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

Dietary inflammatory index and its impact on severity and recurrence of Tourette syndrome in children

BACKGROUND

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by the presence of motor and vocal tics, typically beginning in childhood. Despite significant research efforts, the exact pathophysiology of TS remains incompletely understood. Recent studies suggest that inflammation may play a role in the severity and progression of TS, pointing to the potential influence of dietary and lifestyle factors on the condition. Currently, research on the specific connection between dietary inflammatory index (DII) and TS is still in its early stages, requiring additional clinical and epidemiological studies to validate the strength and specific mechanisms of this connection.

AIM

To investigate the association between DII and the severity, recurrence, and inflammatory levels of TS in children.

METHODS

A total of 207 children diagnosed with TS in the pediatric department of Qingdao Chengyang People's Hospital from January 2022 to January 2023 were selected. They were divided into stable and unstable groups based on follow-up conditions. Before enrollment, general information of the children [age, gender, body mass index (BMI), guardian's education level, DII score, medical history, family history, academic stress, electronic device usage, medication, and disease progression] was assessed, and serum inflammatory levels were measured during follow-up visits. DII scores and Yale Global Tic Severity Scale (YGTSS) scores were calculated. Furthermore, based on YGTSS scores, the children were classified into mild, moderate, and severe groups. The DII, interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-α) levels in each group were compared.

RESULTS

Follow-up surveys were completed by 207 children and their guardians. Among them, 117 children were in the stable group, and 90 were in the recurrent group. We found no statistically significant differences in age, gender, comorbidities, BMI, and disease duration between the two groups (P > 0.05). However, academic stress, electronic device usage, medication, guardian's education level, and DII scores showed statistically significant differences between the groups (P < 0.05). Multifactorial regression analysis revealed that guardian's anxiety level, DII score, medication, academic stress, and family history were statistically significant factors (P < 0.05) affecting the recurrence of TS in children. Therefore, anxiety level, DII score, medication status, electronic device usage, and academic stress were identified as factors influencing the recurrence of TS in children. Among them, DII score, academic stress, and family history had odds ratios (OR) greater than 1, indicating risk factors, whereas medication status and guardian's education level had OR values less than 1, indicating protective factors. According to the YGTSS scores, children were categorized into mild, moderate, and severe groups. Comparative analysis of DII and inflammatory levels in children with different degrees of tic disorders revealed that the severe group had the highest DII and inflammatory levels, followed by the moderate group, and the mild group had the lowest levels. The trend of TS progression was consistent with the DII results. Receiver operating characteristic curves were plotted to predict disease progression in patients with TS via inflammatory markers. The areas under the curve for IL-6, CRP, and TNF-α were 0.894 (95%CI: 0.817-0.969), 0.793 (95%CI: 0.694-0.893), and 0.728 (95%CI: 0.614-0.843) respectively, with statistically significant differences (P < 0.05). According to the Youden index, the optimal cutoff values were IL-6 = 3.775 ng/L (sensitivity 68.1% and specificity 68.4%), CRP = 6.650 mg/L (sensitivity 60.6% and specificity 68.4%), and TNF-α = 0.666 (sensitivity 60.6% and specificity 71.1%).

CONCLUSION

We found a certain correlation between DII and the severity, recurrence, and inflammatory levels of TS in children. Reasonable reduction in the intake of pro-inflammatory foods may be beneficial in reducing the risk of disease progression in children with TS.

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.

Randomized, double-blind, placebo-controlled trial of aripiprazole oral solution in children and adolescents with Tourette's disorder

BACKGROUND

Aripiprazole is the most frequently recommended antipsychotic for the treatment of tics in children and adolescents with Tourette's disorder (TD). However, to date, a randomized controlled trial for aripiprazole oral solution has not been conducted despite being widely preferred by children. Therefore, we examined whether aripiprazole oral solution is effective for treating tics.

METHODS

All patients received a flexible dose of aripiprazole oral solution (1 mg/mL, range: 2-20 mg) with a starting dose of 2 mg. The target dose for patients weighing < 50 kg was 2, 5, and 10 mg/day, and that for patients weighing ≥ 50 kg was 5, 10, 15, and 20 mg/day. The primary efficacy endpoint was the mean change in the Yale Global Tic Severity Scale-total tic score (YGTSS-TTS) from baseline to week 8.

RESULTS

Of the 121 patients enrolled, 59 patients (96.7%) in the aripiprazole group and 53 patients (88.3%) in the placebo group completed the study. The aripiprazole group showed significantly greater improvement in the YGTSS-TTS from baseline to week 8 than the placebo group (least squares mean difference [95% confidence interval (CI)] -5.5 [95% CI - 8.4 to - 2.6]). At week 8, the response rate (i.e., percentage of patients with a Tourette's Syndrome Clinical Global Impression-Improvement score of 1 or 2) of the aripiprazole group (86.4%) was significantly higher than that of the placebo group (56.6%; odds ratio: 3.6, p < 0.001). The incidence of treatment-emergent adverse events (TEAEs) reported in at least one patient was 86.9% in the aripiprazole group and 65.5% in the placebo group. All TEAEs were mild or moderate in severity. No serious adverse events or deaths occurred during the study.

CONCLUSIONS

Our findings suggest that aripiprazole oral solution is an effective, well-tolerated, and safe treatment for children and adolescents with TD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03487783. Registered 4 April 2018.

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.

Licensed Medical Cannabis Use in Gilles de la Tourette Syndrome: A Retrospective Long-term Follow-Up

Background: Medical cannabis (MC) is widely used in clinical practice to treat Gilles de la Tourette syndrome (GTS). However, legislation, multiple modes of administration, and inconsistent plant preparations have limited trials to assess its benefits and long-term safety. For the past decade, licensed MC has been authorized in Israel for use in resistant GTS. We aimed to describe subjects' satisfaction, consumption habits, and THC dose increment during long-term usage. Materials and Methods: A retrospective longitudinal data collection (up to 9 years) on cannabis use habits and structured questionnaires evaluating disease characteristics and MC influence from GTS subjects being treated in the Movement Disorders Unit of the Tel-Aviv Medical Center, Israel. Results: Twenty-five patients (84% male) participated in the study. The mean duration of MC use was 4.0±2.3 years (range 0.5-10). The majority of patients (96%) consumed MC primarily, but not exclusively, through inhalation methods such as smoking or vaporizing dried inflorescence. A linear increase was observed in mean monthly THC dose (p<0.0001) with an average increase of 0.6-0.7 g/year. MC led to a subjectively reported reduction in tics (75% average reduction) and symptoms associated with common comorbidities of GTS. MC was generally well tolerated, although most participants (88%) reported experiencing side effects. Conclusions: A subset of GTS subjects who use MC long term under clinical observation may subjectively improve control of symptoms. Subject-led dose increase can indicate emerging tolerance. Large randomized controlled and observational long-term trials are required to confirm these observations.

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.

