes selectively interact with specific proteins or pathways, enabling researchers to modulate target activity and observe biological effects. When they carry an additional reporter group, they are referred to as labeled chemical probes. Developed through medicinal chemistry, structural biology, and high-throughput screening, effective chemical probes must be selective, potent, and depending on their purpose meet additional criteria such as cell permeability and metabolic stability.This chapter describes high-quality labeled and unlabeled chemical probes targeting ECS constituents that have been successfully applied for various research purposes. CB1R and CB2R, class A G protein-coupled receptors, are activated by 2-AG 1.1, AEA 1.2, and THC 3.1, with numerous ligands developed for these receptors. Imaging techniques like single-photon emission computed tomography, positron emission tomography, and fluorescently labeled CB1R and CB2R probes have enhanced CB receptor studies. CB2R activation generally results in immunosuppressive effects, limiting tissue injury. AEA 1.2 is mainly degraded by fatty acid amide hydrolase (FAAH) or N-acylethanolamine acid amidase (NAAA) into ethanolamine and arachidonic acid (AA) 1.3. FAAH inhibitors increase endogenous fatty acid amides, providing analgesic effects without adverse effects. NAAA inhibitors reduce inflammation and pain in animal models. Diacylglycerol lipase (DAGL) is essential for 2-AG 1.1 biosynthesis, while monoacylglycerol lipase (MAGL) degrades 2-AG 1.1 into AA 1.3, thus regulating cannabinoid signaling. Multiple inhibitors targeting FAAH and MAGL have been generated, though NAAA and DAGL probe development lags behind. Similarly, advancements in inhibitors targeting endocannabinoid (eCB) cellular uptake or trafficking proteins like fatty acid-binding proteins have been slower. The endocannabinoidome (eCBome) includes the ECS and related molecules and receptors, offering therapeutic opportunities from non-THC cannabinoids and eCBome mediators. Ongoing research aims to refine chemical tools for ECS and eCBome study, addressing unmet medical needs in central nervous system disorders and beyond.

The Use of Cannabis-Based Medicine in Selected Neurological Disorders

Cannabis-based medicine (CBM) is used in a wide variety of different neurological disorders. While the use of CBM in the treatment of pain, AIDS wasting, loss of appetite, and spasticity is well established, CBM application in movement disorders and neurodegenerative disorders is still an emerging topic. The purpose of this chapter is to summarize current evidence behind the use of CBM in selected neurological diseases, mainly movement and neurodegenerative disorders. The best evidence for efficacy of CBM is for Tourette syndrome resulting in an improvement of tics and psychiatric comorbidities. In this indication, delta-9-tetrahydrocannabinol (THC)-containing CBMs are recommended. There is limited evidence that CBMs are also effective in Parkinson's disease in which they may improve tremor, but also non-motor symptoms such as pain and sleeping problems. With respect to other neurodegenerative diseases, there is limited evidence that CBMs may improve behavioral symptoms in Huntington's disease. In addition, it has been speculated that CBMs may have neuroprotective effects, but this has not yet been confirmed in the clinical setting.

Emerging therapeutic approaches for Tourette syndrome and other tic disorders - a systematic review of current clinical trials

Tourette syndrome and other tic disorders are prevalent neurodevelopmental disorders typically treated with behavioral techniques or pharmacological interventions, primarily antipsychotics. However, many patients do not achieve sufficient response to conventional treatments, underscoring the need for further research in this area. To provide a comprehensive overview of ongoing research activities, we systematically searched the clinical registries of the World Health Organization (WHO) and of the United States National Institutes of Health (NIH) for currently planned or ongoing registered clinical studies. Our search identified 21 registered studies, of which seven focus specifically on pharmacological interventions. Potential candidates include the dopamine D1 antagonist ecopipam, the phosphodiesterase inhibitor gemlapodect, and cannabis-based therapies. Additionally, several studies are exploring behavioral interventions including Comprehensive Behavioral Interventions for Tics (CBIT) and mindfulness training, neurostimulation including MRI-navigated transcranial stimulation, theta burst stimulation, and deep brain stimulation, traditional Chinese medicine, and other approaches such as microbiota transplantation. Despite the range of research activities underway, the overall landscape remains limited. In this report we will discuss the findings, current developments, and relevant aspects concerning future research including clinical, scientific, and patient perspectives.

Randomized Controlled Trial of Transcranial Direct Current Stimulation over the Supplementary Motor Area in Tourette Syndrome

BACKGROUND

Transcranial direct current stimulation (tDCS) over the supplementary motor area (SMA) has shown promise in Tourette syndrome (TS), but previous studies were limited in size and stimulation duration.

OBJECTIVE

The aim was to explore the efficacy and safety of multiple sessions of cathodal tDCS over the bilateral SMA on tic severity in TS.

METHODS

A double-blind, randomized, sham-controlled trial 1 mA cathodal tDCS over bilateral SMA was performed in participants with TS older than 16 years. The intervention involved two 20-min periods of stimulation with either sham or active tDCS per day, over 5 consecutive days, during which participants actively suppressed tics. Tic severity was measured using the Yale Global Tic Severity Scale Total Tic Severity (YGTSS-TTS, primary outcome) score at baseline, day 5 (visit 5), and 1 week later (visit 6). Questionnaires focusing on comorbidities were performed at baseline and visit 6.

RESULTS

Twenty-four participants were randomly assigned (12 active, 12 sham; 8 women; median age: 26). We observed a significant effect of visit on YGTSS-TSS, but no significant effect of treatment or treatment × visit interaction emerged. In contrast, a statistically significant effect of the treatment × visit interaction was observed for the motor tic subscore, with significantly larger improvement in the active arm. Furthermore, we detected a significantly larger decrease in premonitory urge intensity at visit 6 after active stimulation. No effect was detected on severity of comorbidities.

