Reexamining Tic persistence and Tic-associated impairment in Tourette's Disorder: findings from a naturalistic follow-up study

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.

The female Tourette patient: Sex differences in Tourette Disorder

Tourette Disorder (TD) is a male predominant neurodevelopmental disorder characterized by tics and frequent psychiatric comorbidities. Girls with TD have later peak symptoms, less remission with age, and worse impairment from tics, particularly in adulthood. Female TD patients are less likely to have Attention Deficit Hyperactivity Disorder and more likely to have anxiety and mood disorders. Hyperandrogenism is associated with TD in both sexes, and neuroanatomic sexual dimorphism is reduced in adult TD patients. Some women report catamenial tics, which may relate to estrogen withdrawal or rises in allopregnanolone. Limited data suggest that several neuroanatomic alterations present in boys with TD are not present in girls with TD. Female sex predicts better response to haloperidol. Further research into female tic pathophysiology may influence sex-specific treatment development.

Course of tic disorders over the lifespan

PURPOSE OF REVIEW

To summarize and update information on the course of tic disorders from childhood through later life.

RECENT FINDINGS

Tics tend to improve substantially over the first year after they appear. However, contrary to widespread opinion, tics usually last longer than one year, though usually at minimal severity. Tics often wane to clinical insignificance over the teen years, possibly resurging occasionally over the lifespan. However, in an important minority of patients, tics remain clinically relevant throughout life. Tics rarely first come to clinical attention later in adulthood, but new reports describe additional such cases.

SUMMARY

Recent publications have shown tics to persist past a few months more often than previously thought, though often at minimal severity, and recurrence after an asymptomatic period is common. The safety and efficacy of behavior therapy for tics, together with prospective indicators of early prognosis, make feasible the possibility of bettering the lifetime course of tic disorders with early intervention.

The New Tics study: A Novel Approach to Pathophysiology and Cause of Tic Disorders

We report on the ongoing project "The New Tics Study: A Novel Approach to Pathophysiology and Cause of Tic Disorders," describing the work completed to date, ongoing studies and long-term goals. The overall goals of this research are to study the pathophysiology of Provisional Tic Disorder, and to study tic remission (or improvement) in a prospective fashion. Preliminary data collection for the project began almost 10 years ago. The current study is nearing completion of its third year, and has already reported several novel and important results. First, surprisingly, at least 90% of children who had experienced tics for only a mean of 3 months still had tics at the 12-month anniversary of their first tic, though in some cases tics were seen only with remote video observation of the child sitting alone. Thus almost all of them now had a DSM-5 diagnosis of Tourette's Disorder or Persistent (Chronic) Tic Disorder. Baseline clinical features that predicted 12-month outcome included tic severity, subsyndromal autism spectrum symptoms, an anxiety disorder, and a history of 3 or more phonic tics. Second, we found that poorer tic suppression ability when immediately rewarded for suppression predicted greater tic severity at follow-up. Third, striatal volumes did not predict outcome as hypothesized, but a larger hippocampus at baseline predicted worse severity at follow-up. Enrollment and data collection continue, including functional connectivity MRI (fcMRI) imaging, and additional analyses are planned once the full sample is enrolled.

Long-Term Follow-up of Patients with Tourette's Syndrome

Background

Tourette's Syndrome (TS) is a childhood-onset movement disorder marked by the chronic presence of motor and vocal tics. Research shows that tics associated with TS tend to fade in severity for some (but not all) affected youth, though psychiatric comorbidities that commonly accompany TS may be more persistent. The long-term outcomes of individuals with TS have not been well characterized.

Objective

To characterize long-term clinical outcomes of individuals with TS.

Method

We conducted a long-term (25-32 years) follow-up study of 45 patients with TS who presented to the Tourette's and Tic Disorders Clinic within the Department of Psychiatry at the University of California San Francisco Medical Center, which was staffed by the first author (Thomas L. Lowe, MD [T.L.L.]), between 1983 and 1990. Baseline data were obtained via chart review, and follow-up data were obtained by self-report surveys.

Results

Participants generally reported good psychosocial functioning, attainment of significant social milestones (academic attainment, gainful employment, marriage), and high subjective quality of life. The vast majority of participants (82%) reported improvement in their tics over time, though a significant minority continued to experience at least mild tic-related impairment (26%-40%, depending on metric). Lifetime rates of attention deficit hyperactivity disorder (ADHD) and anxiety disorders, including obsessive-compulsive disorder, were greater than in the general US population. Robust predictors of follow-up outcomes were not found.

Conclusions

These findings reflect a positive overall long-term prognosis for individuals with TS. Providing information about this prognosis at the time of diagnosis may decrease distress in affected individuals and their families. Future studies using planned longitudinal designs that address potential confounds of survey nonresponse are needed to detail long-term outcomes of individuals with TS more precisely.

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.

Remission of Gilles de la Tourette Syndrome after Heat-Induced Dehydration

Heat has been reported to exert variable effects on people with Gilles de la Tourette syndrome (TS). At age 24 years, a 32-year-old right-handed man with TS experienced a marked reduction in tics for two years after undergoing dehydration by entering a hot tub at 103°F (39.4°C) to 104°F (40.0°C) for 3 to 4 hours. On the Yale Global Tic Severity Scale (YGTSS) he scored 55 seven months before dehydration and 13 one month after dehydration. An intense heat exposure and dehydration led to an apparent remission in tics. The remission continued without the use of prescribed or nonprescribed medications or substances for two years until tics returned in the worst ever exacerbation after a tetanus immunization. The heat exposure may have altered at least temporarily his thermostat for normal heat-loss mechanisms through dopaminergic pathways from the anterior hypothalamus to the basal ganglia and the substantia nigra. Whether or not that mechanism or some other mechanism relevant to the heat exposure and/or dehydration is at play, the sudden and marked improvement in his tics needs further attention. Prospective testing of the heat and dehydration effect on tics should be pursued.

