Is Persistent Motor or Vocal Tic Disorder a Milder Form of Tourette Syndrome?

Auditory gating and its clinical correlates in adults with chronic tic disorder and neurotypical adults

BACKGROUND

Over 80% of adults with chronic tic disorder (CTD) experience sensory over-responsivity (SOR), defined as heightened awareness of and/or behavioral reactivity to commonplace environmental stimuli. One potential mechanism underpinning SOR is sensory gating impairment. Sensory gating is the physiologic process whereby redundant stimuli are filtered out in early perceptual stages. In this study, we compared sensory gating between neurotypical and CTD adults and determined if gating indices associated with SOR.

METHODS

Neurotypical (n = 31) and CTD adults (n = 26) completed a clinical assessment, including two SOR measures (Sensory Gating Inventory, SGI; Sensory Perception Quotient, SPQ), and an auditory gating paradigm while monitored on EEG.

RESULTS

CTD adults exhibited greater SOR. Neurotypical and CTD adults did not differ in P50, N100, or P200 gating ratios. In regression analyses, N100 gating ratio was significantly associated with SGI score; the magnitude of this association was greater for neurotypical than CTD adults. No other significant associations emerged between gating ratios and SOR measures.

CONCLUSION

Findings do not support sensory gating impairment as a mechanism underpinning SOR in CTD. The relationship between N100 gating and SOR warrants further investigation.

SIGNIFICANCE

This is the first study to examine auditory gating in individuals with CTD.

Genome-wide association study meta-analysis of 9,619 cases with tic disorders

BACKGROUND

Despite the significant personal and societal burden of tic disorders (TD), treatment outcomes remain modest, necessitating a deeper understanding of their etiology. Family history is the biggest known risk factor and identifying risk genes could accelerate progress in the field.

METHODS

Expanding upon previous sample size limitations, we added 4,800 new TD cases and 971,560 controls, conducting a GWAS meta-analysis with 9,619 cases and 981,048 controls of European ancestry. We attempted to replicate the results in an independent deCODE Genetics GWAS (885 TD cases and 310,367 controls). To characterize GWAS findings, we conducted several post-GWAS gene-based and enrichment analyses.

RESULTS

A genome-wide significant hit (rs79244681, p=2.27x10-08) within MCHR2-AS1 was identified, though it was not replicated. Post-GWAS analyses revealed a 13.8% SNP-heritability and three significant genes: BCL11B, NDFIP2, and RBM26. Common variant risk for TD was enriched within genes preferentially expressed in the cortico-striato-thalamo-cortical circuit (including the putamen, caudate, nucleus accumbens, and Brodman area 9) and five brain cell types (excitatory and inhibitory telencephalon-, inhibitory- di- and mesencephalon, hindbrain-, and medium spiny neurons). TD polygenic risk was enriched within loss-of-function intolerant genes (p=0.0017) and high-confidence neurodevelopmental disorder genes (p=0.0108). Of 112 genetic correlations, 43 were statistically significant, showing high positive correlations with most psychiatric disorders. Of the two SNPs previously associated with TD, one (rs2453763) replicated in an independent sub-sample of our GWAS (p=0.00018).

CONCLUSIONS

This GWAS was still underpowered to identify high-confidence, replicable loci, but the results suggest imminent discovery of common genetic variants for TD.

Optimization of self- or parent-reported psychiatric phenotypes in longitudinal studies

BACKGROUND

The Adolescent Brain Cognitive Development (ABCD) study is a longitudinal study of US adolescents with a wide breadth of psychiatric, neuroimaging and genetic data that can be leveraged to better understand psychiatric diseases. The reliability and validity of the psychiatric data collected have not yet been examined. This study aims to explore and optimize the reliability/validity of psychiatric diagnostic constructs in the ABCD study.

METHODS

Parent-and-child-reported psychiatric data for 11,876 children (aged 9.5 ± 0.5 at first assessment) were examined over 4 years to derive specific constructs for psychiatric diagnoses using longitudinal information. Rates of psychiatric disorders were calculated and compared to those reported in the epidemiological literature.

