Sex differences in patients with Tourette syndrome

Sexual dimorphism in histamine regulation of striatal dopamine

Background

Many neuropsychiatric disorders show sex differences in prevalence and presentation. For example, Tourette's Syndrome (TS) is diagnosed 3-5 times more often in males. Dopamine modulation of the basal ganglia is implicated in numerous neuropsychiatric conditions, including TS. Motivated by an unexpected genetic finding in a family with TS, we previously characterized the modulation of striatal dopamine by histamine.

Methods

We used microdialysis to analyze striatal dopamine response to the targeted infusion of histamine and histamine agonists. siRNA knockdown of histamine receptors was used to identify the cellular mediators of observed effects.

Results

Intracerebroventricular histamine reduced striatal dopamine in male mice, replicating previous work. Unexpectedly, histamine increased striatal dopamine in females. Targeted infusion of selected agonists revealed that the effect in males depends on H2R receptors in the substantia nigra pars compacta (SNc). Knockdown of H2R in SNc GABAergic neurons abrogated the effect, identifying these cells as a key locus of histamine's regulation of dopamine in males. In females, in contrast, H2R had no role; instead, H3R agonists in the striatum increased striatal dopamine. Strikingly, the effect of histamine on dopamine in females was modulated by the estrous cycle, appearing in estrus/proestrus but not in metestrus/diestrus.

Conclusions

These findings confirm the regulation of striatal dopamine by histamine but identify marked sexual dimorphism in and estrous modulation of this effect. These findings may shed light on the mechanistic underpinnings of other sex differences in the striatal circuitry, perhaps including the marked sex differences seen in TS and related neuropsychiatric conditions.

Deep learning with diffusion MRI as in vivo microscope reveals sex-related differences in human white matter microstructure

Biological sex is a crucial variable in neuroscience studies where sex differences have been documented across cognitive functions and neuropsychiatric disorders. While gross statistical differences have been previously documented in macroscopic brain structure such as cortical thickness or region size, less is understood about sex-related cellular-level microstructural differences which could provide insight into brain health and disease. Studying these microstructural differences between men and women paves the way for understanding brain disorders and diseases that manifest differently in different sexes. Diffusion MRI is an important in vivo, non-invasive methodology that provides a window into brain tissue microstructure. Our study develops multiple end-to-end classification models that accurately estimates the sex of a subject using volumetric diffusion MRI data and uses these models to identify white matter regions that differ the most between men and women. 471 male and 560 female healthy subjects (age range, 22-37 years) from the Human Connectome Project are included. Fractional anisotropy, mean diffusivity and mean kurtosis are used to capture brain tissue microstructure characteristics. Diffusion parametric maps are registered to a standard template to reduce bias that can arise from macroscopic anatomical differences like brain size and contour. This study employ three major model architectures: 2D convolutional neural networks, 3D convolutional neural networks and Vision Transformer (with self-supervised pretraining). Our results show that all 3 models achieve high sex classification performance (test AUC 0.92-0.98) across all diffusion metrics indicating definitive differences in white matter tissue microstructure between males and females. We further use complementary model architectures to inform about the pattern of detected microstructural differences and the influence of short-range versus long-range interactions. Occlusion analysis together with Wilcoxon signed-rank test is used to determine which white matter regions contribute most to sex classification. The results indicate that sex-related differences manifest in both local features as well as global features / longer-distance interactions of tissue microstructure. Our highly consistent findings across models provides new insight supporting differences between male and female brain cellular-level tissue organization particularly in the central white matter.

White matter alterations predict outcomes of comprehensive behavioral intervention for tics in children with Tourette syndrome: A diffusion MRI study

AIM

Tourette syndrome (TS) is a neurodevelopmental disorder that cause sudden uncontrolled rapid and repeated vocal sounds or movements called tics. Herein, diffusion magnetic resonance imaging (dMRI) connectometry was implemented to evaluate the white matter connectivity differences among TS patients.

METHODS

A total of 63 TS and 77 typically developed (TD) individuals were enrolled in the present study. dMRI connectometry was utilized to identify differences in connectivity patterns of white matter tracts in TS patients based on quantitative anisotropy (QA). QA was compared between TS and TD patients and correlated with severity scores such as Yale Global Tic Severity Scale (YGTSS) and Premonitory Urge for Tics Scale (PUTS).