Executive control development in Tourette syndrome and its role in tic reduction

Tourette syndrome (TS) is a childhood-onset disorder characterized by motor and vocal tics. Recent findings point to a possible role of executive functions system development in the tic reduction observed with age. The goal of the present work was to track the development of executive functions system measured by well-established cognitive tasks and its correlation with diminished tic severity over time in order to understand the role of executive functions in the remission process observed in most adults. The first study followed 25 young TS patients, measuring their executive functions and clinical condition at three time- points. In the second study we compared executive functions performance of 19 adult TS patients with 19 healthy controls and 12 remitted TS patients. The first study showed that tic reduction is related to the development of the executive functions components associated with response inhibition. The second study similarly showed impaired inhibition ability in TS patients but not in controls or the remitted TS patients. The remitted group performed at normal or even higher levels on certain measures. We conclude that inhibition, an important executive function, is impaired in subjects suffering from TS and that intact executive function development is related to remission processes.

Quality assessment of clinical practice guidelines on tic disorders with AGREE II instrument

To assess the methodological quality of existing clinical practice guidelines (CPGs) on the treatment of tic disorders (TDs) using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument and summarize the guideline recommendations. Five CPGs met our inclusion criteria. The mean percentages for the AGREE II domain scores were: scope and purpose 83.33% (95% confidence interval [CI], 77.78-94.44%), stakeholder involvement 62.22% (95% CI, 38.89-94.44%), rigor of development 47.08% (95% CI, 6.25-83.33%), clarity of presentation 87.78% (95% CI, 72.22-94.44%), applicability 56.67% (95% CI, 33.33-87.50%), and editorial independence 46.67% (95% CI, 8.33-91.67%). There were large differences among the five CPGs concerning the categorization of evidence and recommendations. The recommendations for drug therapy were similar in all five CPGs, although there was controversy in certain areas. The methodological quality of CPGs for TDs was acceptable in terms of scope and purpose, stakeholder involvement, and clarity of presentation. However, CPG developers need to pay more attention to rigorous development processes, applicability, and editorial independence. Developers of future CPGs should improve adherence to the AGREE II guidelines. In addition, high quality studies on the treatment of TDs are needed to provide more evidence for developing guidelines.

Outpatient Treatment of Tic Disorders Among Children and Adults

Introduction

Limited information is available regarding treatment practices in applied settings for children and adults with tic disorders (TDs). We describe, for the first time, the treatment of TDs in U.S. children and adults in the outpatient setting.

Methods

Data from the 2003-2010 National Ambulatory Medical Care Survey and the National Hospital Ambulatory Care Survey were used. Descriptive statistics for modality of treatment and class of pharmacological medications were reported by patient and visit characteristics. Separate multivariable logistic regression models were used to examine associations between patient and visit characteristics and classes of medications prescribed.

Results

One third (n = 99) of the sample did not receive any psychiatric or psychological treatment. Nearly two-thirds received a psychotropic medication. The most common class of medication was alpha-2 agonists (25%), followed by stimulants (23%), serotonin-reuptake inhibitors (SRIs) (19%), atypical antipsychotics (18%), anxiolytics (14%), anticonvulsants (11%), and typical antipsychotics (8%). Comorbid disorders and chronicity of problems were significantly associated with the receipt of certain classes of medications. Relatively few patients (18%) received psychotherapy.

Conclusions

If the decision is made to treat tic disorders, the choice of medication is dependent on the primary complaints, severity, chronicity, and the presence of comorbid psychiatric disorders. In general, comorbid externalizing, anxiety and mood disorders appear to influence treatment decisions in addition to TDs.

The Subjective Quality of Life in Young People With Tourette Syndrome in China

OBJECTIVE

To explore the subjective quality of life (QoL) in children with Tourette Syndrome (TS) in China to provide a basis for more effective interference.

METHOD

A total of 107 patients and 107 controls were enrolled. Subjective QoL was investigated by Inventory of Subjective Life Quality, Family Environment Scale of Chinese Version, and the Yale Global Tic Severity Scale, and a case-control study was performed.

RESULTS

The total score of subjective QoL and family life, school life, peer relationship, cognitive component, environment, self-awareness, cognitive component and depression experience in the TS were lower than control. Patients with co-morbid exhibited significantly lower scores within the subjective QoL family life, peer relationship, school life, self-awareness, and cognitive affective domains.

CONCLUSION

The subjective QoL is impaired and it is important to control clinical symptoms and improve family environment for the improvement of the subjective QoL in TS.

Clinical effectiveness and patient perspectives of different treatment strategies for tics in children and adolescents with Tourette syndrome: a systematic review and qualitative analysis

BACKGROUND

Tourette syndrome (TS) is a neurodevelopmental condition characterised by chronic motor and vocal tics affecting up to 1% of school-age children and young people and is associated with significant distress and psychosocial impairment.

OBJECTIVE

To conduct a systematic review of the benefits and risks of pharmacological, behavioural and physical interventions for tics in children and young people with TS (part 1) and to explore the experience of treatment and services from the perspective of young people with TS and their parents (part 2).

DATA SOURCES

For the systematic reviews (parts 1 and 2), mainstream bibliographic databases, The Cochrane Library, education, social care and grey literature databases were searched using subject headings and text words for tic* and Tourette* from database inception to January 2013.

REVIEW/RESEARCH METHODS

For part 1, randomised controlled trials and controlled before-and-after studies of pharmacological, behavioural or physical interventions in children or young people (aged < 18 years) with TS or chronic tic disorder were included. Mixed studies and studies in adults were considered as supporting evidence. Risk of bias associated with each study was evaluated using the Cochrane tool. When there was sufficient data, random-effects meta-analysis was used to synthesize the evidence and the quality of evidence for each outcome was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. For part 2, qualitative studies and survey literature conducted in populations of children/young people with TS or their carers or in health professionals with experience of treating TS were included in the qualitative review. Results were synthesized narratively. In addition, a national parent/carer survey was conducted via the Tourettes Action website. Participants included parents of children and young people with TS aged under 18 years. Participants (young people with TS aged 10-17 years) for the in-depth interviews were recruited via a national survey and specialist Tourettes clinics in the UK.