RESULTS

The rates of self-reported psychiatric disorders at any single time point (broad diagnostic construct) were higher than indicated by epidemiological studies. Narrow diagnostic constructs, which required the endorsement of psychiatric disorders at a majority of longitudinal assessments, demonstrated a better rate approximation of literature-reported prevalences for most disorders (e.g. the prevalence of broad obsessive-compulsive disorder (OCD) was 13.3% compared to narrow OCD at 2.6% and a literature-reported prevalence of 2.3%). Analysis of comorbidity, using OCD as a representative example, also showed a better approximation of literature-reported comorbidity rates using the narrow construct, with some exceptions.

CONCLUSIONS

Self- or parent-report-based assessments tend to overestimate prevalences of psychiatric disorders in the ABCD Study, particularly when longitudinal data are summed to create lifetime prevalences. Such assessments should be accompanied by more in-depth assessments or clinician-administered structured interviews if using data where accurate disorder classifications are paramount.

A Family Genetic Study of Obsessive Compulsive Disorder in Youth

OBJECTIVE

To use a family genetic study to evaluate familial risk of obsessive compulsive disorder (OCD) and common comorbid illnesses in first-degree relatives of pediatric-onset probands with primary OCD.

METHOD

One hundred and thirty youth with OCD and their 133 siblings and 241 parents and 49 pediatric controls were directly evaluated along multiple domains including psychopathology using structured diagnostic interviews and clinical corroboration.

RESULTS

Rates of anxiety, mood, disruptive behavior, and tic disorders were markedly elevated in the probands while rates in siblings were elevated at rates between the probands and controls. Twenty six percent of first-degree relatives had clinical OCD, 9% had chronic tics or Tourette's disorder, and 21% met criteria for ADHD.

CONCLUSION

Rates of familial transmission of OCD and common comorbid illnesses were significantly higher in our pediatric-onset probands than rates reported in the literature in relatives of those with adult-onset OCD.

Perspectives from Adults with Tourette Syndrome on Research Priorities and Registry Development: A Focus Group Study

Purpose

Adults with Tourette syndrome (TS) have worse mental health, physical health, and quality of life than the general population. The factors contributing to negative outcomes across multiple health domains in adults with TS remain uncertain, in part due to a lack of longitudinal studies in this population. In attempt to address these knowledge gaps, our center has initiated development of a regional registry for adults with TS. During the goal-setting and design phase of registry development, we conducted focus groups with adults with TS to identify research issues of greatest importance to this population and to obtain feedback on design and implementation of an adult TS registry.

Patients and Methods

Participants were recruited from a tertiary care adult TS clinic and from institutional research registries. Focus groups were conducted online and were moderated by a qualitative research expert. Qualitative data analysis was performed using an iterative inductive/deductive approach.

Results

Across four focus groups, adult TS participants (n=22) expressed a variety of research priorities, including developing more effective treatments for tics, identifying risk factors for tic persistence into adulthood, clarifying the interaction between TS symptoms and women's health, clarifying the relationships between TS and other mental and physical health disorders, and addressing day-to-day living issues. Focus group participants were generally enthusiastic about creation of an adult TS registry. They indicated that adults with TS are more likely to engage with a registry that logistically accommodates participants (eg, by offering a wide range of visit times, by providing telehealth options) and that fosters bidirectional interaction (eg, by disseminating results regularly, by involving participants in registry design and implementation, by notifying participants of support resources).

Conclusion

Focus group input clarifies the research priorities of adults with TS and will inform the ongoing development of an adult TS registry.

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.

Early-Life and Family Risk Factors for Tic Disorder Persistence into Adulthood

BACKGROUND

Many children with tic disorders outgrow their tics, but little is known about the proportion of individuals who will continue to require specialist services in adulthood and which variables are associated with tic persistence.

OBJECTIVES

The aims were to estimate the proportion of individuals first diagnosed with tic disorders in childhood who continued to receive tic disorder diagnoses after age 18 years and to identify risk factors for persistence.