Interplay between endocannabinoids and dopamine in the basal ganglia: implications for pain in Parkinson's disease

Pain is a complex phenomenon, and basal ganglia circuitry integrates many aspects of pain including motor, emotional, autonomic, and cognitive responses. Perturbations in dopamine (DA) signaling are implicated in the pathogenesis of chronic pain due to its involvement in both pain perception and relief. Several lines of evidence support the role of endocannabinoids (eCBs) in the regulation of many electrical and chemical aspects of DAergic neuron function including excitability, synaptic transmission, integration, and plasticity. However, eCBs play an even more intricate and intimate relationship with DA, as indicated by the adaptive changes in the eCB system following DA depletion. Although the precise mechanisms underlying DA control on pain are not fully understood, given the high correlation of eCB and DAergic system, it is conceivable that eCBs may be part of these mechanisms.In this brief survey, we describe the reciprocal regulation of eCB-DA neurotransmission with a particular emphasis on the actions of eCBs on ionic and synaptic signaling in DAergic neurons mediated by CB receptors or independent on them. Furthermore, we analyze the eCB-DA imbalance which characterizes pain condition and report the implications of reduced DA levels for pain in Parkinson's disease. Lastly, we discuss the potential of the eCB-DA system in the development of future therapeutic strategies for the treatment of pain.

Human mutations in high-confidence Tourette disorder genes affect sensorimotor behavior, reward learning, and striatal dopamine in mice

Tourette disorder (TD) is poorly understood, despite affecting 1/160 children. A lack of animal models possessing construct, face, and predictive validity hinders progress in the field. We used CRISPR/Cas9 genome editing to generate mice with mutations orthologous to human de novo variants in two high-confidence Tourette genes, CELSR3 and WWC1. Mice with human mutations in Celsr3 and Wwc1 exhibit cognitive and/or sensorimotor behavioral phenotypes consistent with TD. Sensorimotor gating deficits, as measured by acoustic prepulse inhibition, occur in both male and female Celsr3 TD models. Wwc1 mice show reduced prepulse inhibition only in females. Repetitive motor behaviors, common to Celsr3 mice and more pronounced in females, include vertical rearing and grooming. Sensorimotor gating deficits and rearing are attenuated by aripiprazole, a partial agonist at dopamine type II receptors. Unsupervised machine learning reveals numerous changes to spontaneous motor behavior and less predictable patterns of movement. Continuous fixed-ratio reinforcement shows that Celsr3 TD mice have enhanced motor responding and reward learning. Electrically evoked striatal dopamine release, tested in one model, is greater. Brain development is otherwise grossly normal without signs of striatal interneuron loss. Altogether, mice expressing human mutations in high-confidence TD genes exhibit face and predictive validity. Reduced prepulse inhibition and repetitive motor behaviors are core behavioral phenotypes and are responsive to aripiprazole. Enhanced reward learning and motor responding occur alongside greater evoked dopamine release. Phenotypes can also vary by sex and show stronger affection in females, an unexpected finding considering males are more frequently affected in TD.

Recent advances in pharmacological management of attention-deficit/hyperactivity disorder: moving beyond stimulants

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral disorder characterized by impairing inattention and/or hyperactivity and impulsivity in children and adults. Although medications have been available to treat ADHD symptoms for decades, many are stimulant formulations. Stimulants, such as amphetamine and methylphenidate, are available in more than two dozen formulations, but all have similar adverse effects and carry a risk of misuse and dependence.

AREAS COVERED

In the United States (US), several nonstimulants are available to treat ADHD. Two, including atomoxetine and viloxazine extended-release (ER), are approved by the Food and Drug Administration for the treatment of ADHD in children and adults. Two others, clonidine ER and guanfacine ER, are only approved for children and adolescents in the US. Several other compounds are under investigation. Drugs in Phase 3 trials include centanafadine, solriamfetol, and L-threonic acid magnesium salt. Efficacy and safety data for nonstimulants is presented.

EXPERT OPINION

Although many effective formulations for the treatment of ADHD are available, more than 33% of children and 50% of adults discontinue treatment during the first year. The lack of individual drug response and tolerability are reasons many stop treatment. The development of new nonstimulants may offer hope for patients who need medication alternatives.

Plum-blossom needle therapy for Tourette syndrome: A case report

INTRODUCTION

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by the childhood onset of motor and phonic tics, frequently accompanied by behavioral and psychiatric comorbidities. Existing treatments for tics raise safety concerns. In China, acupuncture has been a widely utilized approach for TS, and one specific traditional acupuncture method, plum-blossom needle therapy (PBNT), has exhibited favorable tolerance among pediatric patients. In this report, we present a case of TS treated using PBNT.

CASE PRESENTATION

An 11-year-old boy diagnosed with Tourette syndrome for over five years presented with frequent loud throat clearing, eye blinking, severe abdominal tensing, shoulder shrugging, and upper limb twitching. Plum-blossom needle therapy (PBNT) was administered for 8 weeks, involving two sessions per week. The boy's tic symptoms gradually ameliorated, ultimately becoming minimal following the 8-week treatment period. Specifically, the Yale Global Tic Severity Scale (YGTSS) score decreased from 71 to 20, and the TS Clinical Global Impression Scale of Improvement (CGI-I) score reached 1, signifying 'very much improved' post-treatment. However, the Children and Adolescents' Quality of Life Scale (CAQOL) score exhibited minimal variation, moving from 146 to 150.

CONCLUSION

This case suggests that plum-blossom needle therapy (PBNT) is well-tolerated by children and may be effective in alleviating tics associated with Tourette syndrome (TS). However, further research, particularly large-sample randomized controlled trials, is imperative to establish the efficacy and effectiveness of PBNT.

Abnormal H3K4 enzyme catalytic activity and neuronal morphology caused by ASH1L mutations in individuals with Tourette syndrome

ASH1L potentially contributes to Tourette syndrome (TS) and other neuropsychiatric disorders, as our previous studies have shown. It regulates essential developmental genes by counteracting polycomb-mediated transcriptional repression, which restricts chromatin accessibility at target genes. ASH1L is highly expressed in the adult brain, playing a crucial role in the early stage. However, it remains unclear how ASH1L mutations carried by patients with TS participate in regulating neuronal growth processes leading to TS traits. Five TS families recruited in our study underwent comprehensive physical examinations and questionnaires to record clinical phenotypes and environmental impact factors. We validated the variants via Sanger sequencing and constructed two mutants near the catalytic domain of ASH1L. We conducted molecular modeling, in vitro assays, and primary neuron cultures to find the role of ASH1L in neuronal development and its correlation with TS. In this study, we validated five pathogenic ASH1L rare variants and observed symptoms in patients with simple tics and behavioral comorbidities. Mutations near the catalytic domain of TS patients cause mental state abnormalities and disrupt ASH1L function by destabilizing its spatial conformation, leading to decreased activity of catalytic H3K4, thereby affecting the neurite growth. We need to conduct larger-scale studies on TS patients and perform additional neurological evaluations on mature neurons. We first reported the effects of ASH1L mutations in TS patients, including phenotypic heterogeneity, protein function, and neurological growth. This information contributes to understanding the neurodevelopmental pathogenesis of TS in patients with ASH1L mutations.