RESULTS

For part 1, 70 studies were included in the quantitative systematic review. The evidence suggested that for treating tics in children and young people with TS, antipsychotic drugs [standardised mean difference (SMD) -0.74, 95% confidence interval (CI) -1.08 to -0.41; n = 75] and noradrenergic agents [clonidine (Dixarit(®), Boehringer Ingelheim) and guanfacine: SMD -0.72, 95% CI -1.03 to -0.40; n = 164] are effective in the short term. There was little difference among antipsychotics in terms of benefits, but adverse effect profiles do differ. Habit reversal training (HRT)/comprehensive behavioural intervention for tics (CBIT) was also shown to be effective (SMD -0.64, 95% CI -0.99 to -0.29; n = 133). For part 2, 295 parents/carers of children and young people with TS contributed useable survey data. Forty young people with TS participated in in-depth interviews. Four studies were in the qualitative review. Key themes were difficulties in accessing specialist care and behavioural interventions, delay in diagnosis, importance of anxiety and emotional symptoms, lack of provision of information to schools and inadequate information regarding medication and adverse effects.

LIMITATIONS

The number and quality of clinical trials is low and this downgrades the strength of the evidence and conclusions.

CONCLUSIONS

Antipsychotics, noradrenergic agents and HRT/CBIT are effective in reducing tics in children and young people with TS. The balance of benefits and harms favours the most commonly used medications: risperidone (Risperdal(®), Janssen), clonidine and aripiprazole (Abilify(®), Otsuka). Larger and better-conducted trials addressing important clinical uncertainties are required. Further research is needed into widening access to behavioural interventions through use of technology including mobile applications ('apps') and video consultation.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002059.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Provisional Tic Disorder: What to tell parents when their child first starts ticcing

The child with recent onset of tics is a common patient in a pediatrics or child neurology practice. If the child’s first tic was less than a year in the past, the diagnosis is usually Provisional Tic Disorder (PTD). Published reviews by experts reveal substantial consensus on prognosis in this situation: the tics will almost always disappear in a few months, having remained mild while they lasted. Surprisingly, however, the sparse existing data may not support these opinions.

PTD may have just as much importance for science as for clinical care. It provides an opportunity to prospectively observe the spontaneous remission of tics. Such prospective studies may aid identification of genes or biomarkers specifically associated with remission rather than onset of tics. A better understanding of tic remission may also suggest novel treatment strategies for Tourette syndrome, or may lead to secondary prevention of tic disorders.

This review summarizes the limited existing data on the epidemiology, phenomenology, and outcome of PTD, highlights areas in which prospective study is sorely needed, and proposes that tic disorders may completely remit much less often than is generally believed.

[Tourette syndrome and other tic disorders in DSM-5 – a comment]

The classification of tic disorders has been revised in the new fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The previously expressed suggestion to categorize tic disorders within the "Anxiety and Obsessive Compulsive Disorders" was not implemented. The section "Disorders Usually First Diagnosed in Infancy, Childhood, or Adolescence" was revised and renamed as "Neurodevelopmental Disorders." Tic disorders are classified there as movement disorders. Most of the changes are distinct improvements from both a clinical and a scientific perspective. For example, by removing the adjective "stereotype," the definition of tics is more precise and unified. Also, the new time-oriented criteria are more practical in the clinical setting, e.g., the exclusion criterion of a tic-free interval more than 3 months given for chronic tic disorders has been deleted. The renamings from "Transient" to "Provisional Tic Disorder" as well as from "Chronic" to "Persistent Tic Disorder" are welcome changes from a clinical perspective. Overall, the revision of the criteria is an important step towards providing more clarity and feasibility. However, the revised classification of tic disorders is still based only on clinical experience and not on evidence. Future studies should show whether the revised and improved criteria truly provide the optimal classification.

Practice parameter for the assessment and treatment of children and adolescents with tic disorders

Tic disorders, including Tourette's disorder, present with a wide range of symptom severity and associated comorbidity. This Practice Parameter reviews the evidence from research and clinical experience in the evaluation and treatment of pediatric tic disorders. Recommendations are provided for a comprehensive evaluation to include common comorbid disorders and for a hierarchical approach to multimodal interventions.

Children and adolescents with Tourette's disorder in the USA versus Argentina: behavioral differences may reflect cultural factors

To explore behavioral differences as possible cultural factors in presentation of psychiatric comorbidity in two clinically referred, consecutively ascertained samples of youth with Tourette's disorder (TD) from New York and Buenos Aires. Subjects were evaluated between 2002 and 2010 at the Tics and Tourette's Clinical and Research Program at the New York University Child Study Center in New York and the Interdisciplinary Center for Tourette's, Obsessive Compulsive Disorder (OCD) and Associated Disorders (CITTTA)/Institute of Cognitive Psychology (INECO) in Buenos Aires. Demographic, diagnostic, tic severity (Yale Global Tic Severity Scale; YGTSS), clinical (Child Behavior Check List-Parent version; CBCL), and global functioning (Global Assessment of Functioning; GAF) data were compared using descriptive statistics. The sample included 111 subjects ages 6-17 years, who met DSM-IV-TR diagnostic criteria for TD. Findings revealed that the BA sample (n = 35) was significantly older at initial evaluation at the tic specialty clinic, and had higher frequency of oppositional defiant disorder (ODD), mood and non-OCD anxiety disorders than the NY sample (n = 76). There were no differences in gender distribution, age at tic onset or TD diagnosis, tic severity, proportion with current diagnoses of OCD/OC behavior or attention deficit hyperactivity disorder (ADHD), CBCL internalizing, externalizing, or total problems scores, YGTSS scores, or GAF scores. The observed similarities in demographic features, clinical presentation, rates of ADHD and OCD/OCB, and global impairment may reflect similar phenomenology and illness-related characteristics of TD in these referred youth. Differences in age at initial specialty clinic evaluation and rates of ODD, mood and non-OCD anxiety disorders may need further exploration before they may be considered to reflect cultural factors. Because of these limitations (e.g. small sample size), these results can be regarded only as preliminary.