METHODS

In this Swedish nationwide cohort study including 3761 individuals diagnosed with tic disorders in childhood, we calculated the proportion of individuals whose diagnoses persisted into adulthood. Minimally adjusted logistic regression models examined the associations between sociodemographic, clinical, and family variables and tic disorder persistence. A multivariable model was then fitted, including only variables that were statistically significant in the minimally adjusted models.

RESULTS

Seven hundred and fifty-four (20%) children with tic disorders received a diagnosis of a chronic tic disorder in adulthood. Psychiatric comorbidity in childhood (particularly attention-deficit hyperactivity disorder, obsessive-compulsive disorder, pervasive developmental disorders, and anxiety disorders) and psychiatric disorders in first-degree relatives (particularly tic and anxiety disorders) were the strongest risk factors for persistence. We did not observe statistically significant associations with socioeconomic variables, perinatal complications, comorbid autoimmune diseases, or family history of autoimmune diseases. All statistically significant variables combined explained approximately 10% of the variance in tic disorder persistence (P < 0.0001).

CONCLUSIONS

Childhood psychiatric comorbidities and family history of psychiatric disorders were the strongest risk factors associated with tic disorder persistence into adulthood. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Treatment of Tourette syndrome by acupuncture combined with Chinese medicine based on syndrome differentiation: A review

Tourette syndrome (TS) is a chronic neurodevelopmental disorder characterized by involuntary motor and speech tics, which can greatly reduce the quality of life of patients. The pathophysiology of TS involves both genetic and environmental factors. Assessing TS pathogenesis is complex, and its underlying pathophysiology is not fully understood. It is gratifying that the research in the past 5 years has brought new research progress on the genetic, neurophysiological and brain network changes of TS. However, despite the progress of research, the treatment methods and drugs of modern medicine are still unsatisfactory, and it is difficult to achieve satisfactory results. Traditional Chinese medicine, as a part of complementary and alternative medicine, has unique efficacy in the treatment of TS, and the safety of its treatment is also worthy of attention. Based on the latest achievements in the pathophysiology of TS, this article will discuss the treatment of TS by acupuncture combined with medicine.

Dimensional Assessment of Depression and Anxiety in a Clinical Sample of Adults With Chronic Tic Disorder

OBJECTIVE

Among adults with Tourette syndrome, depression and anxiety symptoms are widely prevalent and consistently associated with poor quality of life. Important knowledge gaps remain regarding mood and anxiety dimensions of the adult Tourette syndrome phenotype. Taking a dimensional approach, this study sought to determine the prevalence, severity, and clinical correlates of depression and anxiety symptoms in a clinical sample of adults with Tourette syndrome and other chronic tic disorders.

METHODS

A retrospective chart review was conducted of all adults with a chronic tic disorder presenting to a tertiary care Tourette syndrome clinic between December 2020 and July 2022. Information extracted during chart review included data from scales administered as part of routine care: Quality of Life in Neurological Disorders (Neuro-QoL) Depression Short Form, Neuro-QoL Anxiety Short Form, Adult Attention-Deficit/Hyperactivity Disorder Self-Report Screening Scale, Dimensional Obsessive-Compulsive Scale, and Yale Global Tic Severity Scale. Relationships between variables were examined by conducting between-group, correlation, and multivariable regression analyses.

RESULTS

Data from 120 adult patients with a chronic tic disorder (77 men and 43 women) were analyzed. Neuro-QoL Anxiety scores were elevated in 66% of the cohort; Neuro-QoL Depression scores were elevated in 26%. Neuro-QoL Anxiety scores were significantly higher than general population norms, whereas Neuro-QoL Depression scores were not. After adjustment for covariates, depressive and anxiety symptom severity scores were significantly associated with each other and with obsessive-compulsive disorder symptom severity but not with tic severity. Sex-based differences emerged in the analyses.

CONCLUSIONS

Among adults with chronic tic disorder, anxiety symptoms were more prevalent and severe than depressive symptoms, co-occurring psychiatric symptoms were more tightly linked with each other than with tic severity, and sex-based differences were evident.

Brief youth self-report screener for tics: Can a subscale of the Motor tic, Obsession and compulsion, and Vocal tic Evaluation Survey (MOVES) identify tic disorders in youth?

