Tic disorders: new developments in Tourette syndrome and related disorders

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

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

Fragile X syndrome: A review of clinical management

The fragile X mental retardation 1 gene, which codes for the fragile X mental retardation 1 protein, usually has 5 to 40 CGG repeats in the 5' untranslated promoter. The full mutation is the almost always the cause of fragile X syndrome (FXS). The prevalence of FXS is about 1 in 4,000 to 1 in 7,000 in the general population although the prevalence varies in different regions of the world. FXS is the most common inherited cause of intellectual disability and autism. The understanding of the neurobiology of FXS has led to many targeted treatments, but none have cured this disorder. The treatment of the medical problems and associated behaviors remain the most useful intervention for children with FXS. In this review, we focus on the non-pharmacological and pharmacological management of medical and behavioral problems associated with FXS as well as current recommendations for follow-up and surveillance.

Dual ameliorative effects of Ningdong granule on dopamine in rat models of Tourette's syndrome

Dopamine (DA) is a key neuromodulator in the brain that supports motor and cognitive functions. Here, we use apomorphine (Apo) and 3,3'-iminodipropionitrile (IDPN) to develop two rat models of Tourette's syndrome (TS), a common neuropsychiatric disorder characterized by stereotyped repetitive involuntary tics. The models enabled the assessment of unique ameliorative effects of Ningdong granule (NDG), a traditional Chinese medicine (TCM) preparation dedicated to the treatment of TS, on the striatal DA content of rats. By using high-performance liquid chromatography (HPLC), we found that long-term administration of NDG could, at least partially, restore the striatal dopamine alterations, either by increasing them after IDPN treatment or by decreasing them after Apo treatment. Taken together, our data indicated that NDG could ameliorate the abnormal striatal DA content dually, and the unique therapeutic property may be meaningful for the treatment of TS.

Impaired activation of the innate immune response to bacterial challenge in Tourette syndrome

OBJECTIVES

Infections resulting in immune activation have been proposed to play an etiological role in a subgroup of patients with Tourette syndrome (TS).

METHODS

In order to further characterize the interaction between pathogens and the innate immune system the toll-like receptor (TLR) 4 on CD14 + monocytes and soluble CD14 (sCD14) levels were analyzed in the serum of 33 Tourette patients and 31 healthy controls. Moreover, collected blood samples were stimulated with lipopolysaccharide (LPS) mimicking a bacterial infection. TLR4 was analysed by flow cytometry, sCD14 was analysed by enzyme-linked immunosorbent assay.

RESULTS

Patients had a lower receptor expression of TLR4 after stimulation with LPS (P = 0.045) and higher levels of sCD14 (unstimulated P = 0.014, after LPS P = 0.045). The increase in TLR4 expression after stimulation with LPS was significantly higher in the control group (P = 0.041).

CONCLUSIONS

Higher levels of sCD14, lower levels of TLR4 expression after stimulation and a diminished up-regulation of TLR4 expression after LPS stimulation in patients might represent an impaired activation of the innate immune response in TS, especially in regard to bacterial infection. The impaired response to pathogens could eventually lead to a higher susceptibility for infections. Recurring infections and a chronic inflammation could trigger and maintain the symptoms of TS.

Immune-mediated animal models of Tourette syndrome

An autoimmune diathesis has been proposed in Tourette syndrome (TS) and related neuropsychiatric disorders such as obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism and anorexia nervosa. Environmental triggers including infection and xenobiotics are hypothesized to lead to the production of brain-directed autoantibodies in a subset of genetically susceptible individuals. Although much work has focused on Group A Streptococcus (GAS), the role of this common childhood infection remains controversial. Animal model studies based on immune and autoantibody findings in TS have demonstrated immunoglobulin (Ig) deposits and stereotypic movements and related behavioral disturbances reminiscent of TS following exposure to GAS, other activators of host anti-microbial responses, soluble immune mediators and anti-GAS or anti-neuronal antibodies. Demonstration of the ability to recreate these abnormalities through passive transfer of serum IgG from GAS-immunized mice into naïve mice and abrogation of this activity through depletion of IgG has provided compelling evidence in support of the autoimmune hypothesis. Immunologically-based animal models of TS are a potent tool for dissecting the pathogenesis of this serious neuropsychiatric syndrome.

Altered monocyte activation markers in Tourette's syndrome: a case-control study

BACKGROUND

Infections and immunological processes are likely to be involved in the pathogenesis of Tourette's syndrome (TS). To determine possible common underlying immunological mechanisms, we focused on innate immunity and studied markers of inflammation, monocytes, and monocyte-derived cytokines.

METHODS

In a cross-sectional study, we used current methods to determine the number of monocytes and levels of C-reactive protein (CRP) in 46 children, adolescents, and adult patients suffering from TS and in 43 healthy controls matched for age and sex. Tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), soluble CD14 (sCD14), IL1-receptor antagonist (IL1-ra), and serum neopterin were detected by immunoassays.

