Tourette Syndrome: Update

Predictive filtering of sensory response via orbitofrontal top-down input

Habituation is a crucial sensory filtering mechanism whose dysregulation can lead to a continuously intense world in disorders with sensory overload. While habituation is considered to require top-down predictive signaling to suppress irrelevant inputs, the exact brain loci storing the internal predictive model and the circuit mechanisms of sensory filtering remain unclear. We found that daily neural habituation in the primary auditory cortex (A1) was reversed by inactivation of the orbitofrontal cortex (OFC). Top-down projections from the ventrolateral OFC, but not other frontal areas, carried predictive signals that grew with daily sound experience and suppressed A1 via somatostatin-expressing inhibitory neurons. Thus, prediction signals from the OFC cancel out behaviorally irrelevant anticipated stimuli by generating their "negative images" in sensory cortices.

Variable schedules of reinforcement do not reliably distinguish habit from goal-directed behavior

Contemporary analyses of neurophysiological mechanisms of associative learning suggest that instrumental behavior can be controlled by separable action and habit processes. An increasingly broad range of human psychiatric and neurological disorders are now associated with maladaptive habit formation. The question of how the brain controls transitions into habit is thus relevant. Widely used training procedures that might differentially generate goal-directed actions or habits are variable schedules of reinforcement. Random interval schedules are known to generate habitual behavior compared with random ratio schedules Here, we report attempt to identify the behavioral characteristics of the bifurcation point of habitual and goal-directed behavior. We compared the time courses of learning in random ratio and random interval schedules with more common for neurophysiological researches parameters. Behavioral differences between schedules emerge early in learning. However, in outcome devaluation test we found that training in the random ratio schedule, but not in the random interval schedule, led to results interpreted as habitual behavior. This result is the opposite of what we expected based on previous research. We assume that the most commonly used variable schedules of reinforcement cannot serve as a reliable tool for analyzing neural mechanisms of habitual and goal-directed behavior.

Safety and Efficacy of Ecopipam in Patients with Tourette Syndrome: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Ecopipam is a selective antagonist of the dopamine D1 receptor, and its efficacy and safety have recently been explored in several clinical trials involving patients with Tourette syndrome (TS). The objectives of this systematic review were to determine the pooled estimate for efficacy [in terms of reduction in tic Yale Global Tic Severity Scale (YGTSS) scores] and safety of oral ecopipam in subjects with TS.

METHODS

All clinical trials that explored the efficacy and/or safety of ecopipam in patients with TS were included to determine the pooled estimate for change in YGTSS, Clinical Global Impression (CGI)-TS, and the severity of comorbid attention-deficit hyperactive disorder (ADHD), obsessive compulsion disorder (OCD), and depressive symptoms, as well as the nature and frequency of adverse effects. Case-series, retrospective studies, and case reports were excluded. Databases, such as PUBMED, EMBASE, Cochrane Central Register of Controlled Trials, and SCOPUS were searched to identify these trials using suitable combination of MESH terms/keywords on 15 June 2024. ROB 2.0 and ROBINS-I tool were used to assess the risk of bias in included randomized-controlled trials (RCTs) and non-randomized intervention studies, respectively, and the GRADE system to determine the certainty of the collated evidence.

RESULTS

A total of 96 records were identified in the database search and 31 records were screened after removing duplicates. After excluding 23 irrelevant records, the full-text review included 8 records. Finally, six publications from three completed clinical trials (two RCTs, with one having an open-label extension) and one ongoing clinical trial were included. A total of 251 participants were included. The pooled estimate for mean change in YGTSS-TTS from baseline to the completion of the randomization period was statistically better in the ecopipam group compared with the placebo group [mean difference: - 3.0, 95% (confidence interval (CI) - 4.2 to - 1.9, I2 = 55%, p < 0.0001]. The ecopipam group also fared statistically better in terms of YGTSS-motor tic score, phonic tic score, as well as CGI-TS-S (p < 0.0001). Changes in depressive and obsessive-compulsive symptoms were comparable in both groups, as well as the incidence of adverse effects.

CONCLUSIONS

Ecopipam is effective in reducing the severity of tics in subjects with TS and has a good safety profile. However, only a limited number of studies were included in the review, with some having small sample sizes and short duration of follow-up.

Movement Disorders and Smart Wrist Devices: A Comprehensive Study

In the medical field, there are several very different movement disorders, such as tremors, Parkinson's disease, or Huntington's disease. A wide range of motor and non-motor symptoms characterizes them. It is evident that in the modern era, the use of smart wrist devices, such as smartwatches, wristbands, and smart bracelets is spreading among all categories of people. This diffusion is justified by the limited costs, ease of use, and less invasiveness (and consequently greater acceptability) than other types of sensors used for health status monitoring. This systematic review aims to synthesize research studies using smart wrist devices for a specific class of movement disorders. Following PRISMA-S guidelines, 130 studies were selected and analyzed. For each selected study, information is provided relating to the smartwatch/wristband/bracelet model used (whether it is commercial or not), the number of end-users involved in the experimentation stage, and finally the characteristics of the benchmark dataset possibly used for testing. Moreover, some articles also reported the type of raw data extracted from the smart wrist device, the implemented designed algorithmic pipeline, and the data classification methodology. It turned out that most of the studies have been published in the last ten years, showing a growing interest in the scientific community. The selected articles mainly investigate the relationship between smart wrist devices and Parkinson's disease. Epilepsy and seizure detection are also research topics of interest, while there are few papers analyzing gait disorders, Huntington's Disease, ataxia, or Tourette Syndrome. However, the results of this review highlight the difficulties still present in the use of the smartwatch/wristband/bracelet for the identified categories of movement disorders, despite the advantages these technologies could bring in the dissemination of low-cost solutions usable directly within living environments and without the need for caregivers or medical personnel.

Comorbidity of physical illnesses and mental disorders in outpatients with tic disorders: a retrospective study using the outpatient case system

Background

Tic disorder, a chronic neurodevelopmental disorder that typically onsets during childhood, is characterized by sudden, involuntary, rapid, and non-rhythmic motor and vocal tics. Individuals with tic disorders often experience physical health issues. The purpose of our retrospective analysis was to elucidate the common comorbid physical diseases and mental disorders and their characteristics of outpatient children with tic disorders in a large public children's hospital in China over the past 5 years.

Methods

Participants were outpatients with tic disorders who visited Beijing Children's Hospital, from January 1, 2018 to December 31, 2022. After the inclusion screening, a total of 523,462 patient visits were included in the analysis. Based on the International Classification of Diseases, 10th Revision (ICD-10) diagnostic system, we employed descriptive statistical analysis to examine the frequently co-occurring somatic diseases in patients with tic disorders, as well as the influence of variables such as age and seasonal variation on these comorbidities.

Results

The top five diseases of total outpatient visits were as follows: Respiratory diseases, Mental and behavioral disorders, Diseases of the eye and adnexal, Digestive disorders, Diseases of the skin and subcutaneous tissue. Among the top five comorbid disease system, the most commonly third- level classification of diseases were upper respiratory tract infections, attention deficit and hyperactivity disorder, conjunctivitis, dyspepsia, dermatitis. Respiratory system diseases experienced a peak in April, while the other four types of diseases reached their peak in August. Additionally, each disease system showed the lowest number of patient visits in February. Additional to the mental and behavioral disorders, the other four disease systems would experience a peak in medical visits between the ages of 4 and 6.

