Subjective versus objective measures of tic severity in Tourette syndrome - The influence of environment

Deep brain stimulation for Tourette's syndrome

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the efficacy and harm of deep brain stimulation for motor symptoms, with psychiatric and behavioural comorbidities, either individually or in combination, in adults and adolescents with Tourette's syndrome compared to placebo, sham intervention, or the best available behavioural and pharmacological treatment.

Contextual Triggers and Tic Severity Across Life Periods: A Retrospective Analysis in Adults with Tic Disorders

In tic disorders (TD), tic expression varies across the lifespan and as a function of contextual factors. This study explored connections between tic expression and contextual triggers across life periods in 74 adults (Mage = 23.2) with TDs. The Tic History and Coping Strategies form assessed retrospective self-reports of contextual antecedents, consequences, and tic severity during four life periods (middle school; 9th/10th grade; 11th/12th grade; college/work) and past month. Tics reportedly worsened during and after school in school-aged years and worsened in the evening during college/work years. Stress and anxiety were reported to consistently trigger tics across time. The impact of activities, places, and emotions did not differ across life periods. Attention-based consequences, most prevalent during middle school, were more common than escape- or avoidance-related consequences across all periods. Findings illuminate how contextual factors may influence tics across life periods and underscore the consistent impact of tic-triggering emotions and attention-related consequences.

Automated Video-Based Approach for the Diagnosis of Tourette Syndrome

BACKGROUND

The occurrence of tics is the main basis for the diagnosis of Gilles de la Tourette syndrome (GTS). Video-based tic assessments are time consuming.

OBJECTIVE

The aim was to assess the potential of automated video-based tic detection for discriminating between videos of adults with GTS and healthy control (HC) participants.

METHODS

The quantity and temporal structure of automatically detected tics/extra movements in videos from adults with GTS (107 videos from 42 participants) and matched HCs were used to classify videos using cross-validated logistic regression.

RESULTS

Videos were classified with high accuracy both from the quantity of tics (balanced accuracy of 87.9%) and the number of tic clusters (90.2%). Logistic regression prediction probability provides a graded measure of diagnostic confidence. Expert review of about 25% of lower-confidence predictions could ensure an overall classification accuracy above 95%.

CONCLUSIONS

Automated video-based methods have a great potential to support quantitative assessment and clinical decision-making in tic disorders.

Development and Validation of an Assessment-Driven Behavioral Intervention for Primary Complex Motor Stereotypies in Young Children

Complex motor stereotypies are rhythmic, repetitive, fixed, and non-goal directed movements (e.g., bilateral flapping/waving movements of the hands/arms). Movements typically begin in early childhood and can occur in otherwise normally developing ("primary") or autistic ("secondary") children. Stereotypies persist, occur multiple times a day, have prolonged durations, can be socially stigmatizing, and may lead to bullying and isolation. Prior behavioral treatment studies have focused on older children (ages 6-12) and report modest reductions in stereotypy (i.e., between 14% and 33%). The current study involves the functional assessment and treatment of five children with Primary Complex Motor Stereotypy using a modified awareness training procedure, differential reinforcement of other behavior, and schedule thinning in a nonconcurrent multiple baseline design. Results suggest a 99% reduction of motor stereotypy from baseline across all participants.

Impact of movie and video game elements on tic manifestation in children

BACKGROUND AND PURPOSE

Children in developed countries spend a significant portion of their waking hours engaging with audiovisual content and video games. The impact of media consumption on children's health and well-being has been widely studied, including its effects on tic disorders. Previous studies have shown that tic frequency can both increase and decrease during activities like gaming and television watching, resulting in mixed findings.

METHODS

To better understand the impact of audiovisual media on tics, we conducted a fine-grained tic manifestation analysis. We focused on the effects of the impact of a movie scene with suspensful elements and a video game designed to heighten anticipation, thought to stimulate phasic and striatal dopamine release. We closely monitored tic frequency throuhghout these experiences based on moment-to-moment tic annotation. The study included 20 participants (19 males aged 7-16) diagnosed with tic disorders (Yale Global Tic Severity Scale≥8), and we tested the replicability of our findings with an independent group of 36 children (15 females, aged 7-15) with tic disorders.

