Prevalence of tic disorders: a systematic review and meta-analysis

The role of neuroactive steroids in tic disorders

Tics are sudden, repetitive movements or vocalizations. Tic disorders, such as Tourette syndrome (TS), are contributed by the interplay of genetic risk factors and environmental variables, leading to abnormalities in the functioning of the cortico-striatal-thalamo-cortical (CSTC) circuitry. Various neurotransmitter systems, such as gamma-aminobutyric acid (GABA) and dopamine, are implicated in the pathophysiology of these disorders. Building on the evidence that tic disorders are predominant in males and exacerbated by stress, emerging research is focusing on the involvement of neuroactive steroids, including dehydroepiandrosterone sulfate (DHEAS) and allopregnanolone, in the ontogeny of tics and other phenotypes associated with TS. Emerging evidence indicates that DHEAS levels are significantly elevated in the plasma of TS-affected boys, and the clinical onset of this disorder coincides with the period of adrenarche, the developmental stage characterized by a surge in DHEAS synthesis. On the other hand, allopregnanolone has garnered particular attention for its potential to mediate the adverse effects of acute stress on the exacerbation of tic severity and frequency. Notably, both neurosteroids act as key modulators of GABA-A receptors, suggesting a pivotal role of these targets in the pathophysiology of various clinical manifestations of tic disorders. This review explores the potential mechanisms by which these and other neuroactive steroids may influence tic disorders and discusses the emerging therapeutic strategies that target neuroactive steroids for the management of tic disorders.

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

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

Circulating retinol and 25(OH)D contents and their association with symptoms in children with chronic tic disorders

The present study measured serum levels of vitamin A (VA) and vitamin D (VD) in children with chronic tic disorders (CTD) and investigated their potential association with CTD and comorbidity of attention deficit hyperactivity disorder (ADHD) and the association of their co-insufficiencies or deficiencies with CTD symptoms. A total of 176 children (131 boys and 45 girls, median age of 9 years) with CTD were recruited as the CTD group. During the same period, 154 healthy children were selected as the healthy control (HC) cohort. Circulating retinol and 25-hydroxyvitamin D (25[OH]D) levels were measured for all participants using high-performance liquid chromatography (HPLC) and tandem mass spectrometry. The Yale Global Tic Severity Scale (YGTSS) was employed for the assessment of tic status and CTD impairment. The Swanson, Nolan, and Pelham Rating Scale (SNAP-IV) and the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) were used to evaluate comorbidity symptoms. CTD pediatric participants exhibited markedly diminished circulating retinol and 25(OH)D levels compared to HCs. Moreover, VA and VD deficiencies and their co-insufficiencies/deficiencies were more prevalent in CTD participants than HCs. Circulating 25(OH)D levels were inversely proportional to the YGTSS motor tic scores. YGTSS scores in CTD children with only VA or VD insufficiency or deficiency or with VA and VD co-insufficiency/deficiency did not differ from those in CTD children with normal VA and VD. CTD children with comorbid ADHD displayed reduced circulating retinol and 25(OH)D concentrations and elevated prevalence of VD deficiency compared to CTD participants without comorbid ADHD. Lower serum retinol content was intricately linked to the presence of elevated CTD and comorbid ADHD. VA and VD deficiencies and their co-insufficiencies/deficiencies were markedly enhanced in CTD pediatric participants compared to HCs. Lower VA concentration was linked to the presence of enhanced CTD and comorbid ADHD. Therefore, children with CTD, especially with comorbid ADHD, may be at a higher risk of VA or VD deficiency, which may prompt the clinicians to consider whether blood tests for VA and VD in CTD children would be helpful for clinical care.

Symptom Severity and Health Impacts of Functional Tic-Like Behaviors in Youth

BACKGROUND

We performed this study to improve understanding of the relationship between functional tic-like behaviors (FTLBs) and quality of life, loneliness, family functioning, anxiety, depression, and suicidality.

METHOD

This cross-sectional study assessed self-reported quality of life, disability, loneliness, depression, anxiety, family functioning, tic severity, and suicide risk in age- and birth-sex matched youth with FTLBs, Tourette syndrome (TS), and neurotypical controls. We performed specific subanalyses comparing individuals with FTLBs who identified as transgender/gender diverse (TGD) with cisgender individuals.

RESULTS

Eighty-two youth participated (age range 11 to 25, 90% female at birth), including 35 with FTLBs, 22 with TS, and 25 neurotypical controls. A significantly higher proportion of participants with FTLB identified as TGD (15 of 35) than TS (two of 22) and neurotypical control (three of 25) participants. Compared with neurotypical controls, individuals with FTLBs had significantly lower quality of life, greater disability, loneliness, social phobia, anxiety symptoms, depressive symptoms, and suicidality. Compared with individuals with TS, individuals with FTLBs had more school/work absences due to tics, had more depressive symptoms, were more likely to be at high risk for suicidality, and had disability in self-care and life activity domains. There were no significant differences between cisgender and TGD participants with FTLB in any of the domains assessed.

CONCLUSIONS

Youth with FTLB have unique health care needs and associations with anxiety, depression, sex, and gender.

The Challenge of Examining Social Determinants of Health in People Living With Tourette Syndrome

BACKGROUND

To examine the association between race, ethnicity, and parental educational attainment on tic-related outcomes among Tourette Syndrome (TS) participants in the Tourette Association of America International Consortium for Genetics (TAAICG) database.

METHODS

723 participants in the TAAICG dataset aged ≤21 years were included. The relationships between tic-related outcomes and race and ethnicity were examined using linear and logistic regressions. Parametric and nonparametric tests were performed to examine the association between parental educational attainment and tic-related outcomes.

RESULTS

Race and ethnicity were collapsed as non-Hispanic white (N=566, 88.0%) versus Other (N=77, 12.0%). Tic symptom onset was earlier by 1.1 years (P < 0.0001) and TS diagnosis age was earlier by 0.9 years (P = 0.0045) in the Other group (versus non-Hispanic white). Sex and parental education as covariates did not contribute to the differences observed in TS diagnosis age. There were no significant group differences observed across the tic-related outcomes in parental education variable.

CONCLUSIONS

Our study was limited by the low number of nonwhite or Hispanic individuals in the cohort. Racial and ethnic minoritized groups experienced an earlier age of TS diagnosis than non-Hispanic white individuals. Tic severity did not differ between the two groups, and parental educational attainment did not affect tic-related outcomes. There remain significant disparities and gaps in knowledge regarding TS and associated comorbid conditions. Our study suggests the need for more proactive steps to engage individuals with tic disorders from all racial and ethnic minoritized groups to participate in research studies.

Sunflower Syndrome: A Survey of Provider Awareness and Management Preferences

BACKGROUND

Sunflower syndrome is a rare photosensitive pediatric epilepsy characterized by stereotyped hand-waving in response to bright lights. These stereotyped movements with maintained awareness can be mistaken for a movement disorder. This study assessed neurology providers' diagnostic reasoning, evaluation, and treatment of Sunflower syndrome.

METHODS

A 32-question anonymized electronic survey, including a clinical vignette and video of hand-waving in sunlight, was distributed to child neurology providers to assess (1) initial diagnosis and evaluation based on clinical information, (2) updated diagnosis and management after electroencephalography (EEG), and (3) prior experience with Sunflower syndrome.

RESULTS

Among 277 viewed surveys, 211 respondents provided information about initial diagnosis and evaluation, 200 about updated diagnosis, 191 about management, and 189 about prior clinical experience. Most providers (135, 64%) suspected seizure, whereas fewer suspected movement disorders (29, 14%) or were unsure of the diagnosis (37, 22%). EEG was recommended by 180 (85%). After EEG, 189 (95%) diagnosed epilepsy, 111 of whom specifically diagnosed Sunflower syndrome. The majority (149, 78%) recommended antiseizure medications (ASMs) and sun avoidance (181, 95%). Only 103 (55%) had managed Sunflower syndrome. Epileptologists and those with prior clinical experience were more likely to suspect a seizure, order an EEG, and offer ASMs than those without prior experience.