Conclusion

Our study highlighted the most common physical diseases and mental disorders in tic disorders, namely the respiratory diseases, specifically upper respiratory tract infections, and mental and behavioral disorders, with ADHD being the most common co-occurring condition.

Deep brain stimulation for Tourette's syndrome

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.

Towards zebrafish models to unravel translational insights of obsessive-compulsive disorder: A neurobehavioral perspective

Obsessive-compulsive disorder (OCD) is a chronic and debilitating illness that has been considered a polygenic and multifactorial disorder, challenging effective therapeutic interventions. Although invaluable advances have been obtained from human and rodent studies, several molecular and mechanistic aspects of OCD etiology are still obscure. Thus, the use of non-traditional animal models may foster innovative approaches in this field, aiming to elucidate the underlying mechanisms of disease from an evolutionary perspective. The zebrafish (Danio rerio) has been increasingly considered a powerful organism in translational neuroscience research, especially due to the intrinsic features of the species. Here, we outline target mechanisms of OCD for translational research, and discuss how zebrafish-based models can contribute to explore neurobehavioral aspects resembling those found in OCD. We also identify possible advantages and limitations of potential zebrafish-based models, as well as highlight future directions in both etiological and therapeutic research. Lastly, we reinforce the use of zebrafish as a promising tool to unravel the biological basis of OCD, as well as novel pharmacological therapies in the field.

Neurodevelopmental Disorders Associated with Gut Microbiome Dysbiosis in Children

The formation of the human gut microbiome initiates in utero, and its maturation is established during the first 2-3 years of life. Numerous factors alter the composition of the gut microbiome and its functions, including mode of delivery, early onset of breastfeeding, exposure to antibiotics and chemicals, and maternal stress, among others. The gut microbiome-brain axis refers to the interconnection of biological networks that allow bidirectional communication between the gut microbiome and the brain, involving the nervous, endocrine, and immune systems. Evidence suggests that the gut microbiome and its metabolic byproducts are actively implicated in the regulation of the early brain development. Any disturbance during this stage may adversely affect brain functions, resulting in a variety of neurodevelopmental disorders (NDDs). In the present study, we reviewed recent evidence regarding the impact of the gut microbiome on early brain development, alongside its correlation with significant NDDs, such as autism spectrum disorder, attention-deficit/hyperactivity disorder, Tourette syndrome, cerebral palsy, fetal alcohol spectrum disorders, and genetic NDDs (Rett, Down, Angelman, and Turner syndromes). Understanding changes in the gut microbiome in NDDs may provide new chances for their treatment in the future.

Use of Medical Cannabis in Patients with Gilles de la Tourette's Syndrome in a Real-World Setting

Objective: Tourette's syndrome (TS) is a neurodevelopmental disorder characterized by vocal and motor tics and other comorbidities. Clinical recommendations for the use of medical cannabis are established, yet further guidance is needed. The aim of this study was to describe the experience of patients with TS with medical cannabis. Materials and Methods: TS patients were recruited from a registry of patients ("Tikun Olam" company). Questionnaires were answered before and after 6 months of treatment. Patients were divided into two groups: (A) patients who responded and (B) patients who did not respond to the follow-up questionnaire. In group A, an analysis was made to evaluate the presence and frequency of motor and vocal tics. The patients' general mood, employment status, quality of life, and comorbidities were also included in the analysis. Results: Seventy patients were identified. The tetrahydrocannabinol and cannabidiol mean daily dose was 123 and 50.5 mg, respectively. In group A, a statistically significant improvement was identified in quality of life (p<0.005), employment status (p=0.027), and in the reduction of the number of medications (p<0.005). Sixty-seven percent and 89% of patients with obsessive-compulsive disorder and anxiety comorbidities, respectively, reported an improvement. No statistically significant improvement was identified in motor tics (p=0.375), vocal tics (p>0.999), tics frequency (p=0.062), or general mood (p=0.129). The most frequent adverse effects were dizziness (n=4) and increased appetite (n=3). Conclusion: Subjective reports from TS patients suggest that medical cannabis may improve their quality of life and comorbidities. More studies are needed to evaluate the efficacy and safety of medical cannabis. Registry in the MOH: https://www.moh.gov.sg/ (Trial number: 0185-19-ASF).

Pivotal Role of Slitrk1 in Adult Striatal Cholinergic Neurons in Mice: Implication in Tourette Syndrome

OBJECTIVE

The SLIT and NTRK-like 1 (SLITRK1) gene mutation and striatal cholinergic interneurons (ChIs) loss are associated with Tourette syndrome (TS). ChIs comprise only 1 to 2% of striatal neurons but project widely throughout the stratum to impact various striatal neurotransmission, including TS-related dopaminergic transmission. Here, we link striatal Slitrk1, ChI function, and dopaminergic transmission and their associations with TS-like tic behaviors.

METHODS

Slitrk1-KD mice were induced by bilaterally injecting Slitrk1 siRNA into their dorsal striatum. Control mice received scrambled siRNA injection. Their TS-like tic behaviors, prepulse inhibition, sensory-motor function and dopamine-related behaviors were compared. We also compared dopamine and ACh levels in microdialysates, Slitrk protein and dopamine transporter levels, and numbers of Slitrk-positive ChIs and activated ChIs in the striatum between two mouse groups, and electrophysiological properties between Slitrk-positive and Slitrk-negative striatal ChIs.

RESULTS

Slitrk1-KD mice exhibit TS-like haloperidol-sensitive stereotypic tic behaviors, impaired prepulse inhibition, and delayed sensorimotor response compared with the control group. These TS-like characteristics correlate with lower striatal Slitrk1 protein levels, fewer Slitrk1-containing ChIs, and fewer activated ChIs in Slitrk1-KD mice. Based on their electrophysiological properties, Slitrk1-negative ChIs are less excitable than Slitrk1-positive ChIs. Slitrk1-KD mice have lower evoked acetylcholine and dopamine levels, higher tonic dopamine levels, and downregulated dopamine transporters in the striatum, increased apomorphine-induced climbing behaviors, and impaired methamphetamine-induced hyperlocomotion compared with controls.

INTERPRETATION

Slitrk1 is pivotal in maintaining striatal ChIs activity and subsequent dopaminergic transmission for normal motor functioning. Furthermore, conditional striatal Slitrk1-KD mice may serve as a translational modality with aspects of TS phenomenology. ANN NEUROL 2023.