RESULTS

We found that CRP and neopterin levels and the number of monocytes were significantly higher in TS patients than in healthy controls. Serum concentrations of TNF-alpha, sIL1-ra, and sCD14 were significantly lower in TS patients. All measured values were within normal ranges and often close to detection limits.

CONCLUSIONS

The present results point to a monocyte dysregulation in TS. This possible dysbalance in innate immunity could predispose to infections or autoimmune reactions.

Tourette syndrome and other tic disorders

Tic disorders, including Tourette syndrome, are an intriguing group of paroxysmal movement abnormalities that begin in childhood, have a fluctuating course, are capable of causing psychosocial and physical problems, and often improve by early adulthood. These disorders are frequently associated with a variety of comorbid problems whose negative effects may exceed those of tics. Therapy is strictly symptomatic and usually includes educational, behavioral, and a variety of pharmacological therapies. Although there is strong evidence supporting an inherited basis, the precise genetic abnormality remains unknown. A proposed poststreptococcal autoimmune etiology remains controversial. Pathophysiologically, tics appear to arise from an alteration within cortico-striatal-thalamo-cortical circuits, but the definitive site is unknown. Evidence supports an abnormality of synaptic neurotransmission, likely involving the dopaminergic system.

Aripiprazole for the treatment of adolescent Tourette's syndrome: a case report

Gilles de la Tourette syndrome (GTS) is a neuropsychiatric, lifelong disorder with onset in childhood. The essential features of this disorder are multiple motor tics and one or more vocalizations. The neurochemical pathophysiology of GTS involves an unknown abnormality in the central dopaminergic system. Atypical antipsychotics, such as aripiprazole, serve as a new therapeutic option for GTS. The authors describe a unique case of Tourette's syndrome (TS) in an adolescent in which aripiprazole resolved the patient's symptoms. A 17-year-old, 5'11'' tall, African American male weighing 220 lbs was diagnosed with TS at 9 years old. By age 16, the patient developed prominent symptoms of intermitted eye blinking, forehead raising, finger snapping, heavy breathing, and head bobbing. Clonidine, in addition to homeopathic remedies (N-acetylcholine and alpha lipoic acid), was administered to the patient without significant diminution of symptoms. Later, aripiprazole was initiated at 5 mg/d. As a result, noticeable symptomatic improvement occurred within 48 hours. Aripiprazole was titrated over the next 4 weeks to 6.5 mg/d, with significant results. Over the next 6 months, aripiprazole was titrated again to 10 mg/d with additional symptom reduction. This case illustrates a patient who responded to aripiprazole with no reported adverse effects, when standard therapy failed to improve symptoms.

Tic symptom profiles in subjects with Tourette Syndrome from two genetically isolated populations

BACKGROUND

Tourette Syndrome (TS) has a complex etiology and wide variability in phenotypic expression. Identifying underlying symptom patterns may be useful for etiological and outcome studies of TS.

METHODS

Lifetime tic and related symptom data were collected between 1996 and 2001 in 121 TS subjects from the Central Valley of Costa Rica and 133 TS subjects from the Ashkenazi Jewish (AS) population in the US. Subjects were grouped by tic symptoms using an agglomerative hierarchical cluster analysis. Cluster membership was tested for association with available ancillary information (age of onset, tic severity, comorbid disorders, medication treatment and family history).

RESULTS

Cluster analysis identified two distinct groups in each sample, those with predominantly simple tics (cluster 1), and those with multiple complex tics (cluster 2). Membership in cluster 2 was correlated with increased tic severity, global impairment, medication treatment, and presence of comorbid obsessive-compulsive symptoms in both samples, and with family history of tics, lower verbal IQ, earlier age of onset, and comorbid obsessive-compulsive disorder and attention-deficit/hyperactivity disorder in the AS sample.

CONCLUSIONS

This study provides evidence for consistent and reproducible symptom profiles in two independent TS study samples. These findings have implications for etiological studies of TS.

Genome scan for Tourette disorder in affected-sibling-pair and multigenerational families

Tourette disorder (TD) is a neuropsychiatric disorder with a complex mode of inheritance and is characterized by multiple waxing and waning motor and phonic tics. This article reports the results of the largest genetic linkage study yet undertaken for TD. The sample analyzed includes 238 nuclear families yielding 304 "independent" sibling pairs and 18 separate multigenerational families, for a total of 2,040 individuals. A whole-genome screen with the use of 390 microsatellite markers was completed. Analyses were completed using two diagnostic classifications: (1) only individuals with TD were included as affected and (2) individuals with either TD or chronic-tic (CT) disorder were included as affected. Strong evidence of linkage was observed for a region on chromosome 2p (-log P = 4.42, P = 3.8 x 10(-5) in the analyses that included individuals with TD or CT disorder as affected. Results in several other regions also provide moderate evidence (-log P >2.0) of additional susceptibility loci for TD.

