Gilles De La Tourette Research Articles

Retraction Note to: Association of Catechol-O-methyltransferase val/met polymorphism with cognitive function in Gilles de la Tourette syndrome patients.

Gilles de la Tourette syndrome (GTS) is a kind of neuropsychiatric disorder with childhood onset. The cognitive dysfunction caused by GTS could affect the growth and learning of children and adolescents. The mechanism of cognitive functions was associated with dopaminergic system, thus we access the associations between polymorphism of some dopaminergic system-related genes including Catechol-O-methyltransferase (COMT) met/val, Dopamine receptor D4 (DRD4) exon III 48 bp VNTR (variable number of tandem repeats), Interleukin 1 (IL-1) Ra 86 bp and IL-1β exon 5, and cognitive functions in GTS patients. Genotyping analysis was performed through polymerase chain reaction (PCR). Test for cognitive functions of GTS patients included modified wisconsin card sorting test (WCST), trail making test, visual reproduction test, stroop test and verbal fluency test. The patients with COMT met/met genotype showed less perseverative errors in modified WCST test compared with patients with COMT val/val genotype (P < 0.05). Meanwhile, patients without allele val had better delayed memory in visual reproduction test, less errors in the stroop test and less perseverative errors in modified WCST test compared with patients with allele val (P < 0.05). However, no significant difference was found in cognitive functions among patients with different genotypes or alleles of polymorphisms of DRD4 exon III 48 bp VNTR, IL-1 Ra 86 bp and IL-1β exon 5 (P > 0.05). Polymorphism of COMT met/val was correlated with cognitive functions in GTS patients. This study provided basis for the analysis of molecular genetic pathology of cognitive dysfunctions in GTS.

THE CONCEPTUAL HISTORY OF BODY IMAGE AND THE SELF

Professor Michael R Trimble Emeritus Professor of Behavioural Neurology at the Institute of Neurology, Queen Square, London, and Honorary Consultant Physician to the Department of Psychological Medicine at The National...

DBS in Dystonia and Other Hyperkinetic Movement Disorders.

The diagnosis and appropriate treatment of hyperkinetic movement disorders require a work up of potentially reversible metabolic, infectious and structural disorders as well as side effects of current medication. In pharmacoresistant movement disorders with a disabling impact on quality of life, deep brain stimulation (DBS) should be considered. At different targets, DBS has become an established therapy for Parkinson's disease (GPi-STN), tremor (VIM) and primary dystonia (GPi) with reasonable perioperative risks and side effects, established guidelines and some clinical and radiological predictive factors. In contrast, for other hyperkinetic movement disorders, including secondary dystonia, Gilles de la Tourette, chorea and ballism, only few data are available. Definite targets are not well defined, and reported results are of less magnitude than those of the recognized indications. In this expanding therapeutical field without worked out recommendations, an individual approach is needed with DBS indication assessment only after rigorous multidisciplinary scrutiny, restricted to expert centres.

Gilles De La Tourette Syndrome: A Case Report

Gilles de la Tourette syndrome otherwise simply known as Tourette Syndrome (TS) is characterized by involuntary movements and phonation; invariably classified as tic disorder1.A tic is an involuntary, sudden, rapid, recurrent, non-rhythmic, stereotyped, motor movement or vocalization. The most common co-occurring disorders with TS are Attention Deficit Hyperkinetic Disorder (ADHD) 50-60% and Obsessive Compulsive Disorder (OCD) 30-70%. This Case report describes the history of a 38-year-old man who showed symptoms of tic disorder, was initially misdiagnosed as having psychosis that later proved to be Tourette Syndrome. The patient was presented to the Psychiatry department in the October 2013 with chief complaints of repetitive turning of face to the left, anger outbursts, involuntary raising of the upper limbs, foul words usage and occasionally counting fingers over the past year that intensified in the 15 days prior to admission. The patient was prescribed a typical anti-psychotic such as Risperidone 2mg twice a day. Consequent admissions over the next one year showed new symptoms such as irritability, sudden movements of both upper and lower limbs, which progressed to jerking, hitting of his forehead multiple times, generalized body weakness, tremors of limbs that invariably led to disturbed sleep patterns. He was given combinations of neuroleptics such as Haloperidol and Olanzapine at doses of 5mg respectively with anti-depressants such as Lorazepam 1mg once daily and Fluoxetine 2omg thrice daily along with an anti-muscaranic agent Trihexyphenidyl 2mg twice daily. The patient was non-compliant with the prescribed medications. The patient reported in June 2015 and was admitted for a period of one month with extra pyramidal symptoms (EPS) as a side effect of the anti Haloperidol. The doctors decreased the dose of Haloperidol to 2.5 mg once daily to minimize his symptoms. Although the tic symptoms decreased effectively during his hospital stay, there were clear abnormalities in his social interaction which the doctors diagnosed later as schizoid personality traits.

