ANALYZING THE INFLUENCE OF TIC‐RELATED TALK ON VOCAL AND MOTOR TICS IN CHILDREN WITH TOURETTE'S SYNDROME

This study examined the effect of tic‐related talk on the vocal and motor tics of 2 boys with Tourette's syndrome. Using ABAB withdrawal designs, the boys were alternately exposed to conditions with and without talk of their tics. For both boys, vocal tics markedly increased when talk pertained to tics and decreased when talk did not pertain to tics, but motor tic covariance was less consistent.     

Comparing the effects of differential reinforcement of other behavior and response-cost contingencies on tics in youth with tourette syndrome

Tics are rapid, repetitive, stereotyped movements or vocalizations that arise from neurobiological dysfunction and are influenced by environmental factors. Although persons with tic disorders often experience aversive social reactions in response to tics, little is known about the behavioral effects of such consequences. Along several dimensions, the present study compared the effects of two treatments on tics: response cost (RC) and differential reinforcement of other behavior (DRO). Four children with Tourette syndrome were exposed to free-to-tic baseline, DRO, RC, and quasibaseline rebound evaluation conditions using an alternating treatments design. Both DRO and RC produced substantial decreases in tics from baseline levels. No differential effects of DRO and RC contingencies were seen on self-reported stress or in the strength of the reflexive motivating operation (i.e., premonitory urge) believed to trigger tics, and neither condition produced tic-rebound effects. Implications of these findings and directions for future research are discussed.     

The development of stimulus control over tics: A potential explanation for contextually-based variability in the symptoms of Tourette syndrome

Research has demonstrated that providing reinforcement for tic-free intervals can decrease tic frequency in controlled analogue settings. The aim of the current study was to determine whether reinforcement could be used to create stimulus control over tic expression. Ten children with chronic tic disorders (including Tourette syndrome) completed four discrimination training sessions. Each session consisted of three exposures to each of three, 5 min conditions presented in a random order. In one condition, participants were reinforced for tic absence on a 10-s fixed interval schedule in the presence of a purple light. In a second condition, participants were instructed to suppress their tics, but were not reinforced for doing so in the presence of an orange light. In a third condition, participants were instructed not to suppress their tics in the presence of two non-illuminated lights. Confirming findings from other studies, results showed that reinforcing tic suppression reduced tic frequency to a greater extent than only providing instructions to suppress. To test for stimulus control, a fifth session was conducted following the aforementioned discrimination training sessions. The fifth session consisted of three exposures to each of three 5 min conditions presented in a random order. In one condition, a purple light was illuminated. In a second condition, an orange light was illuminated. In a third condition, neither light was illuminated. Across all three conditions, instructions to suppress (or not suppress) tics were not provided, and reinforcers for successful suppression were not delivered. Results indicated that in the presence of the purple light, tics were significantly lower than when neither light was illuminated. These findings provide preliminary support for the idea that a history of differential reinforcement in various contexts may play a role explaining variability in tic symptom expression.     

Examining the neural antecedents of tics in Tourette syndrome using electroencephalography

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by the occurrence of motor and vocal tics. TS is associated with cortical–striatal–thalamic–cortical circuit dysfunction and hyper-excitability of cortical limbic and motor regions that lead to the occurrence of tics. Importantly, individuals with TS often report that their tics are preceded by premonitory sensory/urge phenomena (PU) that are described as uncomfortable bodily sensations that precede the execution of a tic and are experienced as an urge for motor discharge. While tics are most often referred to as involuntary movements, it has been argued by some that tics should be viewed as voluntary movements that are executed in response to the presence of PU. To investigate this issue further, we conducted a study using electroencephalography (EEG). We recorded movement-related EEG (mu- and beta-band oscillations) during (1) the immediate period leading up to the execution of voluntary movements by a group of individuals with TS and a group of matched healthy control participants, and (2) the immediate period leading up to the execution of a tic in a group of individuals with TS. We demonstrate that movement-related mu and beta oscillations are not reliably observed prior to tics in individuals with TS. We interpret this effect as reflecting the greater involvement of a network of brain areas, including the insular and cingulate cortices, the basal ganglia and the cerebellum, in the generation of tics in TS. We also show that beta-band desynchronization does occur when individuals with TS initiate voluntary movements, but, in contrast to healthy controls, desynchronization of mu-band oscillations is not observed during the execution of voluntary movements for individuals with TS. We interpret this finding as reflecting a dysfunction of physiological inhibition in TS, thereby contributing to an impaired ability to suppress neuronal populations that may compete with movement preparation processes.     

