Advances in Tourette syndrome: diagnoses and treatment

Aberrant Functional Connectivity of the Salience Network in Adult Patients with Tic Disorders: A Resting-State fMRI Study

Tic disorders (TD) are characterized by the presence of motor and/or vocal tics. Common neurophysiological frameworks suggest dysregulations of the cortico-striatal-thalamo-cortical (CSTC) brain circuit that controls movement execution. Besides common tics, there are other "non-tic" symptoms that are primarily related to sensory perception, sensorimotor integration, attention, and social cognition. The existence of these symptoms, the sensory tic triggers, and the modifying effect of attention and cognitive control mechanisms on tics may indicate the salience network's (SN) involvement in the neurophysiology of TD. Resting-state functional MRI measurements were performed in 26 participants with TD and 25 healthy controls (HC). The group differences in resting-state functional connectivity patterns were measured based on seed-to-voxel connectivity analyses. Compared to HC, patients with TD exhibited altered connectivity between the core regions of the SN (insula, anterior cingulate cortex, and temporoparietal junction) and sensory, associative, and motor-related cortices. Furthermore, connectivity changes were observed in relation to the severity of tics in the TD group. The SN, particularly the insula, is likely to be an important site of dysregulation in TD. Our results provide evidence for large-scale neural deviations in TD beyond the CSTC pathologies. These findings may be relevant for developing treatment targets.

Biomarkers and Tourette syndrome: a systematic review and meta-analysis

Objective

This research aims to investigate whether peripheral biomarkers might differentiate individuals with Tourette syndrome (TS) from those without the condition.

Methods

A broad range of databases was searched through November 2022. This study employed a systematic literature review and subsequent meta-analysis of case-control studies that assessed the aberration of biomarkers of patients with TS and controls.

Results

A total of 81 studies were identified, out of which 60 met the eligibility criteria for inclusion in the meta-analysis. Following a meticulous screening procedure to determine the feasibility of incorporating case-control studies into the meta-analysis, 13 comparisons were statistically significant [CD3+ T cell, CD4+ T cell, CD4+ T cell to CD8+ T cell ratio, NK-cell, anti-streptolysin O antibodies, anti-DNase antibodies, glutamic acid (Glu), aspartic acid (Asp), ferritin (Fe), zinc (Zn), lead (Pb), vitamin D, and brain-derived neurotrophic factor (BDNF)]. Publication bias was found for anti-streptolysin O antibodies. Suggestive associations were evidenced for norsalsolinol (NSAL), neuron-specific enolase (NSE), and S100B.

Conclusion

In this study, we present empirical evidence substantiating the link between several peripheral biomarkers and the early diagnosis of TS. Larger and more standardized studies are necessary to replicate the observed results, elucidate the specificity of the biomarkers for TS, and evaluate their precision for use in clinical settings.

Pediatric neuropsychiatric disorders with motor and nonmotor phenomena

The concept of pediatric autoimmune neuropsychiatric disorders associated with group A beta-hemolytic streptococcus (PANDAS) has become seminal since first introduced more than two decades ago. At the time of this writing, most neurologists, pediatricians, psychiatrists, and general pediatricians will probably have heard of this association or treated an affected child with PANDAS. The concept of an acute-onset, and typically self-limited, postinfectious autoimmune neuropsychiatric disorder resembling PANDAS manifesting vocal and motor tics and obsessive-compulsive disorder has broadened to other putative microbes and related endogenous and exogenous disease triggers. These disorders with common features of hypometabolism in the medial temporal lobe and hippocampus in brain 18fluorodeoxyglucose positron emission tomography fused to magnetic resonance imaging (FDG PET-MRI), form a spectrum: with the neuropsychiatric disorder Tourette syndrome and PANDAS with its well-defined etiopathogenesis at one end, and pediatric abrupt-onset neuropsychiatric syndrome (PANS), alone or associated with specific bacterial and viral pathogens, at the other end. The designation of PANS in the absence of a specific trigger, as an exclusionary diagnosis, reflects the current problem in nosology.

European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part III: pharmacological treatment

In 2011, the European Society for the Study of Tourette Syndrome (ESSTS) published the first European guidelines for Tourette Syndrome (TS). We now present an update of the part on pharmacological treatment, based on a review of new literature with special attention to other evidence-based guidelines, meta-analyses, and randomized double-blinded studies. Moreover, our revision took into consideration results of a recent survey on treatment preferences conducted among ESSTS experts. The first preference should be given to psychoeducation and to behavioral approaches, as it strengthens the patients' self-regulatory control and thus his/her autonomy. Because behavioral approaches are not effective, available, or feasible in all patients, in a substantial number of patients pharmacological treatment is indicated, alone or in combination with behavioral therapy. The largest amount of evidence supports the use of dopamine blocking agents, preferably aripiprazole because of a more favorable profile of adverse events than first- and second-generation antipsychotics. Other agents that can be considered include tiapride, risperidone, and especially in case of co-existing attention deficit hyperactivity disorder (ADHD), clonidine and guanfacine. This view is supported by the results of our survey on medication preference among members of ESSTS, in which aripiprazole was indicated as the drug of first choice both in children and adults. In treatment resistant cases, treatment with agents with either a limited evidence base or risk of extrapyramidal adverse effects might be considered, including pimozide, haloperidol, topiramate, cannabis-based agents, and botulinum toxin injections. Overall, treatment of TS should be individualized, and decisions based on the patient's needs and preferences, presence of co-existing conditions, latest scientific findings as well as on the physician's preferences, experience, and local regulatory requirements.