CONCLUSIONS

Although many providers had not managed Sunflower syndrome, the majority recognized this presentation as concerning for epilepsy. Epilepsy training and prior clinical experience are associated with improved recognition and appropriate treatment. Educational initiatives that increase awareness of Sunflower syndrome may improve patient care.

Prevalence and influencing factors of sleep problems in tic disorders: a meta-analysis

BACKGROUND

Sleep problems are commonly observed in patients with tic disorders. Nevertheless, studies have demonstrated a wide variation in the prevalence of sleep disturbances among this population. Consequently, it remains ambiguous whether sleep issues are inherently characteristic of tic disorders or are influenced by external factors.

METHODS

We conducted a comprehensive search across various databases and performed a meta-analysis to determine the prevalence of sleep problems in tic disorders. Additionally, we assessed pre-existing comorbidities and associated characteristics using meta-regression analysis.

RESULTS

After including 33 studies in the final meta-analysis, we found that the pooled prevalence of sleep problems in tic disorders was 34% (95%CI: 26% to 43%). Meta-regression analysis revealed that the presence of co-occurring symptoms of ADHD (p < 0.05), obsession compulsive disorder/behaviours (p < 0.05), anxiety (p < 0.001), and mood disorders (p < 0.001) was associated with an increased likelihood of experiencing sleep problems.

CONCLUSIONS

Our findings consistently indicate that individuals with tic disorders frequently encounter significant sleep problems. This underscores the importance of routinely screening for sleep problems during clinical assessments. Effectively managing sleep problems in patients with tic disorders is crucial not only for the well-being of the patients themselves but also for their families.

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

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

Applying an Established Exposure Response Prevention Protocol for Young People With Tourette Syndrome in an Intensive, Group Format: A Feasibility Study

BACKGROUND

The motor and vocal tics that characterise Tourette syndrome are stigmatizing and impact on quality of life. Behavioural interventions such as Exposure Response Prevention or Comprehensive Behavioural Interventions for Tics are first line treatment for Tourette syndrome, but availability is limited. This study is the first to explore the impact of an established manualised Exposure Response Prevention treatment protocol, developed for individual therapy, but here uniquely delivered intensively, to a group.

METHODS

A naturalistic study comprised of a consecutive series of children (N = 20), aged 8-16 years (M = 12, SD = 2.17) were offered Exposure Response Prevention in one of two groups, delivered in series within a specialist clinic. Young people received the equivalent of 12 sessions (matching the manualised individual protocol).

RESULTS

The YGTSS and Giles de la Tourette Syndrome Quality of Life Scale for Children and Adolescents (Satisfaction Scale) showed significant improvement following treatment with moderate to large effect sizes. Thirty-five percent of children demonstrated a reliable improvement on the YGTSS Global Tic Severity score.

CONCLUSIONS

These data suggest an established Exposure Response Prevention protocol can be delivered in an intensive, group setting with a positive clinical outcome. Replication in a randomized controlled trial is an important next step.

Prevalence of depression and anxiety in patients with Tourette syndrome; 1997 to 2022: a systematic review and meta-analysis

Tourette Syndrome (TS) is a disorder in which the patient has a history of multiple motor and vocal tics. Depression and anxiety are common in these patients. The results of the studies show different prevalence of these disorders in patients with TS. So, the objective of the present study was to liken the prevalence of depression and anxiety in patients with TS by systematic review and meta-analysis. The present study was conducted according to PRISMA guidelines during 1997-2022. The articles were obtained from Scopus, Embase, PubMed, Web of Science (WoS) and Google Scholar databases. I2 was used to investigate heterogeneity between studies. Data were analyzed by comprehensive meta-analysis software (Version 2). Finally, 12 articles with a sample size of n = 3812 were included in the study. As a result of combining the results of the studies, the total estimate of the prevalence of depression and anxiety in patients with TS was 36.4% (95% confidence interval: 21.1-54.9%) and 53.5% (95% confidence interval: 39.9-66.6%), respectively. The results of meta-regression showed that by increasing mean age (9-31.5 years), the prevalence of depression and anxiety in patients with TS increased significantly (P<0.001). The results of the present study showed that the prevalence of depression and anxiety was high in patients with TS. Therefore, it is suggested that health officials and policy makers design measures to prevent and control these disorders.

Caregiver Perspectives on the Health Care System for Tic Disorders: Utilization and Barriers

OBJECTIVE

This study aimed to understand health care experiences among a sample of caregivers of children with TDs to inform future directions for improving the health care system.

METHODS

We conducted a survey of caregivers of youth with TDs and used descriptive statistics and quantitative analyses to characterize the health care utilization practices of the sample.

RESULTS

The majority (70%) of families first consulted their pediatrician/primary care provider, and caregivers reported receiving care in line with current best practice guidelines. However, caregivers in the current sample perceived a lack of knowledgeability on the part of their first providers, which significantly predicted more providers seen and also reported difficulty finding specialty providers (63% of the sample reported difficulty finding a treatment provider who understood tics).

CONCLUSION

Results suggest that improving caregiver satisfaction with early health care experiences for their child's TD may help to relieve the burden on families and the health care system more broadly, along with continued efforts to increase the number of specialty providers available.

Video-based evaluation system for tic action in Tourette syndrome: modeling, detection, and evaluation

Behavioral ratings based on clinical observations are still the gold standard for screening, diagnosing, and assessing outcomes in Tourette syndrome. Detecting tic symptoms plays an important role in patient treatment and evaluation; accurate tic identification is the key to clinical diagnosis and evaluation. In this study, we proposed a tic action detection method using face video feature recognition for tic and control groups. Through facial ROI extraction, a 3D convolutional neural network was used to learn video feature representations, and multi-instance learning anomaly detection strategy was integrated to construct the tic action analysis and discrimination framework. We applied this tic recognition framework in our video dataset. The model evaluation results achieved average tic detection accuracy of 91.02%, precision of 77.07% and recall of 78.78%. And the tic score curve with postprocessing provided information of how the patient's twitches change over time. The detection results at the individual level indicated that our method can effectively detect tic actions in videos of Tourette patients without the need for fine labeling, which is significant for the long-term evaluation of patients with Tourette syndrome.

An Update on the Diagnosis and Management of Tic Disorders

Tic disorders (TDs) are a group of common neuropsychiatric disorders of childhood and adolescence. TDs may impact the physical, emotional, and social well-being of the affected person. In this review, we present an update on the clinical manifestations, pathophysiology, diagnosis, and treatment of TDs. We searched the PubMed database for articles on tics and Tourette syndrome. More than 400 articles were reviewed, of which 141 are included in this review. TDs are more prevalent in children than in adults and in males than in females. It may result from a complex interaction between various genetic, environmental, and immunological factors. Dysregulation in the cortico-striato-pallido-thalamo-cortical network is the most plausible pathophysiology resulting in tics. TD is a clinical diagnosis based on clinical features and findings on neurological examination, especially the identification of tic phenomenology. In addition to tics, TD patients may have sensory features, including premonitory urge; enhanced and persistent sensitivity to non-noxious external or internal stimuli; and behavioral manifestations, including attention deficit hyperactivity disorders, obsessive-compulsive disorders, and autism spectrum disorders. Clinical findings of hyperkinetic movements that usually mimic tics have been compared and contrasted with those of TD. Patients with TD may not require specific treatment if tics are not distressing. Psychoeducation and supportive therapy can help reduce tics when combined with medication. Dispelling myths and promoting acceptance are important to improve patient outcomes. Using European, Canadian, and American guidelines, the treatment of TD, including behavioral therapy, medical therapy, and emerging/experimental therapy, has been discussed.

