Inter-individual differences in urge-tic associations in Tourette syndrome

Symptom Network Analysis in a Large Sample of Children and Adults with a Chronic Tic Disorder

BACKGROUND

Chronic tic disorders (CTD) are multifaceted disorders characterized by multiple motor and/or vocal tics. They are often associated with complex tics including echophenomena, paliphenomena, and coprophenomena as well as psychiatric comorbidities such as attention deficit/hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD).

OBJECTIVES

Our goal was to uncover the inter-relational structure of CTD and comorbid symptoms in children and adults and to understand changes in symptom structure across development.

METHODS

We used network and graph analyses to uncover the structure of association of symptoms in childhood/adolescence (n = 529) and adulthood (n = 503) and how this structure might change from childhood to adulthood, pinpointing core symptoms as a main target for interventions.

RESULTS

The analysis yielded core symptom networks in young and adult patients with CTD including complex tics and tic-related phenomena as well as touching people and objects. Core symptoms in childhood also included ADHD symptoms, whereas core symptoms in adults included symptoms of OCD instead. Interestingly, self-injurious behavior did not play a core role in the young CTD network, but became one of the central symptoms in adults with CDT. In addition, we found strong connections between complex motor and vocal tics as well as echolalia and echopraxia.

CONCLUSIONS

Next to other complex tics, echophenomena, paliphenomena, and coprophenomena can be regarded core symptoms of CTD. ADHD symptoms are closely related to CTD in childhood, whereas symptoms of OCD and self-injurious behavior are closely associated with CTD in adults. Our results suggest that a differentiation between motor and vocal tics is somewhat arbitrary.

Deep brain stimulation for Tourette's syndrome

OBJECTIVES

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

Exploring the psychometric properties of the premonitory urge for tics scale (PUTS) and its association with psychiatric symptoms in Chinese children with tic disorders

BACKGROUND

The Premonitory Urge for Tics Scale (PUTS) is a common self-report measure of premonitory urges for patients with tic disorders. This study aims to evaluate the Chinese version of the PUTS (PUTS-C) and to explore its association with psychiatric symptoms in Chinese children diagnosed with tic disorders.

METHODS

The psychometric evaluation involved 204 outpatients with tic disorders, aged 7-16 years, who were divided into two age groups: (7-10 years, n = 103; 11-16 years, n = 95).

RESULTS

The PUTS-C demonstrated good internal consistency (McDonald'sω = 0.84) and two-week test-retest reliability (0.76). We observed a statistically significant correlation between the total PUTS-C score and various Yale Global Tic Severity Scale (YGTSS) subscales and total tic severity scores. The PUTS-C score also showed significant correlations with the Children Yale-Brown Obsessive Compulsive Scale (CY-BOCS), Screening Child Anxiety-Related Emotional Disorders (SCARED), and Children's Depression Inventory (CDI). Notably, premonitory urges independently predicted tic severity, beyond the influence of comorbid symptoms. A two-factor structure of the PUTS-C was identified in the total sample through factor analysis.

CONCLUSIONS

The PUTS-C possesses acceptable validity and good reliability. It appears that premonitory urges in Chinese patients with tic disorders are associated with obsessive-compulsive symptoms, anxiety, and depression, but can independently predict tic severity. Specific PUTS-C factors possibly related to motor and vocal tics. Future research should continue to investigate age-related differences and the association with tics and other sensory symptoms.

A Test of the Behavioral Model of Tic Disorders Using a Dynamical Systems Framework

Tic disorders are a class of neurodevelopmental disorders characterized by involuntary motor and/or vocal tics. It has been hypothesized that tics function to reduce aversive premonitory urges (i.e., negative reinforcement) and that suppression-based behavioral interventions such as habit reversal training (HRT) and exposure and response prevention (ERP) disrupt this process and facilitate urge reduction through habituation. However, previous findings regarding the negative reinforcement hypothesis and the effect of suppression on the urge-tic relationship have been inconsistent. The present study applied a dynamical systems framework and within-subject time-series autoregressive models to examine the temporal dynamics of urges and tics and assess whether their relationship changes over time. Eleven adults with tic disorders provided continuous urge ratings during separate conditions in which they were instructed to tic freely or to suppress tics. During the free-to-tic conditions, there was considerable heterogeneity across participants in whether and how the urge-tic relationship followed a pattern consistent with the automatic negative reinforcement hypothesis. Further, little evidence for within-session habituation was seen; tic suppression did not result in a reduction in premonitory urges for most participants. Analysis of broader urge change metrics did show significant disruption to the urge pattern during suppression, which has implications for the current biobehavioral model of tics.