A phenomenological investigation of women with Tourette or other chronic tic disorders

There are little data concerning clinical characteristics of women with Tourette disorder and chronic tic disorders in the extant literature and what is available mostly focuses on treatment-seeking individuals. The present research was conducted to provide a phenomenological characterization of tic disorders among 185 adult women with tic disorders. In addition to providing a descriptive overview of specific tic symptoms, tic severity, self-reported history of other psychiatric conditions, and impairment/lifestyle impact due to tics, this study compares 185 women and 275 men between 18 and 79 years old with tic disorders (who completed an identical battery of measures) based on demographic, social/economic status indicators, psychiatric variables (comorbidity, family psychiatric history, symptom presentation), adaptive functioning/quality of life, and impairment variables among a nonclinical adult sample. Finally, this research examines the relationship between tic severity and impairment indicators among women with tics. Sixty-eight percent of women in our sample reported severe motor tics and 40% reported severe phonic tics. Our exploratory data suggest that a sizeable number of adult women with persistent tics are suffering from psychiatric comorbidity and psychosocial consequences such as underachievement and social distress. Tic severity in women may be associated with lifestyle interference as well as with symptoms of depression and anxiety, and such symptoms may be more common among women with tics than in men with tics.

Surgery for Tourette syndrome

Tourette syndrome is a chronic neuropsychiatric disorder characterized by motor and vocal tics. In the majority of cases, tics are associated by behavioral disorders such as obsessive-compulsive behavior. First symptoms typically appear in early childhood. Mostly symptoms disappear when adulthood is reached. Treatment options consist of behavioral therapy and medication. In refractory cases, surgery may be an option. In the past, several attempts have been made to treat therapy-refractory patients through neurosurgical ablative procedures. In 1999, deep brain stimulation was introduced as a novel treatment option for patients with intractable Tourette syndrome. Up until now, five brain areas have been used or suggested as potential target areas for deep brain stimulation in Tourette syndrome. In the majority of the published cases, there is a clear effect on tics but most studies consist of only a limited number of patients. A strict patient selection is absolutely mandatory. There is a need for double-blinded multicenter trials with inclusion of more patients.

A double-blind, placebo-controlled trial of ω-3 fatty acids in Tourette's disorder

OBJECTIVE

Clinical observations have suggested therapeutic effects for ω-3 fatty acids (O3FA) in Tourette's disorder (TD), but no randomized, controlled trials have been reported. In a placebo-controlled trial, we examined the efficacy of O3FA in children and adolescents with TD.

METHODS

Thirty-three children and adolescents (ages 6-18) with TD were randomly assigned, double-blind, to O3FA or placebo for 20 weeks. O3FA consisted of combined eicosapentaenoic acid and docosahexaenoic acid. Placebo was olive oil. Groups were compared by using (1) intent-to-treat design, with the last-observation-carried-forward controlling for baseline measures and attention-deficit/hyperactivity disorder via (a) logistic regression, comparing percentage of responders on the primary Yale Global Tic Severity Scale (YGTSS)-Tic and secondary (YGTSS-Global and YGTSS-Impairment) outcome measures and (b) analysis of covariance; and (2) longitudinal mixed-effects models.

RESULTS

At end point, subjects treated with O3FA did not have significantly higher response rates or lower mean scores on the YGTSS-Tic (53% vs 38%; 15.6 ± 1.6 vs 17.1 ± 1.6, P > .1). However, significantly more subjects on O3FA were considered responders on the YGTSS-Global measure (53% vs 31%, P = .05) and YGTSS-Impairment measure (59% vs 25%, P < .05), and mean YGTSS-Global scores were significantly lower in the O3FA-treated group than in the placebo group (31.7 ± 2.9 vs 40.9 ± 3.0, P = .04). Obsessive-compulsive, anxiety, and depressive symptoms were not significantly affected by O3FA. Longitudinal analysis did not yield group differences on any of the measures.

CONCLUSIONS

O3FA did not reduce tic scores, but it may be beneficial in reduction of tic-related impairment for some children and adolescents with TD. Limitations include the small sample and the possible therapeutic effects of olive oil.

Youths with ADHD with and without tic disorders: comorbid psychopathology, executive function and social adjustment

Attention deficit/hyperactivity disorder (ADHD) and tic disorders (TD) commonly co-occur. Clarifying the psychiatric comorbidities, executive functions and social adjustment difficulties in children and adolescents of ADHD with and without TD is informative to understand the developmental psychopathology and to identify their specific clinical needs. This matched case-control study compared three groups (n=40 each) of youths aged between 8 and 16 years: ADHD with co-occurring TD (ADHD+TD), ADHD without TD (ADHD-TD) and typically developing community controls. Both ADHD groups had more co-occurring oppositional defiant disorder than the control group, and the presence of TD was associated with more anxiety disorders. TD did not impose additional executive function impairments or social adjustment difficulties on ADHD. Interestingly, for youths with ADHD, the presence of TD was associated with less interpersonal difficulties at school, compared to those without TD. The potential various directions of effects from co-occurring TD should be carefully evaluated and investigated for youths with ADHD.

European clinical guidelines for Tourette syndrome and other tic disorders. Part II: pharmacological treatment

To develop a European guideline on pharmacologic treatment of Tourette syndrome (TS) the available literature was thoroughly screened and extensively discussed by a working group of the European Society for the Study of Tourette syndrome (ESSTS). Although there are many more studies on pharmacotherapy of TS than on behavioral treatment options, only a limited number of studies meets rigorous quality criteria. Therefore, we have devised a two-stage approach. First, we present the highest level of evidence by reporting the findings of existing Cochrane reviews in this field. Subsequently, we provide the first comprehensive overview of all reports on pharmacological treatment options for TS through a MEDLINE, PubMed, and EMBASE search for all studies that document the effect of pharmacological treatment of TS and other tic disorders between 1970 and November 2010. We present a summary of the current consensus on pharmacological treatment options for TS in Europe to guide the clinician in daily practice. This summary is, however, rather a status quo of a clinically helpful but merely low evidence guideline, mainly driven by expert experience and opinion, since rigorous experimental studies are scarce.