Neuroimaging of tic genesis: Present status and future perspectives

Tics are hyperkinetic movements that are distinctive by their variety in semiology and duration and by their ability to be modulated by cognitive control. They are the hallmark of Gilles de la Tourette syndrome. Despite the variety of clinical presentations in this syndrome, dysfunction of cortico-striato-pallido-thalamo-cortical networks is suggested as a core pathophysiological mechanism. We review recent structural and functional neuroimaging studies that focused on the anatomical substrate of tics and their possible genesis. These studies showed a consistent relationship between structural and functional abnormalities within motor cortico-basal ganglia circuits and occurrence of tics. The failure of top-down cortical control over motor pathways because of the atypical trajectory of brain development could be a possible mechanism of tic genesis. Occurrence of tics results in several adaptive mechanisms, including modification of cortico-striatal network activity (reduced functional activation of the primary motor cortex) and neurochemical (increased γ-aminobutyric acid concentrations in the supplementary motor area) and microstructural white matter pathways rearrangements.

Neuroimaging signature of neuropsychiatric disorders.

This review focuses on new findings related to structural and functional changes in large-scale brain networks (i.e., pathoconnectomics) that occur in neuropsychiatric disorders, particularly Parkinson's disease, Alzheimer's disease and Gilles de la Tourette syndrome. Many neuropsychiatric disorders involve dysfunction in neuronal regions that are defined as hubs; these regions are pivotal regions of information transfer in large-scale brain networks. In neuropsychiatric disorders with neurodevelopmental mechanisms, the common connectivity profiles remain unclear as both hyper- and hypoconnectivity profiles have been reported. Neurodegenerative neuropsychiatric disorders are commonly characterized by a diminished local and global efficiency of large-scale brain networks. The connectome, which is largely underpinned by the network science and graph theoretical approaches, is relevant to the field of neuropsychiatry and could be successfully used for the differential diagnosis for neuropsychiatric disorders and for predicting the progression of such disorders. The analysis of large-scale brain network dynamics generates new insights into the mechanisms of action of invasive and noninvasive brain stimulation and guides further investigations of new therapeutic targets.

Childhood-onset multiple self-injurious behaviors in Gilles de la Tourette syndrome

Self injurious behavior, i.e. the deliberate, non-accidental, repetitive infliction of self harm, has been reported in a wide range of neuropsychiatric conditions. Clinical and epidemiological studies have shown that self-injurious behavior can occur in up to one third of patients with Gilles de la Tourette syndrome, a neurodevelopmental disorder, characterized by the presence of multiple motor tics and at least one vocal/phonic tic. This paper describes the case of a patient diagnosed with Gilles de la Tourette syndrome who presented with severe multiple self injurious behaviors since early childhood. On physical examination, we documented a few self-injurious behavior signs including scars in the forehead resulting from repetitive head-banging and bald patches on the scalp due to trichotillomania. Characteristically, self-injurious behaviors were distressing and resistant to treatments (both pharmacotherapy and cognitive behavioral therapy), and were associated with comorbid obsessive-compulsive disorder. This case illustrates the complex nature and difficult management of severe self-injurious behavior in the context of Gilles de la Tourette syndrome and obsessive-compulsive disorder.

Tourette syndrome, co-morbidities and quality of life.