RESULTS

Higher white matter connectivity of corpus callosum and bilateral cingulum as well as lower connectivity of corticothalamic and corticostriatal pathways were evident in TS relative to TD. The baseline YGTSS motor, YGTSS total, and PUTS were negatively correlated with corticostriatal pathway, corticothalamic pathway, and bilateral cingulum integrity, respectively. The changes in tic severity scores were also positively correlated with alterations in the white matter integrity of these brain regions following behavioral therapy.

CONCLUSION

Patients with TS have several abnormalities in their white matter microstructure particularly in the cortico-striato-thalamo-cortical (CSTC) circuit, correlated with the severity of the disease. Besides, the post-behavioral therapy changes in the white matter integrity of these regions are demonstrated as response predictors.

Sex Differences in Youth with Chronic Tic Disorder and Tourette Syndrome: Evaluation of Tic Severity, Psychological Profiles, and Quality of Life

Background: Tourette syndrome (TS) and Chronic Tic Disorder (CT) are neurodevelopmental conditions involving motor and/or phonic tics. Youth with tics may encounter feelings of isolation, diminished self-esteem and quality of life, and academic difficulties. A growing body of scientific literature suggests sex differences in youth with tics, but findings have been mixed so far. Because symptom severity peaks around puberty, understanding sex differences in tic manifestations and associated symptoms during this critical period is essential. Therefore, we aimed to assess sex differences related to tic symptoms, action planning styles, quality of life, and externalizing/internalizing symptoms in youth with tics. Methods: Our sample consisted of 66 youths with tics (19 girls) aged 7-14 (mean = 10 years). Youths were assessed with clinical interviews, as well as self- and parent-reported inventories evaluating tic symptoms, psychological profiles, and quality of life. Results: While no differences in tic symptoms were found, girls exhibited lower functional inflexibility, reduced overall functional planning effectiveness, and higher impairment in the psychological well-being subscale than boys. Additionally, girls had reduced general life satisfaction and social self-esteem. Boys reported more explosive outbursts, higher levels of hyperactivity, and more difficulties with self-concept. Conclusions: Our analyses suggested differences in several manifestations associated with tics. This introduces new perspectives that refine our understanding of sex differences. A better understanding of sex differences in tic disorders may eventually improve outcomes for all individuals living with these conditions.

Sex Differences in People with Tourette Syndrome and Persistent Motor or Vocal Tic Disorder in the Tourette Association of America International Consortium for Genetics Database

Background and Objective

Tourette Syndrome (TS) and Persistent Motor or Vocal Tic Disorders (PMVT) are more prevalent in males (vs. females). Females with TS may have a delay in diagnosis, and more complex tic features (vs. males). With respect to comorbidities, obsessive-compulsive disorder (OCD) is more prevalent in females; attention-deficit hyperactivity disorder (ADHD) is more prevalent in males. Less is known about sex differences in PMVT. This study analyzes sex differences in outcomes among individuals with TS and PMVT in the Tourette Association of America International Consortium for Genetics dataset (TAAICG).

Design/Methods

Data from 2403 individuals (N=2109 TS; N=294 PMVT) from the TAAICG were analyzed to explore the relationship between sex and TS or PMVT outcomes: age at tic onset; age at diagnosis; time-to-diagnosis; tic severity; and comorbidity rates. Regression models were adjusted for age and family relationships to examine the impact of sex on outcomes.

Results

Females with TS (25.5% of the sample) had a later age of symptom onset (6.5±2.8 vs. 6.0±2.7; p=0.001), later age at diagnosis (13.3±11.2 vs. 10.7±8.1; p=0.0001), and a longer time-to-diagnosis [3 (1,7) vs. 2 (1,5), p=0.01] than males. The total Yale-Global Tic Severity Scale (YGTSS) was lower in females with TS (28.4±9.1 vs. 30.7±8.7); p<0.0001); OCD was slightly more prevalent in females (55% vs. 48.7%; p=0.01) although OCD severity did not differ by sex; ADHD was more prevalent in males (55.7% vs 38.9%; p<0.001). Females with TS had 0.46 lower odds of being diagnosed with TS (p<0.00001). Females with PMVT (42.9% of the sample) had an earlier age of symptom onset (7.9±3.3 vs. 8.9±3.7; p=0.05). Motor or vocal tic severity (YGTSS) was not significantly different. OCD, but not ADHD, was more prevalent in females (OCD: 41.9% vs. 22.2%; p<0.001: ADHD:16.5% vs 21.0%; p=0.4).