Agreement between self-, mother and father proxy-reports on health-related quality of life in adolescents with Tourette syndrome

This study aimed to investigate agreement and discrepancies between parent proxy- and adolescent self-reports on assessments of adolescents' health-related quality of life (HRQoL), and the role that individual factors may play in parent-adolescent agreement, in a sample of adolescents with Tourette syndrome (TS) compared to a control group of healthy adolescents. Adolescents aged 12-18 years diagnosed with TS were recruited with their parents from primary and secondary referral centres. Adolescent healthy controls were matched for gender and age. Adolescents and each of their parents completed a set of questionnaires including a HRQoL evaluation of adolescent, the 'Vécu et Santé Perçue de l'Adolescent'. Mother-adolescent, father-adolescent and mother-father agreements on adolescents' HRQoL scores were investigated at individual and group level, both in TS and control groups. Data were available for 75 adolescents, 75 mothers and 63 fathers, in the TS group. Agreement between mother, father proxy-reports and TS adolescents self-reports of HRQoL varied from poor to good, without significant difference with the control group. In TS group, mothers and fathers underestimated adolescents' HRQoL in 'Psychological well-being' subscale and mothers underestimated it in 'Physical 'well-being' subscale, while controls overestimated adolescents' HRQoL in these subscales. Larger mother-adolescent discrepancies for 'Psychological well-being' and 'Physical well-being' subscales were associated with internalizing symptoms. Regarding future studies, comprehensive evaluation of the various dimensions of adolescents' HRQoL with TS requires the integration of the perspectives of both adolescents, mothers and fathers. Clinicians should take into account this point to provide comprehensive care and services.

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.

Common pitfalls, and how to avoid them, in child and adolescent psychopharmacology: Part I

As Faculty of the British Association for Psychopharmacology course on child and adolescent psychopharmacology, we present here what we deem are the most common pitfalls, and how to avoid them, in child and adolescent psychopharmacology. In this paper, we specifically addressed common pitfalls in the pharmacological treatment of attention-deficit/hyperactivity disorder, anxiety, bipolar disorder, depression, obsessive-compulsive disorder and related disorders, and tic disorder. Pitfalls in the treatment of other disorders are addressed in a separate paper (part II).

Efficacy and safety of combined deep brain stimulation with capsulotomy for comorbid motor and psychiatric symptoms in Tourette's syndrome: Experience and evidence

OBJECTIVES

To evaluate the efficacy and safety of combined deep brain stimulation (DBS) with capsulotomy for comorbid motor and psychiatric symptoms in patients with Tourette's syndrome (TS).

METHODS

This retrospective cohort study consecutively enrolled TS patients with comorbid motor and psychiatric symptoms who were treated with combined DBS and anterior capsulotomy at our center. Longitudinal motor, psychiatric, and cognitive outcomes and quality of life were assessed. In addition, a systematic review and meta-analysis were performed to summarize the current experience with the available evidence.

RESULTS

In total, 5 eligible patients in our cohort and 26 summarized patients in 6 cohorts were included. After a mean 18-month follow-up, our cohort reported that motor symptoms significantly improved by 62.4 % (P = 0.005); psychiatric symptoms of obsessive-compulsive disorder (OCD) and anxiety significantly improved by 87.7 % (P < 0.001) and 78.4 % (P = 0.009); quality of life significantly improved by 61.9 % (P = 0.011); and no significant difference was found in cognitive function (all P > 0.05). Combined surgery resulted in greater improvements in psychiatric outcomes and quality of life than DBS alone. The synthesized findings suggested significant improvements in tics (MD: 57.92, 95 % CI: 41.28-74.56, P < 0.001), OCD (MD: 21.91, 95 % CI: 18.67-25.15, P < 0.001), depression (MD: 18.32, 95 % CI: 13.26-23.38, P < 0.001), anxiety (MD: 13.83, 95 % CI: 11.90-15.76, P < 0.001), and quality of life (MD: 48.22, 95 % CI: 43.68-52.77, P < 0.001). Individual analysis revealed that the pooled treatment effects on motor symptoms, psychiatric symptoms, and quality of life were 78.6 %, 84.5-87.9 %, and 83.0 %, respectively. The overall pooled rate of adverse events was 50.0 %, and all of these adverse events were resolved or alleviated with favorable outcomes.

CONCLUSIONS

Combined DBS with capsulotomy is effective for relieving motor and psychiatric symptoms in TS patients, and its safety is acceptable. However, the optimal candidate should be considered, and additional experience is still necessary.

Rethinking Movement Disorders

At present, clinical practice and research in movement disorders (MDs) focus on the "normalization" of altered movements. In this review, rather than concentrating on problems and burdens people with MDs undoubtedly have, we highlight their hidden potentials. Starting with current definitions of Parkinson's disease (PD), dystonia, chorea, and tics, we outline that solely conceiving these phenomena as signs of dysfunction falls short of their complex nature comprising both problems and potentials. Such potentials can be traced and understood in light of well-established cognitive neuroscience frameworks, particularly ideomotor principles, and their influential modern derivatives. Using these frameworks, the wealth of data on altered perception-action integration in the different MDs can be explained and systematized using the mechanism-oriented concept of perception-action binding. According to this concept, MDs can be understood as phenomena requiring and fostering flexible modifications of perception-action associations. Consequently, although conceived as being caught in a (trough) state of deficits, given their high flexibility, people with MDs also have high potential to switch to (adaptive) peak activity that can be conceptualized as hidden potentials. Currently, clinical practice and research in MDs are concerned with deficits and thus the "deep and wide troughs," whereas "scattered narrow peaks" reflecting hidden potentials are neglected. To better delineate and utilize the latter to alleviate the burden of affected people, and destigmatize their conditions, we suggest some measures, including computational modeling combined with neurophysiological methods and tailored treatment. © 2024 International Parkinson and Movement Disorder Society.

Therapeutic use of medical Cannabis in neurological diseases: a clinical update

The use of medical Cannabis has increased in recent years due to changing legal circumstances in many countries. Approval exists only for a few neurological conditions such as rare forms of epilepsy or spasticity in multiple sclerosis. Beyond that, however, medical Cannabis is used for a wide range of neurological conditions and symptoms. In Germany, in parallel with new legislation that has simplified the prescription of medical Cannabis, an accompanying survey has been implemented for which initial data are now available. In this context, our review provides an overview of the evidence for the therapeutic use of medical Cannabis in neurology, the potential benefits, and side effects.