RESULTS

During film viewing, we observed significant synchronization in the temporal tic patterns of various individuals despite diversity in their tic profiles. Furthermore, employing a video game developed for our study, we found that tic frequency increases during anticipation of a pending reward. This finding was replicated in a second experiment with an independent cohort.

CONCLUSIONS

Our results indicate that tic frequency is affected by media elements in the short-term, and call for further investigation of the long-term impacts of exposure to such tic triggers.

Sleep and daytime functioning in children with tourette syndrome: A two-week case-control study with actigraphy and cognitive assessments

There is increasing recognition of the high prevalence of sleep issues in children with Tourette syndrome (TS), a condition characterised by motor and vocal tics. Overnight polysomnography (PSG) has been the primary mode of sleep assessment in the TS literature, despite the extensive use of actigraphy in other neurodevelopmental populations. As a result, there are existing research gaps surrounding day-to-day variability of sleep in TS and links to daytime functioning. This study adopts a naturalistic, intensive longitudinal design to examine sleep in children with TS while considering potential links to tic severity and daytime functioning. Participants were 34 children aged between 8 and 12 years (12 with TS, 22 neurotypical controls). Wrist actigraphs tracked sleep-wake cycles across two weeks and a battery of scales and cognitive assessments measured sleep disturbances and daytime functioning. Mixed models using N = 476 nights of actigraphy data found that relative to controls, children with TS had significantly increased time in bed, increased sleep onset latency, reduced sleep efficiency, lower subjective sleep quality, but comparable actual sleep time. Higher self-report tic severity at bedtime did not predict increased sleep onset latency. In the sleep disturbance scale, 83.33 % of children with TS met the clinical cut-off for a sleep disorder. Parent-report emotional, behavioural, and executive difficulties were greater in the TS group relative to controls, but performance on cognitive tasks was comparable between groups. Together, findings highlight sleep disturbances as an important clinical factor to consider in the management of TS, though further research is required to substantiate findings in larger-scale studies. This study demonstrates the feasibility of assessing sleep via actigraphy in children with TS, supporting more widespread use in the future.

Parent-Report Sleep Disturbances and Everyday Executive Functioning Difficulties in Children with Tourette Syndrome

There is an increasing need to identify and treat sleep disturbances in Tourette syndrome (TS), a neurodevelopmental condition characterized by tics. This study explored sleep, tics, and executive functioning in children with TS (n=136) and neurotypical controls (n=101) through parent-report scales and open-ended questions. 85% of children with TS scored in the clinical range for a sleep disorder. Higher tic severity predicted increased sleep disturbances and executive difficulties. Qualitative insights indicated a bidirectional link between sleep and tics, which warrants consideration in clinical settings. Further research is needed to explore causal links.

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.

Interoception and premonitory urges in children and adolescents with tic disorders

Background

Compared to healthy controls (HCs), adult Tic Disorder (TD) patients exhibit a lower interoceptive accuracy (IAcc) in heartbeat perception. Since the lower IAcc is not evident in children, the age at which tics develop, but in adults only (Pile et al., 2018, https://doi.org/10.1007/s10803-018-3608-8), lower IAcc may reflect a pathological mechanism relevant with regard to tics, premonitory urges (PUs) or the resulting impairment. Although tics are a motor phenomenon, up to date, IAcc has been assessed only with a heartbeat-counting task. This study aims at comparing cardiac and muscular IAcc using two different paradigms and investigates how IAcc is related to premonitory urges in youth.

Method

Interoceptive measures (heartbeat-counting task, muscle tension paradigm) of 28 youth with TD were compared to 23 control participants and related to self-rated premonitory urges and tic symptoms.

Results

TD patients did not differ from HCs in any IAcc measures. However, within TD patients, IAcc explained additional variance in PUs when controlling for tic severity. Muscular IAcc in TD patients is related to urges and tics, but the direction of this association is unclear. IAcc is lower in TD patients than in HCs, indicating imprecise sensory input which is more easily overcome by priors within the predictive coding framework.

