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.

Prevalence of Tourette syndrome among children and adolescents in the United States, 2016-2022.

BACKGROUND: Tourette syndrome (TS) is a neurodevelopmental disorder. The prevalence of TS in 2016-2017 has been reported; however, little is known about the current prevalence and trend in children and adolescents with TS. This study aimed to estimate the prevalence and trend of Tourette syndrome (TS) among US children and adolescents aged 0-17 years from 2016 to 2022. METHODS: We analyzed data from a nationally representative sample of 278,472 children and adolescents aged 0-17 years who participated in the 2016-2022 National Survey of Children's Health (NSCH), a nationwide, population-based, cross-sectional survey of US children and adolescents. TS was defined as the affirmative response in the questionnaire completed by a parent or guardian. RESULTS: Among the 278,472 children and adolescents enrolled, 754 had been diagnosed with TS, with an overall prevalence of 0.23% in all children and adolescents aged 0-17 years. The weighted prevalence by age group was lower than 0.01% in children aged 0-2 years, 0.05% in children aged 3-5 years, 0.28% in children aged 6-11 years, and 0.38% in adolescents aged 12-17 years. There were significant sex and racial/ethnic differences in the overall prevalence of diagnosed TS (i.e., 0.35% in boys and 0.11% in girls, 0.22% in Hispanics, 0.28% in non-Hispanic whites and 0.16% in non-Hispanic blacks). There was no significant change in the estimated prevalence of TS from 2016 to 2022. CONCLUSION: Based on nationally representative data, this study found that the national prevalence of TS among the US children and adolescents differed by sex and race/ethnicity but remained stable from 2016 to 2022.

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.

Efficacy of Clonidine Adhesive Patch for Patients With Tourette Syndrome: A Randomized, Double-blind, Placebo-Controlled, Multicenter Clinical Trial.

OBJECTIVE: This study aimed to explore the efficacy of the clonidine adhesive patch for participants with Tourette syndrome (TS). METHODS: This randomized, double-blind, placebo-controlled, multicenter phase IV clinical trial included participants with TS at 20 centers between May 2012 and March 2015. Treatment efficacy at week 8 was the primary outcome. The Clinical Global Impression-Severity scale and Improvement scale were the secondary endpoints. RESULTS: This trial included 488 participants, with 121 participants in the 2.0-mg/wk group, 119 participants in the 1.5-mg/wk group, 126 participants in the 1.0-mg/wk group, and 122 participants in the placebo group. For Yale Global Tic Severity Scale score reduction rate, compared with the placebo group (39.60 ± 25.56), those of the 2.0-mg/wk group (63.21 ± 32.60) and the 1.5-mg/wk group (68.16 ± 25.88) were statistically significantly different (all P < 0.001). For total Yale Global Tic Severity Scale score, compared with the placebo group (17.0 ± 8.03), the score for the 2.0-mg/wk group was 9.9 ± 8.36 ( P < 0.001); 1.5-mg/wk group, 9.6 ± 8.03 ( P < 0.001); and 1.0-mg/wk group, 10.5 ± 9.28 ( P < 0.001). The Clinical Global Impression-Severity scale and Improvement scale scores were statistically significantly different in the 3 clonidine (or experimental) groups compared with the placebo group (all P < 0.001). CONCLUSIONS: Larger doses of the clonidine adhesive patch such as 1.5 and 2.0 mg/wk are effective in improving the symptoms and overall function of participants 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.

Efficacy of cannabis-based medicine in the treatment of Tourette syndrome: a systematic review and meta-analysis.