Behavior Therapy for Tics via Videoconference Delivery: An Initial Pilot Test in Children

Habit reversal training (HRT) has been proven effective for reducing tics in children with Tourette's syndrome (TS). However, the availability of the intervention is limited. Videoconference technology represents a promising mode through which HRT may be disseminated to underserved areas. Using a multiple-baseline across participants design, the current study tested the effectiveness of videoconference-delivered HRT for 3 children with TS. Similar to results from randomized controlled trials studying face-to-face delivered HRT, videoconference-delivered HRT was effective for reducing tics. All three children demonstrated significant tic reduction following videoconference HRT delivery. All participants and their families rated the delivery modality as acceptable and the therapeutic relationship as strong. These results suggest that videoconference delivery may be a promising method for disseminating behavior therapy for tics.     

The role of the cingulate cortex in the generation of motor tics and the experience of the premonitory urge-to-tic in Tourette syndrome

Tourette syndrome (TS) is a neurological disorder of childhood onset that is characterized by the occurrence of motor and vocal tics. TS is associated with cortical-striatal-thalamic-cortical circuit [CSTC] dysfunction and hyper-excitability of cortical limbic and motor regions that are thought to lead to the occurrence of tics. Individuals with TS often report that their tics are preceded by ‘premonitory sensory/urge phenomena’ (PU) that are described as uncomfortable bodily sensations that precede the execution of a tic and are experienced as a strong urge for motor discharge. While the precise role played by PU in the occurrence of tics is largely unknown, they are nonetheless of considerable theoretical and clinical importance as they form a core component of many behavioural therapies used in the treatment of tic disorders. Recent evidence indicates that the cingulate cortex may play an important role in the generation of PU in TS, and in ‘urges-for-action’ more generally. In the current study, we utilized voxel-based morphometry (VBM) techniques, together with ‘seed-to-voxel’ structural covariance network (SCN) mapping, to investigate the putative role played by the cingulate cortex in the generation of motor tics and the experience of PU in a relatively large group of young people with TS. Whole-brain VBM analysis revealed that TS was associated with clusters of significantly reduced grey matter volumes bilaterally within: the orbito-frontal cortex; the cerebellum; and the anterior and mid-cingulate cortex. Similarly, analysis of SCNs associated with bilateral mid- and anterior cingulate ‘seed’ regions demonstrated that TS is associated with increased structural covariance primarily with the bilateral motor cerebellum; the inferior frontal cortex; and the posterior cingulate cortex.     

Premonitory urges are associated with decreased grey matter thickness within the insula and sensorimotor cortex in young people with Tourette syndrome

Tourette syndrome (TS) is a neurological disorder characterized by vocal and motor tics and is associated with cortical–striatal–thalamic–cortical circuit (CSTC) dysfunction and hyperexcitability of cortical limbic and motor regions, which are thought to lead to the occurrence of tics. Importantly, individuals with TS often report that their tics are preceded by ‘premonitory sensory phenomena’ (PSP) that are described as uncomfortable cognitive or bodily sensations that precede the execution of a tic, and are experienced as a strong urge for motor discharge. While the precise role played by PSP in the occurrence of tics is controversial, PSP are nonetheless of considerable theoretical and clinical importance in TS, not least because they form the core component in many of the behavioural therapies that are currently used in the treatment of tic disorders. In this study, we investigated the brain structure correlates of PSP. Specifically, we conducted a whole‐brain analysis of cortical (grey matter) thickness in 29 children and young adults with TS and investigated the association between grey matter thickness and PSP. We demonstrate for the first time that PSP are inversely associated with grey matter thickness measurements within the insula and sensorimotor cortex. We also demonstrate that grey matter thickness is significantly reduced in these areas in individuals with TS relative to a closely age‐ and gender‐matched group of typically developing individuals and that PSP ratings are significantly correlated with tic severity.     