Conclusion

Females with TS are less likely to be formally diagnosed and have a later age of symptom onset, later age at diagnosis, longer time-to-diagnosis, higher prevalence of OCD, and lower prevalence of ADHD (vs. males). Females with PMVT have an earlier age of symptom onset, higher prevalence of OCD, but similar ADHD prevalence rates (vs. males). Females with TS and PMVT may be clinically different than males with TS. Future research is needed to understand differences longitudinally in TS and PMVT.

A scoping review of oral language and social communication abilities in children with Tourette syndrome

BACKGROUND

Children with Tourette syndrome (TS) have historically experienced problems in academic and social settings, yet their language and communication abilities have not been extensively researched.

AIMS

This scoping review maps the literature on the oral language and social communication abilities of children with TS in order to describe the nature of the current literature, present a summary of major findings and identify where gaps exist.

METHODS

A scoping review was completed to identify studies measuring the oral language or social communication abilities of children with TS. A systematic search of six electronic databases was conducted to obtain published and unpublished literature. All English studies measuring the oral language or social communication abilities of children with TS were included. Information was extracted from records and knowledge was synthesised in a narrative summary.

MAIN CONTRIBUTION

We identified 56 records for inclusion. Almost all records were located in journals within the fields of psychology and psychiatry. Skills most often studied were verbal IQ and verbal fluency. The literature suggests an increased prevalence of language disorders and social communication problems in children with TS; however, literature comprehensively detailing these challenges was scarce. Language strengths were identified in verbal intelligence, story/sentence recall, categorisation and performance on tasks at the single-word level.

CONCLUSIONS

Oral language and social communication skills are important for academic and social success. This review brings scattered literature together to provide up-to-date information about language in children with TS and highlights that there are considerable gaps in our knowledge about language and communication in this population. This scoping review can inform future research and support speech language pathologists in the assessment of young people with TS.

WHAT THIS PAPER ADDS

What is already known on the subject Speech-language pathologists (SLPs) working in various contexts (e.g., schools, mental health teams) are likely to encounter children with Tourette syndrome (TS); however, the description of this population and potential communication characteristics is not well represented in the SLP literature. Previous literature reviews have reported strengths in verbal fluency and morphological processing. Challenges in expressive language, higher order language, social cognition and a propensity towards autistic traits have also been identified. What this paper adds to existing knowledge This review differs from previous narrative reviews by employing a systematic approach to searching for literature. As a result, we identified 25 additional studies that had not been cited in previous reviews and additional relevant findings in 23 previously reviewed studies. This review confirms several previous conclusions about language in children with TS and extends or clarifies several others, thereby providing the most current information on oral language and social communication abilities. The use of current taxonomies of language and social communication helps to organise this literature for clinicians and researchers in speech-language pathology and identifies a need for further research from the SLP perspective. What are the potential or actual clinical implications of this work? These results imply that SLPs should screen children with TS for language disorders and investigate social communication and social interaction development. Clinicians can expect greater challenges in language and communication development for children with complex forms of TS (i.e., those who exhibit co-occurring conditions such as attention-deficit/hyperactivity disorder). The multidisciplinary nature of the current literature implies that clinical collaboration with other disciplines will be of particular benefit to serving this group of children.

Clinical evaluation of premonitory urges in children and adolescents using the Chinese version of Individualized Premonitory Urge for Tics Scale

Background

Premonitory urges (PUs) have been the focus of recent efforts to assess the severity and develop interventions for tic disorders (TD). We aimed to investigate the PUs in TD and its comorbidities from multiple dimensions, using the Chinese version of the Premonitory Urge for Tics Scale (C-PUTS) and the Chinese version of the Individualized Premonitory Urge for Tics Scale (C-IPUTS), in order to provide perspectives for the diagnosis and management of TD in children and adolescents.