Gray matter abnormalities in Tourette Syndrome: a meta-analysis of voxel-based morphometry studies

Tourette syndrome (TS) is a neurobehavioral disorder for which the neurological mechanism has not been elucidated. Voxel-based morphometry (VBM) studies have revealed abnormalities in gray matter volume (GMV) in patients with TS; however, consistent results have not been obtained. The current study attempted to provide a voxel wise meta-analysis of gray matter changes using seed-based d mapping (SDM). We identified ten relevant studies that investigated gray matter alterations in TS patients and performed a meta-analysis using the SDM method to quantitatively estimate regional gray matter abnormalities. Next, we examined the relationships between GMV abnormalities and demographic and clinical characteristics. Our results demonstrated that TS patients had smaller GMV in the bilateral inferior frontal gyri and greater GMV in the cerebellum, right striatum (putamen), and bilateral thalami (pulvinar nucleus) than healthy controls. A meta-regression analysis did not identify correlations between GMV changes and demographic or clinical variables. This meta-analysis confirmed significant and consistent GMV changes in several brain regions of TS patients, primarily in the cortico-striato-thalamo-cortical network.

Tourette's disorder in children and adolescents

Tourette's disorder (TD) is one of the five American Psychiatric Association's 2013 Diagnostic and Statistical Manual of Mental Disorders (DSM-5) classifications of tic disorders. Eponymously linked with the noted 19th century French physician, Gilles de la Tourette [1857-1904], this disorder is identified in 0.3% to 0.7% of the population. It is characterized as a familial neuropsychiatric condition with multiple motor tics and vocal tics (one or more) present for more than 1 year with varying severity. The underlying pathophysiology involves dysfunctional activity of the basal ganglia and circuitry of the frontal cortex as well as dorsolateral striatum deficits. Contributory factors include genetic features interacting with milieu influences. A number of comorbid disorders are seen including obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder (ADHD). Concepts of management are considered including behavioral therapy and pharmacologic approaches with alpha-adrenoceptor agonists, atypical antipsychotics (AAs), haloperidol, pimozide and others. Other management includes botulinum injections and deep brain stimulation in adults.

Social stigma and self-perception in adolescents with tourette syndrome

Tourette syndrome (TS) is a complex neurodevelopmental disorder characterized by multiple motor and vocal tics, which commonly presents with multiple behavioral problems, including co-morbid attention-deficit and hyperactivity disorder and obsessive-compulsive disorder. Both tics and co-morbid conditions have been shown to potentially affect patients’ health-related quality of life. While TS typically presents in childhood, its manifestations peak in severity during adolescence, a critical period in which affected individuals are exposed to potential stigma from peers. Physical and behavioral manifestations can also contribute to stigma, which subsequently leads to poorer health outcomes, discrimination, and a reduced willingness to seek help. The available evidence suggests that young patients with TS can experience reduced social acceptance from peers and difficulties establishing relationships. There is also evidence that some health care professionals share the unhelpful belief that young patients with TS should be disciplined in order to correct their disruptive behavior, based on the erroneous assumption that tics can be consciously controlled. Studies focussed on self-perception in patients with TS have yielded inconsistent results, with some studies showing problems in the domains of self-concept and self-esteem. Feelings of isolation, loneliness, and experiences of bullying have been reported more consistently. Interventions are required to reduce misconceptions about the condition and thus reduce stigma through targeted education and behavioral interventions. A multi-faceted approach that focuses on educating children, adults, and educators about TS would be beneficial to help alleviate stigma. This can be combined with self-advocacy and tailored psychological therapies for young patients with TS. The present paper reviews the current literature on stigma and self-perception in adolescents with TS in order to inform clinical decisions about management strategies and possible interventions to improve health-related quality of life.

Sensory aspects of Tourette syndrome

Motor and vocal tics have long been recognised as the core features of Tourette syndrome (TS). However, patients' first-person accounts have consistently reported that these involuntary motor manifestations have specific sensory correlates. These sensory symptoms are often described as feelings of mounting inner tension ("premonitory urges") and are transiently relieved by tic expression. Multimodal hypersensitivity to external stimuli, perceived as triggers and/or exacerbating factors for specific tic symptoms, is also commonly reported by patients with TS. This article focuses on the rapidly expanding literature on the clinical and neurobiological aspects of the premonitory urge and multimodal hypersensitivity in patients with TS, with particular attention to pathophysiological mechanisms and possible treatment implications. These findings suggest that TS is a neurobehavioural condition characterised by intrinsic perceptual abnormalities involving the insula and sensorimotor areas, in addition to basal ganglia dysfunction. Further research will clarify the role of sensory symptoms in TS, as well as the effects of external sensory input on underlying motor abnormalities.