Cytokine levels reflect tic symptoms more prominently during mild phases

Tic disorder is a neuropsychiatric condition that affects 3% of all children and can have a significant impact on their quality of life. Cytokines, interferons, interleukins, lymphokines, and tumor necrosis factors are involved in the neuroinflammatory circuitry of tic disorders. This study aimed to identify the cytokines involved in the pathogenesis of tic disorders. We enrolled 44 patients with tic disorder and 38 healthy controls. Patients were free of psychotropic medications for at least 3 weeks. Whole blood samples were analyzed using a Luminex® human cytokine multiplex assay kit. Patients were divided into groups with "mild tics" and "above moderate tics" based on Yale Global Tic Severity Scale (YGTSS) scores for comparison. The final analysis included 35 patients (28 male and 7 female) and 31 controls (20 male and 11 female). In the mild tic group, interleukin (IL)-12 p70 negatively correlated with motor tic scores. Granulocyte-macrophage colony-stimulating factor, IL-4, IL-8, and tumor necrosis factor (TNF)-α were positively correlated to phonic tic scores. IL-12 p40 and TNF-α were positively correlated to total tic scores. IL-12 p70 and IL-17a negatively correlated to impairment scores and total YGTSS scores. Tic disorder patients and healthy controls exhibit different cytokine profiles. Only patients with mild symptoms exhibit significant correlations, suggesting that the correlations between cytokine levels and tic symptoms are more relevant during the mild or remission phases. Our results present the importance of IL-1β and TNF-α, among others, but the identification of key cytokines are still necessary.

Efficacy and Safety of Acupuncture Combined with Herbal Medicine for Children and Adolescents with Tourette Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

With the increasing prevalence of Tourette syndrome (TS), the search for alternative therapy for TS is a growing public concern. In recent years, a growing number of randomized controlled trials (RCTs) have revealed the value of acupuncture combined with herbal medicine for the treatment of TS; however, its holistic efficacy and safety remains unclear. This study aimed to evaluate the efficacy and safety of acupuncture combined with herbal medicine and to provide preliminary evidence for clinical practice.

METHODS

Eight databases were searched from their establishment to November 27, 2022, to collect RCTs of acupuncture combined with herbal medicine for TS treatment. Two researchers independently completed the study screening, data extraction, and risk of bias assessment by using NoteExpress, Excel, and Cochrane Risk of Bias Tool 2.0 (RoB 2.0). Stata 15.0 software was applied to conduct meta-analysis.

RESULTS

A total of 1,400 participants in 18 RCTs were included. Compared with the Western medicine, acupuncture combined with herbal medicine had better curative effect in the field of effective rate (risk ratio [RR] = 1.18, 95% CI: [1.12, 1.23], p < 0.05, I2 = 0%), Yale Global Tic Severity Scale (YGTSS) total score (mean difference [MD] = -3.91, 95% CI: [-5.49, -2.33], p < 0.05, I2 = 96.4%), TCM syndrome total score (MD = -2.42, 95% CI: [-3.71, -1.13], p < 0.05, I2 = 87.1%), and serum IgE negative rate (RR = 3.41, 95% CI: [1.69, 6.87], p < 0.05, I2 = 0%). Furthermore, acupuncture combined with herbal medicine reduced the adverse reaction rate (RR = 0.20, 95% CI: [0.14, 0.30], p < 0.05, I2 = 0%) and the recurrence rate (RR = 0.27, 95% CI: [0.13, 0.52], p < 0.05, I2 = 0%).

CONCLUSION

This study demonstrated the efficacy and safety of acupuncture combined with herbal medicine, which is probably a better alternative therapy for TS. However, the small number, low quality, and potential bias of the included studies caused the limitations of our results. More high-quality RCTs are required to provide supplementary evidence in the future.

Hintergrund

Mit der steigenden Prävalenz des Tourette-Syndroms (TS) ist die Suche nach alternativen Therapien für TS zunehmend zu einer Angelegenheit von öffentlichem Interesse geworden. In den vergangenen Jahren zeigte eine immer größer werdende Zahl randomisierter, kontrollierter Studien den Nutzen der Akupunktur in Kombination mit Heilkräutern; ihre ganzheitliche Wirksamkeit und Sicherheit ist jedoch weiterhin nicht klar. Mit dieser Studie sollten die Wirksamkeit und Sicherheit von Akupunktur in Kombination mit Heilkräutern beurteilt und erste Belege für die klinische Praxis gewonnen werden.

Methoden

Acht (8) Datenbanken wurden ab ihrer Einrichtung bis zum 27. November 2022 nach randomisierten kontrollierten Studien (RCTs) über Akupunktur in Kombination mit Heilkräutern zur Behandlung von TS durchsucht. Das Screening der Studien, die Datenextraktion und die Bewertung des Verzerrungsrisikos wurden von zwei unabhängigen Forschern mit Hilfe von NoteExpress, Excel und dem Cochrane Risk of Bias Tool 2.0 (RoB 2.0) durchgeführt. Die Metaanalyse erfolgte mit der Software Stata 15.0.

Ergebnisse

Insgesamt wurden 1400 Teilnehmer in 18 RCTs eingeschlossen. Im Vergleich zur westlichen Medizin (WM) hatte Akupunktur in Kombination mit Heilkräutern eine bessere kurative Wirkung in Bezug auf die Wirksamkeitsrate (RR = 1,18, 95%-KI [1,12, 1,23], p < 0,05, I2 = 0%), den Gesamtscore der Yale Global Tic Severity Scale (YGTSS) (MD = -3,91, 95%-KI [-5,49, -2,33], p < 0,05, I2 = 96,4%), den TCM-Syndrom-Gesamtscore (MD = -2,42, 95%-KI [-3,71, -1,13], p < 0,05, I2 = 87,1%) und die Serum-IgE-Negativrate (RR = 3,41, 95%-KI [1,69, 6,87], p <0,05, I2 = 0 %). Darüber hinaus verringerte Akupunktur in Kombination mit Heilkräutern die Nebenwirkungsrate (RR = 0,20, 95%-KI [0,14, 0,30], p < 0,05, I2 = 0%) sowie die Rezidivrate (RR = 0,27, 95%-KI [0,13, 0,52], p < 0,05, I2 = 0%).

Schlussfolgerung

Diese Studie belegt die Wirksamkeit und Sicherheit der Akupunktur in Kombination mit Heilkräutern, die wahrscheinlich eine bessere alternative Therapie für TS darstellt. Unsere Ergebnisse werden allerdings durch die geringe Zahl, die niedrige Qualität und die potenzielle Verzerrung der eingeschlossenen Studien eingeschränkt. Zukünftig sind weitere hochwertige RCTs erforderlich, die zusätzliche Belege liefern.

Deep brain stimulation alleviates tics in Tourette syndrome via striatal dopamine transmission

Tourette syndrome is a childhood-onset neuropsychiatric disorder characterized by intrusive motor and vocal tics that can lead to self-injury and deleterious mental health complications. While dysfunction in striatal dopamine neurotransmission has been proposed to underlie tic behaviour, evidence is scarce and inconclusive. Deep brain stimulation (DBS) of the thalamic centromedian parafascicular complex (CMPf), an approved surgical interventive treatment for medical refractory Tourette syndrome, may reduce tics by affecting striatal dopamine release. Here, we use electrophysiology, electrochemistry, optogenetics, pharmacological treatments and behavioural measurements to mechanistically examine how thalamic DBS modulates synaptic and tonic dopamine activity in the dorsomedial striatum. Previous studies demonstrated focal disruption of GABAergic transmission in the dorsolateral striatum of rats led to repetitive motor tics recapitulating the major symptom of Tourette syndrome. We employed this model under light anaesthesia and found CMPf DBS evoked synaptic dopamine release and elevated tonic dopamine levels via striatal cholinergic interneurons while concomitantly reducing motor tic behaviour. The improvement in tic behaviour was found to be mediated by D2 receptor activation as blocking this receptor prevented the therapeutic response. Our results demonstrate that release of striatal dopamine mediates the therapeutic effects of CMPf DBS and points to striatal dopamine dysfunction as a driver for motor tics in the pathoneurophysiology of Tourette syndrome.

