Tourettism associated with Huntington's disease

"Unvoluntary" Movement Disorders: Distinguishing between Tics, Akathisia, Restless Legs, and Stereotypies

Tics, stereotypies, akathisia, and restless legs fall at different places on the spectrum of discrete, unwanted and potentially disabling motor routines. Unlike tremor, chorea, myoclonus, or dystonia, this subgroup of abnormal movements is characterized by the subject's variable ability to inhibit or release undesired motor patterns on demand. Though it may be sometimes clinically challenging, it is crucial to distinguish these "unvoluntary" motor behaviors because secondary causes and management approaches differ substantially. To this end, physicians must consider the degree of repetitiveness of the movements, the existence of volitional control, and the association with sensory symptoms, or cognitive-ideational antecedent. This review aims to summarize the current existing knowledge on phenomenology, diagnosis, and treatment of tics, stereotypies, akathisia, and restless leg syndrome.

A Comprehensive Review of Tic Disorders in Children

Tics are characterized by sudden, rapid, recurrent, nonrhythmic movement or vocalization, and are the most common movement disorders in children. Their onset is usually in childhood and tics often will diminish within one year. However, some of the tics can persist and cause various problems such as social embarrassment, physical discomfort, or emotional impairments, which could interfere with daily activities and school performance. Furthermore, tic disorders are frequently associated with comorbid neuropsychiatric symptoms, which can become more problematic than tic symptoms. Unfortunately, misunderstanding and misconceptions of tic disorders still exist among the general population. Understanding tic disorders and their comorbidities is important to deliver appropriate care to patients with tics. Several studies have been conducted to elucidate the clinical course, epidemiology, and pathophysiology of tics, but they are still not well understood. This article aims to provide an overview about tics and tic disorders, and recent findings on tic disorders including history, definition, diagnosis, epidemiology, etiology, diagnostic approach, comorbidities, treatment and management, and differential diagnosis.

Huntington's disease: lessons from prion disorders

Decades of research on the prion protein and its associated diseases have caused a paradigm shift in our understanding of infectious agents. More recent years have been marked by a surge of studies supporting the application of these findings to a broad array of neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Here, we present evidence to suggest that Huntington's disease, a monogenic disorder of the central nervous system, shares features with prion disorders and that, it too, may be governed by similar mechanisms. We further posit that these similarities could suggest that, like other common neurodegenerative disorders, sporadic forms of Huntington's disease may exist.

The spectrum of involuntary vocalizations in humans: A video atlas

In clinical practice, involuntary vocalizing behaviors are typically associated with Tourette syndrome and other tic disorders. However, they may also be encountered throughout the entire tenor of neuropsychiatry, movement disorders, and neurodevelopmental syndromes. Importantly, involuntary vocalizing behaviors may often constitute a predominant clinical sign, and, therefore, their early recognition and appropriate classification are necessary to guide diagnosis and treatment. Clinical literature and video-documented cases on the topic are surprisingly scarce. Here, we pooled data from 5 expert centers of movement disorders, with instructive video material to cover the entire range of involuntary vocalizations in humans. Medical literature was also reviewed to document the range of possible etiologies associated with the different types of vocalizing behaviors and to explore treatment options. We propose a phenomenological classification of involuntary vocalizations within different categorical domains, including (1) tics and tic-like vocalizations, (2) vocalizations as part of stereotypies, (3) vocalizations as part of dystonia or chorea, (4) continuous vocalizing behaviors such as groaning or grunting, (5) pathological laughter and crying, (6) vocalizations resembling physiological reflexes, and (7) other vocalizations, for example, those associated with exaggerated startle responses, as part of epilepsy and sleep-related phenomena. We provide comprehensive lists of their associated etiologies, including neurodevelopmental, neurodegenerative, neuroimmunological, and structural causes and clinical clues. We then expand on the pathophysiology of the different vocalizing behaviors and comment on available treatment options. Finally, we present an algorithmic approach that covers the wide range of involuntary vocalizations in humans, with the ultimate goal of improving diagnostic accuracy and guiding appropriate treatment. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Tic disorders revisited: introduction of the term "tic spectrum disorders"