CONCLUSIONS

This preliminary study suggests that bilateral tDCS over the SMA provides small, but significant benefits in reducing motor tic severity in TS.

Healthcare utilisation and costs associated with poor access to diagnosis and treatment for children and young people with tic disorders

BACKGROUND

There are no specific national guidelines in England to guide healthcare professionals in how to assess or treat young people with tic disorders. Access to evidence-based treatment, including behavioural therapy, is of limited availability.

OBJECTIVES

This study examined the economic impact on services arising from a lack of access to appropriate healthcare services for young people with tic disorders, alongside the impact on school attendance.

METHODS

This study used data from the randomised controlled trial 'ORBIT' (Online Remote Behavioural Intervention for Tics). ORBIT compared online exposure and response prevention behavioural therapy for tics with online psychoeducation and recruited 224 young people aged 9-17 years in England. Here, we explore costs of health service use and school absenteeism from children who participated in the ORBIT trial and present these alongside the economic impact of including ORBIT within a tic service. We supplement ORBIT data with findings from two case studies.

FINDINGS

The data showed that patients have care from several healthcare professionals and miss school due to accessing care for tics. The case studies suggest that most of these contacts with specialist services are unlikely to be supportive. However, adding ORBIT could save the National Health Service £1 million.

CONCLUSIONS

Young people with tic disorders are likely to engage in substantial use of healthcare resources because of inadequate care pathways. The availability of an evidence-based online therapy such as ORBIT could save money to the healthcare system.

CLINICAL IMPLICATIONS

There is a need to improve service provision and develop national guidelines for tic disorders.

TRIAL REGISTRATION NUMBER

ISRCTN70758207, NCT03483493.

Development and Evaluation of a Care Needs Scale for Parents of Children With Tourette Syndrome

ABSTRACT

BACKGROUND: Tourette syndrome (TS) is a chronic neurodevelopmental disorder that begins in school-age children. Although TS is not life-threatening, the tics and comorbidities can impact a child's physical and mental health, as well as interpersonal interactions. Understanding the care needs of parents of children with TS is essential for providing healthcare services that effectively support these children. The aim of the study was to develop and evaluate the psychometric properties of the care needs scale for parents of children with TS (CNS-PCTS) in Taiwan. METHODS: This study used a methodological design. The scale was developed by preliminarily identifying relevant items and dimensions through a systematic review of the literature. A pilot test with 30 participants and exploratory factor analysis (EFA) confirmed the subscales and items pertaining to the care needs of the parents. Data analysis included content validity, item analysis, internal consistency, test-retest reliability, and EFA. The Chinese version of the Pittsburgh Sleep Quality Index was adopted to assess the discriminant validity of the CNS-PCTS. RESULTS: Two hundred fifty-six parents of children with TS completed the scale. The scale-level content validity index was 0.92. The EFA revealed that the CNS-PCTS consisted of 13 items, with the factor loadings ranging from 0.656 to 0.83, and covered 3 factors: getting information about TS, assisting children in social engagement, and obtaining parenting support. The discriminant validity showed a positive correlation between the Chinese version of the Pittsburgh Sleep Quality Index and the CNS-PCTS. Cronbach's α coefficients of the subscales ranged from 0.89 to 0.94, and the intraclass correlation coefficient was 0.94. CONCLUSION: The CNS-PCTS demonstrated satisfactory psychometric properties. It helps health professionals understand parents' care needs and assess the effectiveness of interventions. Confirmatory factor analysis can be performed in future studies to provide more rigorous validity.

Deep brain stimulation for Tourette's syndrome

Tourette's syndrome is a neuropsychiatric disorder characterized by formidable motor and vocal tics. Many individuals also present with comorbid neuropsychiatric conditions. Though patients often benefit from pharmacological and behavioral therapies, a subset of individuals develop severe, treatment-resistant symptoms that might necessitate more invasive interventions, such as Deep Brain Stimulation (DBS). DBS, particularly targeting regions like the globus pallidus internus (GPi) and the centromedian-parafascicular complex (CM-Pf) of the thalamus, has demonstrated effectiveness in reducing tic severity and improving quality of life. This review outlines the mechanism, clinical efficacy, and long-term outcome of DBS in TS. Results from clinical studies reveal significant reductions in tics. However, success with DBS is variable depending on a number of factors, including target selection and electrode placement. The use of DBS has ethical considerations, which include risks to the surgical procedure, the need for full and complete informed consent, and questions about the implications of such treatment on cognitive and emotional growth. Long-term follow-up will be required to ensure appropriate patient outcomes and complication management. Additional research and ethical debate will be needed with advancing DBS technology to ensure responsible and equitable treatment. This paper narratively summarizes the surgical options available for TS, with a focus on the current status of DBS in the management of the disease.