A preliminary study for the clinical effect of one combinational physiotherapy and its potential influence on gut microbial composition in children with Tourette syndrome

Introduction

Tourette syndrome (TS) is a chronic neuropsychiatric disorder with unknown causes and inadequate therapies. Inspired by the important roles of gut microbiota in some mental illnesses, the interactions between gut microbiota and TS via the gut-brain axis have gained more and more attention. This study aimed to characterize the gut microbial profiles in children with TS, and explore the clinical effects of one combinational physiotherapy and its potential influence on gut microbial composition.

Methods

The gut microbial profiles were depicted based on the sequence data of 32 patients and 29 matched health children by 16S rDNA amplicon pyrosequencing. Thirty of thirty-two patients underwent uninterrupted two 10-day courses of combinational physiotherapy, which included a 60-minute cranial electrotherapy stimulation (CES) training followed by a 30-minute biofeedback training per session, 2 sessions a day.

Results

Our results indicated that the gut microbial composition in children with TS was different from that in healthy controls. Multiple GBM neurotransmitter modules obtained through Picrust2 functional predictive analysis were significantly increased in patients, including Histamine degradation, Dopamine degradation, and DOPAC synthesis. Moreover, this combinational physiotherapy could significantly diminish tic activity, whose positive effects were first reported in children with TS. Lastly, different gut microbial compositions and predictive metabolic pathways were also observed between patients before and after this treatment, with lower abundances of the genera (e.g., Dorea) and significant decreases of GBM neurotransmitter modules (e.g. dopamine degradation) in patients after this treatment, indicating that improved clinical symptoms might be accompanied by an improvement of intestinal microenvironment.

Discussion

Children with TS showed a cognizable gut microbial profile, and certain enriched bacteria with pro-inflammatory potential might induce neuroinflammatory responses. This combinational physiotherapy could significantly diminish tic activity, and the gut microbial compositions in patients after this treatment were different from those without any treatment, indicating the existence of bidirectional communication of the gut-brain axis in TS. But studies on the gut microbial characteristics in TS patients, the influences of gut microbiota on tic severity, the efficacy and safety of this treatment, and the bidirectional regulatory mechanism between brain signals and gut microbiota in TS still need to be explored.

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

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

Developmental stuttering, physical concomitants associated with stuttering, and Tourette syndrome: A scoping review

BACKGROUND AND PURPOSE

Developmental stuttering and Tourette syndrome (TS) are common neurodevelopmental disorders. Although disfluencies may co-occur in TS, their type and frequency do not always represent pure stuttering. Conversely, core symptoms of stuttering may be accompanied by physical concomitants (PCs) that can be confused for tics. This scoping review aimed to explore the similarities and differences between stuttering and tics in terms of epidemiology, comorbidities, phenomenology, evolution, physiopathology, and treatment. We also described the nature of PCs in stuttering and disfluencies in TS.

METHODS

A literature search on Medline, Embase and PsycInfo was executed in March 2022. From 426 studies screened, 122 were included in the review (a majority being narrative reviews and case reports).

RESULTS

TS and stuttering have several epidemiological, phenomenological, comorbidity, and management similarities suggesting shared risk factors and physiopathology (involving the basal ganglia and their connections with speech and motor control cortical regions). PCs in stuttering commonly involve the face (eyelids, jaw/mouth/lip movements) and sometimes the head, trunk and limbs. PCs can be present from early stages of stuttering and vary over time and within individuals. The function of PCs is unknown. Some individuals with TS have a distinct disfluency pattern, composed of a majority of typical disfluencies (mostly between-word disfluencies), and a mix of cluttering-like behaviors, complex phonic tics (e.g. speech-blocking tics, echolalia, palilalia), and rarely, atypical disfluencies.

CONCLUSION

Future investigations are warranted to better understand the complex relationships between tics and stuttering and address the management of disfluencies in TS and PCs in stuttering.

Direct additive genetics and maternal effect contribute to the risk of Tourette disorder

BACKGROUND

Risk for Tourette disorder, and chronic motor or vocal tic disorders (referenced here inclusively as CTD), arise from a combination of genetic and environmental factors. While multiple studies have demonstrated the importance of direct additive genetic variation for CTD risk, little is known about the role of cross-generational transmission of genetic risk, such as maternal effect, which is not transmitted via the inherited parental genomes. Here, we partition sources of variation on CTD risk into direct additive genetic effect (narrow-sense heritability) and maternal effect.

METHODS

The study population consists of 2 522 677 individuals from the Swedish Medical Birth Register, who were born in Sweden between 1 January 1973 and 31 December 2000, and followed for a diagnosis of CTD through 31 December, 2013. We used generalised linear mixed models to partition the liability of CTD into: direct additive genetic effect, genetic maternal effect and environmental maternal effect.

RESULTS

We identified 6227 (0.2%) individuals in the birth cohort with a CTD diagnosis. A study of half-siblings showed that maternal half-siblings had twice higher risk of developing a CTD compared with paternal ones. We estimated 60.7% direct additive genetic effect (95% credible interval, 58.5% to 62.4%), 4.8% genetic maternal effect (95% credible interval, 4.4% to 5.1%) and 0.5% environmental maternal effect (95% credible interval, 0.2% to 7%).

CONCLUSIONS

Our results demonstrate genetic maternal effect contributes to the risk of CTD. Failure to account for maternal effect results in an incomplete understanding of the genetic risk architecture of CTD, as the risk for CTD is impacted by maternal effect which is above and beyond the risk from transmitted genetic effect.

Anxiety and depression among caregivers of pediatric patients with tic disorder in western China: A cross-sectional study

BACKGROUND

Caregivers of pediatric patients with tic disorders (TD) are at high risk for anxiety and depression, but the situation of this disorder was rarely reported based on the Chinese population. The purpose of this study was to investigate the prevalence and potential contributing factors of anxiety and depression among caregivers of Chinese pediatric patients with TD.

METHODS

A cross-sectional study was carried out on caregivers of pediatric patients with TD at a women's and children's hospital in western China from January to June 2020. A structured questionnaire was designed to collect data, including socio-demographic information, disease and medication status, family situation and social relationship, cognition and attitude towards TD and treatment. Anxiety and depression were assessed using the self-rating anxiety scale (SAS) and self-rating depression scale (SDS), respectively. The univariate analysis and multivariate logistic regression were used to analyze the cross-sectional data.

RESULTS

A total of 318 participants were included in this study, with a response rate of 89.58% (318/355). The average age of pediatric patients with TD was 8.38 ± 2.54 years, and 78.30% (249/318) of caregivers were aged between 30-50 years old. Overall, 14.78% (47/318) of caregivers presented the symptom of anxiety, with a mean SAS score of 54.81±5.26, and 19.81% (63/318) of caregivers presented the symptom of depression, with a mean SDS score of 59.64±5.83. Logistic regression analysis revealed that the common family relationship (OR = 2.512, p = 0.024), and pediatric patients with unharmonious social relationships (OR = 5.759, p = 0.043) and with introverted personality (OR = 2.402, p = 0.023) were significantly associated with anxiety in caregivers of pediatric patients with TD, as well as the single-parent family (OR = 4.805, p = 0.011), mistaken cognition of TD (OR = 0.357, p = 0.031), and pediatric patients with fewer friends (OR = 3.377, p = 0.006) were significantly associated with depression.