Tourette syndrome is often associated with attention deficit hyperactivity disorder, obsessive compulsive disorder and other co-morbidities, the presence of which can reduce health-related quality of life. The relationship between the number and type of co-morbidities and tic severity upon health-related quality of life has been insufficiently examined in Tourette syndrome populations and not at all in the Australian context. We hypothesised that an increased number of co-morbid diagnoses would be inversely related to health-related quality of life and that the presence of attention deficit hyperactivity disorder and obsessive compulsive disorder in particular would negatively impact health-related quality of life. In all, 83 people with a previously established diagnosis of Tourette syndrome, who responded to a letter of invitation sent to the Tourette Syndrome Association of Australia past-member database, formed the study sample. Participants completed the Gilles de la Tourette Syndrome-Quality of Life Scale and a short form of the National Hospital Interview Schedule to assess tics and related behaviours. Participants with pure-Tourette syndrome had significantly better health-related quality of life than those with Tourette syndrome and three or more co-morbid diagnoses. Few differences were observed between the pure-Tourette syndrome and Tourette syndrome and one or two co-morbid diagnoses groups. Analysis of the impact of individual co-morbid disorders and Tourette syndrome symptoms on health-related quality of life indicated that attention deficit hyperactivity disorder exerted a significant negative effect, as did the presence of complex tics, especially coprolalia and copropraxia. When these variables were examined in multiple regression analysis, number of co-morbidities and the presence of coprophenomena emerged as significant predictors of health-related quality of life. While tics are the defining feature of Tourette syndrome, it appears to be the presence of co-morbidities, attention deficit hyperactivity disorder, in particular, and coprophenomena that have the greater impact on health-related quality of life. This has implications for symptom-targeting in the treatment of Tourette syndrome since all available treatments are symptomatic and not disease modifying.

Palilalie et maladie d’Alzheimer à un stade sévère : une étude de cas

ObjectivesThe literature on the palilalia is relatively rich, probably because it affects several diseases: Parkinson's disease, syndrome of Gilles de la Tourette, Pick's disease, epilepsy, etc. The author, studying precisely palilalia in Alzheimer's disease to a severe stage, ran into a field of desert research. It offers an account of a case study, that of Mrs. L., that raises questions on one hand the possible causes of palilalia, on the other treatment to achieve. If, until now, the causes are defined primarily neurological and treated with pharmacological treatments, it seems that a method of non-drug treatments can sometimes have benefits on palilalia. Patient and methodThe patient in question suffered from Alzheimer's disease to a severe stage, she had many “behavioral and psychological symptoms of dementia” as perambulation, motor and gestural stereotypies, and especially palilalia. The ability to converse with Mrs. L. was profoundly altered, she no longer had access to a speech punctuated with a lexicology and had only a few words, syllables, or sounds of mouth that she repeated indefinitely to try to be heard. The author, a clinical psychologist who accompanied her for many months, tried to appease these verbal manifestations which generates among other residents of the nursing home anxiety, agitation, and aggression. Thus, for many weeks, the author undertook to repeat with her the syllables or words spoken on a different pace, or sang to validate the speech acts of the patient and to better preserve the environment in which it lives. ResultsRepeat the syllables with the patient first allowed her to pronounce other syllables or to conjure a few words. Repeat the syllables on a different pace had the surprising effect of reducing and then stop a few minutes palilalic phenomenon. This method having its limits over the deteriorating health status and increased speech disorders of Mrs. L., the production of long notes sung by the psychologist or the fact of singing syllables of the patient presented longer-lasting effects but unsystematic. ConclusionsIf our hypothesis binding palilalia and anxiety generated by the environment proves to be reinforced in the future by other clinical cases, it would be a considerable advance on the palilalic phenomenon so far only treated by pharmacological treatments. Along the lines of Hate Health Authority, the non-drug approach to ecology of the subject's environment, its preservation, seem to have appeasing effects, including on palilalia. Responding to a painful affect (marked in palilalia by a rapid rate of repetition) with a more pleasant affect (the psychologist using a slower pace) helped mitigate or stop the palilalia. Sing it introduced yet more benefits. Therefore, develop a method of treatment by therapeutic mediation, but here the song remains the possibilities opened appears sensible. An essential condition is still worth noting: these methods worked only on condition of transfer between Mrs. L. and psychologist.

Tic symptom dimensions and their heritabilities in Tourette's syndrome.

Gilles de la Tourette's syndrome (TS) is both genotypically and phenotypically heterogeneous. Gene-finding strategies have had limited success, possibly because of symptom heterogeneity. This study aimed at specifically investigating heritabilities of tic symptom factors in a relatively large sample of TS patients and family members. Lifetime tic symptom data were collected in 494 diagnosed individuals in two cohorts of TS patients from the USA (n=273) and the Netherlands (n=221), and in 351 Dutch family members. Item-level factor analysis, using a tetrachoric correlation matrix in SAS (v9.2), was carried out on 23 tic symptoms from the Yale Global Tic Severity Scale. Three factors were identified explaining 49% of the total variance: factor 1, complex vocal tics and obscene behaviour; factor 2, body tics; and factor 3, head/neck tics. Using Sequential Oligogenic Linkage Analysis Routine, moderate heritabilities were found for factor 1 (h2r=0.21) and factor 3 (h2r=0.25). Lower heritability was found for overall tic severity (h2r=0.19). Bivariate analyses indicated no genetic associations between tic factors. These findings suggest that (i) three tic factors can be discerned with a distinct underlying genetic architecture and that (ii) considering the low tic heritabilities found, only focusing on the narrow-sense TS phenotype and leaving out comorbidities that are part of the broader sense tic phenotype may lead to missing heritability. Although these findings need replication in larger independent samples, they might have consequences for future genetic studies in TS.