The Effect of Nabiximols on Driving Ability in Adults with Chronic Tic Disorders: Results of a Substudy Analysis of the Double-Blind, Randomized, Placebo-Controlled CANNA-TICS Trial

Background: The multicenter, randomized, double-blind, parallel-group, phase IIIb CANNA-TICS (CANNAbinoids in the treatment of TICS) trial showed clear trends for improvement of tics, depression, and quality of life with nabiximols versus placebo in adult patients with Gilles de la Tourette syndrome and other chronic tic disorders. Although in general nabiximols was well tolerated, it is unclear whether treatment using this cannabis extract influences driving skills in patients with chronic tic disorders. Methods: Here we report results of the "Fitness to Drive" substudy of the CANNA-TICS trial. The key endpoint was fitness to drive as a binary criterion with a computerized assessment at baseline and after 9 weeks of stable treatment (week 13) with nabiximols or placebo. A patient was considered unfit to drive according to the German Federal Highway Research Institute guidelines. Results: In the substudy, a total of 64 patients (76.6% men, mean±standard deviation of age: 36.8±13.9) were recruited at two study sites. The number of patients who were fit to drive increased from 24 (55.8%) at baseline to 28 (71.8%) at week 13 among 43 patients treated with nabiximols, and decreased from 14 (66.7%) to 10 (52.6%) among 21 patients who received placebo. The risk difference (nabiximols - placebo) was 0.17 (95% confidence interval=-0.08 to 0.43) in favor of nabiximols. Specifically, only 2 of 24 (8.3%) patients in the nabiximols, but 4 of 14 (28.6%) patients in the placebo group changed for the worse from fit (at baseline) to unfit (at week 13) to drive, whereas 8 of 19 (42.1%) patients in the nabiximols, and only 2 of 7 (28.6%) patients in the placebo group improved from unfit to fit. Conclusion: Treatment with nabiximols does not impair skills relevant to driving in those patients with tic disorders who were fit to drive at baseline and even improved fitness to drive in a subset of patients who were unfit to drive before start of treatment. EudraCT number: 2016-000564-42.

Incidence trend and epidemiology of tic disorders among youths and adults in Korea from 2003 to 2020: A national population-based study

Tic disorder is a highly prevalent neurodevelopmental disorder; however, research on its incidence trends is still rare. We aimed to investigate its annual incidence rates and the characteristics of incident cases in the general Korean population using data from the National Health Insurance Service-National Health Information Database as a proxy measurement for true incidence in the community. The total number of incident cases and incidence rates of tic disorders from 2003 to 2020 were compared between youths and adults. Both the number of incident cases and the annual incidence rates of tic disorders significantly increased from 2003 to 2020. The overall increasing trend in the incidence rates was significantly greater in youths than in adults; however, the incidence rates in adults showed a relatively recent increase. The male predominance regarding the newly diagnosed case number in youths was no longer observed in adults. Tic disorders occurred more commonly in the low-income group than in the high-income group. Neurodevelopmental comorbidities in youths and mood or anxiety disorders and schizophrenia in adults were more frequently observed. Antipsychotic medication adherence was higher in youths than in adults. Efforts are required to raise awareness and promote expert education for adult patients with tic disorders.

Gender Representation in Academic Publications of Tourette Syndrome Research: An Analysis of Authorship Trends

Tourette syndrome, characterized by phonic and motor tics, is a neurodevelopmental disorder that significantly affects the quality of life of people with the condition. With over 1500 articles published in the last decade alone, this study aims to analyze the gender trends in publications related to Tourette syndrome from 2013 to 2022, examining the number of female authors as first authors and predicting future changes in female participation. The aim of this study is to analyze the gender trends of the first author in publications related to "Tourette Syndrome" from PubMed-indexed publications from January 2013 to December 2022. A bibliometric analysis was conducted by the search engine PubMed for articles pertaining to "Tourette Syndrome". NamSor app V.2 (Namsor™ Applied Onomastics, NamSor SAS, Versailles, France), an application programming interface (API), was used to identify the gender of the first publishing author. Statistical analysis and graphic models were produced using R software (R Foundation for Statistical Computing, Vienna, Austria), ARIMA (Autoregressive Integrated Moving Average) model, and DataWrapper (Datawrapper GmbH, Berlin Prenzlauer Berg, Germany). Based on the analysis of 1052 publications on Tourette Syndrome, it was found that 54.8% (n=576) of the first authors were females. A significant association was observed between gender ratios and country of publication. Statistical forecasting models suggest that female participation in Tourette research is expected to rise to approximately 60 by the year 2027. Therefore, the study highlights the progress made in achieving gender parity in Tourette syndrome research, with female-led publications being on par with male-led publications. However, there is still a need to address the global gender gap and geographical disparities in research to work towards a more inclusive and diverse academic environment.

Psychosocial experiences in youth with Tourette syndrome: a systematic review and meta-synthesis

Suffering from Tourette syndrome (TS) disrupts the daily lives and interpersonal relationships of patients. The psychosocial experiences of young people with TS are not yet clear. The aim of the systematic review is to identify and synthesize the psychosocial experiences of young people with TS. A meta-synthesis was conducted. PubMed, EMBASE, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and Chinese Electronic Periodical Services databases were searched for articles published from their inception to February 2023. This review followed the Joanna Briggs Institute's Guidelines for Systematic Reviews according to a previously developed protocol. We used the confidence of synthesized qualitative findings (ConQual) approach to evaluate the credibility and dependability of the synthesized findings. This review included 12 qualitative studies from Western and Asian countries published between 2005 and 2019, representing 190 young people with TS. We identified five synthesized findings: affliction by intractable TS, TS was negatively perceived in the social and cultural context, self-adjustment in response to social interaction, response to receiving various interventions, and positivity in promoting self-acceptance. The ConQual grade for each generated synthesized finding ranged from low to moderate. The psychosocial experiences of youths living with TS are unique and are influenced by their interpersonal relationships, social context, and cultural framework. The findings recommend that healthcare providers assist young people in developing personalized symptom management strategies and provide guidance and care that meets the needs of each individual.

Working Mechanisms of Exposure and Response Prevention in the Treatment of Tourette Syndrome and Tic Disorders Revisited: No Evidence for within-Session Habituation to Premonitory Urges

BACKGROUND

Exposure and response prevention (ERP) has been shown to be an effective treatment for Tourette syndrome (TS) and chronic tic disorders (CTD). ERP is based on voluntary tic suppression in combination with prolonged exposure to premonitory urges preceding tics. A prevailing hypothesis of the working mechanism underlying ERP in tics is habituation to the premonitory urges as a result of prolonged exposure. However, results so far are equivocal. This study aims to further explore the relation between urges and ERP in tics, by investigating the course of premonitory urges during ERP sessions.

METHODS

Using a data-driven approach, within-session habituation to premonitory urge intensity was investigated. In total, 29 TS patients rated urge intensity at seven timepoints during ten 1 h ERP sessions.

RESULTS/CONCLUSIONS

Latent growth modeling showed an increase in urge intensity during the first 15 min of each session followed by a plateau in the remaining 45 min of the session. This does not support the idea of within-session habituation to premonitory urges as a working mechanism of ERP. Other potential underlying working mechanisms are discussed and should be tested in future research.

The shared genetic risk factors between Tourette syndrome and obsessive-compulsive disorder

Tourette syndrome (TS) and obsessive-compulsive disorder (OCD) are two neuropsychiatric disorders that frequently co-occur. Previous evidence suggests a shared genetic diathesis underlying the comorbidity of TS and OCD. This review aims to comprehensively summarize the current literature on the genetic factors linked with TS and its comorbidities, with a focus on OCD. Family studies, linkage analysis, cytogenetic studies, and genome-wide association studies (GWAS) have played a pivotal role in identifying common and rare genetic variants connected with TS and OCD. Although the genetic framework of TS and OCD is complex and multifactorial, several susceptibility loci and candidate genes have been identified that might play a crucial role in the pathogenesis of both disorders. Additionally, post-infectious environmental elements have also been proposed to contribute to the development of TS-OCD, although the dynamics between genetic and environmental factors is not yet fully understood. International collaborations and studies with well-defined phenotypes will be crucial in the future to further elucidate the genetic basis of TS and OCD and to develop targeted therapeutic strategies for individuals suffering from these debilitating conditions.