CONCLUSIONS

Anxiety and depression are prevalent among caregivers of TD pediatric patients, which brings up the importance of psychiatric support for this group. Longitudinal studies need to be conducted to further confirm the causality before interventions to improve mental health are developed.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

INTRODUCTION

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

OBJECTIVES

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

METHODS AND ANALYSIS

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

Clinical characteristics of comorbid tic disorders in autism spectrum disorder: exploratory analysis

BACKGROUND

The frequency, clinical characteristics, and associated symptoms of comorbid tic disorders in individuals with autism spectrum disorder (ASD) remain unclear.

METHODS

We included subsets of individuals from a larger genetic study who were diagnosed with ASD (n = 679; age: 4-18 years) and completed the Yale Global Tic Severity Scale (YGTSS) questionnaire. Based on the YGTSS score, the individuals were divided into two groups: ASD only (n = 554) and ASD with tics (n = 125). Individuals were assessed using the verbal and non-verbal intelligence quotient (IQ), Vineland Adaptive Behavior Scale (VABS-2), Social Responsiveness Scale-2 (SRS-2), Child Behavior Checklists (CBCL), and Yale-Brown Obsessive-Compulsive Scale (YBOCS), followed by between-group comparisons. All statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS) version 26.

RESULTS

Tic symptoms were observed in 125 (18.4%) participants; among them, most participants presented both motor and vocal tics (n = 40, 40.0%). The ASD with tics group had a significantly higher average age and full-scale IQ score than the ASD only group. After adjusting for age, the ASD with tics group had significantly higher scores in the SRS-2, CBCL, and YBOCS subdomains than the ASD only group. Furthermore, all variables except the non-verbal IQ and VABS-2 scores were positively correlated with the YGTSS total score. Finally, the proportion of tic symptoms was significantly higher among individuals with a higher IQ score (≥ 70).

CONCLUSIONS

The IQ score was positively correlated with the proportion of tic symptoms among individuals with ASD. Moreover, the severity of the core and comorbid symptoms of ASD was associated with the occurrence and severity of tic disorders. Our findings suggest the need for appropriate clinical interventions for individuals with ASD. Trial registration This study retrospectively registered participants.

In silico clinical trial evaluating lisdexamfetamine's and methylphenidate's mechanism of action computational models in an attention-deficit/hyperactivity disorder virtual patients' population

Introduction

Attention-deficit/hyperactivity disorder (ADHD) is an impairing psychiatric condition with the stimulants, lisdexamfetamine (LDX), and methylphenidate (MPH), as the first lines pharmacological treatment.

Methods

Herein, we applied a novel in silico method to evaluate virtual LDX (vLDX) and vMPH as treatments for ADHD applying quantitative systems pharmacology (QSP) models. The objectives were to evaluate the model's output, considering the model characteristics and the information used to build them, to compare both virtual drugs' efficacy mechanisms, and to assess how demographic (age, body mass index, and sex) and clinical characteristics may affect vLDX's and vMPH's relative efficacies.

Results and Discussion

We molecularly characterized the drugs and pathologies based on a bibliographic search, and generated virtual populations of adults and children-adolescents totaling 2,600 individuals. For each virtual patient and virtual drug, we created physiologically based pharmacokinetic and QSP models applying the systems biology-based Therapeutic Performance Mapping System technology. The resulting models' predicted protein activity indicated that both virtual drugs modulated ADHD through similar mechanisms, albeit with some differences. vMPH induced several general synaptic, neurotransmitter, and nerve impulse-related processes, whereas vLDX seemed to modulate neural processes more specific to ADHD, such as GABAergic inhibitory synapses and regulation of the reward system. While both drugs' models were linked to an effect over neuroinflammation and altered neural viability, vLDX had a significant impact on neurotransmitter imbalance and vMPH on circadian system deregulation. Among demographic characteristics, age and body mass index affected the efficacy of both virtual treatments, although the effect was more marked for vLDX. Regarding comorbidities, only depression negatively impacted both virtual drugs' efficacy mechanisms and, while that of vLDX were more affected by the co-treatment of tic disorders, the efficacy mechanisms of vMPH were disturbed by wide-spectrum psychiatric drugs. Our in silico results suggested that both drugs could have similar efficacy mechanisms as ADHD treatment in adult and pediatric populations and allowed raising hypotheses for their differential impact in specific patient groups, although these results require prospective validation for clinical translatability.

Hair Cortisol and Perceived Stress-Predictors for the Onset of Tics? A European Longitudinal Study on High-Risk Children

Some retrospective studies suggest that psychosocial stressors trigger the onset of tics. This study examined prospective hypothalamic-pituitary-adrenal (HPA) axis activity and perceived stress prior to tic onset. In the present study, 259 children at high risk for developing tics were assessed for hair cortisol concentration (HCC) and parent-on-child-reported perceived stress four-monthly over a three-year period. We used (i) generalised additive modelling (GAM) to investigate the time effects on HCC (hair samples n = 765) and perceived stress (questionnaires n = 1019) prior to tic onset and (ii) binary logistic regression to predict tic onset in a smaller subsample with at least three consecutive assessments (six to nine months before, two to five months before, and at tic onset). GAM results indicated a non-linear increasing course of HCC in children who developed tics, and a steady HCC course in those without tics, as well as a linear-increasing course of perceived stress in both groups. Logistic regression showed that with a higher HCC in hair samples collected in a range of two to five months before tic onset (which refers to cortisol exposure in a range of four to eight months), the relative likelihood of tic onset rose. Our study suggests increased stress prior to tic onset, as evidenced by higher HCC several months before tic onset.

Behavioral Interventions for Children and Adults with Tic Disorder

Over the past decade, behavioral interventions have become increasingly recognized and recommended as effective first-line therapies for treating individuals with tic disorders. In this article, we describe a basic theoretical and conceptual framework through which the reader can understand the application of these interventions for treating tics. The three primary behavioral interventions for tics with the strongest empirical support (habit reversal, Comprehensive Behavioral Intervention for Tics, and exposure and response prevention) are described. Research on the efficacy and effectiveness of these treatments is summarized along with a discussion of the research evaluating the delivery of these treatments in different formats and modalities. The article closes with a review of the possible mechanisms of change underlying behavioral interventions for tics and areas for future research.

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.

Moderating Role of Depression on the Association of Tic Severity With Functional Impairment in Children

BACKGROUND

Chronic tic disorders (CTDs) commonly co-occur with other psychiatric disorders. CTDs have been linked to functional impairment and reduction in quality of life. Insufficient research is available on depressive symptoms in patients with CTD, especially children and adolescents, yielding conflicting findings. To investigate the presence of depressive symptoms in a cohort of children and young adolescents with CTD and to test whether they moderate the link between tic severity and functional impairment.

METHODS

The sample consisted of 85 children and adolescents (six to 18 years) with a CTD who were treated in a large referral center. Participants were evaluated using gold-standard self- and clinician-reporting instruments to measure tic symptom severity and tic-related functional impairment (Yale Global Tic Severity Scale), depression (Child Depression Inventory), and obsessive-compulsive symptoms (Children Yale Brown Obsessive Compulsive Scale).

RESULTS

Depressive symptoms (mild to severe) were exhibited by 21% of our sample. Study participants with CTD and comorbid obsessive-compulsive disorder (OCD) and/or attention-deficit/hyperactivity disorder had higher rates of depressive symptoms compared with those without comorbidities. Significant correlations were found within and among all tic-related and OCD-related measures, yet depressive symptoms only correlated to tic-related functional impairment. Depression significantly and positively moderated the correlation between tic severity and tic-related functional impairment.