Emerging drugs in Tourette syndrome

Proper education of the patient is the first step in the treatment of Tourette syndrome (TS). Before deciding how to treat the patient, it is important to decide whether to treat the TS-related symptoms. Counselling and behavioural modification may be sufficient for those with mild symptoms. Medications, however, may be considered when symptoms begin to interfere with peer relationships, social interactions, academic or job performance, or with activities of daily living. Therapy must be individualised and the most troublesome symptoms should be targeted first. Antidopaminergic agents are clearly the most effective drugs in the treatment of tics. Although haloperidol and pimozide are the only drugs currently approved by the FDA for the treatment of TS, other dopamine receptor-blocking drugs and tetrabenazine, a dopamine depleting drug, as well as botulinum toxin injections, have been used to treat tics associated with TS. Carefully designed, comparative, longitudinal trials assessing the efficacy and adverse-effect profiles of these drugs, including tardive dyskinesia, are lacking. Selective serotonin reuptake inhibitors are recommended for the treatment of obsessive-compulsive behaviour: a common comorbidity. Psychostimulants, such as methylphenidate, are the treatment of choice for attention deficit hyperactivity disorder. Even though these drugs may transiently increase tics, this does not necessarily constitute a definite contraindication to the use of these drugs in patients with TS. Here, existing and emerging medical treatments in patients with tics and comorbid behavioural disorders associated with TS are reviewed.

An update on the genetics of Gilles de la Tourette syndrome

OBJECTIVES

To summarize the current data suggesting that Gilles de la Tourette syndrome (GTS) is inherited and genetic.

METHODS

The extant literature on family studies, segregation analyses, candidate genes studies and linkage studies of GTS was reviewed and summarized.

RESULTS AND CONCLUSIONS

There is considerable data that suggests that: (1). genetic factors play an important role in the manifestation of GTS; (2). several genes are important with some possibly having major effect; and (3). several regions of the genome have been identified as potential locations of these susceptibility genes.

Tics and problem behaviors in schoolchildren: prevalence, characterization, and associations

OBJECTIVE

Tic disorders are the most common movement disorder diagnosed in children and have symptoms that fluctuate in frequency and intensity over time. We conducted an 8-month longitudinal observational study to determine the variations in frequency of motor tics and associated problem behaviors.

METHODS

A total of 553 children, kindergarten through sixth grade, were observed monthly from November 1999 to June 2000 by 3 raters. Motor tics were recorded by location and rated for severity as none (0), mild (1), moderate (2), or severe (3). Problem behaviors were rated as absent (0), subclinical (1), or clinical (2) in each of 6 categories: disruptive, hyperactive, impulsive, aggressive, anxious, and distracted.

RESULTS

The monthly point prevalence of motor tics ranged from 3.2% to 9.6%, with an overall frequency of 24.4%. The monthly point prevalence of problem behaviors ranged from 2.6% to 11.0%, with an overall frequency of 25.7%. The incidence of motor tics and problem behaviors was significantly higher during the winter months of November through February, compared with the spring months of March through June (motor tics: z = 4.97; problem behaviors: z = 3.79). Motor tics were observed in 2 distinct patterns (isolated and persistent), which varied by the number of months present, gender ratio of affected children, severity of tic symptoms, and association with problem behaviors.

CONCLUSIONS

Motor tics and problem behaviors are frequent occurrences among schoolchildren and seem to occur more frequently during the winter months. For most children, the tics were mild, observed on only 1 occasion, and were not accompanied by problem behaviors.

Neuropsychiatry of the basal ganglia

This review aims to relate recent findings describing the role and neural connectivity of the basal ganglia to the clinical neuropsychiatry of basal ganglia movement disorders and to the role of basal ganglia disturbances in "psychiatric"' states. Articles relating to the relevant topics were initially collected through MEDLINE and papers relating to the clinical conditions discussed were also reviewed. The anatomy and connections of the basal ganglia indicate that these structures are important links between parts of the brain that have classically been considered to be related to emotional functioning and brain regions previously considered to have largely motor functions. The basal ganglia have a role in the development and integration of psychomotor behaviours, involving motor functions, memory and attentional mechanisms, and reward processes.

Tics and its disorders

Tourette syndrome (TS) is familial neuropsychiatric disorder that is characterized by motor and phonic tics that begin in childhood. Once thought of as a rare and debilitating disorder, in the last decade new scientific knowledge suggests that TS and related tic disorders are more common and less debilitating for the majority of individuals. Evidence points toward a spectrum of TS symptomatology that extends beyond the tics disorder to probably include obsessive-compulsive disorder, attention deficit hyperactivity disorder, and mood disorders. Tourette syndrome and its differential diagnosis are discussed in this article with a focus on new developments in classification, etiology, epidemiology, genetics, pathophysiology, and clinical management.