Although the DSM-5 chronic motor tic disorder (CMTD) and Tourette syndrome (TS) are distinct diagnostic categories, there is no genetic or phenotypic evidence that supports this diagnostic categorization. The aim of this study was to compare patients with both diagnoses along a number of clinical characteristics to provide further diagnostic clarity. Our sample consisted of 1018 patients (including adult and child patients) suffering from chronic tic disorders. Tic severity was assessed via Shapiro Tourette-Syndrome Severity Scale (STSS). Lifetime prevalence of other comorbid conditions was assessed in a semi-structured clinical interview. The data were gained through retrospective chart analysis. The two groups did not differ significantly in any of the clinical or demographic variables. Patients only differed in tic severity, with CMTD patients (n = 40) having lower mean tic severity (STSS = 2.0 vs. 2.8; p < 0.001), prevalence of complex motor tics (27.5% vs. 55.9%; p < 0.01), copropraxia (0% vs. 16.2%; p < 0.01) and echopraxia (10.0% vs. 23.8%; p < 0.05), and a markedly lower comorbidity score (1.9 vs. 2.7; p < 0.001) as compared to TS patients (n = 978). Our results suggest that both disorders exist along a symptom severity continuum of which TS constitutes a more severe and CMTD a less severe form. We therefore suggest the introduction of the term "tic spectrum disorders", instead of using different diagnostic categories.

Clinical characterization of dystonia in adult patients with Huntington's disease

BACKGROUND AND PURPOSE

Huntington's disease (HD) is an autosomal dominant, neurodegenerative movement disorder, typically characterized by chorea. Dystonia is also recognized as part of the HD motor phenotype, although little work detailing its prevalence, distribution, severity and impact on functional capacity has been published to date.

METHODS

Patients (>18 years of age) were recruited from the Cardiff (UK) HD clinic, each undergoing a standardized videotaped clinical examination and series of functional assessment questionnaires (Unified Huntington's Disease Rating Scale, Burke-Fahn-Marsden Dystonia Rating Scale and modified version of the Toronto Western Spasmodic Torticollis Rating Scale). The presence and severity of dystonia were scored by four independent neurologists using the Burke-Fahn-Marsden Dystonia Rating Scale and Unified Huntington's Disease Rating Scale. Statistical analysis included Fisher's exact test, Wilcoxon test, anova and calculation of correlation coefficients where appropriate.

RESULTS

Forty-eight patients [91% (48/53)] demonstrated evidence of dystonia, with the highest prevalence in the left upper limb (n = 44, 83%), right upper limb most severely affected and eyes least affected. Statistically significant positive correlations (P < 0.05) were observed between dystonia severity and increasing HD disease stage and motor disease duration. Deterioration in functional capacity also correlated with increasing dystonia severity. No significant relationship was observed with age at motor symptom onset or CAG repeat length.

CONCLUSIONS

We report a high prevalence of dystonia in adult patients with HD, with worsening dystonia severity with increasing HD disease stage and motor disease duration. The recognition and management of dystonic symptoms in routine clinical practice will aid overall symptomatic treatment and functional improvement.

Tics as an initial manifestation of juvenile Huntington's disease: case report and literature review

BACKGROUND

Huntington's disease (HD) is an autosomal dominant disorder, typically characterized by chorea due to a trinucleotide repeat expansion in the HTT gene, although the clinical manifestations of patients with juvenile HD (JHD) are atypical.

CASE PRESENTATION

A 17-year-old boy with initial presentation of tics attended our clinic and his DNA analysis demonstrated mutation in the HTT gene (49 CAG repeats). After treatment, his symptoms improved. Furthermore, we performed literature review through searching the databases and summarized clinical features in 33 JHD patients.

CONCLUSION

The most prevalent symptoms are ataxia, and two cases reported that tics as initial and prominent manifestation in JHD. Among them, 88% patients carried CAG repeats beyond 60 and most of them have family history. This case here illustrates the variable range of clinical symptoms of JHD and the necessity of testing for the HD mutation in young patients with tics with symptoms unable to be explained by Tourette's syndrome (TS).

Dysfunctions of the basal ganglia-cerebellar-thalamo-cortical system produce motor tics in Tourette syndrome

Motor tics are a cardinal feature of Tourette syndrome and are traditionally associated with an excess of striatal dopamine in the basal ganglia. Recent evidence increasingly supports a more articulated view where cerebellum and cortex, working closely in concert with basal ganglia, are also involved in tic production. Building on such evidence, this article proposes a computational model of the basal ganglia-cerebellar-thalamo-cortical system to study how motor tics are generated in Tourette syndrome. In particular, the model: (i) reproduces the main results of recent experiments about the involvement of the basal ganglia-cerebellar-thalamo-cortical system in tic generation; (ii) suggests an explanation of the system-level mechanisms underlying motor tic production: in this respect, the model predicts that the interplay between dopaminergic signal and cortical activity contributes to triggering the tic event and that the recently discovered basal ganglia-cerebellar anatomical pathway may support the involvement of the cerebellum in tic production; (iii) furnishes predictions on the amount of tics generated when striatal dopamine increases and when the cortex is externally stimulated. These predictions could be important in identifying new brain target areas for future therapies. Finally, the model represents the first computational attempt to study the role of the recently discovered basal ganglia-cerebellar anatomical links. Studying this non-cortex-mediated basal ganglia-cerebellar interaction could radically change our perspective about how these areas interact with each other and with the cortex. Overall, the model also shows the utility of casting Tourette syndrome within a system-level perspective rather than viewing it as related to the dysfunction of a single brain area.