Methods

A total of 123 cases were included in the study. The IPUTS was translated, back-translated, culturally adjusted, and pre-investigated to determine the items of the C-IPUTS. The reliability and validity of the C-IPUTS scale were evaluated by a questionnaire survey on children and adolescents with TD at the Developmental Pediatrics Department of the Second Hospital of Jilin University. Meanwhile, the C-PUTS, which had been evaluated and used in China, Yale Global Tic Severity Scale (YGTSS), Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Depression Self-Rating Scale (DSRS), Screen for Childhood Anxiety-Related Disorders (SCARED), Achenbach Child Behavior Checklist (CBCL), and Swanson, Nolan and Pelham, Version IV (SNAP-IV), were used to assess the association of PUs with tics and comorbidities of TD.

Results

All dimensions of the C-IPUTS demonstrated good reliability and validity. Our findings suggested that PUs in children and adolescents in China occurred primarily at the head/face and neck/throat. The different dimensions of the C-IPUTS (number, frequency, and intensity) and C-PUTS were positively correlated with the YGTSS total score, while the C-PUTS was positively correlated with the Y-BOCS, SCARED, DSRS, and SNAP-IV scale total scores. The three dimensions of the C-IPUTS demonstrated correlations with anxiety severity and obsessive-compulsive symptoms.

Conclusion

The C-IPUTS can be used to assess PUs reliably and effectively and provide further information for the C-PUTS from various dimensions in a Chinese setting. PUs relate to obsessive-compulsive symptoms, anxiety, attention deficit hyperactivity, and behavioral problems in children and adolescents with TDs. Accordingly, PUs evaluation using the C-IPUTS combined with the PUTS might provide useful information for future therapies for TDs to achieve greater tic reduction.

Safety and Efficacy of Long-Term Deutetrabenazine Use in Children and Adolescents with Tics Associated with Tourette Syndrome: An Open-Label Extension Study

Background

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by motor and phonic tics.

Objective

To assess the safety and efficacy of deutetrabenazine (Teva Neuroscience, Inc, Parsippany, NJ), a vesicular monoamine transporter 2 inhibitor, in children and adolescents with TS.

Methods

Alternatives for Reducing Tics in TS (ARTISTS) open-label extension (OLE) (NCT03567291) was a 54-week, global, phase 3, open-label extension study of deutetrabenazine (6-48 mg daily) conducted May 28, 2018 to April 3, 2020 with a 2-week randomized withdrawal period. Participants (6-16 years of age) had TS and active tics causing distress or impairment. Safety (primary outcome) was assessed by treatment-emergent adverse events (TEAEs) and clinical laboratory testing. Efficacy was measured by the Yale Global Tic Severity Scale-Total Tic Score (YGTSS-TTS).

Results

The intent-to-treat population (228 participants; mean age, 12.0 years; 79.8% male; 86.4% white) had a median (range) duration of exposure of 28.4 (0.3-52.9) weeks. Of 227 participants in the safety analysis, 161 (70.9%) reported ≥1 TEAE (exposure-adjusted incidence rate, 2.77/patient-year), of which 95 (41.9%) were treatment related. The most frequently reported TEAEs were headaches, somnolence, nasopharyngitis, weight increases, and anxiety. No additional safety signals were observed. Worsening of YGTSS-TTS after the 2-week randomized withdrawal was not statistically significant (least squares mean difference, -0.4; P = 0.78). Several exploratory measures showed sustained improvement throughout the treatment periods.

Conclusions

In this long-term, open-label trial, deutetrabenazine was well tolerated with low frequency of TEAEs. There was no significant difference in tics between treatment arms during the 2-week randomized withdrawal period, however, descriptive statistics and comparison with baseline showed a numeric improvement in tics, quality of life, and other measures.

Have We Forgotten What Tics Are? A Re-Exploration of Tic Phenomenology in Youth with Primary Tics

Background

The first systematic description of tics in a large sample was in 1978.

Objectives

To assess the phenomenology of tics in youth and investigate how age and sex influence tic phenomenology.