Functional Analysis Identified Habit Reversal Components for the Treatment of Motor Tics

This study included brief functional analyses and treatment for motor tics exhibited by two children with Tourette Syndrome. Brief functional analyses were conducted in an outpatient treatment center and results were used to develop individualized habit reversal procedures. Treatment data were collected in clinic for one child and in clinic and school for the other child. Brief functional analysis results were mixed for each child, but provided useful information for informing unique habit reversal components for each child. Treatment results indicated reductions in motor tics for each child. Results are discussed in terms of utility of functional analysis for tics.     

Moral Responsibility and Tourette Syndrome1

Philosophers generally assume that individuals with Tourette syndrome are not responsible for their Tourettic tics, and so not blameworthy for any harm their tics might cause. Yet this assumption is based largely on ignorance of the lived experience of Tourette syndrome. Individuals with Tourette syndrome often experience their tics as freely chosen and reason‐responsive. Yet it still seems wrong to treat a Tourettic individual's tic as on a moral par with others’ actions. In this paper, I examine the options and argue that, if this is correct, then a surprising consequence follows: the standard, motivation‐based theory of desire must be false. I go on to argue that, given what is known about the neurological basis of Tourette syndrome, this is a reasonable conclusion to draw.     

Obsessive-compulsive disorder with and without tic disorder: a comparative study from India

Introduction: Evidence from phenomenological, family, genetic, and treatment studies from Western centers have suggested that tic-related obsessive-compulsive disorder (OCD) could be different from non-tic-related OCD. This study from India investigated the differences in OCD with and without tics, with respect to sociodemographics, symptom profile, and comorbidity, including obsessive-compulsive spectrum disorders, to examine whether the clinical profile of tic-related OCD is similar to that reported previously. Methods: Fifty subjects with OCD and tics (chronic motor tics and Tourette syndrome) were compared with 141 OCD subjects without tics. Results: Subjects having OCD with tics tended to be males, and had an earlier onset of illness. They had more of symmetry/aggressive and religious obsessions, and cleaning, ordering/arranging, hoarding, and repeating compulsions and were associated with trichotillomania and hypochondraisis. Stepwise backward (Wald) regression analysis showed that an early age of onset, male gender, aggressive obsessions, cleaning compulsions, and trichotillomania were significantly associated with tic-related OCD. Conclusion: The findings of this study from India are broadly similar to those reported previously from the West indicating the universality of differences in tic- and non-tic-related OCD. Our findings also support the existing evidence that tics contribute to the heterogeneity of OCD.     

A double-blind,sham-controlled,trial of home-administered rhythmic 10-Hz median nerve stimulation for the reduction of tics,and suppression of the urge-to-tic,in individuals with Tourette syndrome and chronic tic disorder