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

A working group of the European Society for the Study of Tourette Syndrome (ESSTS) has developed the first European assessment guidelines of Tourette Syndrome (TS). The available literature including national guidelines was thoroughly screened and extensively discussed in the expert group of ESSTS members. Detailed clinical assessment guidelines of tic disorders and their comorbidities in both children and adults are presented. Screening methods that might be helpful and necessary for specialists' differential diagnosis process are suggested in order to further analyse cognitive abilities, emotional functions and motor skills. Besides clinical interviews and physical examination, additional specific tools (questionnaires, checklists and neuropsychological tests) are recommended.

Application of Habit Reversal Training for the Treatment of Tics in Early Childhood

Habit-reversal training (HRT) has demonstrated efficacy in adults and in children above 9 years of age with tic disorders. However, less is known about the utility of this treatment with children younger than 9 years of age.This is alarming given that most children with tic disorders experience symptom onset before 9 years and that existing pharmacological treatments show modest efficacy, may have side effects, and may not be an acceptable intervention to parents. With this in mind, this case report documents the use of HRT with a 6-year-old female with pronounced and impairing motor tics. Throughout the course of the treatment (eight sessions) “Megan” showed improvement in her ability to control her symptoms. Furthermore, treatment gains and improved quality of life were maintained at follow-up. This case report suggests the utility of HRT for the treatment of tics in early childhood, with developmental considerations and the integration of family-based skills training.

Clinical Characteristics of Children and Adolescents with a Primary Tic Disorder

The clinical characteristics and rates of co-occurring psychiatric conditions in youth seeking treatment for a chronic tic disorder (CTD) were examined. Children and adolescents (N = 126) with a primary CTD diagnosis were recruited for a randomized controlled treatment trial. An expert clinician established diagnostic status via semi-structured interview. Participants were male (78.6%), Caucasians (84.9%), mean age 11.7 years (SD = 2.3) with moderate-to-severe tics who met criteria for Tourette's disorder (93.7%). Common co-occurring conditions included attention-deficit/hyperactivity disorder (ADHD; 26%), social phobia (21%), generalized anxiety disorder (20%), and obsessive-compulsive disorder (OCD; 19%). Motor and vocal tics with greater intensity, complexity, and interference were associated with increased impairment. Youth with a CTD seeking treatment for tics should be evaluated for non-OCD anxiety disorders in addition to ADHD and OCD. Despite the presence of co-occurring conditions, children with more forceful, complex, and/or directly interfering tics may seek treatment to reduce tic severity.

Tourette's disorder and other tic disorders in DSM-5: a comment

Classification of tic disorders will be revised in the forthcoming edition of the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5). We do not support the suggestion to move tic disorders to "Anxiety and Obsessive-Compulsive Disorders", if the section "Disorders Usually First Diagnosed in Infancy, Childhood, or Adolescence" is not retained. Other than that, most proposed changes of the criteria for tic disorders contain a number of welcome improvements, e.g., the more unified definition of tics including the removal of the term "stereotyped" and the better capture of the temporal pattern of tics (e.g., removal of the maximum 3 months criterion for a tic-free period in chronic tic disorders). But, unfortunately there are some inconsistencies in detail, e.g., the unification of diagnostic criteria for tic disorders had not been consistently pursued in transient tic disorder. In sum, the proposed DSM-5 criteria could be seen as an important step forward particularly in clinical routine. However, continued research is needed to justify the existing and proposed classification of tic disorders as well as to better clarify what other changes should be made in the DSM-5 and beyond.

Quality of Life in Youth With Tourette's Syndrome and Chronic Tic Disorder

This study sought to examine quality of life (QoL) in clinic-referred children and adolescents (n = 59, M age = 11.4+/-2.6 years) with a chronic tic disorder. The QoL scores for tic patients were lower than for healthy controls but higher than for the psychiatric sample on the majority of domains. Children's self-reported QoL scores and a measure of tic severity were moderately and inversely correlated. Parent reports of their child's QoL were weakly related to tic severity. Correlations between parent and child ratings of QoL for children ages 8 to 11 years were generally higher than those for youth ages 12 to 17 years. Finally, externalizing behavior moderated the relations between tic severity and parent-rated QoL, such that tic severity was significantly associated with parent-rated QoL for children with below average externalizing symptoms but not for children 3with above average externalizing symptoms.

Neurobiological substrates of Tourette's disorder

OBJECTIVE

This article reviews the available scientific literature concerning the neurobiological substrates of Tourette's disorder (TD).

METHODS

The electronic databases of PubMed, ScienceDirect, and PsycINFO were searched for relevant studies using relevant search terms.

RESULTS

Neuropathological as well as structural and functional neuroimaging studies of TD implicate not only the sensorimotor corticostriatal circuit, but also the limbic and associative circuits as well. Preliminary evidence also points to abnormalities in the frontoparietal network that is thought to maintain adaptive online control. Evidence supporting abnormalities in dopaminergic and noradrenergic neurotransmission remains strong, although the precise mechanisms remain the subject of speculation.

CONCLUSION

Structural and functional abnormalities in multiple parallel corticostriatal circuits may underlie the behavioral manifestations of TD and related neuropsychiatric disorders over the course of development. Further longitudinal research is needed to elucidate these neurobiological substrates.

Tic disorders: administrative prevalence and co-occurrence with attention-deficit/hyperactivity disorder in a German community sample

Coexistence of tics and attention-deficit/hyperactivity disorder (ADHD) has important clinical and scientific implications. Existing data on the co-occurrence of tic disorders, Tourette Syndrome (TS), and ADHD are largely derived from small-scale studies in selected samples and therefore heterogeneous. The Nordbaden project captures the complete outpatient claims data of more than 2.2 million persons, representing 82% of the regional population in 2003. Based upon the number of diagnosed cases of tic disorders, TS, and ADHD, we determined 12-months administrative prevalence rates as well as rates of co-occurrence. Both tic disorders and ADHD were diagnosed most often in the age group 7-12 years (any tic disorder: 0.8%; ADHD: 5.0%). With increasing age, the administrative prevalence difference in favor of males disappeared, with tic disorders being somewhat more frequently reported in females than males in the age groups above 30 years. The highest rate of ADHD co-occurring with tic disorders was found in adolescents (age 13-18 years, 15.1%). Tic disorders were observed in 2.3% of patients with ADHD. Administrative prevalence rates of tic disorders and TS were substantially lower compared to rates found in community-based epidemiological studies, suggesting that a large number of cases remain undetected and untreated under present conditions of routine outpatient care.