Conclusions

Muscle tension feedback tasks could extend interoceptive trainings aimed at improving IAcc to improve accuracy of urge perception (more precise sensory input) to foster the ability to control tics via HRT. Longitudinal studies could provide further insights in causal relationships between IAcc, premonitory urges and tics.

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.

Die Bedeutung des Vorgefühls bei Tic-Störungen

Zusammenfassung. Theoretischer Hintergrund: Die Funktion des Vorgefühls in der Pathogenese und Aufrechterhaltung von Tic-Störungen (TS) wird in den letzten Jahren verstärkt erforscht. Die mögliche funktionelle Bedeutung der Vorgefühle wird aber noch nicht ausreichend verstanden. Methode: Im vorliegenden Review wird der Kenntnisstand zu Vorgefühlen entlang eines integrativen funktionalen Störungsmodells zusammengefasst. Ergebnisse: Im Vergleich zum Jugendalter nehmen Tic-Symptome bei Tic-Störungen im Erwachsenenalter ab, während immer mehr Betroffene ein Vorgefühl berichten. Hierbei kann zwischen einem allgemeinen Vorgefühl (trait) und dem Drang, Tics auszuführen (state) unterschieden werden. Das Vorgefühl als trait ist abhängig von der Interozeptionsfähigkeit. An den Drang, Tics auszuführen, kann habituiert werden, moderiert von Aufmerksamkeits- und Attributionsprozessen. Durch das Auflösen des Vorgefühl-Tic-Reizreaktionsmusters reduzieren sich die Tic-Symptome. Schlussfolgerung: Für weitere Erkenntnisse in Bezug auf die Bedeutung von Vorgefühl und den Drang, Tics auszuführen, sollten zukünftige Forschungsansätze Drang und allgemeine Vorgefühle in therapeutischen Interventionsstudien berücksichtigen, weitere Interozeptionsparadigmen einbeziehen und die Entwicklung von allgemeinem Vorgefühl und Drang über die Lebensspanne hinweg untersuchen.

Self-reported impact of the COVID-19 pandemic and lockdown on young patients with tic disorders: findings from a case-control study

BACKGROUND

Little is known about the perceived impact of the COVID-19 pandemic and subsequent lockdown measures on young patients with tic disorders. Previous studies focused on clinician and parent ratings of tic severity, whereas the only international self-report data are available for adult populations. We present the first findings from a case-control study on children and adolescents with tics during lockdown in Italy.

METHODS

We surveyed 49 patients aged 6-18 years and 245 matched controls with a newly developed questionnaire covering socio-demographic and clinical data, as well as lockdown-related changes to daily life activities.

RESULTS

About half (53.2%) of the Italian school-age patients who took part in our survey experienced changes in tic severity during lockdown. Perceived increases in tic severity (29.8%) were reported more often than decreases (23.4%). Analogous trends were reported for perceived restlessness and, more significantly, irritability, whereas changes in pain symptoms were less common and were similar in both directions. The presence of tics was associated with increased difficulties with remote learning (p = 0.01), but decreased feelings of missing out on social interactions with schoolmates (p = 0.03).

CONCLUSIONS

Self-reported data on the impact of COVID-19 lockdown in school-age patients with tic disorders indicate perceived changes in tic severity, as well as restlessness and irritability, in about half of the cases. These findings could guide both clinicians and teachers in the implementation of targeted adjustments in the delivery of care and educational strategies, respectively.