Tourette syndrome (TS) and chronic tic disorder (CTD) are neurological disorders of childhood onset characterized by the occurrence of tics; repetitive, purposeless, movements or vocalizations of short duration which can occur many times throughout a day. Currently, effective treatment for tic disorders is an area of considerable unmet clinical need. We aimed to evaluate the efficacy of a home-administered neuromodulation treatment for tics involving the delivery of rhythmic pulse trains of median nerve stimulation (MNS) delivered via a wearable ‘watch-like’ device worn at the wrist. We conducted a UK-wide parallel double-blind sham-controlled trial for the reduction of tics in individuals with tic disorder. The device was programmed to deliver rhythmic (10 Hz) trains of low-intensity (1–19 mA) electrical stimulation to the median nerve for a pre-determined duration each day, and was intended to be used by each participant in their home once each day, 5 days each week, for a period of 4 weeks. Between 18th March 2022 and 26th September 2022, 135 participants (45 per group) were initially allocated, using stratified randomization, to one of the following groups; active stimulation; sham stimulation or to a waitlist (i.e. treatment as usual) control group. Recruited participants were individuals with confirmed or suspected TS/CTD aged 12 years of age or upward with moderate to severe tics. Researchers involved in the collection or processing of measurement outcomes and assessing the outcomes, as well as participants in the active and sham groups and their legal guardians were all blind to the group allocation. The primary outcome measure used to assess the ‘offline’ or treatment effect of stimulation was the Yale Global Tic Severity Scale–Total Tic Severity Score (YGTSS–TTSS) assessed at the conclusion of 4 weeks of stimulation. The primary outcome measure used to assess the ‘online’ effects of stimulation was tic frequency, measured as the number of tics per minute (TPM) observed, based upon blind analysis of daily video recordings obtained while stimulation was delivered. The results demonstrated that after 4-week stimulation, tic severity (YGTSS-TTSS) had reduced by 7.1 points (35 percentile reduction) for the active stimulation group compared to 2.13/2.11 points for the sham stimulation and waitlist control groups. The reduction in YGTSS–TTSS for the active stimulation group was substantially larger, clinically meaningful (effect size = .5) and statistically significant (p = .02) compared to both the sham stimulation and waitlist control groups, which did not differ from one another (effect size = −.03). Furthermore, blind analyses of video recordings demonstrated that tic frequency (tics per minute) reduced substantially (−15.6 TPM) during active stimulation compared to sham stimulation (−7.7 TPM). This difference represents a statistically significant (p < .03) and clinically meaningful reduction in tic frequency (>25 percentile reduction: effect size = .3). These findings indicate that home-administered rhythmic MNS delivered through a wearable wrist-worn device has the potential to be an effective community-based treatment for tic disorders.     

A survey of habit behaviors exhibited by individuals with mental retardation

The purpose of this study was to investigate the prevalence and characteristics of habit behaviors exhibited by individuals with mental retardation living in the community. Two hundred and fifty-nine direct care staff and parents from the upper mid-west and northeast regions of the country completed a survey measuring the prevalence of major habit disorders (bruxism, trichotillomania, motor/vocal tics, and stuttering) and habit behaviors exhibited by individuals with mental retardation being served by community residential agencies. Habit disorders were also subjectively evaluated according to the respondents' perception of the severity and noticeability of the behavior, and naturalness of appearance of the individual. In addition, respondents indicated their usual reaction to the habit disorder. Overall, stuttering was found to be the most prevalent habit disorder (32%), followed by tics (16·6%), bruxism (13·1%), and trichotillomania (5%) for the sample surveyed. Furthermore, differences were found in the prevalence of habit disorders and other habit behaviors by level of mental retardation and age (adults versus children/adolescents). The implications and limitations of the data, as well as suggestions for future investigations of habit disorders and habit behaviors exhibited by individuals with mental retardation, are discussed. © 1998 John Wiley & Sons, Ltd.     

Syntactic and semantic correlates of verbal tics in Gilles de la Tourette's syndrome: a quantitative case study.

A two-hour sample of the speech of a patient suffering from Gilles de la Tourette's syndrome was analyzed. Coprolalic verbal tics are a major symptom of this disorder. In contrast to findings with other speech dysfluencies, verbal tics in Gilles de la Tourette's syndrome tend to occur at points of low information or uncertainty in sentences. They were found to be especially probable before conjunctions and pronouns. Sentences containing verbal tics exhibited more primary process and less secondary process content than sentences not containing tics. Tic sentence words were connotatively less potent, less active, less evaluatively negative, and more aggressive than words in nontic sentences. A neurolinguistic model of the syndrome is proposed: Necessity for grammatical coordination elicits the tic because of overactivity of subcortical centers that mediate this operation. Semantic determinants of the tic hypothetically operate by influencing cortical arousal which in turn triggers the subcortical centers.     