BACKGROUND: Tourette syndrome (TS) is a neurodevelopmental disorder characterized by motor and phonic tics. It is a condition that affects between 0.3% and 0.7% of children, and its pathophysiology remains largely elusive. TS is associated with structural and functional alterations in corticostriatal circuits and neurochemical imbalances. Even though TS is currently incurable, there are established treatment options available, including behavioral therapy and neuroleptics. The use of cannabis-based medicine for tic management is an emerging therapeutic strategy, although its efficacy is still under investigation. It is hypothesized to interact with the endogenous cannabinoid system, but further research is required to ascertain its safety and effectiveness in TS. AIM: In our systematic review and meta-analysis, we aim to assess the effectiveness of cannabis-based medicine in the treatment of TS. METHODS: We searched PubMed, Cochrane, Scopus, and Web of Sciences until February 2024. We included clinical trials and cohort studies investigating the efficacy of cannabis-based medicine in the treatment of TS. Data extraction focused on baseline characteristics of the included studies and efficacy outcomes, including scores on the Yale Global Tic Severity Scale (YGTSS), Premonitory Urge for Tics Scale (PUTS), and Yale-Brown Obsessive Compulsive Scale (Y-BOCS). We conducted the meta-analysis using Review Manager version 5.4. software. We compared the measurements before and after drug intake using mean difference (MD) and 95% confidence interval (CI). RESULTS: In total, 357 articles were identified for screening, with nine studies included in the systematic review and 3 in the meta-analysis. These studies involved 401 adult patients with TS treated with cannabis. YGTSS revealed a significant reduction in total scores (MD = -23.71, 95% CI [-43.86 to -3.55], P = 0.02), PUTS revealed a significant decrease in scores (MD = -5.36, 95% CI [-8.46 to -2.27], P = 0.0007), and Y-BOCS revealed no significant difference in score reduction (MD = -6.22, 95% CI [-12.68 to 0.23], P = 0.06). CONCLUSION: The current study indicates promising and potentially effective outcomes with the use of cannabis-based medicine in mitigating the severity of tics and premonitory urges. However, there is a need for larger, placebo-controlled studies with more representative samples to validate these findings.

The antisaccadic paradigm: A complementary neuropsychological tool in basal ganglia disorders.

This review explores the role of the antisaccadic task in understanding inhibitory mechanisms in basal ganglia disorders. It conducts a comparative analysis of saccadic profiles in conditions such as Parkinson's disease, Tourette syndrome, obsessive-compulsive disorder, Huntington's disease, and dystonia, revealing distinct patterns and proposing mechanisms for impaired performance. The primary focus is on two inhibitory mechanisms: global, pre-emptive inhibition responsible for suppressing prepotent responses, and slower, selective response inhibition. The antisaccadic task demonstrates practicality in clinical applications, aiding in differential diagnoses, treatment monitoring and reflecting gait control. To further enhance its differential diagnostic value, future directions should address issues such as the standardization of eye-tracking protocol and the integration of eye-tracking data with other disease indicators in a comprehensive dataset.

An update on the pharmacological management of Tourette syndrome and emerging treatment paradigms.

INTRODUCTION: Tourette syndrome (TS) is a childhood-onset neurobehavioral disorder characterized by tics. Pharmacotherapy is advised for patients whose symptoms affect their quality of life. AREAS COVERED: The authors review the tic phenomenology and TS diagnostic criteria. The bulk of this article focuses on pharmacotherapeutic options for treating tics. They also highlight pharmacotherapies in the research pipeline. EXPERT OPINION: Tic treatment must be tailored to individual needs. Behavioral therapy is the first line of treatment. Most with bothersome tics need pharmacotherapy and rarely, for medication-refractory cases, surgical therapy is indicated. Alpha-2 agonists are considered in patients with mild tics, especially in those with attention deficit with or without hyperactivity. Second-generation antipsychotics like aripiprazole and tiapride may be considered for severe tics. However, prescribers should be mindful of potential side effects, especially drug-induced movement disorders. Botulinum toxin injections may be considered for focal motor tics. Topiramate can be considered when other treatments are ineffective, and its benefits outweigh the risks. The same holds true for vesicular monoamine transporter-2 inhibitors, as they are deemed to be safe and effective in real-world use and open-label trials despite not meeting primary endpoints in placebo-controlled trials. Cannabinoids may be considered in adults if the approaches above do not control tics.

Prevalence of mass social media-induced illness presenting with Tourette-like behavior in Germany between 2019 and 2021.