Group behavioral interventions for tics and comorbid symptoms in children with chronic tic disorders

Exposure and Response Prevention (ERP), Habit Reversal Training (HRT) and Comprehensive Behavioral Intervention for Tics (CBIT) are effective in reducing tic severity. ERP and HRT have recently gained primary support in a group setting, while CBIT has not been examined similarly. We compared the efficacy of group-CBIT to group-Educational Intervention for Tics (group-EIT) for tics and comorbid symptoms. Children with Tourette Syndrome (TS) or Chronic Tic Disorder (CTD) were randomized to group-CBIT or group-EIT. Tics and comorbid symptoms were assessed in forty-six children pre- and postintervention, and 3-month later. Yale Global Tic Severity Scale (YGTSS) Motor tic severity decreased following both interventions, and was maintained at follow-up for group-CBIT only. The Parent Tic Questionnaire (PTQ) showed significant decrease in total and motor tic severity following group-CBIT only, a gain maintained three months later. YGTSS impairment score decreased following both interventions and was maintained at follow-up. YGTSS vocal tic severity score increased following both interventions, and then decreased significantly at follow up. Co-morbid symptoms including anxiety, behavioral problems, and aggressive behavior decreased following both interventions. Children with behavioral problems benefitted less while children with higher intellectual ability benefit more from intervention. Both group interventions showed efficacy in reducing tic impairment and comorbid symptoms. Group-CBIT was superior to group-EIT in reducing motor tic severity at 3-month follow-up, showing an advantage for tic-focused treatment. Based on the PTQ, group-CBIT was superior to group-EIT in reducing motor, vocal, and total tic scores, a gain maintained three months later. Clinical trial registry information-Group Intervention for Children with Chronic Tics Syndrome: CBIT vs Psychoeducational Intervention URL: http://clinicaltrials.gov , Identifier: NCT02407951, http://www.controlled-trials.com ).

Tourette's syndrome: challenging misconceptions and improving understanding

Tourette's syndrome affects about 1% of the school-age population. Children and young people with the condition exhibit involuntary motor and vocal (also known as phonic) tics. Only 10% of those with Tourette's syndrome have coprolalia, which involves involuntary swearing and inappropriate language. Tourette's syndrome often presents with other conditions such as obsessive-compulsive disorder, autism and attention deficit hyperactivity disorder. Those affected by Tourette's syndrome may be able to manage the condition with little or no professional support, but some may need pharmacological and nonpharmacological input, particularly from mental health services. It is essential that peers, teachers, healthcare staff and members of the public are aware of Tourette's syndrome to ensure that children and young people living with the condition are supported well.

European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part I: assessment

In 2011 a working group of the European Society for the Study of Tourette Syndrome (ESSTS) has developed the first European assessment guidelines for Tourette syndrome (TS). Now, we present an updated version 2.0 of these European clinical guidelines for Tourette syndrome and other tic disorders, part I: assessment. Therefore, the available literature has been thoroughly screened, supplemented with national guidelines across countries and discussions among ESSTS experts. Diagnostic changes between DSM-IV and DSM-5 classifications were taken into account and new information has been added regarding differential diagnoses, with an emphasis on functional movement disorders in both children and adults. Further, recommendations regarding rating scales to evaluate tics, comorbidities, and neuropsychological status are provided. Finally, results from a recently performed survey among ESSTS members on assessment in TS are described. We acknowledge that the Yale Global Tic Severity Scale (YGTSS) is still the gold standard for assessing tics. Recommendations are provided for scales for the assessment of tics and psychiatric comorbidities in patients with TS not only in routine clinical practice, but also in the context of clinical research. Furthermore, assessments supporting the differential diagnosis process are given as well as tests to analyse cognitive abilities, emotional functions and motor skills.

Pharmacological treatment for Tourette syndrome in children and adults: What is the quality of the evidence? A systematic review

BACKGROUND

Tourette syndrome (TS) is a neurodevelopmental disorder characterised by involuntary muscle movements manifesting as motor and vocal tics. In the majority, tics are manageable without medication. Where tics cause discomfort or impair function, behavioural or pharmaceutical treatments may be considered.

AIMS

To provide a meticulous examination of the quality of evidence for the current pharmacological treatments for TS.

METHODS

PubMed and Google Scholar were searched to identify randomised, placebo-controlled trials (RCTs) of aripiprazole, risperidone, clonidine, guanfacine, haloperidol, pimozide, tiapride and sulpiride for the treatment of tics in children and adults with TS. Quality of reporting and risk of bias were assessed against the CONSORT checklist and Cochrane risk of bias criteria, respectively.