Tourette syndrome and obsessive-compulsive disorder: A comprehensive review of structural alterations and neurological mechanisms

Currently, it is possible to study the pathogenesis of Tourette's syndrome (TS) in more detail, due to more advanced methods of neuroimaging. However, medical and surgical treatment options are limited by a lack of understanding of the nature of the disorder and its relationship to some psychiatric disorders, the most common of which is obsessive-compulsive disorder (OCD). It is believed that the origin of chronic tic disorders is based on an imbalance of excitatory and inhibitory influences in the Cortico-Striato-Thalamo-Cortical circuits (CSTC). The main CSTCs involved in the pathological process have been identified by studying structural and neurotransmitter disturbances in the interaction between the cortex and the basal ganglia. A neurotransmitter deficiency in CSTC has been demonstrated by immunohistochemical and genetic methods, but it is still not known whether it arises as a consequence of genetically determined disturbances of neuronal migration during ontogenesis or as a consequence of altered production of proteins involved in neurotransmitter production. The aim of this review is to describe current ideas about the comorbidity of TS with OCD, the involvement of CSTC in the pathogenesis of both disorders and the background of structural and neurotransmitter changes in CSTC that may serve as targets for drug and neuromodulatory treatments.

Physiological and introspective antecedents of tics and movements in adults with tic disorders

OBJECTIVE

To investigate the subjective phenomenon and the neural underpinnings of tics compared with voluntary movements in patients with tic disorders.

METHODS

We recorded electroencephalographic and electromyographic data while subjects completed a Libet clock paradigm. Patients and healthy volunteers reported the times of W (willing to move) and M (movement occurrence) while performing voluntary movements. This was repeated only for the patients for the tics.

RESULTS

In the patients, W and M times preceding voluntary movements and tics did not significantly differ from voluntary movements of healthy volunteers. The Bereitschaftspotentials in the patients were similar to healthy volunteers. Tics were only assessable for 7 patients due to artifacts. Two subjects did not show Bereitschaftspotentials, and they reported the lowest levels of tic voluntariness. 5 subjects did not show beta band event-related desynchronization before tics.

CONCLUSIONS

For patients, the sense of volition for tics is similar to that of their voluntary movements which is similar to normal. Patients showed dissociations between the Bereitschaftspotential and beta desynchronization for tics, with 5/7 showing normal Bereitschaftspotentials and 2/7 showing desynchronization. The absence of desynchronization may suggest attempts to suppress tics.

SIGNIFICANCE

This physiology shows a difference for most tics compared with normal movements.

Teacher Knowledge of Tourette Syndrome and Associated Factors

BACKGROUND

TS is associated with learning disabilities and educational impairment. Teacher knowledge about TS may have a positive impact on students with TS, but factors associated with teacher knowledge of TS are not known.

METHODS

In this cross-sectional study, teachers of youth with TS and of a community control group completed a Teacher Understanding of Tourette Syndrome Survey (TUTS), a pilot questionnaire enquiring about self-perceived understanding, teacher knowledge, and sources of information. We compared TUTS scores between TS and control groups and between those who did and did not use specific sources of information about TS using Wilcoxon rank-sum tests. Bivariate correlation analyses were used to evaluate associations between teacher knowledge and potential contributing factors.

RESULTS

Data from 114 teachers of children with TS and 78 teachers of control subjects were included. Teachers of youth with TS had significantly more knowledge, had higher self-perceived understanding, and used more sources of information than teachers of the control group. Teachers who knew of the Tourette Association of America and who gathered information themselves had higher knowledge about TS than those who did not.

CONCLUSION

Teachers of children with TS know more about TS and use more sources to learn about TS than teachers of children without TS.

G protein-coupled receptors in neurodegenerative diseases and psychiatric disorders

Neuropsychiatric disorders are multifactorial disorders with diverse aetiological factors. Identifying treatment targets is challenging because the diseases are resulting from heterogeneous biological, genetic, and environmental factors. Nevertheless, the increasing understanding of G protein-coupled receptor (GPCR) opens a new possibility in drug discovery. Harnessing our knowledge of molecular mechanisms and structural information of GPCRs will be advantageous for developing effective drugs. This review provides an overview of the role of GPCRs in various neurodegenerative and psychiatric diseases. Besides, we highlight the emerging opportunities of novel GPCR targets and address recent progress in GPCR drug development.

Genetics, molecular control and clinical relevance of habituation learning

Habituation is the most fundamental form of learning. As a firewall that protects our brain from sensory overload, it is indispensable for cognitive processes. Studies in humans and animal models provide increasing evidence that habituation is affected in autism and related monogenic neurodevelopmental disorders (NDDs). An integrated application of habituation assessment in NDDs and their animal models has unexploited potential for neuroscience and medical care. With the aim to gain mechanistic insights, we systematically retrieved genes that have been demonstrated in the literature to underlie habituation. We identified 258 evolutionarily conserved genes across species, describe the biological processes they converge on, and highlight regulatory pathways and drugs that may alleviate habituation deficits. We also summarize current habituation paradigms and extract the most decisive arguments that support the crucial role of habituation for cognition in health and disease. We conclude that habituation is a conserved, quantitative, cognition- and disease-relevant process that can connect preclinical and clinical work, and hence is a powerful tool to advance research, diagnostics, and treatment of NDDs.

Tics and Tourette Syndrome: A Literature Review of Etiological, Clinical, and Pathophysiological Aspects

Tourette syndrome (TS) is a condition characterized by tics produced because of neuropsychiatric malfunctioning occurring in childhood, which becomes less severe in adulthood, followed by a difference in the severity of tics between two persons. TS is a diverse variable in which symptoms vary in different patients. It is associated with comorbidities like obsessive-compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), and depression, and hampers the quality of life. Comorbid disorders must be investigated and treated as part of the clinical approach for all TS patients. Clinicians should be aware of the infrequent but serious neurological problems that can occur in these patients and recommend aggressively treating tics. Currently, there is more emphasis on symptom-based treatments by medicines, but as etiological knowledge improves, we will divert to disease-modifying medications in the future. Behavioral, pharmacological, and surgical methods can treat TS. Neuroleptics, other drugs, and behavioral therapies are the first-line options. Deep brain stimulation is evolving but has its pros and cons. The main focus of this review is on tics characteristics, how to manage and assess them, and limitations in the clinical spectrum.

Sensory over-responsivity and obsessive-compulsive disorder: Measuring habituation and sensitivity through self-report, physiological and behavioral indices

Individuals with obsessive-compulsive disorder (OCD) may report Sensory Over Responsivity (SOR), but evidence for specific shared mechanism is limited. This study investigated a habituation-sensitivity mechanism in individuals with OCD (n = 30). Sensory habituation and sensitivity were compared with a neurotypical sample, divided to high (n = 30) and low (n = 30) obsessive-compulsive symptoms (HOCS and LOCS). Participants completed self-report sensory questionnaires and a physiological protocol measuring Electro Dermal Activity (EDA) while presenting aversive and neutral sounds in two conditions: Aversive stimuli followed by neutral stimuli (AVfirst), or neutral stimuli followed by aversive stimuli (NEfirst). In addition, participants could shorten the stimulus duration by pressing a key. LOCS differed from HOCS and OCD in most sensory self-report scores, with no significant difference between OCD and HOCS. HOCS had no significant differences in habituation patterns across conditions, while OCD had no differences in habituation patterns in AVfirst (p = .08) but significantly slower habituation patterns to the NEfirst neutral stimuli (p < .001). Condition order determined sensitivity for LOCS (AVfirst p = .017; NEfirst p = .045) but not for OCD and HOCS. HOCS and OCD shortened aversive stimuli by key pressing more than LOCS, with no significant difference between OCD and HOCS. The habituation process of individuals with OCD and HOCS was more influenced by stimulus type than by condition order, which might be due to a cognitive bias of prediction. Individuals with elevated OCS have difficulty relying upon sensory input to respond adaptively to the environment. This process can explain the avoidant behavior and complains of individuals with OCD not being able to ignore and to habituate to the sensory environment. These evidence warrants design of psychoeducation and intervention methods for relying on prior sensory information to improve functioning in individuals with OCD and SOR.