French guidelines for the diagnosis and management of Tourette syndrome

The term "Gilles de la Tourette syndrome", or the more commonly used term "Tourette syndrome" (TS) refers to the association of motor and phonic tics which evolve in a context of variable but frequent psychiatric comorbidity. The syndrome is characterized by the association of several motor tics and at least one phonic tic that have no identifiable cause, are present for at least one year and appear before the age of 18. The presence of coprolalia is not necessary to establish or rule out the diagnosis, as it is present in only 10% of cases. The diagnosis of TS is purely clinical and is based on the symptoms defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). No additional tests are required to confirm the diagnosis of TS. However, to exclude certain differential diagnoses, further tests may be necessary. Very frequently, one or more psychiatric comorbidities are also present, including attention deficit hyperactivity disorder, obsessive-compulsive disorder, anxiety, explosive outbursts, self-injurious behaviors, learning disorders or autism spectrum disorder. The condition begins in childhood around 6 or 7 years of age and progresses gradually, with periods of relative waxing and waning of tics. The majority of patients experience improvement by the end of the second decade of life, but symptoms may persist into adulthood in around one-third of patients. The cause of TS is unknown, but genetic susceptibility and certain environmental factors appear to play a role. The treatment of TS and severe forms of tics is often challenging and requires a multidisciplinary approach (involving the general practitioner (GP), pediatrician, psychiatrist, neurologist, school or occupational physicians, psychologist and social workers). In mild forms, education (of young patients, parents and siblings) and psychological management are usually recommended. Medical treatments, including antipsychotics, are essential in the moderate to severe forms of the disease (i.e. when there is a functional and/or psychosocial discomfort linked to tics). Over the past decade, cognitive-behavioral therapies have been validated for the treatment of tics. For certain isolated tics, botulinum toxin injections may also be useful. Psychiatric comorbidities, when present, often require a specific treatment. For very severe forms of TS, treatment by deep brain stimulation offers real therapeutic hope. If tics are suspected and social or functional impairment is significant, specialist advice should be sought, in accordance with the patient's age (psychiatrist/child psychiatrist; neurologist/pediatric neurologist). They will determine tic severity and the presence or absence of comorbidities. The GP will take over the management and prescription of treatment: encouraging treatment compliance, assessing side effects, and combating stigmatization among family and friends. They will also play an important role in rehabilitation therapies, as well as in ensuring that accommodations are made in the patient's schooling or professional environment.

Neuroanatomical and functional correlates in tic disorders and Tourette's syndrome: A narrative review

Tic disorders represent a developmental neuropsychiatric condition whose causes can be attributed to a variety of environmental, neurobiological, and genetic factors. From a neurophysiological perspective, the disorder has classically been associated with neurochemical imbalances (particularly dopamine and serotonin) and structural and functional alterations affecting, in particular, brain areas and circuits involved in the processing and coordination of movements: the basal ganglia, thalamus, motor cortical area, and cingulate cortex; however, more recent research is demonstrating the involvement of many more brain regions and neurotransmission systems than previously observed, such as the prefrontal cortex and cerebellum. In this paper, therefore, we summarize the evidence to date on these abnormalities with the intent to illustrate and clarify the main neuroanatomical differences between patients with tic disorders and healthy individuals.

An Online Mindfulness-Based Group Intervention for Tics: A Pilot Randomized Controlled Trial

BACKGROUND

Current treatments for Tourette syndrome (TS) and persistent tic disorder (PTD) are often insufficiently effective, inaccessible, and frequently associated with adverse events. Thus, we must continue to develop and test effective, accessible, and safe treatment options.

OBJECTIVE

We aimed to conduct a pilot randomized controlled trial (RCT) comparing a novel, videoconference-delivered group mindfulness-based intervention for tics (MBIT) to videoconference-delivered group psychoeducation, relaxation, and supportive therapy (PRST) for adults with TS or PTD.

METHODS

Thirty-two adults with TS or PTD were randomly assigned to receive 8 weeks of either MBIT or PRST. Tic severity, tic-related impairment, and global improvement were assessed by a trained, independent evaluator who was masked to treatment condition at baseline (week 0), posttreatment (week 9), 1-month follow-up, and 6-month follow-up. All study procedures were conducted online via secure videoconferencing.

RESULTS

Twenty-eight participants began treatment and were included in analyses. MBIT, relative to PRST, was associated with a significantly greater decline in tic severity (d = 0.85) and tic-related impairment (d = 0.99) from baseline to posttreatment. Treatment response was significantly higher in MBIT (69%) than in PRST (13%). Neither treatment resulted in serious adverse effects. The durability of treatment outcomes is also reported and discussed.

CONCLUSIONS

The results from this pilot RCT suggest that videoconference-delivered group MBIT may be an efficacious, accessible, and safe intervention for adults with tics. Future research is necessary to confirm these preliminary findings. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Deep brain stimulation for Tourette's syndrome

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the efficacy and harm of deep brain stimulation for motor symptoms, with psychiatric and behavioural comorbidities, either individually or in combination, in adults and adolescents with Tourette's syndrome compared to placebo, sham intervention, or the best available behavioural and pharmacological treatment.

Clinical management of children with tic disorder: insights from therapeutic visits in China-a real-world study

Objective

This retrospective study aims to investigate the treatment of tic disorder (TD) in Dongfang Hospital affiliated with Beijing University of Chinese Medicine, explore its underlying mechanism, and provide valuable insights for future research and clinical management of TD.

Methods

The electronic medical records of children with TD, from 2015 to 2021, were extracted from the information system of Dongfang Hospital affiliated with Beijing University of Chinese Medicine. The clinical characteristics of TD, utilization patterns of Chinese herbal medicine and synthetic drugs in prescriptions, as well as their pharmacological effects, were statistically described and categorized. In addition, association rules and network pharmacology were employed to identify core prescriptions (CPs) and elucidate their microscopic molecular mechanisms in treating TD.

Results

The age range of the children was from 6 to 11 years, with a higher proportion of male participants than female ones. The average duration of treatment was 6 weeks. Regimen Z for the treatment of TD can be summarized as follows: Chinese herbal medicine [Saposhnikoviae Radix (FangFeng), Puerariae Lobatae Radix (GeGen), Uncariae Ramulus cum Uncis (GouTeng), Acori Tatarinowii Rhizoma (ShiChangPu), Chuanxiong Rhizoma (ChuanXiong)] and vitamins [lysine, inosite, and vitamin B12 oral solution] form the basic treatment, combined with immunomodulators, antibiotics, electrolyte-balancing agents, and antiallergic agents. CPs primarily exerted their effects through the modulation of gene expression (transcription), the immune system, and signal transduction pathways, with interleukin-4 and interleukin-13 pathways being particularly crucial. Among the lysine synthetic drugs used, inosite and vitamin B12 oral solution were the most frequently prescribed.