Starting in 2019, in Germany the first well documented outbreak of mass sociogenic illness induced by social media (mass social media-induced illness; MSMI) occurred presenting with functional Tourette-like behaviors (FTB). This study aimed to provide first data on the prevalence rate of MSMI-FTB in Germany between 2019 and 2021 in the general population. We conducted a large-scale representative population survey in cooperation with the USUMA market and social research institute. Between August and December 2021, n = 2.509 people (mean age: 49.5 years, range: 16-95 years, n = 1.276 females) were randomly selected, visited in their households, interviewed, and asked to answer for themselves, but also for close family members (n = 6.744). Thus, in total, we received answers for n = 9.253 people. Probable MSMI-FTB was found in n = 33 individuals (mean age at onset: 30.5 years, n = 8 females). Based on strict criteria, the diagnosis of MSMI-FTB was considered highly likely in 16/33 individuals (mean age at onset: 25.6 years, n = 2 females) corresponding to prevalence rates of 0.17% (CIlower = 0.10, CIupper = 0.28) and 0.36% (CIlower = 0.25, CIupper = 0.50), respectively. This is the first large-scale, population representative study investigating the prevalence of MSMI-FTB in the general population in Germany between 2019 and 2021. Based on the prevalence rates found, MSMI-FTB is highly relevant for health economy. Accordingly, we suggest educating healthcare professionals and the general public to avoid misdiagnosis and inefficient treatment.

Automated Video-Based Approach for the Diagnosis of Tourette Syndrome.

BACKGROUND: The occurrence of tics is the main basis for the diagnosis of Gilles de la Tourette syndrome (GTS). Video-based tic assessments are time consuming. OBJECTIVE: The aim was to assess the potential of automated video-based tic detection for discriminating between videos of adults with GTS and healthy control (HC) participants. METHODS: The quantity and temporal structure of automatically detected tics/extra movements in videos from adults with GTS (107 videos from 42 participants) and matched HCs were used to classify videos using cross-validated logistic regression. RESULTS: Videos were classified with high accuracy both from the quantity of tics (balanced accuracy of 87.9%) and the number of tic clusters (90.2%). Logistic regression prediction probability provides a graded measure of diagnostic confidence. Expert review of about 25% of lower-confidence predictions could ensure an overall classification accuracy above 95%. CONCLUSIONS: Automated video-based methods have a great potential to support quantitative assessment and clinical decision-making in tic disorders.

A Novel PDE10A Inhibitor for Tourette Syndrome and Other Movement Disorders.

BACKGROUND: Tourette syndrome is a neurodevelopmental movement disorder involving basal ganglia dysfunction. PDE10A inhibitors modulate signaling in the striatal basal ganglia nuclei and are thus of interest as potential therapeutics in treating Tourette syndrome and other movement disorders. METHODS: The preclinical pharmacology and toxicology, human safety and tolerability, and human PET striatal enzyme occupancy data for the PDE10A inhibitor EM-221 are presented. RESULTS: EM-221 inhibited PDE10A with an in vitro IC50 of 9 pM and was >100,000 selective vs. other PDEs and other CNS receptors and enzymes. In rats, at doses of 0.05-0.50 mg/kg, EM-221 reduced hyperlocomotion and the disruption of prepulse inhibition induced by MK-801, attenuated conditioned avoidance, and facilitated novel object recognition, consistent with PDE10A's inhibition. EM-221 displayed no genotoxicity and was well tolerated up to 300 mg/kg in rats and 100 mg/kg in dogs. In single- and multiple-day ascending dose studies in healthy human volunteers, EM-221 was well tolerated up to 10 mg, with a maximum tolerated dose of 15 mg. PET imaging indicated that a PDE10A enzyme occupancy of up to 92.8% was achieved with a ~24 h half-life. CONCLUSIONS: The preclinical and clinical data presented here support the study of EM-221 in phase 2 trials of Tourette syndrome and other movement disorders.

Transcranial sonography of subcortical structures in tic/tourette disorder.