Tics are unwanted, repetitive movements and sounds that frequently present during childhood. They are typically brief and purposeless, but can create significant distress for individuals, and often co-occur with other neuropsychiatric conditions. Thus, early identification of tics is warranted. Unfortunately, tics are often misdiagnosed, and because tics may wax and wane, identification can be difficult, especially in the context of routine clinical visits. There are limited tools that can be used to reliably identify tics in clinical practice, especially in non-specialty settings. The purpose of the current study was to evaluate the performance of the Motor tic, Obsession and compulsion, and Vocal tic Evaluation Survey (MOVES), a self-report scale with some support as a screening tool. In addition, the performance of a subset of questions (the MOVES-6) was evaluated for rapid screening. Participants were recruited across two study sites and included children and adolescents diagnosed with Tourette syndrome (n = 151) or another persistent tic disorder (n = 10) and community controls (n = 74). Results suggest both the MOVES and the MOVES-6 have high sensitivity (90% and 88%, respectively) and at least acceptable specificity (77% and 86%, respectively) compared with expert assessment of tic disorders, suggesting that both versions can identify tic disorders without high proportions of false negatives. Both versions were highly sensitive with acceptable specificity regardless of sex, race/ethnicity, and age. The MOVES and MOVES-6 show promise as a screener for tics or tic disorders, but additional research is needed, particularly in a general population setting.

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.

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.

Sex differences in patients with Tourette syndrome

BACKGROUND

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by the presence of motor and phonic tics. It is at least three times more common in males compared with females; however, the clinical phenomenology between sexes has not been fully examined. We aimed to contrast the clinical features between males and females with TS and chronic tic disorder.

METHODS

We studied 201 consecutive patients fulfilling the diagnostic criteria for TS, persistent (or chronic) motor and vocal tic disorder and provisional tic disorder that were considered within the TS spectrum disorder. We performed blinded evaluations of video-recordings and retrospectively reviewed the clinical charts of all patients.

RESULTS

Age ranges between 4 and 65 years. Males represented 77.6% of patients in the cohort. Overall, no differences were observed in the frequency, distribution and complexity of tics between sexes, except for a higher frequency of attention-deficit/hyperactivity disorder (ADHD) (P = .003) among males. Patients younger than 18-years old, in addition to a higher frequency of ADHD (P = .026), males had a statistically higher frequency of complex motor tics (P = .049) and earlier age at onset (P = .072) than females in the multivariate regression analysis. However, these differences were lost in patients older than 18 years, due to increased complexity of tics in females with aging.

CONCLUSIONS

A sexual dimorphism was observed between patients with TS mainly before age of 18 years, suggesting an earlier onset of some types of tics and ADHD in males compared to females.

Sleep and chronotype in adults with persistent tic disorders

OBJECTIVE

This study examined sleep disorders and sleep medication use rates, nighttime tics, and sleep and chronotype in relation to tic and co-occurring symptoms in adults with persistent tic disorders (PTDs), including Tourette's disorder (TD).

METHODS

One hundred twenty-five adult internet survey respondents rated sleep history, sleep, chronotype, tic severity, impairment, attention deficit hyperactivity disorder, obsessive-compulsive symptoms, anxiety, depression, and emotional and behavioral dyscontrol.

RESULTS

Bruxism, insomnia, tic-related difficulty falling asleep, and melatonin use were commonly endorsed. Sleep disturbance correlated with impairment, obsessive-compulsive symptoms, and emotional and behavioral dyscontrol. Eveningness correlated with vocal and total tic severity only in TD. Controlling for age and sex, age, impairment, and obsessive-compulsive symptoms predicted sleep disturbance, and age and tic severity predicted chronotype.

CONCLUSIONS

Impairment and obsessive-compulsive symptoms play a role in sleep disturbance in adults with PTDs, and may be intervention targets. Eveningness relates to tic severity, which may suggest the utility of interventions to advance chronotype.