Diagnostic Hierarchy of Tic Disorders in Real-World Clinical Practice

Objectives

According to the 10th revision of the International Classification of Diseases, the main categories of tic disorders (F95.0, F95.1, and F95.2) follow a diagnostic hierarchy based on the duration and diversity of tic symptoms. The present study investigated the use of this diagnostic hierarchy in real-world clinical practice.

Methods

Based on the National Health Insurance Service-National Health Information Database, the diagnosis of transient tic disorder (F95.0) made after a diagnosis of chronic motor or vocal tic disorder (F95.1) or Tourette's syndrome (F95.2) and diagnosis of chronic motor or vocal tic disorder (F95.1) made after a diagnosis of Tourette's syndrome (F95.2) were referred to as type A errors. The diagnosis of transient tic disorder (F95.0) repeated after a period of >12 months was referred to as type B error. Demographic and clinical differences according to the diagnostic error types were analyzed using analysis of variance, Student's t-tests, and chi-squared tests.

Results

Most participants (96.5%) were without errors in the diagnosis of tic disorders. Higher proportions of males (p=0.005) and antipsychotic prescriptions (p<0.001) were observed in patients with type A or B diagnostic errors. A higher proportion of health insurance holders was observed among those with type A errors (p=0.027).

Conclusion

Errors were absent in majority of the tic diagnoses in real-world clinical practice in terms of the diagnostic hierarchy.

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.

New insights of metabolite abnormalities in the thalamus of rats with iminodiproprionitrile-induced tic disorders

Introduction

This study aimed to investigate pathological changes in the "Glutamate (Glu)-γ-aminobutyric acid (GABA)" loop and apply widely targeted metabolomic analysis technology to comprehensively explore metabolite abnormalities/ in the thalamus of rats with tic disorders (TD).

Methods

Wistar rats were randomized into control, TD, and tiapride (Tia) groups. Iminodipropionitrile (IDPN) was used to induce TD in rats. The Tia group was administered tiapride. Neurotransmitter levels in the thalamus of rats in the three groups were measured using UPLC-3Q MS. And, the protein expression levels of Glu decarboxylase (GAD65/67) and GABA transporter protein (GAD-T) were measured using western blotting. The mRNA expression levels of these genes were evaluated using real-time polymerase chain reaction. Lastly, other metabolites in the thalamus were detected by widely targeted metabolomic analysis between TD and Control group rats.

Results

The Glu level, Glu/GABA ratio, and Asp level in the TD group were significantly higher (all p < 0.001) than those of the Control group, whereas the GABA and Gly levels were lower (p < 0.001 and p = 0.009, respectively). The Tia group exhibited a significant reduction in the Glu level (p = 0.001) compared with the TD group. The protein expression level of GAD67 in TD group was higher (p = 0.009) and the mRNA expression levels of GAD65, GAD67, and GAT-1 were lower (p < 0.05) than those of the Control group. The Tia group did not display any differences in GAD65, GAD67, or GAT-1 expression. Widely targeted metabolomic analysis revealed that 34 substances were abnornal between the TD and Control groups (9 upregulated and 25 downregulated). Neurosteroids (progesterone, corticosterone) exhibited distinct differences. Metabolite analysis using the Kyoto encyclopedia for genes and genomes indicated that the steroid hormone biosynthesis pathway may be involved in TD pathogenesis.

Conclusion

This study revealed metabolic abnormalities in the thalamus of rats with TD. The interaction between neurotransmitters and neurosteroid biosynthesis represents a new direction for future studies.

Cariprazine in an Adolescent with Tourette Syndrome with Comorbid Attention Deficit Hyperactive Disorder and Depression: A Case Report

Tourette syndrome is a complex neuropsychiatric condition that manifests in childhood and is often associated with other psychiatric comorbidities. This case report describes a young male with Tourette syndrome with major depressive disorder and attention deficit hyperactivity disorder (ADHD) who experienced troublesome side effects due to his existing medications (escitalopram, risperidone, and methylphenidate). In order to control his tics, ameliorate depressive symptoms, and eliminate side effects of stiffness and sedation, risperidone was switched to cariprazine, a third-generation antipsychotic medication with D3-D2 partial agonism. In addition, the antidepressant dose was also increased. With the new combination, the patient reported good control of his tics, together with significant improvement in depressive symptoms and no side effects. Based on this case and the reviewed literature, cariprazine might be a viable option for patients with Tourette syndrome with other comorbid illnesses who are prone to side effects of medication.

Tourette syndrome and obsessive-compulsive disorder: A comprehensive review of structural alterations and neurological mechanisms

Currently, it is possible to study the pathogenesis of Tourette's syndrome (TS) in more detail, due to more advanced methods of neuroimaging. However, medical and surgical treatment options are limited by a lack of understanding of the nature of the disorder and its relationship to some psychiatric disorders, the most common of which is obsessive-compulsive disorder (OCD). It is believed that the origin of chronic tic disorders is based on an imbalance of excitatory and inhibitory influences in the Cortico-Striato-Thalamo-Cortical circuits (CSTC). The main CSTCs involved in the pathological process have been identified by studying structural and neurotransmitter disturbances in the interaction between the cortex and the basal ganglia. A neurotransmitter deficiency in CSTC has been demonstrated by immunohistochemical and genetic methods, but it is still not known whether it arises as a consequence of genetically determined disturbances of neuronal migration during ontogenesis or as a consequence of altered production of proteins involved in neurotransmitter production. The aim of this review is to describe current ideas about the comorbidity of TS with OCD, the involvement of CSTC in the pathogenesis of both disorders and the background of structural and neurotransmitter changes in CSTC that may serve as targets for drug and neuromodulatory treatments.

Creative thinking in Tourette's syndrome: A comparative study of patients and healthy controls

INTRODUCTION

Tourette's syndrome is a neurological disorder characterized by tics, that may interfere with patients' everyday life. Research suggested that creative thinking (namely, divergent and convergent thinking) could help patients cope with their symptoms, and therefore it can be a resource in non-pharmacological interventions. The present study aimed at investigating (i) possible differences in creative thinking between Tourette's syndrome patients and healthy controls and (ii) whether creative thinking can support patients in coping with their symptomatology.

METHODS

A group of 25 Tourette's syndrome patients and 25 matched healthy controls underwent an assessment of creative thinking, fluid intelligence, and depressive symptoms. Creative thinking was compared between patients and healthy controls after controlling for fluid intelligence and depressive symptoms. Moreover, the moderating role of divergent and convergent thinking on the subjective impact of tics was tested in a group of 30 patients.

RESULTS

Tourette's syndrome patients outperformed healthy controls in convergent thinking. Moreover, divergent thinking was found as a significant moderator of the relationship between tics severity and the subjective impact in Tourette's syndrome patients.