Patients with Gilles de la Tourette syndrome have widespread personality differences

Only little is known about pathological personality traits in patients with Gilles de la Tourette syndrome (GTS). The aim of this study was to further investigate the prevalence of personality traits in adults with GTS. We used a variety of rating scales to assess not only personality traits, but also severity of tics, quality of life, and comorbidities (obsessive-compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), depression), in a large group (n=50) of patients. Our major finding was that pathological personality traits are very common in patients with GTS encompassing a wide range of different personality traits, but most typically personality traits related to cluster C. Demand-anxious was the most common personality trait, while histrionic personality trait was absent. Patients’ quality of life was more impaired by personality traits than comorbidities. Personality traits were more common in patients with comorbid OCD and depression, while comorbid ADHD had no influence. Our findings, therefore, corroborate the hypothesis that GTS plus OCD represents a more severe subtype of GTS, and support the assumption that OCD and depression, but not ADHD, are part of the GTS spectrum.

Cognitive-behavioral therapy induces sensorimotor and specific electrocortical changes in chronic tic and Tourette's disorder

BackgroundTic disorders, such as the Gilles de la Tourette syndrome and persistent tic disorder, are neurodevelopmental movement disorders involving impaired motor control. Hence, patients show repetitive unwanted muscular contractions in one or more parts of the body. A cognitive-behavioral therapy, with a particular emphasis on the psychophysiology of tic expression and sensorimotor activation, can reduce the frequency and intensity of tics. However, its impact on motor activation and inhibition is not fully understood. MethodsTo study the effects of a cognitive-behavioral therapy on electrocortical activation, we recorded the event-related potentials (ERP) and lateralized readiness potentials (LRP), before and after treatment, of 20 patients with tic disorders and 20 healthy control participants (matched on age, sex and intelligence), during a stimulus–response compatibility inhibition task. The cognitive-behavioral therapy included informational, awareness training, relaxation, muscle discrimination, cognitive restructuration and relapse prevention strategies. ResultsOur results revealed that prior to treatment; tic patients had delayed stimulus-locked LRP onset latency, larger response-locked LRP peak amplitude, and a frontal overactivation during stimulus inhibition processing. Both stimulus-locked LRP onset latency and response-locked LRP peak amplitude normalized after the cognitive behavioral therapy completion. However, the frontal overactivation related to inhibition remained unchanged following therapy. ConclusionsOur results showed that P300 and reaction times are sensitive to stimulus–response compatibility, but are not related to tic symptoms. Secondly, overactivity of the frontal LPC and impulsivity in TD patients were not affected by treatment. Finally, CBT had normalizing effects on the activation of the pre-motor and motor cortex in TD patients. These results imply specific modifications of motor processes following therapy, while inhibition processes remained unchanged. Given that LRPs are partially generated within the sensorimotor and supplementary motor area, the reported reduction in tic frequency and improvements of LRPs components suggest that CBT induced a physiological change in patients' motor area.

Structural Connectivity in Gilles de la Tourette Syndrome.

Investigators from Centre de Reference National Maladie Rare 'Syndrome Gilles de la Tourette' and Sorbonne University report white matter abnormalities in the pathways connecting the cerebral cortex, basal ganglia, and thalamus in a group of 49 adults with Tourette syndrome (TS).

Premonitory urge to tic in Tourette's is associated with interoceptive awareness.