Conclusion

The regimen Z drug treatment holds significant importance in the field, as it exerts its therapeutic effects through a multitude of pathways and intricate interventions. Chinese herbal medicine primarily regulates immune system-related pathways, while synthetic drugs predominantly consist of vitamins.

Tourette syndrome research highlights from 2023

In this, the tenth annual update for the F1000Research Tics collection, we summarize research reports from 2023 on Gilles de la Tourette syndrome and other tic disorders. The authors welcome article suggestions and thoughtful feedback from readers.

Definition, diagnosis and classification of infection-related movement disorders: Consensus proposal

BACKGROUND

Infection-related movement disorders (IRMD) present a complex diagnostic challenge due to the broad phenotypic spectrum, the variety of possible infectious aetiologies, and the complicated underlying mechanisms. Yet, a comprehensive framework for classifying IRMD is lacking.

METHODS

An international consensus panel under the directives of the Movement Disorders Society Infection-Related Movement Disorders Study Group developed a comprehensive definition and a consensus classification system. Case scenarios were used for validation.

RESULTS

A definition for IRMD and a two-axis-based classification system consisting of six descriptors are proposed, intended as tools for researchers and clinicians. Collected information on clinical characteristics, investigational findings, the infectious organism and presumed pathogenesis facilitate the evaluation of diagnostic certainty.

CONCLUSION

The proposed framework will serve for optimised diagnostic algorithms, systematic aggregation of informative datasets across studies, and ultimately improved care and outcome of patients with IRMDs.

Clonidine Patch for Tourette Syndrome With Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

To explore the efficacy and safety of clonidine adhesive patch in Tourette syndrome (TS) patients with comorbid attentiondeficit/hyperactivity disorder (ADHD).

METHODS

This study was conducted on a sample of children and adolescents with TS who had comorbid ADHD between May 2012 and March 2015. The patients were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, and were randomly assigned to four different dose groups: 1.0 mg/week, 1.5 mg/week, 2.0 mg/week and placebo group, and the symptom was evaluated by Swanson, Nolan, and Pelham Rating Scale, Version IV (SNAP-IV) and Yale Global Tic Severity Scale scales every 2 weeks. The primary outcome was tic disorders (TD) effective rate at week 8.

RESULTS

One hundred and twenty-seven TS patients with comorbid ADHD in 2.0 mg/week (n=35), 1.5 mg/week (n=27), 1.0 mg/week (n=36) and placebo groups (n=29) were included in this subgroup analysis. The TD effective rate of the 2.0 mg, 1.5 mg, and 1.0 mg groups at week 8 were significantly better than that in placebo group (85.7%, 81.5%, and 86.1% vs. 20.7%, all p<0.0001). All groups demonstrated significant improvements in SNAP-IV total scale scores compared to baseline (p=0.0004), with treatment groups showing only a trend for better performance compared to placebo group at week 8, without statistical differences (22.1±15.41, 21.3±11.96, and 21.2±12.48 vs. 26.0±13.37, p=0.3385). A total of 9 adverse reactions occurred, all recovered spontaneously without additional medication.

CONCLUSION

Clonidine adhesive patch could safely and effectively reduce the tic symptoms of TS patients with comorbid ADHD, and might be potentially helpful in the ADHD symptoms control.

Placebo and Nocebo Responses in Pharmacological Trials of Tic Disorders: A Meta-Analysis

BACKGROUND

Clinical trials of new drugs for tic disorders (TD) often fail to yield positive results. Placebo and nocebo responses play a vital role in interpreting the outcomes of randomized controlled trials (RCTs), yet these responses in RCTs of TD remain unexplored.

OBJECTIVE

The aim was to assess the magnitude of placebo and nocebo responses in RCTs of pharmacological interventions for TD and identify influencing factors.

METHODS

A systematic search of the Embase, Medline, Cochrane Central Register of Controlled Trials, and PsycINFO databases was conducted. Eligible studies were RCTs that compared active pharmacological agents with placebos. Placebo response was defined as the change from baseline in TD symptom severity in the placebo group, and nocebo response as the proportion experiencing adverse events (AEs) in this group. Subgroup analysis and meta-regression were performed to explore modifying factors.

RESULTS

Twenty-four trials involving 2222 participants were included in this study. A substantial placebo response in TD symptom severity was identified, with a pooled effect size of -0.79 (95% confidence interval [CI] -0.99 to -0.59; I2 = 67%). Forty-four percent (95% CI 27% to 63%; I2 = 92%) of patients experienced AEs while taking inert pills. Sample size, study design, and randomization ratio were correlated with changes in placebo and nocebo responses.

CONCLUSION

There were considerable placebo and nocebo responses in TD clinical trials. These results are of great relevance for the design of future trials and for clinical practice in TD.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration ID CRD42023388397. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The Association of Quality of Life with Psychosocial Factors in Adolescents with Tourette Syndrome

Individuals with Tourette syndrome (TS) have poorer quality of life (QoL) than their peers, yet factors contributing to poor QoL in this population remain unclear. Research to date has predominantly focused on the impact of tics and psychiatric symptoms on QoL in TS samples. The aim of this cross-sectional, multi-informant study was to identify psychosocial variables that may impact adolescent QoL in TS. Thirty-eight adolescents aged 13 to 17 with TS and 28 age-matched controls participated with a caregiver. No group differences were found on QoL, although the TS group reported reduced QoL compared to population normative data. In the TS group, reduced QoL was associated with lower self-esteem, poorer family functioning, higher stress, and greater depression and anxiety; QoL was unrelated to tic severity. In regression analyses, after adjusting for covariates, family functioning was the strongest predictor of QoL. These results emphasize the need to further explore the influence of psychosocial factors, particularly family functioning, on QoL in adolescents with TS.