What makes tics tick? Insights into Tourette syndrome

This issue of Biomedical Journal provides the reader with articles concerning the latest understanding of Tourette syndrome (TS), the relation to genetic predisposition, defects in the dopaminergic system, and related comorbidities which further complications like sleep disruption. Treatment approaches for TS, attention deficit hyperactivity disorder and developmental coordination disorder are discussed. The second section of this issue offers insights into inside out integrin activation and its link to T cell activation, demonstrates how polarity in immune cells allows adoption to specialized functions, and describes the endosomal signaling of internalized T cell receptors (TCRs). The link between mutations in TCR signaling and immunodeficiencies is elucidated, as well as the interactions of thymocyte-expressed molecule involved in selection in T cell development. Additionally, we learn about a potential biomarker for colorectal cancer, screening tools for determining frailty in older adults, surgical approaches in spinal metastases, the influence of autophagy on mating behavior, and the effect of nitrite administration on SNARE proteins associated with insulin secretion. Finally, parameters for surgery in breast cancer are discussed, as well as gender and age dependent pain perception in a lysosomal storage disease, and the use of laser meridian massage in opioid use disorder. Three letters complement this issue, one concerning neuroimaging in pediatric COVID-19 patients, and two discussing the role of cancer antigen-125 and renal impairment in ovarian cancer patients.

Tourette's syndrome: challenging misconceptions and improving understanding

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

Efficacy of Behavioural Intervention, Antipsychotics, and Alpha Agonists in the Treatment of Tics Disorder in Tourette’s Syndrome

Tourette's Syndrome (TS), in which patients have sudden, repeated, involuntary twitches and movements, called tics, is a condition of the nervous system. They can be motor, vocal, simple, or complex tics. It can be physically, emotionally, mentally, and socially distressing and challenging for those suffering from it. Usually, it is accompanied by various comorbidities like attention-deficit hyperactivity disorder, obsessive-compulsive disorder, and sleep disorders. A variety of environmental and genetic factors are also associated with tics in TS like the first-degree relatives are more at risk of developing TS.TS is heterogeneous with complicated patterns of inheritance and phenotypic manifestations. There is a strong association between common single nucleotide polymorphisms (SNP, s) in the SLITRK1 gene and TS. Environmental factors like prenatal, postnatal, and perinatal factors directly influence tics in TS. These factors are low birth weight, intrauterine growth retardation (IGR), and various infections. The treatment of TS can be broadly classified into non-pharmacological and pharmacological treatment. Non-pharmacological therapy includes various behavioural interventions that can be helpful in situations when patients are tolerant of medical treatments. Psychoeducation and counselling play an essential role in the treatment of TS. It is vital to give a proper understanding to the patient and their family about the disease. Cognitive-behavioral intervention for tics, cognitive-behavioral therapy, exposure and response prevention, relaxation techniques, deep brain stimulation, and habit reversal training are the commonly used therapies for tics. These therapies have shown good efficacy because it improves the Yale Global Tic Severity Scale score (YGTSS) significantly. And they show effectiveness in patients who are irresponsive to medical treatment. The main lines of medical treatment are antipsychotics and alpha agonists. Typical (haloperidol, pimozide) or atypical (aripiprazole, risperidone, olanzapine) Antipsychotics differ in their side effects, efficacy, and tolerance in different age groups of children. Haloperidol was the first drug approved by the Food and Drug Administration for tics, but later on, new developments and improvements were made as far as drug therapy is concerned. The alpha-agonist most commonly used is clonidine which is also available in the form of adhesive patches. Another alpha agonist which is also widely used is guanfacine. Botulinum toxin and baclofen have also shown efficacy in dealing with tics in TS with other comorbidities. We will review in this article all the main lines of treatment and their effectiveness in TS.

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.

Tonic Tics in Gilles de la Tourette Syndrome

AIM

Tonic tics (TTs) are a part of a clinical picture of Gilles de la Tourette syndrome (GTS) and manifest themselves as sustained and isometric contraction of a muscle group devoid of the movement effect or accompanied by only slight visible motion. The aim of this study was to evaluate the prevalence and phenomenology of TTs, and to assess the clinical associations of TTs with tic severity and comorbidities in patients with GTS.

METHODS

We performed a one-time registration study in a cohort of 241 consecutive outpatients with GTS aged 5 to 50 years (188 males, 153 patients under the age of 18 years). All patients were personally interviewed and examined.

RESULTS

TTs occurred in 85.2% of adults and 63.9% of children and adolescents. Most frequently reported types of TTs were tensing of the abdomen (58.7%), neck (52.7%), and upper limbs (50.3%). Multivariate statistical analysis showed a significant correlation between TTs and the total number of simple tics, total number of complex tics, and age at evaluation. In the group of children and adolescents, an additional significant variable was the duration of GTS. In the group of adults, significant parameters were total number of simple tics, total number of complex tics, peak tic severity ever experienced, premonitory urges, and the presence of dystonic tics.

CONCLUSION

TTs belong to the tic spectrum, common and early symptoms of GTS, are associated with overall a greater number of tics which are more severe, and with more comorbidities.

The Histaminergic System in Neuropsychiatric Disorders

Histamine does not only modulate the immune response and inflammation, but also acts as a neurotransmitter in the mammalian brain. The histaminergic system plays a significant role in the maintenance of wakefulness, appetite regulation, cognition and arousal, which are severely affected in neuropsychiatric disorders. In this review, we first briefly describe the distribution of histaminergic neurons, histamine receptors and their intracellular pathways. Next, we comprehensively summarize recent experimental and clinical findings on the precise role of histaminergic system in neuropsychiatric disorders, including cell-type role and its circuit bases in narcolepsy, schizophrenia, Alzheimer's disease, Tourette's syndrome and Parkinson's disease. Finally, we provide some perspectives on future research to illustrate the curative role of the histaminergic system in neuropsychiatric disorders.

Association Between Tic Aggravation and Methylphenidate in Youth With Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

This study aimed to determine the tic aggravation event rate and cumulative incidence rate in the use of methylphenidate (MPH) treatment in attention-deficit/hyperactivity disorder (ADHD) and the factors that influence tic aggravation.

METHODS

We conducted a retrospective chart review of children and adolescents aged between 6 to 15 years, who were diagnosed with ADHD from January 2017 to December 2019. A total of 121 subjects were included. The MPH dosage, psychiatric family history, comorbidity and past history of tics were assessed through chart review and the psychological examinations data were included. Collected data were analyzed using Cox regression and Kaplan-Meier survival analysis.