Motor excitability during movement preparation in Tourette syndrome

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by the occurrence of motor and vocal tics. TS has been linked to the impaired operation of cortical‐striatal‐thalamic‐cortical circuits that give rise to hyper‐excitability of cortical motor areas, which may be exacerbated by dysfunctional intra‐cortical inhibitory mechanisms. That said, many individuals gain control over their tics during adolescence and it has been suggested that this increased control arises as a result of the development of mechanisms that operate to suppress corticospinal excitability (CSE) ahead of volitional movements. Here we used single‐pulse transcranial magnetic stimulation (TMS) in conjunction with a manual Go/NoGo task to investigate alterations in CSE ahead of volitional movements in a group of adolescents with TS (N = 10). Our study demonstrated that CSE, as measured by TMS‐induced motor‐evoked potentials (MEPs), was significantly reduced in the TS group in the period immediately preceding a finger movement. More specifically, we show that individuals with TS, unlike their age‐matched controls, do not exhibit the predicted increase in mean MEP amplitude and decrease in MEP variability that immediately precede the execution of volitional movements in typically developing young adults. Finally, we report that the magnitude of the rise in MEP amplitude across the movement preparation period in TS is significantly negatively correlated with clinical measures of motor tic severity, suggesting that individuals with severe motor tics are least able to modulate motor cortical excitability.     

Thermal sensitivity in Tourette syndrome: preliminary report

The effects of heat on tic symptoms were studied in a sample of 78 adults with Tourette syndrome. 62 men and 16 women completed a survey concerning the type, onset, and course of their tics. 10 adult male subjects also participated in a thermal challenge during which ambient temperature was raised from 22 degrees C to 35 degrees C following a control period. Of the 78, 24% or 19 reported increased tics upon exposure to heat. Compared to the remaining 59 subjects, there were no differences in sex distribution, current age, or overall course of illness. In the thermal challenge, there was general increase in tics that was correlated with sweat rate (r = .55, p = .001). This effect was prominent in 5 of 10 subjects (rs = .29 to .63). There were no mean differences in current age, age of onset, or current severity of symptoms between the five subjects of each group. Tic symptoms in a subgroup of patients with Tourette syndrome may be sensitive to heat. Abnormal heat regulation is not a likely explanation for the observed increase in tics. The increase may be due to normal heat-loss mechanisms through dopaminergic pathways.     

The Premonitory Urge to Tic: Measurement,Characteristics, and Correlates in Older Adolescents and Adults

In addition to motor and/or vocal tics, many individuals with Tourette syndrome (TS) or chronic tic disorder (CTD) report frequent, uncomfortable sensory phenomena that immediately precede the tics. To date, examination of these premonitory sensations or urges has been limited by inconsistent assessment tools. In this paper, we examine the psychometric properties of a nine-item self-report measure, the Premonitory Urge to Tic Scale (PUTS) and examine the characteristics and correlates of the premonitory urge to tic in a clinical sample of 122 older adolescents and adults with TS or CTD. The PUTS demonstrated adequate internal consistency, temporal stability, and concurrent validity. Premonitory urges were endorsed by the majority of individuals. Most individuals reported some relief from the urges after completing a tic and being able to stop their tics even if only temporarily. Degree of premonitory urges was not significantly correlated with age, and we did not observe any gender differences. Degree of premonitory urges was significantly correlated with estimated IQ and tic severity, but not severity of comorbid obsessive–compulsive disorder or attention-deficit hyperactivity disorder. Also, it was not related to concomitant medication status. These findings represent another step forward in our understanding of the premonitory sensations associated with TS and CTD.     

Motor excitability is reduced prior to voluntary movements in children and adolescents with Tourette syndrome

Tourette syndrome (TS) is a neuro‐developmental disorder characterized by the occurrence of motor and vocal tics: involuntary, repetitive, stereotyped behaviours that occur with a limited duration, often typically many times in a single day. Previous studies suggest that children and adolescents with TS may undergo compensatory, neuroplastic changes in brain structure and function that help them gain control over their tics. In the current study we used single‐pulse and dual‐site paired‐pulse transcranial magnetic stimulation (TMS), in conjunction with a manual choice reaction time task that induces high levels of inter‐manual conflict, to investigate this conjecture in a group of children and adolescents with TS, but without co‐morbid Attention Deficit Hyperactivity Disorder (ADHD). We found that performance on the behavioural response‐conflict task did not differ between the adolescents with TS and a group of age‐matched typically developing individuals. By contrast, our study demonstrated that cortical excitability, as measured by TMS‐induced motor‐evoked potentials (MEPs), was significantly reduced in the TS group in the period immediately preceding a finger movement. This effect is interpreted as consistent with previous suggestions that the cortical hyper‐excitability that may give rise to tics in TS is actively suppressed by cognitive control mechanisms. Finally, we found no reliable evidence for altered patterns of functional inter‐hemispheric connectivity in TS. These results provide evidence for compensatory brain reorganization that may underlie the increased self‐regulation mechanisms that have been hypothesized to bring about the control of tics during adolescence.     