RESULTS

Seventeen RCTs were identified. Response rates reached 88.6% for aripiprazole, 68.9% for clonidine, 62.5% for risperidone and 19% for guanfacine. Statistically significant improvements were reported for all medications compared to placebo in at least one study and for at least one measure of tic severity. Most studies predated the CONSORT and Cochrane criteria and did not score highly when assessed on these measures.

CONCLUSIONS

There are relatively few placebo-controlled trials of commonly prescribed medications. Studies are often of poor quality and short duration. There is evidence for the efficacy of each medication, but no drug is clearly superior. Clonidine and guanfacine are better tolerated than antipsychotics, but less effective. There is too little evidence to determine whether adults respond differently from children.

Dissociation of tic generation from tic expression during the sleep-wake cycle

Motor tics, the hallmark of Tourette syndrome (TS), are modulated by different behavioral and environmental factors. A major modulating factor is the sleep-wake cycle in which tics are attenuated to a large extent during sleep. This study demonstrates a similar reduction in tic expression during sleep in an animal model of chronic tic disorders and investigates the underlying neural mechanism. We recorded the neuronal activity during spontaneous sleep-wake cycles throughout continuous GABA_A antagonist infusion into the striatum. Analysis of video streams and concurrent kinematic assessments indicated tic reduction during sleep in both frequency and intensity. Extracellular recordings in the striatum revealed a state-dependent dissociation between motor tic expression and their macro-level neural correlates ("LFP spikes") during the sleep-wake cycle. Local field potential (LFP) spikes, which are highly correlated with tic expression during wakefulness, persisted during tic-free sleep and did not change their properties despite the reduced behavioral expression. Local, micro-level, activity near the infusion site was time-locked to the LFP spikes during wakefulness, but this locking decreased significantly during sleep. These results suggest that whereas LFP spikes encode motor tic generation and feasibility, the behavioral expression of tics requires local striatal neural activity entrained to the LFP spikes, leading to the propagation of the activity to downstream targets and consequently their motor expression. These findings point to a possible mechanism for the modulation of tic expression in patients with TS during sleep and potentially during other behavioral states.

Overlapping sleep disturbances in persistent tic disorders and attention-deficit hyperactivity disorder: A systematic review and meta-analysis of polysomnographic findings

INTRODUCTION

Persistent tic disorders (PTDs) and attention-deficit hyperactivity disorder (ADHD) are common neurodevelopmental conditions which tend to co-occur. Both diagnoses are associated with sleep problems. This systematic review and meta-analysis investigates overlaps and distinctions in objective sleep parameters based on diagnosis (PTD-only, PTD + ADHD, and ADHD-only).

METHODS

Databases were searched to identify studies with objective sleep measures in each population. Meta-analyses were conducted using a random effects model.

RESULTS

Polysomnography was the only measure included in all three groups. Twenty studies met final inclusion criteria, combining PTD-only (N = 108), PTD + ADHD (N = 79), and ADHD-only (N = 316). Compared to controls (N = 336), PTD-only and PTD + ADHD groups had significantly lower sleep efficiency and higher sleep onset latency. PTD + ADHD also had significantly increased time in bed and total sleep time. No significant differences were observed between ADHD-only groups and controls.

DISCUSSION

Different sleep profiles appear to characterise each population. PTD + ADHD was associated with more pronounced differences. Further research is required to elucidate disorder-specific sleep problems, ensuring appropriate identification and monitoring of sleep in clinical settings.

Pediatric Prevention: Tic Disorders

It is not clear whether the development of tics can be prevented. Contextual variables can impact tic expression; therefore, shifting attention to behaviors that reduce tics is an important part of decreasing tic severity. Several medications are effective in reducing tic severity, but side effects restrict their use. Behavioral treatment is the gold standard psychotherapy intervention for tic disorders, with Comprehensive Behavioral Intervention for Tics being the most well-supported nonpharmacological treatment. Although children may be unable to prevent the development of tics, they can still use several strategies to reduce tic severity and impairment.