Tourette syndrome is a neuropsychiatric disorder characterized by vocal and motor tics. Tics represent a cardinal symptom traditionally associated with a dysfunction of the basal ganglia leading to an excess of the dopamine neurotransmitter. This view gives a restricted clinical picture and limits therapeutic approaches because it ignores the influence of altered interactions between the basal ganglia and other brain areas. In this respect, recent evidence supports a more articulated framework where cerebellum and cortex are also involved in tic production. Building on these data, we propose a computational model of the basal ganglia-cerebellar-thalamo-cortical network to investigate the specific mechanisms underlying motor tic production. The model reproduces the results of recent experiments and suggests an explanation of the system-level processes underlying tic production. Moreover, it furnishes predictions related to the amount of tics generated when there are dysfunctions in the basal ganglia-cerebellar-thalamo-cortical circuits. These predictions could be important in identifying new brain target areas for future therapies based on a system-level view of Tourette syndrome.

Upper facial chorea in Huntington disease

To provide a systematic description of component movements of upper facial chorea in Huntington disease, consecutive videos of 25 active patients with confirmed diagnosis were scored on eye opening, eye closing, and procerus/corrugator contractions. Of the 25 patients evaluated, 76% exhibited intermittently widened palpebral fissures associated with frontalis contractions. Brief periods of repetitive but irregular blinking were observed in 16%. 8% had brief spasms of the orbital portion of the orbicularis oculi muscles. In addition, brief contractions of procerus and corrugator supercilii muscles were noted in 52%.

Mouse models of neurodevelopmental disease of the basal ganglia and associated circuits

This chapter focuses on neurodevelopmental diseases that are tightly linked to abnormal function of the striatum and connected structures. We begin with an overview of three representative diseases in which striatal dysfunction plays a key role--Tourette syndrome and obsessive-compulsive disorder, Rett's syndrome, and primary dystonia. These diseases highlight distinct etiologies that disrupt striatal integrity and function during development, and showcase the varied clinical manifestations of striatal dysfunction. We then review striatal organization and function, including evidence for striatal roles in online motor control/action selection, reinforcement learning, habit formation, and action sequencing. A key barrier to progress has been the relative lack of animal models of these diseases, though recently there has been considerable progress. We review these efforts, including their relative merits providing insight into disease pathogenesis, disease symptomatology, and basal ganglia function.

Huntington's disease masquerading as spinocerebellar ataxia

Huntington's disease (HD) is a neurodegenerative disorder of the central nervous system characterised by the presence of choreic abnormal movements, behavioural or psychiatric disturbances and dementia. Noteworthy, despite atypical motor symptoms other than chorea have been reported as initial presentation in some patients, a very few number of HD patients, presenting at onset mostly cerebellar dysfunction masquerading dominant spinocerebellar ataxias (SCA), were occasionally reported. We report the case of a 42-year-old man with a 5-year history of gait disturbance, dysarthria and cognitive impairment and familial antecedents of dementia and movement disorders. Initially the clinical picture suggested the diagnosis of a dominant SCA, but finally a diagnosis of HD was made based on the molecular evidence of abnormal 39 Cytosine-Adenine-Guanine (CAG) repeats in exon 1 of Huntingtin gene. The authors highlight the importance of suspecting HD in the aetiology of spinocerebellar ataxias when dementia is a prominent feature in the proband or their family.