Oral delta 9-tetrahydrocannabinol improved refractory Gilles de la Tourette syndrome in an adolescent by increasing intracortical inhibition: a case report

OBJECTIVE

To describe the clinical course of the Delta 9-tetrahydrocannabinol (Delta 9-THC) treatment of a boy with Gilles de la Tourette Syndrome (TS) and comorbid attention-deficit/hyperactivity disorder (ADHD) in relation to Delta 9-THC plasma levels and intracortical inhibition measured by transcranial magnetic stimulation.

METHODS

The clinical course and pharmacological and neurophysiological measures are reported in a 15-year-old boy with treatment refractory TS plus ADHD leading to severe physical and psychosocial impairment.

RESULTS

Administration of Delta 9-THC improved tics considerably without adverse effects, allowing parallel stimulant treatment of comorbid ADHD. Along with the Delta 9-THC treatment, intracortical inhibition was increased, reflected in the enhanced short-interval intracortical inhibition and the prolongation of the cortical silent period.

CONCLUSIONS

Our observation suggests that Delta 9-THC might be a successful alternative in patients with severe TS refractory to classic treatment. Particularly in the case of stimulant-induced exacerbation of tics, Delta 9-THC might enable successful treatment of comorbid ADHD. The enhancement of intracortical inhibition might be mediated by modulating release of several neurotransmitters including dopamine and gamma-aminobutyric acid. Further studies are needed to substantiate our findings.

Adults with Tourette's syndrome with and without attention deficit hyperactivity disorder

OBJECTIVE

Comorbidity between Tourette's syndrome (TS) and attention deficit hyperactivity disorder (ADHD) is high. In children, those with both TS+ADHD fare less well than those with TS-only on measures of both psychopathology and behaviour. The objective of this study was to document such measures in adult patients.

METHOD

Eighty adults with TS-only were compared to 64 with TS+ADHD using a clinical interview and standardised measures of depression, anxiety and obsessionality.

RESULTS

The two groups were no different on measures of TS severity. TS+ADHD patients had significantly more depression, anxiety, obsessive-compulsive behaviour and maladaptive behaviours than patients with TS-only. There were also significant differences in the incidence of copro- and echo-phenomena and family history of ADHD.

CONCLUSION

The finding of increased overall behavioural difficulties and psychopathology in adult patients with TS+ADHD when compared with TS-only is in agreement with previous findings in children with TS. Appropriate treatment of ADHD in TS patients during childhood may prevent many behavioural problems in adulthood.

Coprophenomena in Tourette syndrome

The aims of this descriptive study were to examine the prevalence and associations of coprophenomena (involuntary expression of socially unacceptable words or gestures) in individuals with Tourette syndrome. Participant data were obtained from the Tourette Syndrome International Database Consortium. A specialized data collection form was completed for each of a subset of 597 consecutive new patients with Tourette syndrome from 15 sites in seven countries. Coprolalia occurred at some point in the lifetime of 19.3% of males and 14.6% of females, and copropraxia in 5.9% of males and 4.9% of females. Coprolalia was three times as frequent as copropraxia, with a mean onset of each at about 11 years, 5 years after the onset of tics. In 11% of those with coprolalia and 12% of those with copropraxia these coprophenomena were one of the initial symptoms of Tourette syndrome. The onsets of tics, coprophenomena, smelling of non-food objects, and spitting were strongly intercorrelated. Early onset of coprophenomena was not associated with its longer persistence. The most robust associations of coprophenomena were with the number of non-tic repetitive behaviors, spitting, and inappropriate sexual behavior. Although coprophenomena are a frequently feared possibility in the course of Tourette syndrome, their emergence occurs in only about one in five referred patients. Because the course and actual impact of coprophenomena are variable, additional prospective research is needed to provide better counseling and prognostic information.

The prevalence and epidemiology of Gilles de la Tourette syndrome. Part 2: tentative explanations for differing prevalence figures in GTS, including the possible effects of psychopathology, aetiology, cultural differences, and differing phenotypes

As has been demonstrated, Gilles de la Tourette Syndrome (GTS) occurs in at least 1% of the population worldwide. However, earlier studies suggested a lower prevalence. In addition, the prevalence figures for different studies very between 0.4% and 3.8%. Moreover, the prevalence appears to vary in some parts of the world and races, with a lower rate in Afro-Americans and sub-Saharan black Africans. In this the second part of the review, possible reasons for the differences in prevalence and epidemiology are discussed. Tentative explanations for differing prevalence figures in GTS include problems with the diagnosis of GTS, the multidimensional nature of tics, as well as other tic factors including the waxing and waning of symptoms and the suppressibility of symptoms. Other factors inherent to GTS include the fact that there is no diagnostic test and indeed no definitive diagnosis other than clinical, the fact that psychosocial stresses can lead to increased tic severity, and that comorbid disorders may mask tics. The varying methods of study employed can also effect prevalence. There may be some regional differences in GTS as well, which may be due to a lack of awareness of GTS, or it may be a true reflection of low prevalence as in some populations GTS does appear rare. With regard to the sub-Saharan Africa data and possibly the African American data, matters are much more complex than meets the eye. The following reasons are all possible for the apparent rarity in these populations and include (i) other medical priorities and less propensity to seek health care, (ii) lack of awareness of GTS, (iii) chance, (iv) ethnic and epigenetic differences and reasons, (v) genetic and allelic differences in different races, and (vi) an admixture of races. The aetiology of GTS is also complex, with influences from complex genetic mechanisms, pre- and perinatal difficulties and, in a subgroup, some infections, possibly by epigenetic mechanisms. These may well affect phenotype and, thus, prevalence. There have even been suggestions that people with GTS are increasing. Recent data suggests that GTS is not a unitary condition and that there may well be different types of GTS. The prevalence of GTS in these individual subtypes is unknown. It is suggested that a new nomenclature be adopted for GTS in future, pending further genetic and phenomenological studies. To what extent the aetiology affects the phenotype and, thus, the prevalence is still unclear.