Functional neuroimaging studies demonstrate disinhibition of the cortico-striatal-thalamo-cortical circuit. However, structural imaging studies revealed conflicting results, some suggesting smaller volumes of the caudate nucleus (CN) in children with Gilles de la Tourette syndrome (TS). Here we wanted to find out whether transcranial sonography (TCS) detects alterations of raphe nuclei, substantia nigra, lenticular nucleus (LN), or CN in children with Tic disorder or TS (TIC/TS).The study included 25 treatment-naive children (age: 12.2 ± 2.5 years) with a DSM-V based diagnosis of Tic disorder or TS (10 subjects), without other psychiatric or neurologic diagnosis, and 25 healthy controls (age: 12.17 ± 2.57 years), matched for age and sex. Parental rating of behavioral, emotional abnormalities, somatic complaints and social competencies of the participants were assessed using the Child Behavior Check List (CBCL/4-18R). TCS of deep brain structures was conducted through the preauricular acoustic bone windows using a 2.5-MHz phased-array ultrasound system. Fisher's exact test and Mann-Whitney-U test were used for comparisons between TIC/TS patients and healthy volunteers. The number of participants with hyperechogenic area of left CN in the TIC/TS sample was increased, compared to the healthy control group. TIC/TS patients with hyperechogenic CN showed an increased occurrence of thought- and obsessive-compulsive problems. This TCS study revealed pathologic structural changes in CN, its higher occurrence in TIC/TS compared to healthy controls and the relation to comorbidity of thought problems. Further research should focus on the molecular cause of these alterations, probably the disturbed iron metabolism.

Structural Variants and Implicated Processes Associated with Familial Tourette Syndrome.

Gilles de la Tourette syndrome (GTS) is a neurodevelopmental psychiatric disorder with complex and elusive etiology with a significant role of genetic factors. The aim of this study was to identify structural variants that could be associated with familial GTS. The study group comprised 17 multiplex families with 80 patients. Structural variants were identified from whole-genome sequencing data and followed by co-segregation and bioinformatic analyses. The localization of these variants was used to select candidate genes and create gene sets, which were subsequently processed in gene ontology and pathway enrichment analysis. Seventy putative pathogenic variants shared among affected individuals within one family but not present in the control group were identified. Only four private or rare deletions were exonic in LDLRAD4, B2M, USH2A, and ZNF765 genes. Notably, the USH2A gene is involved in cochlear development and sensory perception of sound, a process that was associated previously with familial GTS. In addition, two rare variants and three not present in the control group were co-segregating with the disease in two families, and uncommon insertions in GOLM1 and DISC1 were co-segregating in three families each. Enrichment analysis showed that identified structural variants affected synaptic vesicle endocytosis, cell leading-edge organization, and signaling for neurite outgrowth. The results further support the involvement of the regulation of neurotransmission, neuronal migration, and sound-sensing in GTS.

Tourette Syndrome: A Catalyst for Operationalizing Neurodiversity.

Our goal, taking Tourette syndrome as a case example, is to introduce neurologists to, and motivate discussion on, the neurodiversity paradigm. This philosophical construct considers some neurologic conditions in diversity, instead of simply disease. Moving from philosophical idea to empirical construct draws from patient and family perspectives on (1) quality of life and discrimination, (2) disability pride, and (3) unique profiles of different patient cohorts. Listening to patient voices, attending to family, advocacy group, and societal views on neurologic disorders can strengthen precision neurology practice. Dialogs on neurodiversity, including antitherapy sentiments, offer to enhance neurologic care, patient agency, and autonomy; encourage respectful communications with patients who challenge the idea their condition is pathologic; and to set the stage for future empirical investigations and practice guidelines.

Neural representations of statistical and rule-based predictions in Gilles de la Tourette syndrome.

Gilles de la Tourette syndrome (GTS) is a disorder characterised by motor and vocal tics, which may represent habitual actions as a result of enhanced learning of associations between stimuli and responses (S-R). In this study, we investigated how adults with GTS and healthy controls (HC) learn two types of regularities in a sequence: statistics (non-adjacent probabilities) and rules (predefined order). Participants completed a visuomotor sequence learning task while EEG was recorded. To understand the neurophysiological underpinnings of these regularities in GTS, multivariate pattern analyses on the temporally decomposed EEG signal as well as sLORETA source localisation method were conducted. We found that people with GTS showed superior statistical learning but comparable rule-based learning compared to HC participants. Adults with GTS had different neural representations for both statistics and rules than HC adults; specifically, adults with GTS maintained the regularity representations longer and had more overlap between them than HCs. Moreover, over different time scales, distinct fronto-parietal structures contribute to statistical learning in the GTS and HC groups. We propose that hyper-learning in GTS is a consequence of the altered sensitivity to encode complex statistics, which might lead to habitual actions.