Use of Medical Cannabis in Patients with Gilles de la Tourette's Syndrome in a Real-World Setting

Objective: Tourette's syndrome (TS) is a neurodevelopmental disorder characterized by vocal and motor tics and other comorbidities. Clinical recommendations for the use of medical cannabis are established, yet further guidance is needed. The aim of this study was to describe the experience of patients with TS with medical cannabis. Materials and Methods: TS patients were recruited from a registry of patients ("Tikun Olam" company). Questionnaires were answered before and after 6 months of treatment. Patients were divided into two groups: (A) patients who responded and (B) patients who did not respond to the follow-up questionnaire. In group A, an analysis was made to evaluate the presence and frequency of motor and vocal tics. The patients' general mood, employment status, quality of life, and comorbidities were also included in the analysis. Results: Seventy patients were identified. The tetrahydrocannabinol and cannabidiol mean daily dose was 123 and 50.5 mg, respectively. In group A, a statistically significant improvement was identified in quality of life (p<0.005), employment status (p=0.027), and in the reduction of the number of medications (p<0.005). Sixty-seven percent and 89% of patients with obsessive-compulsive disorder and anxiety comorbidities, respectively, reported an improvement. No statistically significant improvement was identified in motor tics (p=0.375), vocal tics (p>0.999), tics frequency (p=0.062), or general mood (p=0.129). The most frequent adverse effects were dizziness (n=4) and increased appetite (n=3). Conclusion: Subjective reports from TS patients suggest that medical cannabis may improve their quality of life and comorbidities. More studies are needed to evaluate the efficacy and safety of medical cannabis. Registry in the MOH: https://www.moh.gov.sg/ (Trial number: 0185-19-ASF).

A Double-Blind, Randomized, Controlled Crossover Trial of Cannabis in Adults with Tourette Syndrome

Background: The number of effective evidence-based treatment options for patients with Tourette syndrome (TS) is limited. Emerging evidence shows cannabinoids as promising for the treatment of tics. Objectives: To compare the efficacy and tolerability of single doses of three vaporized medical cannabis products and placebo in reducing tics in adults with TS. Methods: In a randomized, double-blind, crossover design, each participant received a vaporized single 0.25 g dose of Δ9-tetrahydrocannabinol (THC) 10%, THC/cannabidiol (CBD) 9%/9%, CBD 13%, and placebo at 2-week intervals. Our primary outcome was the Modified Rush Video-Based Tic Rating Scale (MRVTRS), taken at baseline and at 0.5, 1, 2, 3, and 5 h after dose administration. Secondary measures included the Premonitory Urge for Tics Scale (PUTS), Subjective Units of Distress Scale (SUDS), and Clinical Global Impression-Improvement (CGI-I). Correlations between outcomes and cannabinoid plasma levels were calculated. Tolerability measures included open-ended and specific questions about adverse events (AEs). Results: Twelve adult patients with TS were randomized, with nine completing the study. There was no statistically significant effect of product on the MRVTRS. However, there was a significant effect of THC 10%, and to a lesser extent THC/CBD 9%9%, versus placebo on the PUTS, SUDS, and CGI-I. As well, there were significant correlations between plasma levels of THC and its metabolites, but not CBD, with MRVTRS, PUTS, and SUDS measures. There were more AEs from all cannabis products relative to placebo, and more AEs from THC 10% versus other cannabis products, particularly cognitive and psychomotor effects. Most participants correctly identified whether they had received cannabis or placebo. Conclusions: In this pilot randomized controlled trial of cannabis for tics in TS, there was no statistically significant difference on the MRVTRS for any of the cannabis products, although the THC 10% product was significantly better than placebo on the secondary outcome measures. Also, THC and metabolite plasma levels correlated with improvement on all measures. The THC 10% product resulted in the most AEs. ClinicalTrials.gov ID: NCT03247244.

Study protocol: A cross-sectional survey of clinicians to identify barriers to clinical practice guideline implementation in the assessment and treatment of persistent tic disorders

INTRODUCTION

Eight members of the International Parkinson's Disease and Movement Disorders Society Tic and Tourette Syndrome Study Group formed a subcommittee to discuss further barriers to practice guideline implementation. Based on expert opinion and literature review, the consensus was that practice variations continue to be quite broad and that many barriers in different clinical settings might negatively influence the adoption of the American Academy of Neurology and the European Society for the Study of Tourette Syndrome published guidelines.

OBJECTIVES

1) To identify how clinical practices diverge from the existing American Academy of Neurology and European Society for the Study of Tourette Syndrome guidelines, and 2) to identify categories of barriers leading to these clinical care gaps.

METHODS AND ANALYSIS

This article presents the methodology of a planned cross-sectional survey amongst healthcare professionals routinely involved in the clinical care of patients with persistent tic disorders, aimed at 1) identifying how practices diverge from the published guidelines; and 2) identifying categories of barriers leading to these clinical care gaps. Purposeful sampling methods are used to identify and recruit critical persistent tic disorders stakeholders. The analysis will use descriptive statistics.

CANNA-TICS: Efficacy and safety of oral treatment with nabiximols in adults with chronic tic disorders - Results of a prospective, multicenter, randomized, double-blind, placebo controlled, phase IIIb superiority study

Preliminary data suggest that cannabis-based medicines might be a promising new treatment for patients with Tourette syndrome (TS)/chronic tic disorders (CTD) resulting in an improvement of tics, comorbidities, and quality of life. This randomized, multicenter, placebo-controlled, phase IIIb study aimed to examine efficacy and safety of the cannabis extract nabiximols in adults with TS/CTD (n = 97, randomized 2:1 to nabiximols:placebo). The primary efficacy endpoint was defined as a tic reduction of ≥ 25% according to the Total Tic Score of the Yale Global Tic Severity Scale after 13 weeks of treatment. Although a much larger number of patients in the nabiximols compared to the placebo group (14/64 (21·9%) vs. 3/33 (9·1%)) met the responder criterion, superiority of nabiximols could formally not be demonstrated. In secondary analyses, substantial trends for improvements of tics, depression, and quality of life were observed. Additionally exploratory subgroup analyses revealed an improvement of tics in particular in males, patients with more severe tics, and patients with comorbid attention deficit/hyperactivity disorder suggesting that these subgroups may benefit better from treatment with cannabis-based medication. There were no relevant safety issues. Our data further support the role of cannabinoids in the treatment of patients with chronic tic disorders.