RESULTS

Tic aggravation event rates without a past history of tics were 2.9% with MPH treatment in ADHD. Past history of tics, total MPH dosage and age were the factors associated with tic aggravation ([HR 21.46, p<0.001], [HR 0.94, p=0.023], [HR 0.79, p=0.021] for each). Cumulative incidence of tic aggravation was different between groups with or without past tic history. When treated with MPH, all tic aggravation appeared within approximately eight months but for subjects with a past history of tic, aggravation showed within approximately six months (p<0.001).

CONCLUSION

Tic aggravation event rate was significantly low especially in the group without a past history of tics with the use of MPH in ADHD. However, a thorough assessment of past history of tics, and close monitoring during the first six-eight months of treatment with MPH is needed to avert a potential worsening of tics.

Cognitive Tic-Like Phenomena in Gilles de la Tourette Syndrome

Coprolalia and echophenomena repeated in the patients’ mind (CTPh—cognitive tic-like phenomena) have been rarely recognized as part of Gilles de la Tourette syndrome (GTS) symptomatology and their assignment to tics, OCD or other psychopathologies has not been settled. The aim of the paper was to assess the incidence and clinical associations of CTPh in GTS, and to establish if CTPh belong to the tic spectrum. We performed a prospective, one-registration study on a cohort of 227 consecutive patients with GTS. CTPh were diagnosed during the interview and defined as brief, sudden, involuntary thoughts that had corresponding complex vocal tics. CTPh occurred at some point in the lives of 34 (15.0%) patients. The median age at onset of CTPh was 14.5 years (IQR: 10.5–17.5). CTPh were found more frequently in adults, with the most frequent onset in adolescence (44.1%). Four mental phenomena resembling tics were recognized: echolalia (n = 17), coprolalia (n = 16), palilalia (n = 13) and repeating of words in the mind (n = 7). The older the age of patients, the more severe tics, and anxiety disorder significantly correlated with CTPh. CTPh may be considered as a part of tic spectrum with a substantial impact of anxiety disorder. CTPh are a late and age-related symptom of GTS.

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.

Very-Low-Dose Levodopa Therapy for Pediatric Neurological Disorders: A Preliminary Questionnaire in Japan

Introduction: Post-synaptic dopamine receptor supersensitivity (DARSS) has been extensively researched by Dr. Masaya Segawa, who has investigated the efficacy of very-low-dose levodopa therapy (VLDT; 0.5-1 mg/kg/day). Considerable Japanese research supports the possibility that VLDT could be used to treat pediatric neurological disorders. We conducted an on-line survey in 2014 to collect real-world data on the use of VLDT to treat DARSS. Methods: A two-step survey, including a screening test and questionnaire, was posted on a private internet site that could be accessed via the VLDT Research Group home page, and 1,165 pediatric neurologists across Japan were invited to complete it. Results: A total of 25 respondents reported prescribing VLDT; 19 used VLDT to treat autism spectrum disorder, 14 for tics, 12 for speech delay, 9 for Rett syndrome, 7 for attention-deficit/hyperactivity disorder, intellectual disability, and 6 for sleep problems. Twelve respondents reported prescribing a dose of 0.5 mg/kg. Twenty-two reported that VLDT was effective for treating behavioral problems, and twenty reported a good efficacy for treating motor symptoms. Adverse events had a low incidence. Notably, respondents chose VLDT for its possible action in DARSS and for its safety. VLDT was commonly used for behavioral problems in patients younger than 5 years, and for motor symptoms in aged 5-9 years. Conclusion: VLDT could safely treat behavioral and motor symptoms in pediatric neurological disorders. In contrast, dopamine antagonists are associated with potent efficacy, but with adverse effects such as sleepiness and obesity. Further surveys should be conducted with a broader participants.

Regulatory effects of Ningdong granule on microglia-mediated neuroinflammation in a rat model of Tourette's syndrome

Tourette's syndrome (TS) is an inherited neurologic disorder characterized by involuntary stereotyped motor and vocal tics. Its pathogenesis is still unclear and its treatment remains limited. Recent research has suggested the involvement of immune mechanisms in the pathophysiology of TS. Microglia are the brain's resident innate immune cells. They can mediate neuroinflammation and regulate brain development and homeostasis. A traditional Chinese medicine (TCM), Ningdong granule (NDG), has been found to be efficacious in the treatment of TS while causing few adverse reactions. In the current study, a rat model of 3,3'-iminodipropionitrile (IDPN)-induced TS was used to explore the regulating effects and mechanisms of NDG on microglia-mediated neuroinflammation. IDNP led to robust pathological changes and neurobehavioral complications, with activation of microglia in the striatum of rats with TS. After activation by IDNP, microglia strongly responded to this specific injury, and TNF-α, IL-6, and MCP-1 were released in the striatum and/or serum of rats with TS. Interestingly, NDG inhibited the activation of microglia and decreased the abnormal expression of TNF-α, IL-6, and MCP-1 in the striatum and/or serum of rats with TS, thus controlling tics. However, there were no significant changes in the striatum and/or serum of rats with TS after treatment with haloperidol. The anti-TS action of haloperidol might occur not through microglial activation and neuroinflammation but through the DAT system, thus controlling tics. In conclusion, microglia might play key roles in mediating neuroinflammatory responses in TS, triggering the release of TNF-α, IL-6, and MCP-1.NDG inhibited tics in rats with TS, and this mechanism may be associated with a reduction in the increased number of activated microglia and a decrease in the expression of pro-inflammatory cytokines and chemokines in the striatum and/or serum.

Corneal collagen cross-linking for management of keratoconus in patients affected by Tourette syndrome

PURPOSE

To present a series of two patients affected by Tourette syndrome (TS) and progressive keratoconus.

CASE SERIES

Two young male patients with keratoconus and TS were referred to our center. In both patients eye rubbing was present and in one patient, an ocular tic was present determining blepharospasm. Progression of keratoconus occurred in both cases and corneal collagen cross-linking (CXL) was performed. All treated eyes showed topographic stability with stable refraction and conserved visual acuity, with a follow-up period ranging from 1.5 to 2.5 years.

CONCLUSION

Patients with keratoconus and TS should be observed frequently to document topographical and refractive changes, and in case of progressing disease, CXL should be performed in order to prevent further progression.

Brain functional connectivity in chronic tic disorders and Gilles de la Tourette syndrome

The pathophysiology of chronic tic disorder (cTD) and Gilles de la Tourette syndrome (GTS) is characterized by the dysfunction of both motor and non - motor cortico - striatal - thalamo - cortical (CSTC) circuitries, which leads to tic release and comorbids. A role of fronto - parietal network (FPN) connectivity breakdown has been postulated for tic pathogenesis, given that the FPN entertain connections with limbic, paralimbic, and CSTC networks. Our study was aimed at characterizing the FPN functional connectivity in cTD and GTS in order to assess the role of its deterioration in tic severity and the degree of comorbids. We recorded scalp EEG during resting state in patients with cTD and GTS. The eLORETA current source densities were analyzed, and the lagged phase synchronization (LPS) was calculated to estimate nonlinear functional connectivity between cortical areas. We found that the FPN functional connectivity in delta band was more detrimental in more severe GTS patients. Also, the sensorimotor functional connectivity in beta2 band was stronger in more severe cTD and GTS patients. FPN functional connectivity deterioration correlated with comorbids presence and severity in patients with GTS. Our data suggest that a FPN disconnection may contribute to the motoric symptomatology and comorbid severity in GTS, whereas sensorimotor disconnection may contribute to tic severity in cTD and GTS. Although preliminary, our study points out a differently disturbed brain connectivity between patients with cTD and GTS. This may serve as diagnostic marker and potentially interesting base to develop pharmacological and noninvasive neuromodulation trials aimed at reducing tic symptomatology.