Cross-disorder comparison of sensory over-responsivity in chronic tic disorders and obsessive-compulsive disorder

BACKGROUND

Sensory over-responsivity (SOR) refers to excessively intense and/or prolonged behavioral responses to environmental stimuli typically perceived as non-aversive. SOR is prevalent in several neurodevelopmental disorders, including chronic tic disorders (CTDs) and obsessive-compulsive disorder (OCD). Few studies have examined the extent and clinical correlates of SOR across disorders, limiting insights into the phenomenon's transdiagnostic clinical and biological relevance. Such cross-disorder comparisons are of particular interest for CTDs and OCD given their frequent co-occurrence.

OBJECTIVE

We sought to compare the magnitude of SOR between adults with CTD and adults with OCD and to identify the clinical factors most strongly associated with SOR across these disorders.

METHODS

We enrolled 207 age- and sex-matched participants across four diagnostic categories: CTD without OCD (designated "CTD/OCD-"; n = 37), CTD with OCD ("CTD/OCD+"; n = 32), OCD without tic disorder ("OCD"; n = 69), and healthy controls (n = 69). Participants completed a self-report battery of rating scales assessing SOR (Sensory Gating Inventory, SGI), obsessive-compulsive symptoms (Dimensional Obsessive-Compulsive Scale, DOCS), inattention and hyperactivity (Adult ADHD Self-Report Screening Scale for DSM-5, ASRS-5), anxiety (Generalized Anxiety Disorder-7), and depression (Patient Health Questionnaire-9). CTD participants were also administered the Yale Global Tic Severity Scale (YGTSS). To examine between-group differences in SOR, we compared SGI score across all groups and between pairs of groups. To examine the relationship of SOR with other clinical factors, we performed multivariable linear regression.

RESULTS

CTD/OCD-, CTD/OCD+, and OCD participants were 86.7%, 87.6%, and 89.5%, respectively, more likely to have higher SGI total scores than healthy controls. SGI total score did not differ between CTD/OCD-, CTD/OCD+, and OCD groups. In the regression model of log-transformed SGI total score, OCD diagnosis, DOCS score, and ASRS-5 score each contributed significantly to model goodness-of-fit, whereas CTD diagnosis and YGTSS total tic score did not.

CONCLUSION

SOR is prevalent in adults with CTD and in adults with OCD but does not significantly differ in magnitude between these disorders. Across CTD, OCD, and healthy control adult populations, SOR is independently associated with both obsessive-compulsive and ADHD symptoms, suggesting a transdiagnostic relationship between these sensory and psychiatric manifestations. Future cross-disorder, longitudinal, and translational research is needed to clarify the role and prognostic import of SOR in CTDs, OCD, and other neurodevelopmental disorders.

Altered Interoceptive Sensibility in Adults With Chronic Tic Disorder

BACKGROUND

Interoception refers to the sensing, interpretation, integration, and regulation of signals about the body's internal physiological state. Interoceptive sensibility is the subjective evaluation of interoceptive experience, as assessed by self-report measures, and is abnormal in numerous neuropsychiatric disorders. Research examining interoceptive sensibility in individuals with chronic tic disorders (CTDs), however, has yielded conflicting results, likely due to methodologic differences between studies and small sample sizes.

OBJECTIVE

We sought to compare interoceptive sensibility between adults with CTD and healthy controls, adjusting for co-occurring psychiatric symptoms, and to examine the relationship of interoceptive sensibility with other CTD clinical features, in particular, premonitory urge.

METHODS

We recruited adults with CTDs and sex- and age-matched healthy controls to complete the Multidimensional Assessment of Interoceptive Awareness, Version 2 (MAIA-2), as well as a battery of measures assessing psychiatric symptoms prevalent in CTD populations. CTD participants additionally completed scales quantifying tic severity, premonitory urge severity, and health-related quality of life. We conducted between-group contrasts (Wilcoxon rank-sum test) for each MAIA-2 subscale, analyzed the effect of psychiatric symptoms on identified between-group differences (multivariable linear regression), and examined within-group relationships between MAIA-2 subscales and other clinical measures (Spearman rank correlations, multivariable linear regression).