Global dysrhythmia of cerebro-basal ganglia-cerebellar networks underlies motor tics following striatal disinhibition

Motor tics, a cardinal symptom of Tourette syndrome (TS), are hypothesized to arise from abnormalities within cerebro-basal ganglia circuits. Yet noninvasive neuroimaging of TS has previously identified robust activation in the cerebellum. To date, electrophysiological properties of cerebellar activation and its role in basal ganglia-mediated tic expression remain unknown. We performed multisite, multielectrode recordings of single-unit activity and local field potentials from the cerebellum, basal ganglia, and primary motor cortex using a pharmacologic monkey model of motor tics/TS. Following microinjections of bicuculline into the sensorimotor putamen, periodic tics occurred predominantly in the orofacial region, and a sizable number of cerebellar neurons showed phasic changes in activity associated with tic episodes. Specifically, 64% of the recorded cerebellar cortex neurons exhibited increases in activity, and 85% of the dentate nucleus neurons displayed excitatory, inhibitory, or multiphasic responses. Critically, abnormal discharges of cerebellar cortex neurons and excitatory-type dentate neurons mostly preceded behavioral tic onset, indicating their central origins. Latencies of pathological activity in the cerebellum and primary motor cortex substantially overlapped, suggesting that aberrant signals may be traveling along divergent pathways to these structures from the basal ganglia. Furthermore, the occurrence of tic movement was most closely associated with local field potential spikes in the cerebellum and primary motor cortex, implying that these structures may function as a gate to release overt tic movements. These findings indicate that tic-generating networks in basal ganglia mediated tic disorders extend beyond classical cerebro-basal ganglia circuits, leading to global network dysrhythmia including cerebellar circuits.

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.

Huntington's disease - clinical signs, symptoms, presymptomatic diagnosis, and diagnosis

HD is a complex illness, with a broad clinical picture that begins years before clear motor onset and evolves over decades to a terminal state of extreme disability. It challenges the resources of families and communities and the skills of medical and ancillary health care providers. A broader understanding of the phenotypes, progression, and genetic basis of HD may elevate the standard of care for these deserving patients.

Tetrabenazine as anti-chorea therapy in Huntington disease: an open-label continuation study. Huntington Study Group/TETRA-HD Investigators

Background

Tetrabenazine (TBZ) selectively depletes central monoamines by reversibly binding to the type-2 vesicular monoamine transporter. A previous double blind study in Huntington disease (HD) demonstrated that TBZ effectively suppressed chorea, with a favorable short-term safety profile (Neurology 2006;66:366-372). The objective of this study was to assess the long-term safety and effectiveness of TBZ for chorea in HD.

Methods

Subjects who completed the 13-week, double blind protocol were invited to participate in this open label extension study for up to 80 weeks. Subjects were titrated to the best individual dose or a maximum of 200 mg/day. Chorea was assessed using the Total Maximal Chorea (TMC) score from the Unified Huntington Disease Rating Scale.

Results

Of the 75 participants, 45 subjects completed 80 weeks. Three participants terminated due to adverse events (AEs) including depression, delusions with associated previous suicidal behavior, and vocal tics. One subject died due to breast cancer. The other 26 subjects chose not to continue on with each ensuing extension for various reasons. When mild and unrelated AEs were excluded, the most commonly reported AEs (number of subjects) were sedation/somnolence (18), depressed mood (17), anxiety (13), insomnia (10), and akathisia (9). Parkinsonism and dysphagia scores were significantly increased at week 80 compared to baseline. At week 80, chorea had significantly improved from baseline with a mean reduction in the TMC score of 4.6 (SD 5.5) units. The mean dosage at week 80 was 63.4 mg (range 12.5-175 mg).

Conclusions

TBZ effectively suppresses HD-related chorea for up to 80 weeks. Patients treated chronically with TBZ should be monitored for parkinsonism, dysphagia and other side effects including sleep disturbance, depression, anxiety, and akathisia.

Trial Registration

Clinicaltrials.gov registration number (initial study): NCT00219804

Expression of Mutated Huntingtin Fragment in the Putamen Is Sufficient to Produce Abnormal Movement in Non-human Primates

Huntington's disease (HD) is a neurological disorder characterized by striatal degeneration, motor symptoms and complex neuropsychiatric alterations. There is currently no genetic model of HD in non-human primates (NHPs). In this study we investigated neuropathological and behavioral changes following injections of lentiviral vectors encoding a fragment of mutated huntingtin (Htt171-82Q) into the dorsolateral sensorimotor putamen of macaques. In the first study, we injected Htt171-82Q into one hemisphere and a lentiviral vector encoding Htt171-19Q or saline into the other, and studied the animals for 9 weeks. During this period, when apomorphine was administered into Htt171-19Q/82Q animals, it induced progressive chorea, dystonia and ipsilateral turning behavior, whereas animals infected with Htt171-19Q/19Q showed no abnormal behavior. After 9 weeks, the putamen of animals infected with Htt171-82Q presented neuritic and nuclear Htt aggregates, reactive astrocytes and loss of the neuronal marker NeuN. In a second study, we injected Htt171-82Q bilaterally into the dorsolateral putamen. From week 15 after infection, these animals progressively developed spontaneous dyskinesia of the legs, arms, and trunk and, in one case, tics that persisted for up to 30 weeks. The present study constitutes a proof-of-principle for the development of a genetic model of HD in NHP.