Molecular Landscape of Tourette's Disorder

Tourette's disorder (TD) is a highly heritable childhood-onset neurodevelopmental disorder and is caused by a complex interplay of multiple genetic and environmental factors. Yet, the molecular mechanisms underlying the disorder remain largely elusive. In this study, we used the available omics data to compile a list of TD candidate genes, and we subsequently conducted tissue/cell type specificity and functional enrichment analyses of this list. Using genomic data, we also investigated genetic sharing between TD and blood and cerebrospinal fluid (CSF) metabolite levels. Lastly, we built a molecular landscape of TD through integrating the results from these analyses with an extensive literature search to identify the interactions between the TD candidate genes/proteins and metabolites. We found evidence for an enriched expression of the TD candidate genes in four brain regions and the pituitary. The functional enrichment analyses implicated two pathways ('cAMP-mediated signaling' and 'Endocannabinoid Neuronal Synapse Pathway') and multiple biological functions related to brain development and synaptic transmission in TD etiology. Furthermore, we found genetic sharing between TD and the blood and CSF levels of 39 metabolites. The landscape of TD not only provides insights into the (altered) molecular processes that underlie the disease but, through the identification of potential drug targets (such as FLT3, NAALAD2, CX3CL1-CX3CR1, OPRM1, and HRH2), it also yields clues for developing novel TD treatments.

Emerging therapies and recent advances for Tourette syndrome

Tourette syndrome is the most prevalent hyperkinetic movement disorder in children and can be highly disabling. While the pathomechanism of Tourette syndrome remains largely obscure, recent studies have greatly improved our knowledge about this disease, providing a new perspective in our understanding of this condition. Advances in electrophysiology and neuroimaging have elucidated that there is a reduction in frontal cortical volume and reduction of long rage connectivity to the frontal lobe from other parts of the brain. Several genes have also been identified to be associated with Tourette syndrome. Treatment of Tourette syndrome requires a multidisciplinary approach which includes behavioral and pharmacological therapy. In severe cases surgical therapy with deep brain stimulation may be warranted, though the optimal location for stimulation is still being investigated. Studies on alternative therapies including traditional Chinese medicine and neuromodulation, such as transcranial magnetic stimulation have shown promising results, but still are being used in an experimental basis. Several new therapies have also recently been tested in clinical trials. This review provides an overview of the latest findings with regards to genetics and neuroimaging for Tourette syndrome as well as an update on advanced therapeutics.

Tourette syndrome research highlights from 2021

We summarize selected research reports from 2021 relevant to Tourette syndrome that the authors consider most important or interesting. The authors welcome article suggestions and thoughtful feedback from readers.

Prevalence of nail biting and its chronological relationship with tics in child and adolescent outpatients with Tourette syndrome: a single-centre, retrospective observational study

OBJECTIVE

To evaluate the prevalence of nail biting in child and adolescent outpatients at a single institution and the chronological relationship between nail biting and tics in patients with Tourette syndrome (TS) with or without attention-deficit hyperactivity disorder (ADHD).

DESIGN

Retrospective observational study.

SETTING

Teaching hospital in Taiwan.

PARTICIPANTS

All participants were aged 4-18 years, including 535 patients with TS, 230 patients with provisional tic disorder and 1460 patients without neurological or psychiatric disorders (controls).

OUTCOME MEASURES

Presence of nail biting, starting age for nail biting and starting age for motor and/or vocal tics.

RESULTS

Nail biting was more commonly observed in patients with TS (56.6%) than in patients with provisional tic disorder (27.4%) or controls (15.0%), regardless of sex (all p<0.020). Nail biting was also more common in patients with TS with ADHD than in those without (75.0% vs 47.6%; p<0.001), but the starting age was significantly later in those with concomitant ADHD than without (5.3 vs 3.8 years; p<0.001). In patients with TS, the onset of nail biting occurred earlier than that of tics, regardless of ADHD status.

CONCLUSION

Nail biting was more prevalent and occurred earlier than tics in patients with TS, regardless of ADHD status, in the study population.

Neurosurgical management of Tourette syndrome: A literature review and analysis of a case series treated with deep brain stimulation

Tourette syndrome (TS) is a heterogeneous disorder, which clinical presentation includes both multiple motor and vocal tics and commonly associated psychiatric conditions (obsessive-compulsive disorder, attention deficit hyperactivity disorder, depression, anxiety, etc.). Treatment options primarily consist of non-pharmacological interventions (habit reversal training, relaxation techniques, cognitive behavioral therapy, and social rehabilitation) and pharmacotherapy. In case of the intractable forms, neurosurgical treatment may be considered, primarily deep brain stimulation (DBS). DBS appear to be effective in medically intractable TS patients, although, the preferential brain target is still not defined. The majority of studies describe small number of cases and the issues of appropriate patient selection and ethics remain to be clarified. In this article, we review the main points in management of TS, discuss possible indications and contraindications for neurosurgical treatment, and analyze our experience of DBS in a case series of refractory TS patients with the focus on target selection and individual outcomes.