The Efficacy and Tolerability of the Clonidine Transdermal Patch in the Treatment for Children with Tic Disorders: A Prospective, Open, Single-Group, Self-Controlled Study

BACKGROUND

To evaluate the efficacy and tolerability of a clonidine transdermal patch in the treatment of children with tic disorders (TD) and to establish a predictive model for patients.

METHODS

Forty-one patients who met the inclusion criteria entered into 12 weeks of prospective, open, single-group, self-controlled treatment with a clonidine transdermal patch. The Yale Global Tic Severity Scale (YGTSS) was employed before therapy (baseline) and at 4, 8, and 12 weeks after therapy.

RESULTS

(1) The total effect rates of treatment with a clonidine transdermal patch were 29.27, 53.66, and 63.41% at 4, 8, and 12 weeks, respectively. Compared with the baseline, the differences were significant at three different observation periods. (2) Compared to the level of 25% reduction, there were significant decreases in the score-reducing rate of motor tic and total tic severities at 12 weeks. (3) If the disease course was ≤24 months and the motor tic score was <16 at the baseline, there was an effective rate of 100% for treatment with the clonidine transdermal patch. If the disease course was ≤24 months and the motor tic score was >16, there was an effective rate of 57.1%. If the disease course was >24 months and the clinical classification was chronic TD, there was an effective rate of 62.5%. If the disease course was >24 months and the clinical classification was Tourette's syndrome, 90% of the patients were invalid. (4) The main adverse events were rash, slight dizziness, and headache.

CONCLUSION

(1) When patients were pretreated with a D2-dopamine receptor antagonist that was ineffective or not tolerated well, switching to a clonidine transdermal patch treatment was effective and safe. (2) A clonidine transdermal patch could be a first-line medication for mild and moderate TD cases that are characterized by motor tics.

Neurological, Metabolic, and Psychiatric Adverse Events in Children and Adolescents Treated With Aripiprazole

Aripiprazole is a partial dopamine agonist with only minor neurological and psychiatric adverse effects, making it a potential first-line drug for the treatment of psychiatric disorders. However, the evidence of its use in children and adolescents is rather sparse. The aim of this case study is to discuss adverse drug reaction (ADR) reports concerning aripiprazole-associated neurological and psychiatric events in children and adolescents. The ADR report database at Danish Medicines Agency was searched for all ADRs involving children and adolescents (<18 years) reported by the search term [aripiprazole] AND all spontaneous reports since the introduction of aripiprazole in 2003 until December 31, 2015. Nineteen case reports were included in the study and included both patients with psychotic disorders (PS group) and nonpsychotic disorders (non-PS group). The PS group consisted of 5 patients with schizophrenia and psychoses, not otherwise specified; and the non-PS group consisted of fourteen cases including autism spectrum disorders, attention deficit and hyperactivity disorder, obsessive-compulsive disorder, and Tourette syndrome. The main reported adverse effects in the non-PS group were chronic insomnia, Parkinsonism, behavioral changes psychoses, and weight gain, whereas the adverse effects in the PS group was predominantly anxiety, convulsions, and neuroleptic malignant syndrome. Although aripiprazole is considered safe and well tolerated in children and adolescents, severe adverse events as neuroleptic malignant syndrome, extreme insomnia, and suicidal behavior has been reported to health authorities. Clinicians should pay attention to these possible hazards when prescribing aripiprazole to this vulnerable group of patients.

Safety and efficacy of aripiprazole for the treatment of pediatric Tourette syndrome and other chronic tic disorders

Tourette syndrome is a childhood-onset chronic tic disorder characterized by multiple motor and vocal tics and often accompanied by specific behavioral symptoms ranging from obsessionality to impulsivity. A considerable proportion of patients report significant impairment in health-related quality of life caused by the severity of their tics and behavioral symptoms and require medical intervention. The most commonly used medications are antidopaminergic agents, which have been consistently shown to be effective for tic control, but are also associated with poor tolerability because of their adverse effects. The newer antipsychotic medication aripiprazole is characterized by a unique mechanism of action (D2 partial agonism), and over the last decade has increasingly been used for the treatment of tics. We conducted a systematic literature review to assess the available evidence on the efficacy and safety of aripiprazole in pediatric patients with Tourette syndrome and other chronic tic disorders (age range: 4–18 years). Our search identified two randomized controlled trials (involving 60 and 61 participants) and ten open-label studies (involving between six and 81 participants). The majority of these studies used two validated clinician-rated instruments (Yale Global Tic Severity Scale and Clinical Global Impression scale) as primary outcome measures. The combined results from randomized controlled trials and open-label studies showed that aripiprazole is an effective, safe, and well-tolerated medication for the treatment of tics. Aripiprazole-related adverse effects (nausea, sedation, and weight gain) were less frequent compared to other antidopaminergic medications used for tic management and, when present, were mostly transient and mild. The reviewed studies were conducted on small samples and had relatively short follow-up periods, thus highlighting a need for further trials to assess the long-term use of aripiprazole in pediatric patients with Tourette syndrome and other chronic tic disorders with measurement of its efficacy using both clinician-rated and self-report scales.