Premonitory Urge in Patients with Tics and Functional Tic-like Behaviors

BACKGROUND

Premonitory urges (PU) are well described in primary tics, but their frequency and intensity in functional tic-like behaviors (FTLB) are unclear.

OBJECTIVE

To study the experience of PU in patients with FTLB.

METHODS

We compared the results of the premonitory urge for tics scale (PUTS) in adults with tics and FTLB in the University of Calgary Adult Tic Registry.

RESULTS

We included 83 patients with tics and 40 with FTLB. When comparing patients with tics, FTLB with tics and FTLB only, we did not detect significant differences either in the total PUTS score (P = 0.39), or in any of the individual PUTS item sub-scores (P values ranging between 0.11 and 0.99).

CONCLUSIONS

Patients with FTLB report PU at similar frequency and intensity to patients with tics. This finding confirms that PU are not a useful feature to discriminate FTLB from tics.

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical evaluation of premonitory urges in children and adolescents using the Chinese version of Individualized Premonitory Urge for Tics Scale

Background

Premonitory urges (PUs) have been the focus of recent efforts to assess the severity and develop interventions for tic disorders (TD). We aimed to investigate the PUs in TD and its comorbidities from multiple dimensions, using the Chinese version of the Premonitory Urge for Tics Scale (C-PUTS) and the Chinese version of the Individualized Premonitory Urge for Tics Scale (C-IPUTS), in order to provide perspectives for the diagnosis and management of TD in children and adolescents.

Methods

A total of 123 cases were included in the study. The IPUTS was translated, back-translated, culturally adjusted, and pre-investigated to determine the items of the C-IPUTS. The reliability and validity of the C-IPUTS scale were evaluated by a questionnaire survey on children and adolescents with TD at the Developmental Pediatrics Department of the Second Hospital of Jilin University. Meanwhile, the C-PUTS, which had been evaluated and used in China, Yale Global Tic Severity Scale (YGTSS), Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Depression Self-Rating Scale (DSRS), Screen for Childhood Anxiety-Related Disorders (SCARED), Achenbach Child Behavior Checklist (CBCL), and Swanson, Nolan and Pelham, Version IV (SNAP-IV), were used to assess the association of PUs with tics and comorbidities of TD.

Results

All dimensions of the C-IPUTS demonstrated good reliability and validity. Our findings suggested that PUs in children and adolescents in China occurred primarily at the head/face and neck/throat. The different dimensions of the C-IPUTS (number, frequency, and intensity) and C-PUTS were positively correlated with the YGTSS total score, while the C-PUTS was positively correlated with the Y-BOCS, SCARED, DSRS, and SNAP-IV scale total scores. The three dimensions of the C-IPUTS demonstrated correlations with anxiety severity and obsessive-compulsive symptoms.

Conclusion

The C-IPUTS can be used to assess PUs reliably and effectively and provide further information for the C-PUTS from various dimensions in a Chinese setting. PUs relate to obsessive-compulsive symptoms, anxiety, attention deficit hyperactivity, and behavioral problems in children and adolescents with TDs. Accordingly, PUs evaluation using the C-IPUTS combined with the PUTS might provide useful information for future therapies for TDs to achieve greater tic reduction.

Non-just-right experiences are more closely related to OCD than tics in Tourette patients

Complex tics and obsessive or compulsive behaviour can be difficult to differentiate diagnostically. The majority of adult patients with Tourette syndrome report experiencing premonitory urges before tics. Some of these experiences have been linked to non-just-right experiences (NJRE), which are frequently reported by patients with obsessive-compulsive disorder or behaviours (OCD/OCB). We aimed to assess whether NJRE are more closely related to tics and tic-associated premonitory urges or whether they are more closely associated with OCD. A total of N = 111 patients (mean age = 34.77 + /-12.93; N = 37 female) with a confirmed diagnosis of Tourette syndrome completed the premonitory urges for tic disorders scale (PUTS), the revised non-just-right experiences scale (NJRE-QR), and questionnaires regarding their tic severity, and comorbid OCD/OCB. A multi-trait-multi-methods matrix was calculated to examine associations amongst scales measuring tic-related and OCB-related phenomena. The PUTS correlated overall higher with tic questionnaires than with OCD/OCB questionnaires. The NJRE correlated higher with OCD symptoms than with tic severity. The results indicate that non-just-right experiences are more closely associated with comorbid OCB than with tics in patients with Tourette syndrome.