CONCLUSIONS

Findings highlighted the specific impact of convergent and divergent thinking on Tourette's syndrome patients. Considering the supportive role of creative thinking in Tourette's syndrome, our results confirm that higher levels of divergent thinking may reduce the tic-related discomfort. These findings suggest the potential positive implications of creative thinking in non-pharmacological interventions for Tourette's syndrome.

Patients' experience of accessing support for tics from primary care in the UK: an online mixed-methods survey

BACKGROUND

Tics are common in children and young people and may persist into adulthood. Tics can cause challenges with social, occupational, physical, and academic functioning. The current study explores the perceptions of adults with tics and parents/carers of young people with tics regarding their experience of accessing support from professionals in primary care in the UK.

METHODS

Two online cross-sectional surveys were completed by 33 adults with tics and 94 parents/carers of children with tics. Participants were recruited across three online tic support groups. Tic specialist psychologists, academic researchers, and people with lived experience of tics provided feedback on the surveys before they were made available online. Mixed-method analyses were conducted on the surveys. Qualitative data from the free-text responses were analysed using thematic analysis and triangulated with quantitative findings where appropriate.

RESULTS

While some participants felt supported by general practitioners (GPs), many felt dismissed. The impact of tics was not always explored, nor information on tics provided, during the consultation. Although 78.7% of participants were referred to secondary care for their tics, some struggled to get the referral. Within secondary care, most adult respondents were assessed by neurologists whilst young people were typically assessed by paediatricians or psychiatrists. Most of these secondary care clinicians did not specialise in tic disorders, with only 27.9% of participants being assessed by tic specialists. Mode waitlist time was 3-6 months for young people and longer for adult respondents. Some participants were referred to multiple secondary care services, spanning neurology, paediatrics, and psychiatry, with each stating that they do not provide support for tics. 21% of participants mentioned being discharged from secondary care with no ongoing support. Almost one-third of respondents accessed support within private healthcare.

CONCLUSIONS

Generally, more negative than positive experiences were reported. Possible contributing factors included a lack of clear tic referral pathways, long waitlists, a lack of information about tics provided in primary care appointments and a lack of support offered following diagnosis by secondary care services, together with poor access to tic specialist clinicians. This study highlights areas where improvements to UK services for tics can be made.

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.

Premonitory Urge and Tic Severity, Comorbidities, and Quality of Life in Chronic Tic Disorders

BACKGROUND

Tics are intimately associated with premonitory urges (PU) but knowledge about urges is still limited, with small sample sizes often limiting the generalizability of findings.

OBJECTIVES

This study addressed the following open questions: (1) is tic severity associated with urge severity, (2) how common is relief, (3) which comorbidities are associated with urges, (4) are urges, tics, and comorbidities associated with lower quality of life, and (5) can complex and simple, motor and vocal tics be differentiated based on PU?

METHODS

N = 291 patients who reported a confirmed diagnosis of chronic primary tic disorder (age = 18-65, 24% female) filled out an online survey assessing demographic data, comorbid conditions, location, quality and intensity of PU, as well as quality of life. Every tic was recorded, and whether the patient experienced a PU, the frequency, intensity, and quality of that urge.

RESULTS

PU and tic severity were significantly associated, and 85% of urge-related tics were followed by relief. A diagnosis of attention deficit/hyperactivity disorder (ADHD) or depression, female gender, and older age increased the likelihood of experiencing PU, while more obsessive compulsive (OCD) symptoms and younger age were associated with higher urge intensities. PU, complex vocal tics, ADHD, OCD, anxiety, and depression were related to lower quality of life. Motor and vocal, complex and simple tics did not differ regarding PU intensity, frequency, and quality, or relief.

CONCLUSIONS

The results shed light on the relationship between PU, tics, comorbidities, age, gender, and quality of life in tic disorders.

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.

"Unvoluntary" Movement Disorders: Distinguishing between Tics, Akathisia, Restless Legs, and Stereotypies

Tics, stereotypies, akathisia, and restless legs fall at different places on the spectrum of discrete, unwanted and potentially disabling motor routines. Unlike tremor, chorea, myoclonus, or dystonia, this subgroup of abnormal movements is characterized by the subject's variable ability to inhibit or release undesired motor patterns on demand. Though it may be sometimes clinically challenging, it is crucial to distinguish these "unvoluntary" motor behaviors because secondary causes and management approaches differ substantially. To this end, physicians must consider the degree of repetitiveness of the movements, the existence of volitional control, and the association with sensory symptoms, or cognitive-ideational antecedent. This review aims to summarize the current existing knowledge on phenomenology, diagnosis, and treatment of tics, stereotypies, akathisia, and restless leg syndrome.

Pimozide Increases a Delayed Rectifier K+ Conductance in Chicken Embryo Vestibular Hair Cells

Pimozide is a conventional antipsychotic drug largely used in the therapy for schizophrenia and Tourette's syndrome. Pimozide is assumed to inhibit synaptic transmission at the CNS by acting as a dopaminergic D₂ receptor antagonist. Moreover, pimozide has been shown to block voltage-gated Ca²⁺ and K⁺ channels in different cells. Despite its widespread clinical use, pimozide can cause several adverse effects, including extrapyramidal symptoms and cardiac arrhythmias. Dizziness and loss of balance are among the most common side effects of pimozide. By using the patch-clamp whole-cell technique, we investigated the effect of pimozide [3 μM] on K⁺ channels expressed by chicken embryo vestibular type-II hair cells. We found that pimozide slightly blocks a transient outward rectifying A-type K⁺ current but substantially increases a delayed outward rectifying K⁺ current. The net result was a significant hyperpolarization of type-II hair cells at rest and a strong reduction of their response to depolarizing stimuli. Our findings are consistent with an inhibitory effect of pimozide on the afferent synaptic transmission by type-II hair cells. Moreover, they provide an additional key to understanding the beneficial/collateral pharmacological effects of pimozide. The finding that pimozide can act as a K⁺ channel opener provides a new perspective for the use of this drug.

Comparative efficacy, tolerability, and acceptability of pharmacological interventions for the treatment of children, adolescents, and young adults with Tourette's syndrome: a systematic review and network meta-analysis

BACKGROUND

In clinical practice guidelines there is no consensus about the medications that should be initially offered to children and young people with Tourette's syndrome. To provide a rigorous evidence base that could help guide decision making and guideline development, we aimed to compare the efficacy, tolerability, and acceptability of pharmacological interventions for Tourette's syndrome.

METHODS

For this systematic review and network meta-analysis, we searched the Cochrane Central Register of Controlled Trials, Embase, PsycINFO, PubMed, Web of Science, the WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov, for published and unpublished studies from database inception to Nov 19, 2021. We included double-blind randomised controlled trials of any medication administered as a monotherapy for at least 1 week against another medication or placebo in children and adolescents (aged ≥4 years and ≤18 years), adults (>18 years), or both, diagnosed with Tourette's syndrome according to standardised criteria. We excluded studies that exclusively recruited participants with comorbid attention-deficit hyperactivity disorder or obsessive-compulsive disorder. The primary outcome was change in severity of tic symptoms (efficacy). Secondary outcomes were treatment discontinuations due to adverse events (tolerability) and for any reason (acceptability). Pharmacological interventions were examined considering medication categories and medications individually in separate analyses. Summary data were extracted and pooled with a random-effects network meta-analysis to calculate standardised mean differences for efficacy and odds ratios for tolerability and acceptability, with 95% CIs. The Confidence in Network Meta-Analysis (CINeMA) framework was used to assess the certainty of evidence. The protocol was pre-registered in PROSPERO (CRD42022296975).