The prevalence and epidemiology of Gilles de la Tourette syndrome. Part 1: the epidemiological and prevalence studies

The prevalence and epidemiology of Gilles de la Tourette syndrome (GTS) are more complex than was once thought. Until fairly recently, GTS was thought to be a rare and, according to some, a psychogenically mediated disorder. Prevalence depends, at least in part, on the definition of GTS, the type of ascertainment, and epidemiological methods used. However, in dedicated specialist GTS clinics, the majority of patients were noted to have positive family histories of tics or GTS, and large, extended, multiply-affected GTS pedigrees indicated that many family members had undiagnosed tics or GTS: it was therefore realized that GTS was far from uncommon. Seven early epidemiological studies reported that GTS was uncommon or rare for a variety of reasons. More recently, however, two pilot studies and 12 large definitive studies in mainstream school and school-age youngsters in the community, using similar multistage methods, have documented remarkably consistent findings, demonstrating prevalence figures for GTS of between 0.4% and 3.8% for youngsters between the ages of 5 and 18 years. Of the 420,312 young people studied internationally, 3,989 (0.949%) were diagnosed as having GTS. It is therefore suggested that a figure of 1% would be appropriate for the overall international GTS prevalence figure. There were however, "outliers" to the figure. For instance, GTS does seem to be substantially rarer in African-American people and has been reported only very rarely in sub-Saharan black African people. GTS is found in all other cultures, although to possibly differing degrees. In all cultures where GTS has been reported, the phenomenology is similar, highlighting the biological underpinnings of the disorder.

Case series: Sensory intolerance as a primary symptom of pediatric OCD

INTRODUCTION

Marked intolerance or intrusive re-experiencing of ordinary sensory stimuli that in turn drive functionally impairing compulsive behaviors are occasionally seen in young children with OCD.

METHODS

We describe a number of children with DSM-IV OCD ascertained from a family genetic study of pediatric OCD, whose intolerance of ordinary sensory stimuli created significant subjective distress and time-consuming ritualistic behavior that was clinically impairing.

RESULTS

In each case, these sensory symptoms were the primary presenting symptoms and were experienced in the absence of intrusive thoughts, images, or ideas associated with "conventional" OCD symptoms.

CONCLUSIONS

These symptoms suggest abnormalities in sensory processing and integration in at least a subset of OCD patients. Recognition of these sensory symptoms and sensory-driven behaviors as part of the broad phenotypic variation in children with OCD could help clinicians more easily identify OCD patients and facilitate treatment.

Tourette syndrome and tic disorders: a decade of progress

OBJECTIVE

This is a review of progress made in the understanding of Tourette syndrome (TS) during the past decade including models of pathogenesis, state-of-the-art assessment techniques, and treatment.

METHOD

Computerized literature searches were conducted under the key words "Tourette syndrome," "Tourette disorder," and "tics." Only references from 1996-2006 were included.

RESULTS

Studies have documented the natural history of TS and the finding that tics usually improve by the end of the second decade of life. It has also become clear that TS frequently co-occurs with attention-deficit/hyperactivity disorder), obsessive-compulsive disorder, and a range of other mood and anxiety disorders. These comorbid conditions are often the major source of impairment for the affected child. Advances have also been made in understanding the underlying neurobiology of TS using in vivo neuroimaging and neurophysiology techniques. Progress on the genetic front has been less rapid. Proper diagnosis and education (involving the affected child and his or her parents, teachers, and peers) are essential prerequisites to the successful management of children with TS. When necessary, modestly effective antitic medications are available, although intervening to treat the comorbid attention-deficit/hyperactivity disorder and/or obsessive-compulsive disorder is usually the place to start.

CONCLUSIONS

Prospective longitudinal studies and randomized clinical trials have led to the refinement of several models of pathogenesis and advanced our evidence base regarding treatment options. However, fully explanatory models are needed that would allow for more accurate prognosis and the development of targeted and efficacious treatments.

Tic disorders and ADHD: answers from a world-wide clinical dataset on Tourette syndrome

BACKGROUND

Tourette syndrome (TS) is a neurodevelopmental disorder with frequent comorbidity with Attention- deficit-Hyperactivity disorder (ADHD). The impact of this association is still a matter of debate.

METHOD

Using the TIC database containing 6,805 cases, the clinical differences were ascertained between subjects with and without ADHD.

RESULTS

The reported prevalence of ADHD in TS was 55%, within the range of many other reports. If the proband was diagnosed with ADHD, a family history of ADHD was much more likely. ADHD was associated with earlier diagnosis of TS and a much higher rate of anger control problems, sleep problems, specific learning disability, OCD, Oppositional-defiant disorder, mood disorder, social skill deficits, sexually inappropriate behaviour, and self-injurious behaviour. Subjects with seizures and with Developmental Coordination Disorder also had high rates of ADHD. Anxiety disorder, however, was not more frequent. Preliminary data suggest that most behavioural difficulties in ADHD are associated with the Combined or Hyperactive-Impulsive Subtypes of ADHD. Every large site (>200 cases) had a significantly increased rate of anger control problems in cases with ADHD.

CONCLUSION

Subjects with TS have high rates of ADHD and complex associations with other disorders. Clinically the findings confirm other research indicating the importance of ADHD in understanding the behavioural problems often associated with the diagnosis of TS. Additional ADHD comorbidity should be taken into account in diagnosis, management, and training.

Psychosocial stress predicts future symptom severities in children and adolescents with Tourette syndrome and/or obsessive-compulsive disorder

BACKGROUND

The goals of this prospective longitudinal study were to monitor levels of psychosocial stress in children and adolescents with Tourette syndrome (TS) and/or obsessive-compulsive disorder (OCD) compared to healthy control subjects and to examine the relationship between measures of psychosocial stress and fluctuations in tic, obsessive-compulsive (OC), and depressive symptom severity.