Premonitory Urge and Tic Severity, Comorbidities, and Quality of Life in Chronic Tic Disorders

BACKGROUND

Tics are intimately associated with premonitory urges (PU) but knowledge about urges is still limited, with small sample sizes often limiting the generalizability of findings.

OBJECTIVES

This study addressed the following open questions: (1) is tic severity associated with urge severity, (2) how common is relief, (3) which comorbidities are associated with urges, (4) are urges, tics, and comorbidities associated with lower quality of life, and (5) can complex and simple, motor and vocal tics be differentiated based on PU?

METHODS

N = 291 patients who reported a confirmed diagnosis of chronic primary tic disorder (age = 18-65, 24% female) filled out an online survey assessing demographic data, comorbid conditions, location, quality and intensity of PU, as well as quality of life. Every tic was recorded, and whether the patient experienced a PU, the frequency, intensity, and quality of that urge.

RESULTS

PU and tic severity were significantly associated, and 85% of urge-related tics were followed by relief. A diagnosis of attention deficit/hyperactivity disorder (ADHD) or depression, female gender, and older age increased the likelihood of experiencing PU, while more obsessive compulsive (OCD) symptoms and younger age were associated with higher urge intensities. PU, complex vocal tics, ADHD, OCD, anxiety, and depression were related to lower quality of life. Motor and vocal, complex and simple tics did not differ regarding PU intensity, frequency, and quality, or relief.

CONCLUSIONS

The results shed light on the relationship between PU, tics, comorbidities, age, gender, and quality of life in tic disorders.

Cognitive and Neural Mechanisms of Behavior Therapy for Tics: A Perception-Action Integration Approach

European clinical guidelines recommend the use of Exposure and Response Prevention (ERP) and Comprehensive Behavioral Intervention for Tics (CBIT) as first-line treatments for tic disorders. Although ongoing efforts in research are being made to understand the mechanisms underlying these behavioral approaches, as of yet, the neurophysiological mechanisms behind behavioral interventions are poorly understood. However, this is essential to tailor interventions to individual patients in order to increase compliance and efficacy. The Theory of Event Coding (TEC) and its derivative BRAC (Binding and Retrieval in Action Control) provide a theoretical framework to investigate cognitive and neural processes in the context of tic disorders. In this context, tics are conceptualized as a phenomenon of enhanced perception-action binding, with premonitory urges constituting the perceptual and the motor or vocal expression constituting the action part of an event file. Based on this, CBIT is assumed to strongly affect stimulus-response binding in the context of response selection, whereas the effects of ERP presumably unfold during stimulus-response binding in the response inhibition context. Further studies are needed to clarify the neurophysiological processes underlying behavioral interventions to enable the individualization and further development of therapeutic approaches for tic disorders.

Tourette syndrome: clinical features, pathophysiology, and treatment

Tourette syndrome is a chronic neurodevelopmental disorder characterised by motor and phonic tics that can substantially diminish the quality of life of affected individuals. Evaluating and treating Tourette syndrome is complex, in part due to the heterogeneity of symptoms and comorbidities between individuals. The underlying pathophysiology of Tourette syndrome is not fully understood, but recent research in the past 5 years has brought new insights into the genetic variations and the alterations in neurophysiology and brain networks contributing to its pathogenesis. Treatment options for Tourette syndrome are expanding with novel pharmacological therapies and increased use of deep brain stimulation for patients with symptoms that are refractory to pharmacological or behavioural treatments. Potential predictors of patient responses to therapies for Tourette syndrome, such as specific networks modulated during deep brain stimulation, can guide clinical decisions. Multicentre data sharing initiatives have enabled several advances in our understanding of the genetics and pathophysiology of Tourette syndrome and will be crucial for future large-scale research and in refining effective treatments.