FINDINGS

Of the 12 088 records identified through the database search, 88 records representing 39 randomised controlled trials were included in the network meta-analysis; these 39 randomised controlled trials comprised 4578 participants (mean age 11·8 [SD 4·5] years; 3676 [80·8%] male participants) and evaluated 23 individual medications distributed across six medication categories. When considering medication categories, first-generation (standardised mean difference [SMD] -0·65 [95% CI -0·79 to -0·51]; low certainty of evidence) and second-generation (-0·71 [-0·88 to -0·54]; moderate certainty of evidence) antipsychotic drugs, as well as α-2 agonists (-0·21 [-0·39 to -0·03]; moderate certainty of evidence), were more efficacious than placebo. First-generation and second-generation antipsychotic drugs did not differ from each other (SMD 0·06 [95% CI -0·14 to 0·25]; low certainty of evidence). However, both first-generation (SMD 0·44 [95% CI 0·21 to 0·66]) and second-generation (0·49 [0·25 to 0·74]) antipsychotic drugs outperformed α-2 agonists, with moderate certainty of evidence. Similar findings were observed when individual medications were considered: aripiprazole (SMD -0·60 [95% CI -0·83 to -0·38]), haloperidol (-0·51 [-0·88 to -0·14]), olanzapine (-0·83 [-1·49 to -0·18]), pimozide (-0·48 [-0·84 to -0·12]), risperidone (-0·66 [-0·98 to -0·34]), and clonidine (-0·20 [-0·37 to -0·02]) all outperformed placebo, with moderate certainty of evidence. Antipsychotic medications did not differ from each other, but there was low to very low certainty of evidence for these comparisons. However, aripiprazole (SMD -0·40 [95% CI -0·69 to -0·12]) and risperidone (-0·46 [-0·82 to -0·11]) outperformed clonidine, with moderate certainty of evidence. Heterogeneity or inconsistency only emerged for a few comparisons. In terms of tolerability and acceptability, there were no relevant findings for any of the efficacious medication categories or individual medications against each other or placebo, but there was low to very low certainty of evidence associated with these comparisons.

INTERPRETATION

Our analyses show that antipsychotic drugs are the most efficacious intervention for Tourette's syndrome, while α-2 agonists are also more efficacious than placebo and could be chosen by those who elect not to take antipsychotic drugs. Shared decision making about the degree of tic-related severity and distress or impairment, the trade-offs of efficacy and safety between antipsychotic drugs and α-2 agonists, and other highly relevant individual factors that could not be addressed in the present analysis, should guide the choice of medication for children and young people with Tourette's syndrome.

FUNDING

None.

Tourette syndrome: clinical features, pathophysiology, and treatment

Tourette syndrome is a chronic neurodevelopmental disorder characterised by motor and phonic tics that can substantially diminish the quality of life of affected individuals. Evaluating and treating Tourette syndrome is complex, in part due to the heterogeneity of symptoms and comorbidities between individuals. The underlying pathophysiology of Tourette syndrome is not fully understood, but recent research in the past 5 years has brought new insights into the genetic variations and the alterations in neurophysiology and brain networks contributing to its pathogenesis. Treatment options for Tourette syndrome are expanding with novel pharmacological therapies and increased use of deep brain stimulation for patients with symptoms that are refractory to pharmacological or behavioural treatments. Potential predictors of patient responses to therapies for Tourette syndrome, such as specific networks modulated during deep brain stimulation, can guide clinical decisions. Multicentre data sharing initiatives have enabled several advances in our understanding of the genetics and pathophysiology of Tourette syndrome and will be crucial for future large-scale research and in refining effective treatments.

Common practical questions - and answers - at the British Association for Psychopharmacology child and adolescent psychopharmacology course

The British Association for Psychopharmacology course on child and adolescent psychopharmacology has been run for more than 20 years and is currently a very popular course, attracting around 140 delegates/year from across the United Kingdom and abroad. As Faculty of recent sessions of the course, we have selected the most common questions we have been asked in recent years and provided evidence-based and/or expert-informed answers. We have included 27 questions and answers related to attention-deficit/hyperactivity disorder, anxiety and depressive disorders, autism spectrum disorder, bipolar disorder, eating disorders, epilepsy (in differential diagnosis or comorbid with mental health conditions), obsessive-compulsive disorder, personality disorders, psychotic spectrum disorders, and tics/Tourette syndrome in children and young people. We hope that this article will be helpful for prescribers in their daily clinical practice and we look forward to further, high-level evidence informing the answers to these and other questions in child and adolescent psychopharmacology.

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.

Tourette syndrome and other tic disorders of childhood

Tics are repetitive, patterned, and nonrhythmic movements or vocalizations/audible sounds that are misplaced in context. Phenomenology and characteristics of tics (e.g., premonitory urge, suppressibility) differentiate them from compulsions, stereotypies, functional tic-like behaviors, and other types of hyperkinetic movement disorders. With a prevalence of approximately 1% in school-aged boys, Tourette syndrome (TS) is considered a common childhood-onset neurodevelopmental disorder, defined by the combination of at least two motor tics and at least one phonic tic lasting more than 1 year. TS is a highly heritable disorder, with a wide spectrum of severity. In some individuals, tics can cause pain, distress, functional impairment, or stigmatization. About 90% of individuals with TS have at least one mental health comorbidity (attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, anxiety/depressive disorders). These comorbidities significantly impact patients' quality of life and must therefore be screened and managed accordingly in this population. Treatment of tics is based on behavioral therapies targeting tics (habit reversal training included in the comprehensive behavioral intervention for tics, and exposure and response prevention for tics), in association with medication if needed (e.g., alpha-2-agonists, second-generation antipsychotics). Deep brain stimulation is considered an experimental option in the most severe, treatment-resistant patients. In adulthood, less than 25% of individuals still have moderate or severe tics.

Potential relationship between Tourette syndrome and gut microbiome

OBJECTIVE

In this article, the author aims to discuss and review the relationship between gut microbiota and Tourette syndrome, and whether the change in gut microbiota can affect the severity of Tourette syndrome.

SOURCES

Literature from PubMed, Google Scholar, and China National Knowledge Infrastructure was mainly reviewed. Both original studies and review articles were discussed. The articles were required to be published as of May 2022.

SUMMARY OF THE FINDINGS

Current studies on the gut microbiome have found that the gut microbiome and brain seem to interact. It is named the brain-gut-axis. The relationship between the brain-gut axis and neurological and psychiatric disorders has been a topic of intense interest. Tourette syndrome is a chronic neurological disease that seriously affects the quality of life of children, and there appears to be an increase in Ruminococcaceae and Bacteroides in the gut of patients with Tourette syndrome. After clinical observation and animal experiments, there appear to be particular gut microbiota changes in Tourette syndrome. It provides a new possible idea for the treatment of Tourette syndrome. Probiotics and fecal microbial transplantation have been tried to treat Tourette syndrome, especially Tourette syndrome which is not sensitive to drugs, and some results have been achieved.