A Review on Functional Analyses of Tics

Tic disorders are characterized by a class of responses assumed to be neurobiological in origin. Still, several studies have shown that tic frequency can be influenced by antecedent environmental events and social consequences. Prior reviews have summarized the effects of environmental events but have not examined relations between tic diagnosis, behavioral deficits (e.g., intellectual disability), tic topography, and the consequences observed to maintain tics. These variables might be important when attempting to predict or identify relevant consequences. A more thorough understanding of the variables that maintain and give rise to tics might also be useful in predicting responsiveness to treatment and intervention refinement. We reviewed and summarized results from the 13 attempts to experimentally identify maintaining consequences for tics (i.e., functional analyses) that have been published to date. We examined patterns of functions across tic diagnoses (i.e., Tourette's syndrome or not), communication impairments (i.e., an intellectual disability or reported language difficulty), and tic topography. Results suggested that individuals with Tourette's syndrome and those without communication impairments are more likely to have functional analysis outcomes consistent with automatic reinforcement, but exceptions in both directions highlight the utility of functional analysis in treating tics.

The psychology of Tourette disorder: Revisiting the past and moving toward a cognitively-oriented future

Tourette syndrome is a neurodevelopmental disorder characterized by chronic tics (i.e., repetitive and stereotyped movements and vocalizations) and premonitory urges (i.e., aversive sensations preceding tics that are alleviated once a tic is performed). Research supports that dysfunctional neurobiological and psychological processes interact and contribute to the development and maintenance of tics. However, psychological theories of Tourette syndrome and accompanying research have mainly focused on the emotional states (e.g., anxiety and frustration) and behavioural principles (i.e., operant conditioning) that play a role in tic exacerbation. This selective review summarizes key discoveries pertaining to the emotional and behavioural aspects of Tourette syndrome but also proposes a more comprehensive, cognitively-oriented conceptualization of the disorder. Specifically, it is proposed that maladaptive beliefs about discomfort and about one's ability to cope with discomfort underlie negative appraisals of unpleasant sensory experiences in individuals with Tourette syndrome. It is further suggested that these beliefs lead individuals to perceive premonitory urges in a catastrophic manner and thereby enhance tic frequency. Concrete research avenues to empirically examine these hypotheses are outlined and clinical implications for the field of cognitive-behaviour therapy are discussed.

Efficacy of Habit Reversal Training in Children With Chronic Tic Disorders: A Within-Subject Analysis

The aim of this study is to evaluate a cognitive-behavioral treatment for children and adolescents with tic disorder including habit reversal training (HRT) in a sample of children and adolescents (n = 27). Multiple outcome measures were used to assess the effects of the treatment on tic symptoms. In addition, impairment/subjective burden ratings and the self-efficacy to control tics were assessed. A within-subject design with two phases (8 weeks diagnostic; 16 sessions treatment) was analyzed using multilevel modeling (MLM). During the treatment phase, significant improvements in tic symptoms, impairment, and self-efficacy to control tics were found on most outcome measures. Treatment effects were found on the clinical rating of tic symptoms (Yale Global Tic Severity Scale [YGTSS]), the self-efficacy to control tics, and the video-observed motor tic frequency by comparing the improvements during treatment with the course of the outcome measures during the preceding diagnostic phase.

Current behavioral assessments of movement disorders in children

Pediatric movement disorders (PMDs) are common and have recently received increasing attention. As these disorders have special clinical features, the selection of appropriate behavioral assessment tools that can clearly distinguish movement disorders from other diseases (eg, epilepsy and neuromuscular disorders) is crucial for achieving an accurate diagnosis and treatment. However, few studies have focused on behavioral assessments in children. The present report attempts to provide a critical review of the available subjective and objective assessment tests for common PMDs. We believe that the principles of objectification, multi-purpose use, and simplification are also applicable to the selection and development of satisfactory pediatric behavioral assessment tools. We expect that the development of wearable sensors, virtual reality, and augmented reality will lead to the establishment of more reliable and simple tests. In addition, more rigorous randomized controlled trials that have been specifically designed to evaluate behavioral testing in children are also expected in the future.