METHODS

Consecutive ratings of tic, OC and depressive symptom severity were obtained for 45 cases and 41 matched healthy control subjects over a two-year period. Measures of psychosocial stress included youth self-report, parental report, and clinician ratings of long-term contextual threat. Structural equation modeling for unbalanced repeated measures was used to assess the temporal sequence of psychosocial stress with the severity of tic, OC and depressive symptoms.

RESULTS

Subjects with TS and OCD experienced significantly more psychosocial stress than did the controls. Estimates of psychosocial stress were predictive of future depressive symptoms. Current levels of psychosocial stress were also a significant predictor of future OC symptom severity, but not vice versa. Current OC symptom severity was a predictor of future depressive symptom severity, but not vice versa. Current levels of psychosocial stress and depression were independent predictors of future tic severity, even after controlling for the effect of advancing chronological age.

CONCLUSIONS

The impact of antecedent psychosocial adversity is greater on future depressive symptoms than for tic and/or OC symptoms. Worsening OC symptoms are also a predictor of future depressive symptoms. Advancing chronological age is robustly associated with reductions in tic severity.

Tics en niños y adolescentes: análisis retrospectivo de 78 casos

INTRODUCTION

Tics are the most frequent abnormal movement in children. A familial history of tics and a personal and familial history of neurobehavioral disturbances are common in children with this abnormality. Tics may seriously compromise daily activities in affected individuals.

OBJECTIVE

To identify the characteristics of tics in children and adolescents followed-up in the Neuropediatric Unit of the Hospital Geral de Santo António.

MATERIALS AND METHODS

We performed a retrospective analysis of patients with tics based on information collected from medical records. The diagnostic criteria of the DSM IV-TR 2000 of the American Psychiatric Association were used.

RESULTS

The medical records of 78 children were analyzed, 84.6 % of whom were boys. More than one third of the patients were aged 4 to 8 years old. In 5.1 % of the patients tics developed before the age of 2 years. A familial history of tics, depression and obsessive disorder traits was found in approximately 30 % of patients. The most frequent comorbidity was attention deficit hyperactivity disorder (67.9 %). The occurrence of pediatric autoimmune neuropsychiatric disorders associated with streptococcus infection (PANDAS) was suggested in five patients. In all patients, motor tics occurred before vocal tics. In more than two thirds of the patients, tics were simple. In 59.0 % of the patients, tics were chronic, and in 45.7 % of these met the criteria for Tourette's syndrome. A total of 43.1 % of the patients with chronic tics received pharmacotherapy, risperidone being the most frequently used drug.

CONCLUSIONS

In general the results of the present study are in agreement with those of previous studies, underlining the need to consider a diagnosis of tics in young children and highlighting the importance of identification and appropriate treatment of comorbidities.

Mood disorders and Gilles de la Tourette's syndrome: An update on prevalence, etiology, comorbidity, clinical associations, and implications

Gilles de la Tourette's syndrome (GTS) consists of multiple motor tics and one or more phonic tics. Psychopathology occurs in approximately 90% of GTS patients, with attention-deficit/hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD) being common. Depression is common, with a lifetime risk of 10% and a prevalence of between 1.8% and 8.9%. Depression and depressive symptoms are found to occur in 13% and 76% of GTS patients attending specialist clinics, respectively. In controlled studies embracing over 700 GTS patients, the patients were significantly more depressed than controls in all but one instance. In community and epidemiological studies, depression in GTS individuals was evident in two of five investigations. Clinical correlates of depression in people with GTS appear to be: tic severity and duration, the presence of echophenomena and coprophenomena, premonitory sensations, sleep disturbances, obsessive-compulsive behaviors/OCD, self-injurious behaviors, aggression, conduct disorder (CD) in childhood, and, possibly, ADHD. Depression in people with GTS has been shown to result in a lower quality of life, potentially leading to hospitalization and suicide. The etiology of depression appears to be multifactorial. Bipolar affective disorder (BAD) and GTS may be related in some individuals. However, it is noted that sample sizes in most of these studies were small, and it is unclear at the present time as to why BAD may be overrepresented among GTS patients.

Tourette syndrome: the self under siege

Tourette syndrome is a neurodevelopmental disorder characterized by motor and vocal tics--rapid, repetitive, stereotyped movements or vocalizations. Tourette syndrome typically has a prepubertal onset, and boys are more commonly affected than girls. Symptoms usually begin with transient bouts of simple motor tics. By age 10 years, most children are aware of nearly irresistible somatosensory urges that precede the tics. These urges likely reflect a defect in sensorimotor gating because they intrude into the child's conscious awareness and become a source of distraction and distress. A momentary sense of relief typically follows the completion of a tic. Over the course of hours, tics occur in bouts, with a regular intertic interval. Tics increase during periods of emotional excitement and fatigue. Tics can become "complex" in nature and appear to be purposeful. Tics can be willfully suppressed for brief intervals and can be evoked by the mere mention of them. Tics typically diminish during periods of goal-directed behavior, especially those that involve both heightened attention and fine motor or vocal control, as occur in musical and athletic performances. Over the course of months, tics wax and wane. New tics appear, often in response to new sources of somatosensory irritation, such as the appearance of a persistent vocal tic (a cough) following a cold. Over the course of years, tic severity typically peaks between 8 and 12 years of age. By the end of the second decade of life, many individuals are virtually tic free. Less than 20% of cases continue to experience clinically impairing tics as adults. Tics rarely occur in isolation, and other coexisting conditions--such as behavioral disinhibition, hypersensitivity to a broad range of sensory stimuli, problems with visual motor integration, procedural learning difficulties, attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder, depression, anxiety, and emotional instability--are often a greater source of impairment than the tics themselves. Emerging behavioral treatments of Tourette syndrome are based in part on an understanding of the moment-to-moment experience of somatosensory urges and motor response. With identification of specific genes of major effect and advances in our understanding of the neural circuitry of sensorimotor gating, habit formation, and procedural memory--together with insights from postmortem brain studies, in vivo brain imaging, and electrophysiologic recordings--we might be on the threshold of a deeper understanding of the phenomenology and natural history of Tourette syndrome.