CONCLUSIONS

Findings suggest that depression plays an important part as a moderator in the link between tic severity and functional impairment in children and adolescents. Our study highlights the importance of screening for and treating depression in patients with CTD.

Where Do Neurodevelopmental Disorders Go? Casting the Eye Away from Childhood towards Adulthood

Neurodevelopmental disorders (NDDs) encompass a group of complex conditions with onset during the early developmental period. Such disorders are frequently associated with a number of neuropsychiatric features, the most prevalent ones being autism spectrum disorder, attention-deficit/hyperactivity disorder, intellectual disability, communication and specific learning disorders, and motor disorders. These conditions are characterized by wide genetic and clinical variability, and although they were previously conceptualized as childhood-limited disorders, NDDs are progressively being recognized as persistent conditions with a potentially relevant impact on the quality of life and overall functioning during adult life. In addition, emerging evidence seems to point towards the hypothesis of a neurodevelopmental continuum, according to which NNDs could portray different time-dependent outcomes, depending on the severity of the altered brain development. Despite representing lifelong phenotypes, they are often not promptly identified and/or managed in adulthood. In this regard, specific guidelines on clinical and therapeutic approaches for these conditions have not yet been delineated. In this view, future research investigations should be encouraged to broaden available knowledge, characterize the clinical course of NDDs across an individual’s lifespan, and better understand the patterns of aging-related concerns in adults with an NDD diagnosis. Additionally, considering the difficulties many young adults encounter while transitioning from childhood to adult mental health services, new, specific programs should be developed and existing programs should be implemented to improve the transition process and for the management of NDDs in adulthood.

Clinical Characteristics of Children With Tourette Syndrome With and Without Sleep Disorder

BACKGROUND

Sleep problems are common in children with Tourette Syndrome (TS). However, research regarding their demographic and clinical profile is limited.

METHODS

We examined characteristics of 114 children aged five to 17 years with a lifetime diagnosis of TS and compared children with sleep disorder (n = 32) and without sleep disorder (n = 82). Parent report from the 2014 National Survey of the Diagnosis and Treatment of ADHD and Tourette Syndrome provided demographics and clinical information, other diagnosed disorders, medication use, TS severity, and impairment.

RESULTS

More children with TS with sleep disorder were from households with lower parental education (P < 0.01) and poverty (P = 0.04); had other diagnoses (P = 0.03), including obsessive-compulsive disorder (P < 0.01), oppositional defiant disorder or conduct disorder (P < 0.01), attention-deficit/hyperactivity disorder (ADHD) (P = 0.02), and autism (P = 0.03); and had ever used TS medication (P = 0.01) than children with TS without sleep disorder. More children with TS with sleep disorder had severe TS symptoms (P <0.01), tic-related impairment (P<0.01), and severe ADHD symptoms (P < 0.01) compared with children with TS without sleep disorder.

CONCLUSIONS

Findings suggest greater parent-reported impact and tic-related interference in children with TS with sleep disorder compared with TS without sleep disorder. Results underscore the importance of monitoring and intervention for TS exacerbations, other diagnosed disorders, and medication use, and consideration of socioeconomic context in sleep disorder management and prevention in children with TS.

Atlantoaxial Subluxation Associated With Chronic Motor Tics

Head jerking is one of the most common symptoms of motor tics, and because of this, patients are at an increased risk of cervical spine disorders. However, there have been no reports of atlantoaxial subluxation in the English literature. To the best of our knowledge, this is the first case of atlantoaxial subluxation associated with chronic motor tics. A 41-year-old man with a history of chronic motor tics since childhood was diagnosed with high cervical myelopathy due to atlantoaxial subluxation. The patient underwent posterior fusion surgery using atlantoaxial instrumentation and an autologous bone graft. Although screw breakage occurred as an early postoperative instrumentation failure, the clinical outcome was excellent after surgery without recurrence of subluxation. Other techniques such as atlantoaxial transarticular fixation and occipitocervical fusion followed by long-term external immobilization might be treatment options at the initial surgery, or in case of postoperative recurrent atlantoaxial subluxation.

Exposure and Response Prevention for Children and Adolescents with Tourette Syndrome Delivered via Web-Based Videoconference versus Face-to-Face Method

Chronic tic disorders, such as Tourette syndrome, are characterized by motor and vocal tics. Tics present a considerable burden for some patients, and therefore, effective treatment is important. One evidence-based treatment option is a behavioral therapy called exposure and response prevention (ERP). Despite its effectiveness, access to ERP remains limited due to a lack of treatment sites. Web-based videoconferences can connect patients at home with a therapist located in the hospital, allowing for treatment delivery over a wide geographic area. The primary aim of this study was to compare the development of tics during and 1 year after ERP delivery, respectively, via web-based videoconferences and traditional face-to-face methods in a naturalistic setting. In total, 116 patients treated using either the face-to-face method (n = 72) or web-based videoconferences (n = 44) were included. The primary outcome measure was tic severity. In both training modalities, tic severity decreased during ERP and the effect lasted in the follow-up period. No statistically significant differences in tic severity between the training modalities were found at baseline, last training session, or at follow-up. Our results suggest that ERP delivered via web-based videoconferences is a good alternative to the traditional face-to-face method.

Exposure and Response Prevention: Evaluation of Tic Severity Over Time for Children and Adolescents with Tourette Syndrome and Chronic Tic Disorders

Tourette syndrome and chronic tic disorders are characterized by the presence of tics. Different behavioral therapies have shown to be efficacious for treating tics in children and adolescents, but Exposure and Response Prevention (ERP) is a less researched method. However, ERP is a method often used in the clinical setting. Therefore, the present study evaluated the severity of tics over time from beginning of ERP to follow-up approximately 1 year after last training session.In total, 116 patients treated with ERP face to face or ERP via web-based videoconferencing were included. The primary outcome measure was tic severity measured with the Danish version of the Yale Global Tic Severity Scale.The results showed that tic severity decreased during ERP and lasted in the follow-up period, with a statistically higher decrease in the group with patients who completed ERP as planned and the group that stopped earlier than planned because of reduction in tics, compared with those who dropped out due to lack of motivation (p < 0.001).The study concludes that ERP seems to have an immediate and a long-term effect on severity of tics, especially in those who complete the program or those who discontinue earlier due to good results.

The correlation between prenatal maternal active smoking and neurodevelopmental disorders in children: a systematic review and meta-analysis

OBJECTIVE

To systematically evaluate the association between maternal active smoking during pregnancy and Tourette syndrome (TS), chronic tic disorder (CTD), and developmental coordination disorder (DCD) in children, and to provide evidence-based medical references to reduce the incidence of neurodevelopmental disorders in children.

METHOD

We searched PubMed, Web of Science, Embase, and Cochrane Library to obtain relevant articles published before 4 August 2021. Two reviewers independently assessed the articles for eligibility and extracted data.

RESULTS

We included eight studies involving a total of 50,317 participants (3 cohort, 3 case-control, and 2 cross-sectional studies). The pooled effect estimates suggested that prenatal maternal active smoking is related to an increased risk of neurodevelopmental disorders (OR = 1.91, 95% CI: 1.30-2.80), especially DCD (OR = 2.25, 95% CI: 1.35-3.75). Maternal active smoking during pregnancy is not associated with TS (OR = 1.07, 95% CI: 0.66-1.73) in children.

CONCLUSION

In this meta-analysis, we found evidence for a correlation between active smoking exposure in pregnant women and neurodevelopmental disorders in children. Owing to the differences in sample size, smoking categories and diagnostic methods, further research is needed to validate our results.

Global Epidemiology of Movement Disorders: Rare or Underdiagnosed?