A contribution of aberrant interoceptive awareness to the perception of premonitory urges in Gilles de la Tourette syndrome (GTS) has been hypothesized. We assessed interoceptive awareness in 19 adults with GTS and 25 age-matched healthy controls using the heartbeat counting task. We also used multiple regression to explore whether the severity of premonitory urges was predicted by interoceptive awareness or severity of tics and obsessive-compulsive symptoms. We observed lower interoceptive awareness in GTS compared with controls. Interoceptive awareness was the strongest predictor of premonitory urges in GTS, with greater interoceptive awareness being associated with more urges. Greater tic severity was also associated with higher rates of premonitory urges. The observed relationship between severity of premonitory urges and interoceptive awareness suggests that interoception might be involved in self-reported premonitory urges in GTS. High levels of interoceptive awareness might reflect a self-attentive capacity to perceive urges.

Tic Phenomenology and Tic Awareness in Adults With Autism

Background: Tics are common in people with autism spectrum disorder (ASD). However, their phenomenology and characteristics have not been studied in detail. Methods: Based on video sequences of 21 adults with ASD without intellectual disability and 16 adults with Gilles de la Tourette syndrome (GTS), tic severity, tic repertoires, and tic awareness were determined. Results: Ten ASD and all GTS participants had tics during video recordings. The ASD group had significantly fewer tics, compared to GTS. Tic distribution and tic repertoires were comparable, but more restricted in ASD. All GTS participants, but only 5 of the 10 ASD participants, were aware of their tics. Conclusions: Tics are common in adults with ASD. They are indistinguishable from tics in GTS and are similarly distributed, but less severe. Tic awareness is limited in ASD.

Altered structure of cortical sulci in gilles de la Tourette syndrome: Further support for abnormal brain development.

Gilles de la Tourette syndrome is a neurodevelopmental disorder characterized by the presence of motor and vocal tics. We hypothesized that patients with this syndrome would present an aberrant pattern of cortical formation, which could potentially reflect global alterations of brain development. Using 3 Tesla structural neuroimaging, we compared sulcal depth, opening, and length and thickness of sulcal gray matter in 52 adult patients and 52 matched controls. Cortical sulci were automatically reconstructed and identified over the whole brain, using BrainVisa software. We focused on frontal, parietal, and temporal cortical regions, in which abnormal structure and functional activity were identified in previous neuroimaging studies. Partial correlation analysis with age, sex, and treatment as covariables of noninterest was performed amongst relevant clinical and neuroimaging variables in patients. Patients with Gilles de la Tourette syndrome showed lower depth and reduced thickness of gray matter in the pre- and post-central as well as superior, inferior, and internal frontal sulci. In patients with associated obsessive-compulsive disorder, additional structural changes were found in temporal, insular, and olfactory sulci. Crucially, severity of tics and of obsessive-compulsive disorder measured by Yale Global Tic severity scale and Yale-Brown Obsessive-Compulsive scale, respectively, correlated with structural sulcal changes in sensorimotor, temporal, dorsolateral prefrontal, and middle cingulate cortical areas. Patients with Gilles de la Tourette syndrome displayed an abnormal structural pattern of cortical sulci, which correlated with severity of clinical symptoms. Our results provide further evidence of abnormal brain development in GTS.

Deep brain stimulation for psychiatric diseases: what are the risks?

Despite the application of deep brain stimulation (DBS) as an efficient treatment modality for psychiatric disorders, such as obsessive-compulsive disorder (OCD), Gilles de la Tourette Syndrome (GTS), and treatment refractory major depression (TRD), few patients are operated or included in clinical trials, often for fear of the potential risks of an approach deemed too dangerous. To assess the surgical risks, we conducted an analysis of publications on DBS for psychiatric disorders. A PubMed search was conducted on reports on DBS for OCD, GTS, and TRD. Forty-nine articles were included. Only reports on complications related to DBS were selected and analyzed. Two hundred seventy-two patients with a mean follow-up of 22 months were included in our analysis. Surgical mortality was nil. The overall mortality was 1.1 %: two suicides were unrelated to DBS and one death was reported to be unlikely due to DBS. The majority of complications were transient and related to stimulation. Long-term morbidity occurred in 16.5 % of cases. Three patients had permanent neurological complications due to intracerebral hemorrhage (2.2 %). Complications reported in DBS for psychiatric diseases appear to be similar to those reported for DBS in movement disorders. But class I evidence is lacking. Our analysis was based mainly on small non-randomized studies. A significant number of patients (approximately 150 patients) who were treated with DBS for psychiatric diseases had to be excluded from our analysis as no data on complications was available. The exact prevalence of complications of DBS in psychiatric diseases could not be established. DBS for psychiatric diseases is promising, but remains an experimental technique in need of further evaluation. A close surveillance of patients undergoing DBS for psychiatric diseases is mandatory.