A double-blind, randomized, sham-controlled study of cranial electrotherapy stimulation as an add-on treatment for tic disorders in children and adolescents

AIM

The aim of this study was to determine the efficacy and safety of cranial electrotherapy stimulation (CES) as an add-on treatment for TD.

METHODS

A randomized, double-blind, sham-controlled trial was conducted at an outpatient, single-center academic setting. A total of 62 patients aged 6-17 years with TD and lack of clinical response to 4 weeks' pharmacotherapy were enrolled. Patients were divided randomly into 2 groups and given 4 weeks' treatment, including 30 min sessions of active CES (500 μA-2 mA) or sham CES (lower than 100 μA) per day for 40 d on weekdays. Change in Yale Global Tic Severity Scale (YGTSS), Clinical Global Impression-severity of illness-severity (CGI-S) and Hamilton Anxiety Scale-14 items (HAMA-14) were performed at baseline, week 2, week 4. Adverse events (AEs) were also evaluated.

RESULTS

53 patients (34 males and 9 females) completed the trial, including 29 in the active CES group and 24 in the sham CES group. Both groups showed clinical improvement in tic severities compared to baseline respectively at week 4. Participants receiving active CES showed a reduction of 31.66 % in YGTSS score, compared with 23.96 % in participants in sham CES group, resulting in no significant difference between the two groups (t = 1.54, p = 0.13).

CONCLUSION

Four-week's treatment of CES for children and adolescents with TD is effective and safe, but the improvement for tic severity may be related to placebo effect.

Children from nuclear families with bad parental relationship could develop tic symptoms

BACKGROUND

Studies have reported the impact of chronic childhood and adolescent tic disorder (TD) on families. However, few researches focused on the relationship between family environment and diagnosis of TD. We aim to assess the influence of couple relationship and family structure on the onset of TD.

METHODS

A total of 660 parents of patients with TD (aged 6-12 years) and 641 parents of controls completed questionnaires. Couple relationship and family structure were selected by regression of binary logistic analysis as the risk factors. Couple relationship was divided into the harmonious, common, hostile, and divorced. Family structure included unconventional family, nuclear family, and unite family. Multivariate correspondence analysis was designed to explore relationships among categorical variables of couple relationship and family structure.

RESULTS

There were significant associations between TD and couple relationship (Exp B = 1.310, p = .006, 95% CI = 1.080-1.590), family structure (Exp B = 0.668, p = .001, 95% CI = 0.526 ~ 0.847), gender (Exp B = 0.194, p < .001, 95% CI = 0.149-0.254), respectively. Obviously contradicted and common couple relationships were risk factors for TD compared with the harmonious and divorced. Children form unconventional family or nuclear family were prone to develop TD. Interestingly, divorced parents had the same protective effect as harmonious parents. The OR value could increase with the number and level of those risk factors.

CONCLUSIONS

In conclusion, children from nuclear families with bad parental relationship could be more likely to develop tic symptoms. The family intervention of children with TD should focus on family structure and parental relationship.

Sensory Habituation as a Shared Mechanism for Sensory Over-Responsivity and Obsessive-Compulsive Symptoms

Background

Some individuals who suffer from obsessive-compulsive (OC) disorder (OCD), report disturbing sensory preoccupations. The inability to stop obsessing over stimuli resonates with a difficulty in sensory habituation. Impaired sensory habituation, to a degree that clearly dysregulates response to sensory stimuli, and impairs participation in everyday activities, can be part of a disorder known as sensory over-responsivity (SOR). Although previous studies indicated a correlation between OCD and SOR, physiological experiments show that individuals with OCD are not more sensitive to sensory stimuli than controls. In the current study, we (1) validated a sensory habituation psycho-physiological protocol and (2) tested whether a "slow to habituate" mechanism can explain the occurrence of elevated SOR and OC symptoms.

Methods

We designed a protocol to test auditory sensory habituation through electrodermal activity (EDA) recording. The protocol included two randomly ordered aversive and neutral sound conditions; each set of six everyday life sounds was presented as a continuous stimulus. During the presentation of sounds, EDA was measured and participants could press a button to shorten the stimuli. Participants also completed sensory and OC symptom questionnaires. Participants included 100 typically developing adults that were divided into high versus low OC symptom groups. Mixed models analysis was used throughout to meet the need for capturing the temporal nature of habituation.

Results

Distinct physiological indices were computed to measure sensitivity versus habituation. Habituation was slower in the aversive versus neutral condition. Sensitivity was higher for the aversive stimuli. Self-report of sensory habituation and sensitivity partially correlated with the physiological habituation indices. A comparison of the physiological pattern between those with high versus low OC symptoms revealed significant differences in the habituation and sensitivity indices, across conditions.

Conclusion

The interplay between SOR and OC symptoms can be explained by a "slow to habituate" mechanism. Identifying behavioral and physiological markers of sensory problems in OCD is important for assessment, intervention and the discovery of underlying mechanisms.

Tics and Tourette's syndrome

Tics and Tourette's syndrome are common hyperkinetic movement disorders seen mostly in the pediatric age group. Tics are defined as sudden, rapid, recurrent, nonrhythmic motor movements or vocalization, generally preceded by urge. Tourette's syndrome is defined as the presence of both motor and phonic tics for more than 1 year in patients with onset less than 18 years old. Most of these hyperkinetic movement disorders improve in adulthood. This review emphasizes the clinical pearls in the diagnosis and distinguishing it from other movement disorders. The treatment ranges from behavioral therapies, medical management, and also surgical treatment such as deep brain stimulation that is limited to refractory patients.

Anterior Limb of Internal Capsule and Bed Nucleus of Stria Terminalis Stimulation for Gilles de la Tourette Syndrome with Obsessive-Compulsive Disorder in Adolescence: A Case of Success

Gilles de la Tourette syndrome (GTS) is a neurobehavioral disorder comprising motor and vocal tics. In most cases it is associated with other disorders such as obsessive-compulsive disorder (OCD). In refractory cases deep brain stimulation (DBS) is a valid treatment option. This paper describes the case of a 15-year-old adolescent with an extremely refractory GTS with associated OCD. The patient developed catatonia associated with OCD, which partially remitted after electroconvulsive therapy. At the peak of the disease the Yale Global Tic Severity Scale (YGTSS) was 100 and the patient required sedation and intubation. All medical treatment options were unsuccessful. Bilateral DBS of the anterior limb of internal capsule (ALIC)/bed nucleus of stria terminalis (BST) region was performed, using a target below the BST and a trajectory through the ALIC, with stimulation of contacts 0 and 3. Two weeks after surgery sedatives were suspended and the patient was successfully extubated. One year after surgery the patient reached a YGTSS of 19, representing an 81% improvement. OCD completely resolved. Adverse events were a superficial infection and weight gain. In conclusion, this ALIC/BST stimulation appears to have been an effective and safe treatment for GTS with OCD in this case. Young age should not be an exclusion criterion for DBS in severe GTS and OCD. Further studies should be pursued for this target.