Methods

Children and adolescents with primary tic disorders have been prospectively included in our Registry in Calgary, Canada, since 2017. We examined tic frequency and distribution using the Yale Global Tic Severity Scale, differences between sexes, and changes in tic severity with age and with mental health comorbidities.

Results

A total of 203 children and adolescents with primary tic disorders were included (76.4% males; mean age = 10.7 years, 95% CI = 10.3-11.1). At first assessment, the most common simple motor tics were eye blinking (57%), head jerks/movements (51%), eye movements (48%) and mouth movements (46%); 86% had at least one simple facial tic. The most frequent complex motor tics were tic-related compulsive behaviors (19%). Throat clearing was the most common simple phonic tic (42%); 5% only had coprolalia. Females had higher frequency and intensity of motor tics than males (P = 0.032 and P = 0.006, respectively), associated with greater tic-related impairment (P = 0.045). Age was positively correlated with the Total Tic Severity Score (coefficient 0.54, P = 0.005), along with the number, frequency and intensity of motor tics but not with their complexity. Psychiatric comorbidities were associated with greater tic severity.

Conclusions

Our study suggests that age and sex affect clinical presentation in youth with tics. The phenomenology of tics in our sample was similar to the 1978 description of tics, and contrasts with functional tic-like behaviors.

European Society for the Study of Tourette Syndrome 2022 criteria for clinical diagnosis of functional tic-like behaviours: International consensus from experts in tic disorders

BACKGROUND AND PURPOSE

In 2020, health professionals witnessed a dramatic increase in referrals of young people with rapid onset of severe tic-like behaviours. We assembled a working group to develop criteria for the clinical diagnosis of functional tic-like behaviours (FTLBs) to help neurologists, pediatricians, psychiatrists, and psychologists recognize and diagnose this condition.

METHODS

We used a formal consensus development process, using a multiround, web-based Delphi survey. The survey was based on an in-person discussion at the European Society for the Study of Tourette Syndrome (ESSTS) meeting in Lausanne in June 2022. Members of an invited group with extensive clinical experience working with patients with Tourette syndrome and FTLBs discussed potential clinical criteria for diagnosis of FTLBs. An initial set of criteria were developed based on common clinical experiences and review of the literature on FTLBs and revised through iterative discussions, resulting in the survey items for voting.

RESULTS

In total, 24 members of the working group were invited to participate in the Delphi process. We propose that there are three major criteria and two minor criteria to support the clinical diagnosis of FTLBs. A clinically definite diagnosis of FTLBs can be confirmed by the presence of all three major criteria. A clinically probable diagnosis of FTLBs can be confirmed by the presence of two major criteria and one minor criterion.

CONCLUSIONS

Distinguishing FTLBs from primary tics is important due to the distinct treatment paths required for these two conditions. A limitation of the ESSTS 2022 criteria is that they lack prospective testing of their sensitivity and specificity.

Rare copy number variants in males and females with childhood attention-deficit/hyperactivity disorder

While childhood attention-deficit/hyperactivity disorder (ADHD) is more prevalent in males than females, genetic contributors to this effect have not been established. Here, we explore sex differences in the contribution of common and/or rare genetic variants to ADHD. Participants were from the Adolescent Brain and Cognitive Development study (N = 1253 youth meeting DSM-5 criteria for ADHD [mean age = 11.46 years [SD = 0.87]; 31% female] and 5577 unaffected individuals [mean age = 11.42 years [SD = 0.89]; 50% female], overall 66% White, non-Hispanic (WNH), 19% Black/African American, and 15% other races. Logistic regression tested for interactions between sex (defined genotypically) and both rare copy number variants (CNV) and polygenic (common variant) risk in association with ADHD. There was a significant interaction between sex and the presence of a CNV deletion larger than 200 kb, both in the entire cohort (β = -0.74, CI = [-1.27 to -0.20], FDR-corrected p = 0.048) and, at nominal significance levels in the WNH ancestry subcohort (β = -0.86, CI = [-1.51 to -0.20], p = 0.010). Additionally, the number of deleted genes interacted with sex in association with ADHD (whole cohort. β = -0.13, CI = [-0.23 to -0.029], FDR-corrected p = 0.048; WNH. β = -0.17, CI = [-0.29 to -0.050], FDR-corrected p = 0.044) as did the total length of CNV deletions (whole cohort. β = -0.12, CI = [-0.19 to -0.044], FDR-corrected p = 0.028; WNH. β = -0.17, CI = [-0.28 to -0.061], FDR-corrected p = 0.034). This sex effect was driven by increased odds of childhood ADHD for females but not males in the presence of CNV deletions. No similar sex effect was found for CNV duplications or polygenic risk scores. The association between CNV deletions and ADHD was partially mediated by measures of cognitive flexibility. In summary, CNV deletions were associated with increased odds for childhood ADHD in females, but not males.