In this manuscript, we review the epidemiology of movement disorders including Parkinson's disease (PD), atypical parkinsonism, essential tremor, dystonia, functional movement disorders, tic disorders, chorea, and ataxias. We emphasize age-, sex-, and geography-based incidence and prevalence, as well as notable trends including the rising incidence and prevalence of PD. Given the growing global interest in refining clinical diagnostic skills in recognizing movement disorders, we highlight some key epidemiological findings that may be of interest to clinicians and health systems tasked with diagnosing and managing the health of patients with movement disorders.

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.

Abnormal dynamics of brain functional networks in children with Tourette syndrome

Tourette syndrome (TS) is a childhood-onset neurodevelopmental disorder characterized by the presence of multiple motor and vocal tics. Research using resting-state functional magnetic resonance imaging (rfMRI) have found aberrant static functional connectivity (FC) and its topological properties in the brain networks of TS. Our study is the first to investigate the dynamic functional connectivity (dFC) in the whole brain network of TS patients, focusing on the temporal properties of dFC states and the temporal variability of topological organization. The rfMRI data of 36 male children with TS and 27 matched healthy controls were collected and further analyzed by group spatial independent component analysis, sliding windows approach based dFC analysis, k-means clustering analysis, and graph theory analysis. The clustering analysis identified three dFC states. Of these states, state 2, characterized by increased inter-network connections in subcortical network (SCN), sensorimotor network (SMN), and default mode network (DMN), and decreased inter-network connections between salience network (SAN) and executive control network (ECN), was found to have higher fractional window and dwell time in TS, which was also positively correlated with tic severity. TS patients also exhibited higher temporal variability of whole-brain-network global efficiency and local efficiency, and higher temporal variability of nodal efficiency and local efficiency in SCN, DMN, ECN, SAN, and SMN. Additionally, temporal variability of the efficiency and local efficiency in insula was positively correlated with tic severity. Our findings revealed abnormal temporal property of dFC states and temporal variability of topological organization in TS, providing new insights into clinical diagnoses and neuropathology of TS.

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

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

Developing a Phenotype Risk Score for Tic Disorders in a Large, Clinical Biobank

Importance

Tics are a common feature of early-onset neurodevelopmental disorders, characterized by involuntary and repetitive movements or sounds. Despite affecting up to 2% of young children and having a genetic contribution, the underlying causes remain poorly understood, likely due to the complex phenotypic and genetic heterogeneity among affected individuals.

Objective

In this study, we leverage dense phenotype information from electronic health records to identify the disease features associated with tic disorders within the context of a clinical biobank. These disease features are then used to generate a phenotype risk score for tic disorder.

Design

Using de-identified electronic health records from a tertiary care center, we extracted individuals with tic disorder diagnosis codes. We performed a phenome-wide association study to identify the features enriched in tic cases versus controls (N=1,406 and 7,030; respectively). These disease features were then used to generate a phenotype risk score for tic disorder, which was applied across an independent set of 90,051 individuals. A previously curated set of tic disorder cases from an electronic health record algorithm followed by clinician chart review was used to validate the tic disorder phenotype risk score.

Main Outcomes and Measures

Phenotypic patterns associated with a tic disorder diagnosis in the electronic health record.

Results

Our tic disorder phenome-wide association study revealed 69 significantly associated phenotypes, predominantly neuropsychiatric conditions, including obsessive compulsive disorder, attention-deficit hyperactivity disorder, autism, and anxiety. The phenotype risk score constructed from these 69 phenotypes in an independent population was significantly higher among clinician-validated tic cases versus non-cases.

Conclusions and Relevance

Our findings provide support for the use of large-scale medical databases to better understand phenotypically complex diseases, such as tic disorders. The tic disorder phenotype risk score provides a quantitative measure of disease risk that can be leveraged for the assignment of individuals in case-control studies or for additional downstream analyses.

The Tourette OCD Alberta Network: Development of a Continuing Professional Development Program for Community Based Mental Health Therapists

The Tourette OCD Alberta Network (TOAN) supports mental health therapists to improve the delivery of care to patients with Tourette syndrome (TS) and OCD in Alberta. We evaluated the professional development needs of health care workers to develop a continuing professional development (CPD) webinar series. Health care workers demonstrated an urgent need to access a CPD program grounded in evidenced based knowledge about TS and OCD. While 80% of health care workers treated children with TS and OCD, 50% had no formal training. A curriculum consisting of a series of twelve live, online webinars was developed and delivered between September 2020 and June 2021, covering a range of clinical topics. The webinars were attended on average by 63 attendees, with the outcome of a positive knowledge gain. In future, the educational program will need to reflect the ongoing developing clinical understanding of TS and OCD.

Social media as an incubator of personality and behavioral psychopathology: Symptom and disorder authenticity or psychosomatic social contagion?

There has been an increasing recognition among both medical and psychological professionals, as well as the public media, of a concerning trend for child and adolescent users of audiovisual-based, algorithmic social media platforms (e.g., TikTok) to present with or claim functional psychiatric impairment that is inconsistent with or distinct from classic psychiatric nosology. In this short communication, we provide a detailed historical overview of this transdiagnostic phenomenon and suggest a conceptual model to organize thinking and research examining it. We then discuss the implications of our suggested model for accurate assessment, diagnosis, and medical-psychiatric treatment. We believe there is an urgent need for focused empirical research investigation into this concerning phenomenon that is related to the broader research and discourse examining social media influences on mental health.

Cross-sectional investigation of quality of life determinants among children with tic disorders: The roles of family environmental and clinical factors

Objective

To examine the association between family environmental and clinical factors with the whole range of quality of life (QOL) in children with tic disorders (TD).

Methods

A hospital-based cross-sectional study was conducted among children with TD. All participants were given a family environmental survey and scale evaluations with Yale Global Tic Severity Scale (YGTSS), Achenbach Child Behavior Checklist (CBCL) and PedsQL-Generic Core Scale of the Chinese Version (PedsQL). Variable selection and data analysis was done by the least absolute shrinkage and selection operator (LASSO) method and multivariate logistic regression analysis.

Results

A total of 363 TD cases were included in the analysis. YGTSS scores, total CBCL score had significant negative correlations with PedsQL scores (P < 0.05). Of the total 15 factors, 8, 6, 11, 7, 5, 10 potential predictors with nonzero coefficients were identified by LASSO regression models of physical functioning, emotional functioning, social functioning, school functioning, social-psychological domain and PedsQL total scale respectively. Results of multivariate logistic regression analysis showed older age (physical functioning, ORs: 1.77, 3.67; total scale: ORs: 1.73, 2.28), no presence of chronic conditions (school functioning, OR: 1.61), moderate/severe tic severity (physical functioning, OR: 0.57; social functioning, OR: 0.44; social-psychological domain, OR: 0.57), co-morbid behavioral problems (physical functioning, OR: 0.52; emotional functioning, OR: 0.31; social functioning, OR: 0.30; school functioning, OR: 0.35; social-psychological domain, OR: 0.34; total scale, OR: 0.30), no fully parental involvement in care (physical functioning, OR: 0.62), higher paternal (physical functioning, ORs: 2.89, 2.07) and maternal education level (social functioning, ORs: 1.74, 2.03), democratic parenting pattern (emotional functioning, OR: 1.89; social functioning, OR: 2.17; social-psychological domain, OR: 2.33; total scale, OR: 2.11) and inharmony family relationship (emotional functioning, OR: 0.47; total scale, OR: 0.50) were the most important determinants to QOL of TD.

Conclusions

This study identifies several QOL determinants among children with TD. Clinicians should be encouraged to screen for family environmental and clinical factors in TD patients, and take tailored interventions to help TD children improve their QOL.