CONCLUSIONS

The relationship between gut microbiota and Tourette syndrome and how to alleviate Tourette syndrome by improving gut microbiota are new topics, more in-depth and larger sample size research is still needed.

Mechanism of Qihuang needle therapy in the management of tic disorders: a clinical trial protocol

Background

Qihuang needle therapy is a newly developed acupuncture therapy to treat tic disorders in clinical practice. However, the mechanism to reduce tic severity remains unknown. Changes in intestinal flora and circulation metabolites are perhaps the potential pathogenesis of tic disorders. As a result, we present a protocol for a controlled clinical trial using multi-omics analysis to probe the mechanism of the Qihuang needle in managing tic disorders.

Methods

This is a matched-pairs design, controlled, clinical trial for patients with tic disorders. Participants will be allocated to either an experimental group or a healthy control group. The main acupoints are Baihui (GV20), Yintang (EX-HN3), and Jueyinshu (BL14). The experimental group will receive Qihuang needle therapy for a month, while the control group will receive no interventions.

Expected outcomes

The change in the severity of the tic disorder is set as the main outcome. Secondary outcomes include gastrointestinal severity index and recurrence rate, which will be calculated after a 12-week follow-up. Gut microbiota, measured by 16S rRNA gene sequencing; serum metabolomics, assessed via LC/MS; and serum zonulin, assessed by enzyme-linked immunosorbent assay (ELISA), will be used as biological specimen analysis outcomes. The present study will investigate the possible interactions between intestinal flora and serum metabolites and the improvement of clinical profiles, which may elucidate the mechanism of Qihuang needle therapy for tic disorders.

Trial registration

This trial is registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn/). Registration number: ChiCTR2200057723, Date: 2022-04-14.

Understanding inter-individual variability in pharmacokinetics/pharmacodynamics of aripiprazole in children with tic disorders: Individualized administration based on physiological development and CYP2D6 genotypes

Objective: This study aims to develop a combined population pharmacokinetic (PPK) model for aripiprazole (ARI) and its main active metabolite dehydroaripiprazole (DARI) in pediatric patients with tic disorders (TD), to investigate the inter-individual variability caused by physiological and genetic factors in pharmacokinetics of ARI and optimize the dosing regimens for pediatric patients. Methods: A prospective PPK research was performed in Chinese children with TD. Totally 84 patients aged 4.83-17.33 years were obtained for the pharmacokinetic analysis. 27 CYP2D6 and ABCB1 gene alleles were detected. Moreover, the clinical efficacy was evaluated according to reduction rate of Yale Global Tic Severity Scale (YGTSS) score at the 12th week comparing with the baseline. Monte Carlo simulations were used to evaluate and optimize dosing regimens. Results: The PPK model was established to predict the concentrations of ARI and DARI. Body weight and CYP2D6 genotype were the significant covariates affecting the clearance of ARI. The DARI/ARI metabolic ratios (MRs) of AUC24h, Cmin and Cmax at the steady state of results were ultra-rapid metabolizers (UMs) > normal metabolizers (NMs) > intermediated metabolizers (IMs). MRs could be used to distinguish UMs or IMs from other patients. The best predictor of clinical efficacy for TD was the trough concentration of ARI and the cut-off point was 101.636 ng/ml. Conclusion: The pharmacokinetics of ARI and DARI in pediatric TD were significantly influenced by body weight and CYP2D6 genotype. Individualized dosing regimens were recommended for pediatric patients with TD to ensure clinical efficacy.

Trends of Tourette Syndrome in children from 2011 to 2021: A bibliometric analysis

Objective

Analyze the research status of Tourette Syndrome (TS) in children by CiteSpace and determine the current research hotspots and frontiers.

Materials and methods

We chose publications indexed in the Web of Science Core Collection (WoSCC) database for studies related to TS in children from 2011 to 2021. We built online cooperation maps of countries/regions, institutions, authors, journals, references, and keywords by CiteSpace, and identified hotspots and frontiers of study for children’s TS.

Results

A total of 1,232 publications about TS in children were downloaded from the WoSCC. The USA (414) was the country with the highest rate of production, and University College London (87) was the institution that had the highest publication rate. Andrea Eugenio Cavanna was the most prolific author (39 papers). There was inactive cooperation between institutions, countries/regions, and authors. The Journal of European Child &amp; Adolescent Psychiatry was the most active journal. Hot topics focused on epidemiology, comorbidities, deep brain stimulation, behavioral therapy, basal ganglia, pharmacological treatment, and risk factors of TS in children.

Conclusion

According to the CiteSpace results, this study found that authors, countries/regions, and institutions were not actively working together. Current research hotspots mainly consist of epidemiology, comorbidities, deep brain stimulation, behavior therapy, and basal ganglia. The main research trends include comorbidities, pharmacological treatment, and risk factors. Therefore, international cooperation should be strengthened in the future, and it should be mindful of the psychiatric comorbidities of TS, the choice of intervention measures, and early warning of risk factors.

Co-Occurrence of Tic Disorders and Attention-Deficit/Hyperactivity Disorder-Does It Reflect a Common Neurobiological Background?

BACKGROUND

The co-existence of tic disorders and attention-deficit/hyperactivity disorder (TD + ADHD) has proven to be highly important in daily clinical practice. The factor ADHD is not only associated with further comorbidities, but also has a long-term negative psychosocial effect, while the factor TD is usually less disturbing for the major part of the patients. It remains unclear how far this is related to a different neurobiological background of the associated disorders or whether TD + ADHD reflects a common one.

OBJECTIVE

This review provides an update on the neurobiological background of TD + ADHD in order to better understand and treat this clinical problem, while clarifying whether an additive model of TD + ADHD holds true and should be used as a basis for further clinical recommendations.

METHOD

A comprehensive research of the literature was conducted and analyzed, including existing clinical guidelines for both TD and ADHD. Besides genetical and environmental risk factors, brain structure and functions, neurophysiological processes and neurotransmitter systems were reviewed.

RESULTS

Only a limited number of empirical studies on the neurobiological background of TD and ADHD have taken the peculiarity of co-existing TD + ADHD into consideration, and even less studies have used a 2 × 2 factorial design in order to disentangle the impact/effects of the factors of TD versus those of ADHD. Nevertheless, the assumption that TD + ADHD can best be seen as an additive model at all levels of investigation was strengthened, although some overlap of more general, disorder non-specific aspects seem to exist.

CONCLUSION

Beyond stress-related transdiagnostic aspects, separate specific disturbances in certain neuronal circuits may lead to disorder-related symptoms inducing TD + ADHD in an additive way. Hence, within a classificatory categorical framework, the dimensional aspects of multilevel diagnostic-profiling seem to be a helpful precondition for personalized decisions on counselling and disorder-specific treatment in TD + ADHD.

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.