RESULTS

Between adults with CTD (n = 48) and healthy controls (n = 48), MAIA-2 Noticing and Not-Worrying subscale scores significantly differed. After adjusting for covariates, lower MAIA-2 Not-Worrying subscale scores were significantly associated with female sex (β = 0.42, p < 0.05) and greater severity of obsessive-compulsive symptoms (β = -0.028, p < 0.01), but not with CTD diagnosis. After adjusting for severity of tics and obsessive-compulsive symptoms, a composite of MAIA-2 Noticing, Attention Regulation, Emotional Awareness, Self-Regulation, Body Listening, and Trusting subscales (β = 2.52, p < 0.01) was significantly associated with premonitory urge.

CONCLUSION

Study results revealed three novel findings: adults with CTD experience increased anxiety-associated somatization and increased general body awareness relative to healthy controls; anxiety-associated somatization is more closely associated with sex and obsessive-compulsive symptoms than with CTD diagnosis; and increased general body awareness is associated with greater severity of premonitory urges.

The Obsessive-Compulsive Symptoms in Tic Disorders and the Psychometric Properties of Children's Yale-Brown Obsessive-Compulsive Scale: An Evidence-Based Survey in a Chinese Sample

OBJECTIVE

Patients with tic disorders (TDs) usually also have obsessive-compulsive disorder (OCD). The severity of obsessive-compulsive symptoms (OCSs) in TD is widely evaluated using the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS). However, there is no survey on the severity of OCSs in patients with TD based on a Chinese sample, and the reliability and validity of the CY-BOCS in patients with TD have not been well established in China. This study examined the severity of OCSs in TDs and the psychometric properties of the CY-BOCS in Chinese pediatric patients with TD.

METHODS

A total of 367 patients who were diagnosed with TD [152 with Tourette syndrome (TS)] were enrolled in the Department of Psychiatry at Beijing Children's Hospital in China. The mean age of the patients was 9.21 ± 2.06 years (range: 5-16 years). The Yale Global Tic Severity Scale (YGTSS) and CY-BOCS were used as screening tools. The psychometric properties of the CY-BOCS were assessed using Cronbach's alpha, test-retest reliability, and construct validity.

RESULTS

The OCSs in TDs were 3.93 ± 5.15 based on the CY-BOCS in the whole sample. The older adolescent group showed higher scores than the young adolescent groups (Z = -3.37, p = 0.001). However, the young adolescent group showed a higher incidence rate of OCSs than the older adolescent group (p < 0.01). Men with TDs also showed a higher incidence rate of OCSs than women (p = 0.03). The reliability and validity analyses of the CY-BOCS showed Cronbach's alpha and test-retest reliability values of 0.81 and 0.82, respectively. The CY-BOCS showed an acceptable level in the two-factor structure (obsession and compulsive) in patients with TD. The comparative fit index (CFI) was 0.84 for TD, 0.86 for Tourette, 0.94 for the younger adolescent group, and 0.74 for the older adolescent group.

CONCLUSION

More OCSs were identified in the TS group and the older adolescent group with TDs. The CY-BOCS showed good psychometric properties in children and adolescents with TD, especially in younger patients with TD. OCSs might be associated with age and functional impairment of TD.

Questioning the definition of Tourette syndrome-evidence from machine learning

Tics in Tourette syndrome are often difficult to discern from single spontaneous movements or vocalizations in healthy people. In this study, videos of patients with Tourette syndrome and healthy controls were taken and independently scored according to the Modified Rush Videotape Rating Scale. We included n = 101 patients with Tourette syndrome (71 males, 30 females, mean age 17.36 years ± 10.46 standard deviation) and n = 109 healthy controls (57 males, 52 females, mean age 17.62 years ± 8.78 standard deviation) in a machine learning-based analysis. The results showed that the severity of motor tics, but not vocal phenomena, is the best predictor to separate and classify patients with Tourette syndrome and healthy controls. This finding questions the validity of current diagnostic criteria for Tourette syndrome requiring the presence of both motor and vocal tics. In addition, the negligible importance of vocalizations has implications for medical practice, because current recommendations for Tourette syndrome probably also apply to the large group with chronic motor tic disorders.

Recent progress on Tourette syndrome

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