Patterns and Predictors of Tic Suppressibility in Youth With Tic Disorders

Tic suppression is the primary target of tic disorder treatment, but factors that influence voluntary tic inhibition are not well understood. Several studies using the Tic Suppression Task have demonstrated significant inter-individual variability in tic suppressibility but have individually been underpowered to address correlates of tic suppression. The present study explored patterns and clinical correlates of reward-enhanced tic suppression in youth with tic disorders using a large, pooled dataset. Individual-level data from nine studies using the Tic Suppression Task were pooled, yielding a sample of 99 youth with tic disorders. Analyses examined patterns of tic suppressibility and the relationship between tic suppressibility and demographic and clinical characteristics. A large majority of youth demonstrated a high degree of tic suppression, but heterogeneous patterns of tic suppressibility were also observed. Better tic suppressibility was related to older age and more frequent tics but unrelated to other clinical variables, including presence of psychiatric comorbidity, psychotropic medication status, tic and premonitory urge severity, and self-rated tic suppressibility. The mechanisms underlying the observed heterogeneity in reward-enhanced tic suppressibility warrant further investigation. The Tic Suppression Task is a promising method for testing mechanistic hypotheses related to tic suppression.

Tourette syndrome and other chronic tic disorders: an update on clinical management

INTRODUCTION

The management of Tourette syndrome (TS) and other chronic tic disorders occurs in multiple stages and begins with comprehensive assessment and complex psychoeducation. Behavioral and pharmacological interventions (second stage) are needed when tics cause physical or psychosocial impairment. Deep brain stimulation surgery or experimental therapies represent the third stage. Areas covered: Discussed are recent advances in assessment and therapy of chronic tic disorders, encompassing the three stages of intervention, with the addition of experimental, non-invasive brain stimulation strategies. A PubMed search was performed using as keywords: 'tic disorders', 'Tourette syndrome', 'assessment', 'rating scales', 'behavioral treatment', 'pharmacological treatment', 'deep brain stimulation', 'transcranial magnetic (or current) stimulation', and 'transcranial current stimulation'. More than 300 peer-reviewed articles were evaluated. The studies discussed have been selected on the basis of novelty and impact. Expert commentary: Comprehensive assessment of tic disorders and psychoeducation are crucial to a correct active management approach. Behavioral treatments represent first line of active interventions, with increasing potential offered by telehealth. Antipsychotics and alpha agonists remain first line pharmacological interventions for tics, although VMAT-2 inhibitors appear promising. Deep brain stimulation is a potential option for medically refractory, severely disabled patients with tics, but age and target selection require further investigation.

Tourette syndrome research highlights from 2016

This article presents highlights chosen from research that appeared during 2016 on Tourette syndrome and other tic disorders. Selected articles felt to represent meaningful advances in the field are briefly summarized.

Tourette syndrome research highlights from 2016

This article presents highlights chosen from research that appeared during 2016 on Tourette syndrome and other tic disorders. Selected articles felt to represent meaningful advances in the field are briefly summarized.

What makes you tic? Translational approaches to study the role of stress and contextual triggers in Tourette syndrome

Tourette syndrome (TS) is a neurodevelopmental condition characterized by multiple, recurring motor and phonic tics. Rich empirical evidence shows that the severity of tics and associated manifestations is increased by several stressors and contextual triggers; however, the neurobiological mechanisms responsible for symptom exacerbation in TS remain poorly understood. This conceptual gap partially reflects the high phenotypic variability in tics, as well as the existing difficulties in operationalizing and standardizing stress and its effects in a clinical setting. Animal models of TS may be highly informative tools to overcome some of these limitations; these experimental preparations have already provided critical insights on key aspects of TS pathophysiology, and may prove useful to identify the neurochemical alterations induced by different stressful contingencies. In particular, emerging knowledge on the role of contextual triggers in animal models of TS may inform the development of novel pharmacological interventions to reduce tic fluctuations in this disorder.