Functional brain networks associated with the urge for action: Implications for pathological urge.

Tics in Tourette syndrome (TS) are often preceded by sensory urges that drive the motor and vocal symptoms. Many everyday physiological behaviors are associated with sensory phenomena experienced as an urge for action, which may provide insight into the neural correlates of this pathological urge to tic that remains elusive. This study aimed to identify a brain network common to distinct physiological behaviors in healthy individuals, and in turn, examine whether this network converges with a network we previously localized in TS, using novel 'coordinate network mapping' methods. Systematic searches were conducted to identify functional neuroimaging studies reporting correlates of the urge to micturate, swallow, blink, or cough. Using activation likelihood estimation meta-analysis, we identified an 'urge network' common to these physiological behaviors, involving the bilateral insula/claustrum/inferior frontal gyrus/supplementary motor area, mid-/anterior- cingulate cortex (ACC), right postcentral gyrus, and left thalamus/precentral gyrus. Similarity between the urge and TS networks was identified in the bilateral insula, ACC, and left thalamus/claustrum. The potential role of the insula/ACC as nodes in the network for bodily representations of the urge to tic are discussed.

Bedtime Regularity and Sleep Sufficiency in Children With Tourette Syndrome.

BACKGROUND: Despite research demonstrating sleep disturbance in children with Tourette syndrome (TS), few studies have examined bedtime regularity and sleep sufficiency, two important sleep health dimensions. Therefore, this study examined bedtime regularity and sleep sufficiency in children with TS relative to matched healthy control subjects, and its associated demographic, clinical, and behavioral factors. METHODS: Participants were 384 parents or caregivers of children aged three to 17 years, including 192 with current TS and 192 matched healthy control subjects drawn from the 2020-2021 cycle of the National Survey of Children's Health. Parents completed questions assessing demographic (i.e., age, race, sex), clinical (i.e., attention-deficit/hyperactivity disorder [ADHD], autism spectrum disorder, anxiety, depression, tic severity, behavioral or conduct problems, ADHD medication, health condition-related impairment), and behavioral (i.e., screen time) characteristics. Mann-Whitney U test and chi-square test of independence were performed to compare groups on bedtime regularity and sleep sufficiency, respectively. Ordinal regression and binary logistic regression without and with backward elimination were performed to evaluate indicators of bedtime regularity and sleep sufficiency, respectively, in children with TS. RESULTS: Children with current TS had significantly poorer bedtime regularity, but not sleep sufficiency, relative to matched healthy control subjects. In children with TS, anxiety and two or more hours of daily screen time were associated with higher likelihood of poor bedtime regularity. Autism was associated with lower likelihood of insufficient sleep, and depression was associated with increased likelihood of insufficient sleep. CONCLUSIONS: Findings put forth screen time, anxiety, and depression as intervention targets to optimize sleep health in children with TS.

Case Report: Second-order Contrast Sensitivity in Tourette Syndrome. / Olgu Sunumu: Tourette Sendromunda Ikinci Düzey Kontrast Duyarliligi.

disease, characterized by motor and vocal tics with no changes in the ocular structures in the ophthalmological evaluations. The visual field evaluations suggest a reduction in central visual field sensitivity. The studies on visual function in this population is scarce. In this case report we present a patient with GTS who has significant alterations in the measure of contrast sensitivity for second order vision without any vision complaints. This reduction occurred in the measure of contrast sensitivity with a white noise carrier for practically all tested space frequencies. The mean contrast sensitivity for first and second-order stimuli with a pink-noise carrier was normal. The second order contrast sensitivity with a white noise carrier is dependent on local and lateral inhibition since it includes many local luminance components. The existence of this sensitivity suggests that specific visual processing mechanisms are affected. Keywords: Tourette Syndrome, Contrast Sensitivity, Contrast Psychophysical Channels, Second-Order Perception.