Identifying Factors Associated with the Recurrence of Tic Disorders

Tic disorders are neurological disorders that are prone to fluctuation and recurrence. It is important to study the factors related to disease recurrence and to subsequently provide suggestions for clinical treatment. A retrospective study was conducted to assess patients with recurrent and non-recurring tic disorders diagnosed in the Pediatric Tic Disorder Clinic of the First Affiliated Hospital of Tianjin University of Traditional Chinese Medicine, China, and to extract various factors—such as fetal status; medication, allergy, and family history; social and psychological factors; blood lead content; electroencephalogram (EEG); disease duration; type of tics; and disease severity—and identify factors associated with recurrence. The recurrence rate of tic disorders was approximately 45.10% in this study. The childbirth conditions, surgery/trauma, respiratory tract infection, allergy, stress, consumption of tiapride, and severity of tic disorders were factors related to and affected disease recurrence.

Medical Cannabis for Gilles de la Tourette Syndrome: An Open-Label Prospective Study

Objectives. Assessing the effectiveness and tolerability of medical cannabis (MC) treatment on Gilles de la Tourette syndrome (GTS) patients. Methods. We report on an open-label, prospective study on the effect of MC on adult GTS patients. MC mode of use was decided by the treating neurologist and the patient. Δ9-Tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) content within MC product and monthly dose were titrated during the study. Following treatment initiation, patients were assessed after 4 and 12 weeks for efficacy, tolerability, and side effects. Results. Eighteen patients entered the study. Baseline Yale Global Tic Severity Scale- (YGTSS) Total (range 0-100) was $60.3\pm 17.1$ . Three patients did not reach the end of follow-up period. The most common mode of administration was smoking (80%). Following twelve weeks of treatment, a significant 38% average reduction ( $p=0.002$ ) of YGTSS-Total and a 20% reduction ( $p=0.043$ ) of Premonitory Urge for Tic Scale (PUTS) were observed. Common side effects were dry mouth (66.7%), fatigue (53.3%), and dizziness (46.7%). Three patients suffered from psychiatric side effects including worsening of obsessive compulsive disorder (stopped treatment), panic attack, and anxiety (resolved with treatment modification). Six patients (40%) reported cognitive side effects regarding time perception, visuospatial disorientation, confusion, slow processing speed, and attention. Conclusions. MC treatment demonstrates good efficacy and tolerability in adult GTS patients. Predilection for smoking rather than using oil drops requires further comparative studies to evaluate the efficacy of each. Cognitive and psychiatric side effects have to be monitored and addressed.

ONLINE-TICS: Internet-Delivered Behavioral Treatment for Patients with Chronic Tic Disorders

Comprehensive Behavioral Intervention for Tics (CBIT) is considered a first-line therapy for tics. However, availability of CBIT is extremely limited due to a lack of qualified therapists. This study is a multicenter (n = 5), randomized, controlled, observer-blind trial including 161 adult patients with chronic tic disorders (CTD) to provide data on efficacy and safety of an internet-delivered, completely therapist-independent CBIT intervention (iCBIT Minddistrict^®) in the treatment of tics compared to placebo and face-to-face (f2f) CBIT. Using a linear mixed model with the change to baseline of Yale Global Tic Severity Scale-Total Tic Score (YGTSS-TTS) as a dependent variable, we found a clear trend towards significance for superiority of iCBIT (n = 67) over placebo (n = 70) (−1.28 (−2.58; 0.01); p = 0.053). In addition, the difference in tic reduction between iCBIT and placebo increased, resulting in a significant difference 3 (−2.25 (−3.75; −0.75), p = 0.003) and 6 months (−2.71 (−4.27; −1.16), p < 0.001) after the end of treatment. Key secondary analysis indicated non-inferiority of iCBIT in comparison to f2f CBIT (n = 24). No safety signals were detected. Although the primary endpoint was narrowly missed, it is strongly suggested that iCBIT is superior compared to placebo. Remarkably, treatment effects of iCBIT even increased over time.

European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part IV: deep brain stimulation

In 2011 the European Society for the Study of Tourette Syndrome (ESSTS) published its first European clinical guidelines for the treatment of Tourette Syndrome (TS) with part IV on deep brain stimulation (DBS). Here, we present a revised version of these guidelines with updated recommendations based on the current literature covering the last decade as well as a survey among ESSTS experts. Currently, data from the International Tourette DBS Registry and Database, two meta-analyses, and eight randomized controlled trials (RCTs) are available. Interpretation of outcomes is limited by small sample sizes and short follow-up periods. Compared to open uncontrolled case studies, RCTs report less favorable outcomes with conflicting results. This could be related to several different aspects including methodological issues, but also substantial placebo effects. These guidelines, therefore, not only present currently available data from open and controlled studies, but also include expert knowledge. Although the overall database has increased in size since 2011, definite conclusions regarding the efficacy and tolerability of DBS in TS are still open to debate. Therefore, we continue to consider DBS for TS as an experimental treatment that should be used only in carefully selected, severely affected and otherwise treatment-resistant patients.

Protocol of a randomized controlled trial to investigate the efficacy and neural correlates of mindfulness-based habit reversal training in children with Tourette syndrome

BACKGROUND

Tourette syndrome (TS) is a developmental neuropsychiatric disorder. Behavior therapy, especially habit reversal training (HRT), has gradually become regarded as one of the core therapies for TS. Mindfulness approaches can improve psychological adjustment and reduce stress and anxiety, suggesting potential benefits when incorporated into behavior therapy. To improve the efficacy of HRT, we combined it with mindfulness, an approach named mindfulness-based habitual reversal training (MHRT). The aim of this protocol is to investigate the efficacy and neural mechanisms of MHRT for TS.