Sex and gender in neurodevelopmental conditions

Health-related conditions often differ qualitatively or quantitatively between individuals of different birth-assigned sexes and gender identities, and/or with different gendered experiences, requiring tailored care. Studying the moderating and mediating effects of sex-related and gender-related factors on impairment, disability, wellbeing and health is of paramount importance especially for neurodivergent individuals, who are diagnosed with neurodevelopmental conditions with uneven sex/gender distributions. Researchers have become aware of the myriad influences that sex-related and gender-related variables have on the manifestations of neurodevelopmental conditions, and contemporary work has begun to investigate the mechanisms through which these effects are mediated. Here we describe topical concepts of sex and gender science, summarize current knowledge, and discuss research and clinical challenges related to autism, attention-deficit/hyperactivity disorder and other neurodevelopmental conditions. We consider sex and gender in the context of epidemiology, behavioural phenotypes, neurobiology, genetics, endocrinology and neighbouring disciplines. The available evidence supports the view that sex and gender are important contributors to the biological and behavioural variability in neurodevelopmental conditions. Methodological caveats such as frequent conflation of sex and gender constructs, inappropriate measurement of these constructs and under-representation of specific demographic groups (for example, female and gender minority individuals and people with intellectual disabilities) limit the translational potential of research so far. Future research and clinical implementation should integrate sex and gender into next-generation diagnostics, mechanistic investigations and support practices.

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

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

Polygenic risk score-based phenome-wide association study identifies novel associations for Tourette syndrome

Tourette Syndrome (TS) is a complex neurodevelopmental disorder characterized by vocal and motor tics lasting more than a year. It is highly polygenic in nature with both rare and common previously associated variants. Epidemiological studies have shown TS to be correlated with other phenotypes, but large-scale phenome wide analyses in biobank level data have not been performed to date. In this study, we used the summary statistics from the latest meta-analysis of TS to calculate the polygenic risk score (PRS) of individuals in the UK Biobank data and applied a Phenome Wide Association Study (PheWAS) approach to determine the association of disease risk with a wide range of phenotypes. A total of 57 traits were found to be significantly associated with TS polygenic risk, including multiple psychosocial factors and mental health conditions such as anxiety disorder and depression. Additional associations were observed with complex non-psychiatric disorders such as Type 2 diabetes, heart palpitations, and respiratory conditions. Cross-disorder comparisons of phenotypic associations with genetic risk for other childhood-onset disorders (e.g.: attention deficit hyperactivity disorder [ADHD], autism spectrum disorder [ASD], and obsessive-compulsive disorder [OCD]) indicated an overlap in associations between TS and these disorders. ADHD and ASD had a similar direction of effect with TS while OCD had an opposite direction of effect for all traits except mental health factors. Sex-specific PheWAS analysis identified differences in the associations with TS genetic risk between males and females. Type 2 diabetes and heart palpitations were significantly associated with TS risk in males but not in females, whereas diseases of the respiratory system were associated with TS risk in females but not in males. This analysis provides further evidence of shared genetic and phenotypic architecture of different complex disorders.

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.

Oromandibular tics associated with Tourette syndrome

BACKGROUND

Tourette syndrome (TS) is the most common cause of chronic tics. Patients with TS frequently manifest motor tics involving the eyes and face but oromandibular (OM) tics have been rarely studied.

MATERIALS AND METHODS

We reviewed the medical records and video-recordings of 155 consecutive patients with TS in our movement disorders clinic. In addition, we studied 35 patients with classic tardive dyskinesia (TD) and compared their clinical and demographic features with those with TS.