Alterations in the Nervous System and Gut Microbiota after β-Hemolytic Streptococcus Group A Infection-Characteristics and Diagnostic Criteria of PANDAS Recognition

The objective of this paper is to review and summarize conclusions from the available literature regarding Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS). The authors have independently reviewed articles from 1977 onwards, primarily focusing on the etiopathology, symptoms, differentiation between similar psychiatric conditions, immunological reactions, alterations in the nervous system and gut microbiota, genetics, and the available treatment for PANDAS. Recent research indicates that PANDAS patients show noticeable alterations within the structures of the central nervous system, including caudate, putamen, globus pallidus, and striatum, as well as bilateral and lentiform nuclei. Likewise, the presence of autoantibodies that interact with basal ganglia was observed in PANDAS patients. Several studies also suggest a relationship between the presence of obsessive-compulsive disorders like PANDAS and alterations to the gut microbiota. Further, genetic predispositions-including variations in the MBL gene and TNF-α-seem to be relevant regarding PANDAS syndrome. Even though the literature is still scarce, the authors have attempted to provide a thorough insight into the PANDAS syndrome, bearing in mind the diagnostic difficulties of this condition.

Mental health is biological health: Why tackling "diseases of the mind" is an imperative for biological anthropology in the 21st century

The germ theory of disease and the attendant public health initiatives, including sanitation, vaccination, and antibiotic treatment, led to dramatic increases in global life expectancy. As the prevalence of infectious disease declines, mental disorders are emerging as major contributors to the global burden of disease. Scientists understand little about the etiology of mental disorders, however, and many of the most popular psychopharmacological treatments, such as antidepressants and antipsychotics, have only moderate-to-weak efficacy in treating symptoms and fail to target biological systems that correspond to discrete psychiatric syndromes. Consequently, despite dramatic increases in the treatment of some mental disorders, there has been no decrease in the prevalence of most mental disorders since accurate record keeping began. Many researchers and theorists are therefore endeavoring to rethink psychiatry from the ground-up. Anthropology, especially biological anthropology, can offer critical theoretical and empirical insights to combat mental illness globally. Biological anthropologists are unique in that we take a panhuman approach to human health and behavior and are trained to address each of Tinbergen's four levels of analysis as well as culture. The field is thus exceptionally well-situated to help resolve the mysteries of mental illness by integrating biological, evolutionary, and sociocultural perspectives.

Ictal swearing network confirmed by stereoencephalography: a case report

Ictal swearing, characterized by episodic utterance of deistic, visceral and other taboo words and phrases, is a rare manifestation of epilepsy. Limited manifestation of that elucidate neural network about manifestation of. Here we report a 43-year-old right-handed man who has suffered from refractory epilepsy manifestation of ictal swearing. The stereoencephalography(SEEG) investigation located the seizure onset zone in left orbito-frontal cortex and the involvement of left orbito-frontal and right hippocampus in the propagation of epileptic activities. Surgical resection has made the patient seizure-free. The present case gives us better understanding of these ictal phenomena and helps to optimize the placement of SEEG electrodes in refractory epilepsy patient with ictal swearing.

Neural activation and connectivity during cued eye blinks in Chronic Tic Disorders

Objective

The pathophysiology of Chronic Tic Disorders (CTDs), including Tourette Syndrome, remains poorly understood. The goal of this study was to compare neural activity and connectivity during a voluntary movement (VM) paradigm that involved cued eye blinks among children with and without CTDs. Using the precise temporal resolution of electroencephalography (EEG), we used the timing and location of cortical source resolved spectral power activation and connectivity to map component processes such as visual attention, cue detection, blink regulation and response monitoring. We hypothesized that neural activation and connectivity during the cued eye blink paradigm would be significantly different in regions typically associated with effortful control of eye blinks, such as frontal, premotor, parietal, and occipital cortices between children with and without CTD.

Method

Participants were 40 children (23 with CTD, 17 age-matched Healthy Control [HC]), between the ages of 8–12 (mean age = 9.5) years old. All participants underwent phenotypic assessment including diagnostic interviews, behavior rating scales and 128-channel EEG recording. Upon presentation of a cue every 3 s, children were instructed to make an exaggerated blink.

Results

Behaviorally, the groups did not differ in blink number, latency, or ERP amplitude. Within source resolved clusters located in left dorsolateral prefrontal cortex, posterior cingulate, and supplemental motor area, children with CTD exhibited higher gamma band spectral power relative to controls. In addition, significant diagnostic group differences in theta, alpha, and beta band power in inferior parietal cortex emerged. Spectral power differences were significantly associated with clinical characteristics such as tic severity and premonitory urge strength. After calculating dipole density for 76 anatomical regions, the CTD and HC groups had 70% overlap of top regions with the highest dipole density, suggesting that similar cortical networks were used across groups to carry out the VM. The CTD group exhibited significant information flow increase and dysregulation relative to the HC group, particularly from occipital to frontal regions.

Conclusion

Children with CTD exhibit abnormally high levels of neural activation and dysregulated connectivity among networks used for regulation and effortful control of voluntary eye blinks.

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First cortical source level EEG study on brain activity and connectivity in CTD.

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Children with CTD exhibit aberrant levels of neural activation and connectivity.

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Neural activation was significantly associated with tic severity and premonitory urge.

Differentiating tics from functional (psychogenic) movements with electrophysiological tools

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Clinical observations alone often fail to discriminate functional jerky movements and jerks due to a tic disorder.

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Neurophysiological studies with EEG and polymyography assist with differentiating these conditions with more certainty.

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Further studies are needed for understanding the value, sensitivity and specificity of these techniques.

Objective

We report on two patients that presented to our clinic with the differential diagnosis of functional movement disorder vs tic disorder.

Case reports

The first patient is a 23-year-old woman with a 3-year history of repetitive involuntary neck flexion movements. The second patient is a 59-year-old man with a 10-month history of involuntary trunk jerks. In both cases, the polyelectromyographic study and the observation of Bereitschaftspotential helped us in making the final diagnosis.

Significance

The use of electrophysiological tools can be helpful in making the distinction between functional movement disorders and tic disorders.