Overcoming the phenomenological Perpetuum mobile in clinical cognitive neuroscience for the benefit of replicability in research and the societal view on mental disorders

Cognitive neuroscience comes in many facets, and a particularly large branch of research is conducted in individuals with mental health problems. This article outlines why it is important that cognitive neuroscientists re-shape their role in mental health research and re-define directions of research for the next decades. At present, cognitive neuroscience research in mental health is too firmly rooted in categorial diagnostic definitions of mental health conditions. It is discussed why this hampers a mechanistic understanding of brain functions underlying mental health problems and why this is a problem for replicability in research. A possible solution to these problems is presented. This solution affects the strategy of research questions to be asked, how current trends to increase replicability in research can or cannot be applied in the mental health field and how data are analyzed. Of note, these aspects are not only relevant for the scientific process, but affect the societal view on mental disorders and the position of affected individuals as members of society, as well as the debate on the inclusion of so-called WEIRD and non-WEIRD people in studies. Accordingly, societal and science political aspects of re-defining the role of cognitive neuroscientists in mental health research are elaborated that will be important to shape cognitive neuroscience in mental health for the next decades.

Tourette syndrome research highlights from 2021

We summarize selected research reports from 2021 relevant to Tourette syndrome that the authors consider most important or interesting. The authors welcome article suggestions and thoughtful feedback from readers.

Urge-tic associations in children and adolescents with Tourette syndrome

Premonitory urges preceding tics are a cardinal feature of Gilles de la Tourette syndrome (GTS), a developmental disorder usually starting during middle childhood. However, the temporal relation between urges and tics has only been investigated in adults. In 25 children and adolescents with GTS (8–18 years), we assess urge-tic associations, including inter-individual differences, correlation to clinical measures, and in comparison to a previously reported sample of adult GTS patients. Group-level analyses confirmed positive associations between urges and tics. However, at the individual level, less than half of participants showed positive associations, a similar proportion did not, and in two participants, the association was reversed. Tic expression and subjective urge levels correlated with corresponding clinical scores and participants with more severe tics during the urge monitor exhibited stronger urge-tic associations. Associations between reported urge levels and instantaneous tic intensity tended to be less pronounced in children and adolescents than in adult GTS patients. The observed heterogeneity of urge-tic associations cast doubt on the notion that tics are directly caused by urges. More severe tics may facilitate anticipation of tics and thereby lead to more pronounced urge-tic associations, consistent with a hypothesis of urges as a byproduct of tics.

Mass social media-induced illness presenting with Tourette-like behavior

Currently, we are facing a new manifestation of functional neurological disorder presenting with functional Tourette-like behavior (FTB). This study aimed to show characteristics of this phenotype presenting as an outbreak of "mass social media-induced illness" (MSMI) and to explore predisposing factors. Between 5-9/2021, we prospectively investigated 32 patients (mean/median age: 20.1/18 years, range: 11-53 years, n = 16 females) with MSMI-FTB using a neuro-psychiatric examination, a comprehensive semi-structured interview and aspects of the Operationalized Psychodynamic Diagnostic System. In contrast to tics, numbers of complex movements and vocalizations were nine times greater than of "simple" symptoms, and of vocalizations one and a half times greater than of movements. In line with our hypothesis of MSMI, symptoms largely overlapped with those presented by German YouTuber Jan Zimmermann justifying his role as "virtual" index case in current outbreak. Typically, symptoms started abruptly at a mean age of 19 years and deteriorated gradually with no differences between males and females. In all patients, we identified timely-related psychological stressors, unconscious intrapsychic conflicts, and/or structural deficits. Nearly all patients (94%) suffered from further psychiatric symptoms including abnormalities in social behavior (81%), obsessive-compulsive behavior (OCB) (47%), Tourette syndrome (TS) (47%), anxiety (41%), and depression (31%), about half (47%) had experienced bullying, and 75% suffered from coexisting somatic diseases. Our data suggest that pre-existing abnormalities in social behavior and psychiatric symptoms (OCB, anxiety, and depression), but also TS in combination with timely-related psychological stressors, unconscious intrapsychic conflicts, and structural deficits predispose to contagion with MSMI-FTB.