Executive and Attention Functioning Among Children in the PANDAS Subgroup

Evidence from past studies indicates that adults and children with Obsessive-Compulsive Disorder (OCD) and Tourette syndrome (TS) experience subtle neuropsychological deficits. Less is known about neuropsychological functioning of children and adolescents with a symptom course consistent with the PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infection) subgroup of OCD and tics. To provide such information, we administered three tests of attention control and two of executive function to 67 children and adolescents (ages 5–16) diagnosed with OCD and/or tics and a symptom course consistent with the PANDAS subgroup and 98 healthy volunteers (HV) matched by age, sex, and IQ. In a paired comparison of the two groups, the PANDAS subjects were less accurate than HV in a test of response suppression. Further, in a two-step linear regression analysis of the PANDAS group in which clinical variables were added stepwise into the model and in the second step matching variables (age, sex, and IQ) were added, IQ emerged as a predictor of performance on this task. In the same analysis, ADHD diagnosis and age emerged as predictors of response time in a continuous performance task. Subdividing the PANDAS group by primary psychiatric diagnosis revealed that subjects with TS or OCD with tics exhibited a longer response time compared to controls than subjects with OCD only, replicating previous findings within TS and OCD. This study demonstrates that children with PANDAS exhibit neuropsychological profiles similar to those of their primary psychiatric diagnosis.     

Cluster Analysis of the Yale Global Tic Severity Scale (YGTSS): Symptom Dimensions and Clinical Correlates in an Outpatient Youth Sample

Tic disorders are heterogeneous, with symptoms varying widely both within and across patients. Exploration of symptom clusters may aid in the identification of symptom dimensions of empirical and treatment import. This article presents the results of two studies investigating tic symptom clusters using a sample of 99 youth (M age = 10.7, 81% male, 77% Caucasian) diagnosed with a primary tic disorder (Tourette’s disorder or chronic tic disorder), across two university-based outpatient clinics specializing in tic and related disorders. In Study 1, a cluster analysis of the Yale Global Tic Severity Scale (YGTSS) identified four symptom dimensions: predominantly complex tics; simple head/face tics; simple body tics; and simple vocal/facial tics. In Study 2, these clusters were shown to be differentially associated with demographic and clinical characteristics. Findings lend support to prior research on tic phenomenology, help to organize treatment goals, and suggest symptom dimensions of tic disorders for further evaluation.     

Habit reversal versus supportive psychotherapy in Tourette's disorder: a randomized controlled trial and predictors of treatment response

Tourette syndrome (TS) is characterized by chronic motor and vocal tics. Habit reversal therapy (HR) is a behavioral treatment for tics which has received recent empirical support. The present study compared the efficacy of HRT in reducing tics, improving life-satisfaction and psychosocial functioning in comparison with supportive psychotherapy (SP) in outpatients with TS. In addition, we investigated whether impairments in response inhibition in patients with TS predict response to HR treatment which specifically aims to inhibit tics. Thirty adult outpatients with DSM-IV TS were randomized to 14 individual sessions of HR (n = 15); or SP (n = 15). HR but not SP reduced tic severity over the course of the treatment. Both groups improved in life-satisfaction and psychosocial functioning during active treatment. Reductions in tic severity (HR) and improvements in life-satisfaction and psychosocial functioning (HR and SP) remained stable at the 6-month follow-up. The extent of pre-treatment response inhibition impairment in the HR group predicted reductions in tic-severity from pre- to post-treatment. Our results suggest that HR has specific tic-reducing effects although SP is effective in improving life-satisfaction and psychosocial functioning. Assessments of response inhibition may be of value for predicting treatment response to HR.