Adult-Onset Gilles de la Tourette Syndrome: Psychogenic or Organic? The Challenge of Abnormal Neurophysiological Findings

Gilles de la Tourette syndrome (GTS) is characterized by multiple motor and vocal tics. Adult-onset cases are rare and may be due to "reactivation" of childhood tics, or secondary to psychiatric or genetic diseases, or due to central nervous system lesions of different etiologies. Late-onset psychogenic motor/vocal tics resembling GTS have been described. Neurophysiology may serve to differentiate organic from functional GTS. Altered blink reflex pre-pulse inhibition (BR-PPI), blink reflex excitability recovery (BR-ERC), and short-interval intracortical inhibition (SICI) have been described in GTS. We report a 48-years-old male, who developed numerous motor/vocal tics 2 months after sustaining non-commotional craniofacial trauma in a car accident. Both his father and brother had died earlier in car crashes. He presented with blepharospasm-like forced lid closure, forceful lip pursing, noisy suction movements, and deep moaning sounds, occurring in variable combinations, without warning symptoms or internal "urge." Tics showed low distractibility and these increased with attention. Standard magnetic resonance imaging, electroencephalography, and evoked potentials were unremarkable. Neuropsychology diagnosed moderately impaired intellect, attention, and executive functions. Psychiatric assessment revealed somatization disorder and generalized anxiety. BR-PPI was unremarkable, while BR-ERC was enhanced, even showing facilitation at short intervals. SICI was markedly reduced at 1 and 3 ms and intracortical facilitation (ICF) was enhanced at 10 ms. The patient fulfilled Fahn and Williams' diagnostic criteria for a psychogenic movement disorder. Neurophysiology, however, documented hyperexcitability of motor cortex and brainstem. We suggest that-similar to what has been reported in psychogenic dystonia-a pre-existing predisposition may have led to the functional hyperkinetic disorder in response to severe psychic stress.

Behavioral responses to anxiogenic tasks in young adult rats with neonatal dopamine depletion

The dopaminergic neural system plays a crucial role in motor regulation as well as regulation of anxiety-related behaviors. Although rats with neonatal dopamine depletion exhibit motor hyperactivity and have been utilized as animal models of attention deficit hyperactivity disorder, characterization of their behavior under anxiogenic conditions is lacking. In the present study, we investigated behavioral responses to anxiogenic stimuli in young adult rats with neonatal dopamine depletion using the open field (OF), elevated plus maze (EPM), and light/dark (L/B) box tests. The OF and EPM tests were performed under low-light and bright-light conditions. The ameliorative effects of pretreatment with methamphetamine (MAP) or atomoxetine (ATX) on abnormal behaviors induced by neonatal dopamine depletion were also assessed. Rats that underwent 6-hydroxydopamine treatment 4 day after birth showed significant increases in motor activity and decreases in anxiety-related behaviors in OF tests under both conditions and in EPM tests under bright-light conditions. Furthermore, rats with neonatal dopamine depletion did not show normal behavioral responsiveness to changes in the intensity of anxiogenic stimuli. Pretreatment with MAP (4 mg/kg) and ATX (1.2 mg/kg/day) ameliorated motor hyperactivity but not abnormal anxiety-related behaviors. These results suggest that the dopaminergic system plays a crucial role in the development of neural networks involved in locomotion as well as in those involved in anxiety-related behavior. The results indicate that the mechanisms underlying the abnormal anxiolytic responses partially differ from those underlying motor hyperactivity.

Self-concept and self-esteem in patients with chronic tic disorders: A systematic literature review

Chronic tic disorders are neurodevelopmental conditions characterized by the presence of motor and/or phonic tics and often accompanied by co-morbid behavioral problems. Chronic tic disorders can negatively affect the level of functioning of young patients across social and family domains, with possible repercussions on their self-perception. We conducted a systematic literature review to assess the clinical correlates of both components of self-perception (self-concept, i.e. what patients think about themselves, and self-esteem, i.e. how they feel about their self-concept) in patients with chronic tic disorders. Reported levels of self-perception varied widely across studies, partly due to the methodological heterogeneity of the reviewed literature. Poor self-concept and self-esteem appeared to be more strongly related to the presence of psychiatric co-morbidities (especially obsessive-compulsive disorder, attention-deficit and hyperactivity disorder, and anxiety disorders) than to tic severity. Poor peer relationship, social difficulties, as well as problems with parents' acceptance were identified as further risk factors for low self-perception. Finally, the reviewed studies highlighted a link between self-perception and quality of life in patients with chronic tic disorders, alongside the protective role of good social adjustment. This information can therefore assist treating clinicians in the choice of tailored therapeutic interventions for this patient population, including behavioral management techniques that can improve self-concept and self-esteem through increased self-efficacy.

Olfactory functioning in adults with Tourette syndrome

Tourette syndrome is a chronic tic disorder characterized by motor and vocal tics. Comorbidities such as attention deficit hyperactivity disorder and obsessive compulsive disorder can be found. The overlap between neuroanatomical regions and neurotransmitter systems in the olfactory system and the pathophysiology of Tourette syndrome let us hypothesize altered olfactory performance in Tourette syndrome. The main objective of this study was to systematically assess olfactory functioning in subjects with Tourette syndrome and to compare it to healthy controls. We assessed 28 adults with Tourette syndrome (age 33.1±9.4 years, disease duration 23.7±9.7 years) and 28 healthy controls (age 32.9±9.0 years) matched in regard to age, sex, education and smoking habits. The “Sniffin Sticks” test battery was applied to assess odor threshold, discrimination, and identification. Additionally, the combined score of the odor threshold test, the odor discrimination test and the odor identification test of the “Sniffin Sticks” test battery was calculated. Although it was not the primary aim of this study, we assessed whether tics and comorbidity could contribute to olfactory alterations in adults with Tourette syndrome. Therefore, clinical scores were used to assess severity of tics and co-morbidity such as attention deficit hyperactivity disorder, obsessive compulsive disorder, anxiety and depression in subjects with Tourette syndrome. Pathology of the nasal cavities was excluded with rhinoendoscopy. Independent sample t-tests were applied to compare performance in olfactory tests. In the case of statistically significant differences (critical p-value: 0.05), multiple linear regression analysis was carried out to explore whether tic severity, social impairment, co-morbidity or medical treatment had an impact on the differences found. Descriptive values are reported as mean ± standard deviation. Tourette syndrome subjects showed lower combined scores (Tourette syndrome subjects 31.9 ± 5.1 versus healthy controls 35.0 ± 3.1; p = 0.007), odor identification scores (Tourette syndrome subjects 12.4 ± 2.0 versus healthy controls 13.7 ± 1.4; p = 0.008) and odor discrimination scores (Tourette syndrome subjects 12.1 ± 2.1 versus healthy controls 13.2 ± 1.6; p = 0.041) in comparison to healthy subjects, while there was no difference in odor threshold (Tourette syndrome subjects 7.3 ± 2.7 versus healthy controls 8.1 ± 2.2; p = 0.22). Seven out of 28 Tourette syndrome subjects (25%) scored in the range of the age- and sex-dependent combined score for hyposmia, while two of 28 healthy controls (7%) had a similar low combined score. None of the participants were found to have functional anosmia. Multiple linear regression analyses suggest that social impairment may a predictor for low combined score and odor identification score in Tourette syndrome subjects (p = 0.003). Compared to healthy controls, altered olfaction in adults with Tourette syndrome was found in this study. Normal odor threshold level but lower scores at tasks involving supra-threshold odor concentrations point towards a central-nervous alteration in the processing of olfactory information in Tourette syndrome.