RESULTS

We identified 41 patients with OM tics (26.5%). Although patients with OM tics had a greater overall tic severity and higher frequency of.complex motor and phonic tics, in the bivariate analysis, only comorbid dystonic tics (P = 0.001), greater number of affected body parts (P = 0.012) and more frequent eye-rolling tics (P = 0.059) were included in the final regression model after controlling for other variables. When compared with patients with OM tics, patients with classic TD had more frequently masticatory movements (sensitivity, 0.86; specificity, 0.95), continuous tongue movements (sensitivity, 0.71; specificity, 1.0) and continuous OM movements (sensitivity, 0.4; specificity, 1.0).

CONCLUSIONS

OM tics are common and often troublesome or even disabling symptoms in patients with TS. They may be difficult to differentiate from TD, but the latter is typically manifested by continuous orolingual and masticatory movements.

Childhood Predictors of Long-Term Tic Severity and Tic Impairment in Tourette's Disorder

Tics peak in late childhood and decline during adolescence. Yet, for some with Tourette's disorder, tics persist into adulthood. We evaluated childhood predictors of adult tic severity and tic impairment, and change over time. Eighty adolescents/adults were evaluated 11 years following a randomized-controlled trial of behavior therapy. An independent evaluator rated tic severity and tic impairment at baseline, posttreatment, and long-term follow-up. At baseline, parents completed demographics/medical history, and youth tic, internalizing, and externalizing symptom ratings. Youth rated premonitory urge severity and family functioning. After controlling for prior tic treatment effects, female sex and higher tic severity predicted higher tic severity in adulthood; and female sex, no stimulant medication use, higher tic severity, and poorer family functioning predicted higher tic impairment. Higher tic severity and premonitory urge severity predicted smaller reductions in tic severity, whereas higher externalizing symptoms predicted greater reduction in tic severity. Female sex predicted smaller reduction in tic impairment, and externalizing symptoms predicted greater reduction in tic impairment. Female sex and childhood tic severity are important predictors of tic severity and tic impairment in adulthood. Family functioning, premonitory urge severity, and tic severity are important modifiable targets for early or targeted intervention to improve long-term outcomes.

Diagnosis and Management of Functional Tic-Like Phenomena

Over the past 3 years, a global phenomenon has emerged characterized by the sudden onset and frequently rapid escalation of tics and tic-like movements and phonations. These symptoms have occurred not only in youth known to have tics or Tourette syndrome (TS), but also, and more notably, in youth with no prior history of tics. The Tourette Association of America (TAA) convened an international, multidisciplinary working group to better understand this apparent presentation of functional neurological disorder (FND) and its relationship to TS. Here, we review and summarize the literature relevant to distinguish the two, with recommendations to clinicians for diagnosis and management. Finally, we highlight areas for future emphasis and research.

The clinical phenomenology and correlations of oculogyric tics

BACKGROUND

Oculogyric tics are identified in a substantial proportion of patients with Tourette syndrome (TS) and related tic-disorders. Nevertheless, studies assessing its frequency and clinical correlations are lacking.

MATERIALS AND METHODS

We reviewed video-recordings and clinical history of 201 patients with TS and chronic motor/phonic tic disorder, diagnosed according to DSM-5.

RESULTS

Oculogyric tics presented in 22.4% of our patients. Transient upward gaze was the most common phenomenology in patients with simple oculogyric tics; whereas eye-closure followed by upward and lateral deviations was the most commonly observed phenomenon in patients with combined oculogyric tics. Oculogyric tics have a median duration of 799 ms (range 299-34,500 ms). Patients with oculogyric tics were younger (P = 0.023) and had a higher frequency of cranial tics (P = 0.037) compared to those without oculogyric tics. No differences in tic severity, frequency of attention-deficit/hyperactivity disorder, obsessive-compulsive disorder or use of dopamine receptor antagonists were observed in patients with and without oculogyric tics.

CONCLUSIONS

Oculogyric tics are a common phenomenology in chronic tic disorders. They are more common in younger patients with TS and are markers of other cranial tics, but not of TS severity or comorbid neuropsychiatric syndromes.