Clinical and psychological features distinguishing obsessive-compulsive and chronic tic disorders

Medical and biogenetic research has suggested that obsessive-compulsive disorder and chronic (multiple) tic disorder may share a common etiology. This article reviews corresponding evidence for psychological similarities and differences between the two disorders. There are similarities in self-management strategies, psychological traits (both report high scores on different aspects of perfectionism) and in the ego-syntonic-ego-dystonic cycle of the impulsive-compulsive behavior. Situational cues likely to elicit or worsen the problem differ between the disorders as do associated emotions, comorbidity and background styles of action. In both disorders, cognitive factors, such as anticipations and appraisals of the problem, can play a role in onset and maintenance of the problem, and this raises the question as to whether cognitive or behavioral factors are best addressed in treatment. Psychological characteristics, such as lack of confidence, may contribute to apparent performance deficit. Psychological evaluation, particularly functional analysis, may aid in differential diagnosis between the two disorders, lead to improvement in treatment matching, and in understanding of the multidetermined etiology.

The genetics of Tourette syndrome

Twin and family studies demonstrate that Tourette syndrome (TS) is a genetic disorder. Early segregation analyses of family data were consistent with the hypothesis of autosomal dominant transmission; however, more recent studies suggest that the mode of inheritance is more complex. Current findings suggest that there are genes of major effect with other genes acting as modifiers. Several genome scans have been completed and several regions of interest have been identified that may harbor susceptibility genes for TS. Work is currently underway to replicate and extend these initial results.

Increased anti-streptococcal antibodies in patients with Tourette's syndrome

Infection or postinfectious phenomena have been postulated to play a role in the pathogenesis of children afflicted with the typical symptoms of Tourette's syndrome (TS). We investigated whether an increase of titers of antistreptococcal antibodies can be reproduced in our children with TS, and whether this increase is restricted to children. We examined the titers of two different antistreptococcal antibodies, antistreptolysin (ASL) and anitDNase B, both in children and adults. Titer s of ASO and antiDNase B were measured (1) in 13 children/adolescents suffering from TS and in an aged-matched comparison group;(2) in 23 adult patients, a comparison group of 23 aged-matched controls, and in another group of 17 aged-matched, non-medicated acute schizophrenics. ASO and antiDNase B titers were determined by laser nephelometry using a commercially available kit. Two antistreptococcal cut-off levels were compared (> 250 U/ml and 400 U/ml). As expected, increases ASO titers (>400 IU/ml) were found in a higher portion of children/adolescents with TS compared to controls. Regarding adults, titers >250 U/ml for both antistreptococcal antigens were found in significantly more TS patients than in schizophrenic patients or healthy control subjects. The mean values of ASO and antiDNase titers were significantly higher in both groups of TS patients compared to control children/adolescents, to the comparison groups of healthy adults and to schizophrenics. No difference in antistreptococcal titers was found between schizophrenics and the group of healthy adults. TS patients exhibited higher antistreptococcal titers than age-matched comparison groups of both children/adolescents and adults using different types of calculation. Our findings support the theory that a postinfectious immune mechanism may play a role in the pathogenesis of TS. The mechanism still needs to be elucidated.

Obsessive-Compulsive Disorder and Tourette's Syndrome

Obsessive-compulsive behavior (OCB) or full-blown obsessive-compulsive disorder (OCD) afflict more than 50% of patients with Tourette's syndrome (TS) and often are more debilitating than the tic disorder itself. Medications for OCD, including selective serotonin reuptake inhibitors (SSRIs), help patients with TS and OCD, particularly in combination with low-dose antipsychotic drugs, but seldom eliminate OCD entirely. Behavioral therapies are more effective as medications for the treatment of OCD. A combination of cognitive behavioral therapy and medication is the treatment of choice for most patients with TS and OCD.

A complete genome screen in sib pairs affected by Gilles de la Tourette syndrome. The Tourette Syndrome Association International Consortium for Genetics

Gilles de la Tourette syndrome is a neuropsychiatric disorder characterized by waxing and waning multiple motor and phonic tics with a complex mode of inheritance. Previous attempts, which used large multigenerational families to localize susceptibility loci, have been unsuccessful. In this report, the results of the first systematic genome scan, using 76 affected-sib-pair families with a total of 110 sib pairs, are summarized. While no results reached acceptable statistical significance, the multipoint maximum-likelihood scores (MLS) for two regions (4q and 8p) were suggestive (MLS > 2.0). Four additional genomic regions also gave multipoint MLS scores between 1.0 and 2.0.