METHODS/DESIGN

We will perform a randomized control trial (RCT) to evaluate the efficacy and neural mechanisms of MHRT. The sample will include 160 participants (including 120 patients with TS and 40 healthy controls). The patient sample will be randomly divided into three groups exposed to three different types of training: MHRT, HRT, and psychoeducation and supportive therapy (PST). Participants will be assessed and undergo resting-state fMRI scans at baseline and at the end of the 12-week training. The Yale Global Tic Severity Scale (YGTSS) and Premonitory Urge for Tic Scale (PUTS) will be used to assess the severity of tic symptoms and premonitory urges. The primary outcomes are change scores on the YGTSS and other assessments from baseline and the end of the training. The secondary outcomes are the neural correlates of these trainings among these groups based on graph theory, which is used to characterize brain functional connectivity networks. The default mode network (DMN) and the salience network (SN) will be assessed (which have been associated with mindfulness as well as the generation of tic symptoms) by network parameters, including clustering coefficients and shortest path lengths. Changes in these network parameters will be regarded as the neural correlates of the behavioral training.

DISCUSSION

MHRT was newly developed for the treatment of TS. MHRT may lead to greater reductions in tic severity than traditional HRT. Changes in the network parameters of the DMN and SN may show associations with the efficacy of MHRT.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn, ChiCTR2100053077, China.

Treatment failure in persistent tic disorders: an expert clinicians' consensus-based definition

A standardized definition of treatment failure in the management of tics is currently lacking. Such definition would prevent persistent use of unnecessary interventions and help clinicians to determine when to offer less established treatments (e.g., deep brain stimulation surgery). To achieve an expert consensus-based definition of failure of medical treatments for tics, we used a multi-step, multi-round, web-based Delphi approach involving international specialist clinicians with specific expertise in tic disorders. These experts were identified through professional networks or consortia related to chronic tic disorders. We created a survey and reviewed the questions with stakeholders prior to two rounds of Delphi surveys, followed by a final review and discussion among research team members. Both survey rounds were completed using a sample of 36 expert stakeholders from 14 countries, including neurologists, psychiatrists, and clinical psychologists. The Delphi process led to consensus on 10 statements which formed the final definition of treatment failure. The definition was structured and operationalized according to two separate sections, one for behavioral and one for pharmacological treatments. Core components of the definition and its operationalization included lack of efficacy, adherence, and tolerability, as well as a definition of failure of behavioral therapies as a whole, and of pharmacological therapies as a whole. The group concluded that the components of this specific definition reflect the range and complexity of characteristics to consider in establishing tic-related treatment failure. Future research should assess the feasibility of this operational definition and whether it will change clinical decision-making and improve management outcomes.

Recent progress on Tourette syndrome

Tic disorders and Tourette syndrome are the most common movement disorders in children and are characterized by movements or vocalizations. Clinically, Tourette syndrome is frequently associated with comorbid psychiatric symptoms. Although dysfunction of cortical–striatal–thalamic–cortical circuits with aberrant neurotransmitter function has been considered the proximate cause of tics, the mechanism underlying this association is unclear. Recently, many studies have been conducted to elucidate the epidemiology, clinical course, comorbid symptoms, and pathophysiology of tic disorders by using laboratory studies, neuroimaging, electrophysiological testing, environmental exposure, and genetic testing. In addition, many researchers have focused on treatment for tics, including behavioral therapy, pharmacological treatment, and surgical treatment. Here, we provide an overview of recent progress on Tourette syndrome.

Diagnostic Approach to Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infections (PANDAS): A Narrative Review of Literature Data

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) are clinical conditions characterized by the sudden onset of obsessive-compulsive disorder and/or tics, often accompanied by other behavioral symptoms in a group of children with streptococcal infection. PANDAS-related disorders, including pediatric acute-onset neuropsychiatric syndrome (PANS), childhood acute neuropsychiatric symptoms (CANS), and pediatric infection triggered autoimmune neuropsychiatric disorders (PITANDs), have also been described. Since first defined in 1998, PANDAS has been considered a controversial diagnosis. A comprehensive review of the literature was performed on PubMed and Scopus databases, searching for diagnostic criteria and diagnostic procedures of PANDAS and related disorders. We propose a test panel to support clinicians in the workout of PANDAS/PANS patients establishing an appropriate treatment. However, further studies are needed to improve our knowledge on these acute-onset neuropsychiatric conditions.

The Efficacy of Acupuncture on Tic Disorders in Children: A Retrospective and Propensity Score-Matched Study

Background : Acupuncture has been considered as a complementary or alternative therapy for children with tic disorders (TD), but its efficacy remains largely unknown. This study retrospectively examined the efficacy of acupuncture treatment for TD in children over the course of 12 weeks. Methods: Data were collected from Traditional Chinese Medicine clinics in a public pediatric hospital in Shanghai between June 2020 and March 2021. A total of 250 patients with TD were included in the study, with 122 patients exposed to acupuncture therapy combined with conventional treatment (observation group), and 128 patients exposed to conventional treatment alone (control group). Propensity score matching analyses were used to balance baseline characteristics, resulting in 78 matched patients for each group. Reductions in the Yale Global Tic Severity Scale (YGTSS) total score were analyzed in the two groups after 12 weeks of treatment. Results: The two groups reached equilibrium in terms of baseline demographic characteristics and YGTSS total score after the propensity score matching (P > 0.05). Compared to the control group, the reduction in the YGTSS total score after 12 weeks of treatment was greater for the observation group (OR = 2.94, 95% CI: 1.03, 8.39, P = 0.04), and this association was stronger for patients who had significant vocal tics (β = 0.29, 95% CI: 0.88, 2.68, P = 0.001). The clinical efficacy for the observation group was significantly better than the control group. Conclusions: We provided preliminary evidence supporting the therapeutic effect of acupuncture for TD in children. Hence, our findings indicate that acupuncture could be an adjuvant treatment efficacious for TD in children, especially for vocal tics.