Tourette syndrome and other tic disorders of childhood

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

Association of Pre- and Perinatal Risk Factors With Tourette Syndrome or Chronic Tic Disorders in a Korean School-Age Population

Objectives

Tic disorders are highly heritable; however, growing evidence suggests that environmental factors play a significant role in their pathogenesis. Studies on these factors have been inconsistent, with conflicting results. Therefore, this study aimed to examine the associations of pre- and perinatal exposure to Tourette syndrome (TS) or chronic tic disorders (CTD) in Korean school-aged children.

Methods

This case-control study used data from a large prospective cohort study. The primary outcome was TS/CTD diagnosis according to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) criteria and Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version-Korean Version. Demographic, pre-, and perinatal information was obtained from the maternal questionnaires. Data between the TS/CTD and control groups were compared using the chi-squared or Student's t-test, as appropriate. Two-step logistic regression analyses were used to test the association between TS/CTD and pre- and perinatal risk factors.

Results

We included of 223 children (78 with TS/CTD and 145 controls). Significant differences in the demographic data between the two groups were observed. The male sex ratio, mean parental age, parental final education level, and family history of tics were included as confounders. In the final adjusted multivariable model, TS/CTD was significantly associated with antiemetic exposure during pregnancy (odds ratio [OR]=16.61, 95% confidence interval [CI] 1.49-185.22, p=0.02) and medically assisted reproduction (OR=7.89, 95% CI 2.28-27.28, p=0.01).

Conclusion

Antiemetic exposure and medically assisted reproduction are significantly associated with the risk of TS/CTD. These results should be replicated in future prospective and gene-by-environment studies.

The correlation between tic disorders and allergic conditions in children: A systematic review and meta-analysis of observational studies

Aim

To evaluate the correlation between tic disorders and allergies and to inform strategies for the treatment and prevention of tic disorders.

Methods

We conducted online searches of the MEDLINE, Embase, Cochrane, CNKI, CBM, WanFang, and VIP Information databases. Case-control studies and cohort studies related to tic disorders and allergic conditions were searched. Two researchers screened the literature, extracted data, and evaluated quality in strict accordance with the predetermined retrieval strategy and inclusion criteria. Finally, RevMan 5.4 software was used to conduct a meta-analysis. We used the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach to rating the certainty of evidence about each allergy outcome as high, moderate, low, or very low.

Results

We obtained seven eligible studies involving eight allergic conditions. The following allergic conditions were significantly associated with the presence of a tic disorder: asthma (OR = 1.90, 95% CI = 1.57-2.30, P < 0.001), allergic rhinitis (OR = 2.61, 95% CI = 1.90-3.57, P < 0.001), allergic conjunctivitis (OR = 3.65, 95% CI = 1.53-8,67, P = 0.003), eczema (OR = 3.87, 95% CI = 2.24-6.67, P < 0.001) and food allergy (OR = 2.79, 95% CI = 1.56-4.99, P < 0.001). There was no significant correlation between atopic dermatitis, urticaria, drug allergy, and tic disorder.

Conclusion

The occurrence of tic disorders may be associated with the presence of certain allergic disorders. However, whether allergy is one of the causes of tic disorders remains unclear.

Systematic review registration

The registration number for this systematic review is PROSPERO: CRD42021231658.

Acupuncture and other traditional Chinese medicine therapies in the treatment of children's tic syndrome: A network meta-analysis

Background

Tic disorders (TD) are a kind of neuropsychiatric disease that frequently occur among preschool and school-age children, mainly characterized by motor tics or sometimes accompanied by vocal tics, and its pathogenesis is still unclear. The clinical manifestations are mainly characterized by chronic multiple movements, rapid muscle twitching, involuntary occurrence, and language disorder. Acupuncture, tuina, traditional Chinese medicine, and other methods are commonly used in clinical treatments, which have unique therapeutic advantages but have not been recognized and accepted by the international community. This study conducted a quality evaluation and meta-analysis of the currently published randomized controlled trials (RCTs) of acupuncture for TD in children in order to provide reliable evidence-based medical evidence for acupuncture for TD.

Methods

All the randomized controlled trials (RCTs) using the intervention methods acupuncture + traditional Chinese medical herbs, acupuncture + tuina, and acupuncture, and the control group using Western medicine were included in the analysis. The main outcomes were obtained by using the Yale Global Tic Severity Scale (YGTSS), the Traditional Chinese medicine (TCM) syndrome score scale, and clinical treatment efficiency. Secondary outcomes included adverse events. The risk of bias in the included studies was assessed according to the tool recommended by Cochrane 5.3. The risk of bias assessment chart, risk of bias summary chart, and evidence chart in this study will be produced using R and Stata software.

Results

There were 39 studies that met the inclusion criteria, including 3,038 patients. In terms of YGTSS, the TCM syndrome score scale changes and shows a clinically effective rate, and we found that acupuncture combined with Chinese medicine is the best treatment.

Conclusion

Acupuncture + traditional Chinese medical herbs may be the best therapy to improve TD in children. At the same time, compared with Western medicine commonly used in clinical practice, acupuncture and acupuncture combined with tuina therapy have better effects on improving TD in children.

Boosted dopamine and blunted serotonin in Tourette syndrome - evidence from in vivo imaging studies

The precise cortical and subcortical mechanisms of Tourette syndrome (TS) are still not fully understood. In the present retrospective analysis, adolescent and adult medication-naïve patients showed increased DA transporter (DAT) binding in nucleus caudate (CAUD), putamen (PUT) and/or whole neostriatum (NSTR). D₂ receptor (R) binding and DA release were not different from controls throughout the nigrostriatal and mesolimbocortical system. When patients were medication-free (either medication-naïve or under withdrawal), DAT was still increased in PUT, but not different from controls in CAUD, NSTR and ventral striatum (VSTR). SERT was unaltered in midbrain/pons (MP), but decreased in PUT, thalamus (THAL) and hypothalamus. D₂R was unaltered throughout the nigrostriatal and mesolimbocortical system, while DA release was not different from controls in PUT, CAUD and NSTR, but elevated in VSTR. 5-HT_2AR binding was unaltered in neocortex and cingulate. In acutely medicated adults, DAT was unaltered in PUT, but still increased in CAUD, whereas DA release remained unaltered throughout the nigrostriatal and mesolimbocortical system. When part of the patients was acutely medicated, vesicular monoamine transporter (VMAT2), DAT, SERT and DA synthesis were not different from controls in striatal regions, whereas D₂R was decreased in NSTR, THAL, frontal cortex and limbic regions. Conversely, 5-HT_2AR binding was unaltered in striatal regions and THAL, but increased in neocortical and limbic areas. It may be hypothesized that both the DA surplus and the 5-HT shortage in key regions of the nigrostriatal and mesolimbic system are relevant for the bouts of motor activity and the deficiencies in inpulse control.

Polygenic and environmental determinants of tics in the Avon Longitudinal Study of Parents and Children

Tourette syndrome (TS) is caused by multiple genetic and environmental factors. Yet, little is known about the interplay of these factors in the occurrence of tics. We investigated whether polygenic risk score (PRS) of TS and pregnancy-related factors together enhance the explained variance of tic occurrence in the Avon Longitudinal Study of Parents and Children (N_cases  = 612; N_controls  = 4,201; 50% male; mean age 13.8 years). We included a cumulative adverse pregnancy risk score, maternal anxiety and depression, and maternal smoking and alcohol use during pregnancy. We investigated possible joint effects of genetic and pregnancy-related risk factors using a multivariable approach, and explored mediation effects between the pregnancy-related risk factors in explaining tic presence. The PRS and the cumulative adverse pregnancy risk score, maternal anxiety, or maternal depression explained significantly more variance of tic presence compared to models including only the PRS. Furthermore, we found that the cumulative adverse pregnancy risk score mediated the association between several pregnancy-related factors (maternal anxiety, depression, and smoking) and tics. The combination of a PRS and pregnancy-related risk factors explained more variance of tics in a general population cohort compared to studying these factors in isolation.