Selective dysfunction of basal ganglia subterritories: From movement to behavioral disorders.

Historically, Parkinson's disease (PD) was defined as a pure movement disorder. Currently, it is widely accepted that this disease is also characterized by nonmotor signs, such as depression, apathy, and anxiety. On the other hand, the consideration of Gilles de la Tourette syndrome (GTS) as a neuropsychiatric disorder has also been debated. In this review, we will focus on these two disorders, which combine both motor and behavioral features and in which dysfunction of cortical and subcortical regions was suggested. Anatomical, experimental, and clinical data are reported to support the involvement of basal ganglia (BG) in cognitive and motivational functions in addition to motor control. In PD, the nonmotor signs could result from the heterogeneity of dopaminergic lesions and excessive activation of the dopamine receptors, particularly within the limbic neuronal networks. Experimental results obtained on nonhuman primates using local disinhibition within functional territories of BG allowed the precise mapping of their motor and nonmotor functions. Thus, impairment of inhibitory control inside specific striatal territories induced behavioral disorders and abnormal movements, which had striking similarities to clinical expressions of GTS. Establishing such a relationship between BG subterritories and motor and behavioral disorders could potentially be helpful for future target choices for DBS in many neuropsychiatric disorders. Furthermore, it is also of great interest for therapeutic research and for the efficient targeting of symptom relief to determine the precise pharmacological effects of the two main modulators of BG function, which are dopamine and serotonin.

Alexithymia in Neurological Disease: A Review.

Alexithymia has been considered a personality trait characterized by difficulties identifying and describing feelings and an externally oriented thinking style. A high rate of alexithymia is reported among patients with psychiatric and psychosomatic disorders. In this review, the authors examined the literature regarding the prevalence and importance of alexithymia in patients with neurological disorders. A systematic search of the computerized databases MEDLINE and PubMed was conducted in order to identify papers on alexithymia in neurological disease. Key search terms used included "traumatic brain injury," "head trauma," "head injury," "stroke," "epilepsy," "brain tumor," "multiple sclerosis," "Alzheimer's disease," "Parkinson's disease," "Huntington's disease," "Gilles de la Tourette syndrome," "dystonia," "psychogenic movement disorders," "functional movement disorders," "nonepileptic attacks," and "nonepileptic seizures." These search terms were paired with "alexithymia." Alexithymia seems to be a common feature of neurological disease, with most evidence available for patients with traumatic brain injury, stroke, and epilepsy. However, it is not clear how independent it is from affective disorders such as depression and anxiety, which are themselves very common in neurological conditions. Identification of alexithymia could be relevant for prognosis and therapeutic decisions in patients with neurological disease and is certainly worthy of further study. Tools with which to measure alexithymia and delineation from affective disorders and apathy are important methodological issues for future work.

Uncommon applications of deep brain stimulation in hyperkinetic movement disorders.

BackgroundIn addition to the established indications of tremor and dystonia, deep brain stimulation (DBS) has been utilized less commonly for several hyperkinetic movement disorders, including medication-refractory myoclonus, ballism, chorea, and Gilles de la Tourette (GTS) and tardive syndromes. Given the lack of adequate controlled trials, it is difficult to translate published reports into clinical use. We summarize the literature, draw conclusions regarding efficacy when possible, and highlight concerns and areas for future study.MethodsA Pubmed search was performed for English-language articles between January 1980 and June 2014. Studies were selected if they focused primarily on DBS to treat the conditions of focus.ResultsWe identified 49 cases of DBS for myoclonus-dystonia, 21 for Huntington's disease, 15 for choreacanthocytosis, 129 for GTS, and 73 for tardive syndromes. Bilateral globus pallidus interna (GPi) DBS was the most frequently utilized procedure for all conditions except GTS, in which medial thalamic DBS was more common. While the majority of cases demonstrate some improvement, there are also reports of no improvement or even worsening of symptoms in each condition. The few studies including functional or quality of life outcomes suggest benefit. A limited number of studies included blinded on/off testing. There have been two double-blind controlled trials performed in GTS and a single prospective double-blind, uncontrolled trial in tardive syndromes. Patient characteristics, surgical target, stimulation parameters, and duration of follow-up varied among studies.DiscussionDespite these extensive limitations, the literature overall supports the efficacy of DBS in these conditions, in particular GTS and tardive syndromes. For other conditions, the preliminary evidence from small studies is promising and encourages further study.