Seminar on choreas

Chorea is one of the major types of involuntary movement disorders originating from dysfunctional neuronal networks interconnecting the basal ganglia and frontal cortical motor areas. The syndrome is characterised by a continuous flow of random, brief, involuntary muscle contractions and can result from a wide variety of causes. Diagnostic work-up can be straightforward in patients with a positive family history of Huntington's disease or acute-onset hemichorea in patients with lacunar stroke, but it can be a challenging and complex task in rare autoimmune or genetic choreas. Principles of management focus on establishing an aetiological classification and, if possible, removal of the cause. Preventive strategies may be possible in Huntington's disease where genetic counselling plays a major part. In this review we summarise the current understanding of the neuroanatomy and pathophysiology of chorea, its major aetiological classes, and principles of diagnostic work-up and management.

The search for cerebral biomarkers of Huntington's disease: a review of genetic models of age at onset prediction

The mutation causing Huntington's disease is an expanded CAG trinucleotide repeat number beyond 35 in the 5' translated region of the gene. The mutation penetrance varies widely and depends on the CAG expansion length, the low pathological triplet range (36-41) showing a very low penetrance, possibly associated with late ages at onset. No research has so far yielded biomarkers for accurately predicting either age at onset or disease progression in at risk individuals. Specific markers able to follow-up mutation carrier subjects from the pre-symptomatic stages of life are crucial for testing experimental neuroprotective preventive therapies. Nevertheless, the factor accounting for the largest percentage of age at onset variation is the expanded repeat number within the gene. Over the years, this factor has helped in setting up models for genetically predicting age at onset. Once available for practical application in clinics, such models allowed phenotype-genotype correlations that were hitherto inconceivable. In this review, we discuss how these genetic models have been applied in clinical practice and comment on their potential value in searching for cerebral biomarkers of disease onset and severity and in designing trials of therapeutic drugs.

[Gilles de la Tourette syndrome: a self-administered assessment questionnaire]

INTRODUCTION

An association of patients with Gilles de la Tourette syndrome enabled us to gather a large body of information regarding the disease manifestations, and patient-perceived consequences.

METHOD

350 questionnaires were sent to patients belonging to the AFSGT (French Association of Patients Suffering from Gilles de la Tourette Syndrome). 187 responses were received (53 percent). The patients were divided into four groups: those with motor tics, vocal tics, complex tics and complex tics with coprolalia. This last group corresponds to the DSM IV definition of "Tourette Disorder". The questions were grouped in five sections: simple manifestations, complex manifestations, family study, treatment and psycho-affective perception (social and in the context of schooling).

RESULTS

The study of the simple manifestations of the disorder revealed the homogeneity of the four groups with an age of onset at on average 7 years and a male-to-female ratio of 3.5. The first signs of the disorder are motor tics of the face and neck, and the disorder shows a variable and fluctuating course characterized by periods of decreased or absent symptoms. Familial cases (58 percent) are found in all four groups. The complex signs included in part of behaviors corresponding to the definition of tics: sudden, brusque, repetitive, varied, escape despite efforts to repress them and reappearance more intensely after a period of conscious control. The complex signs also consisted of accompanying factors such as agitation, need to organize, classify or count. Treatments have been of limited success and a significant number of patients have abandoned treatment entirely. Our study demonstrates that this condition seriously affects the daily life of patients, including family and social relations, schooling and occupational life. No patients suffering from transient tics responded to our survey, but such tics were reported in family members.

CONCLUSION

Overall, the condition is considered to be single family of disorders, despite the broad phenotypic spectrum, from transitory cases by children to very severe forms. Escape despite efforts to repress tics and the rebound after control tics is characteristic of the Georges Gilles de la Tourette syndrome.

Secondary tics and tourettism

Motor and phonic tics are most frequently due to Tourette syndrome, but there are many other causes of tics. We analyzed data on 155 patients with tics and co-existent disorders (101M/54F; mean age 40.5 +/- 20.2 years). Fourteen (9.0%) patients had tics associated with an insult to the basal ganglia, such as head trauma (N = 4, 2.5%), stroke (N = 2, 1.2%), encephalitis (N = 3, 1.9%) and other causes. In addition, certain drugs, toxins, and post-infectious causes were associated with tics. Rarely, peripheral injury can cause movement disorders, including tics (N = 1, 0.6%). Pervasive developmental disorders, including Asperger's syndrome (N = 13, 8.3%), mental retardation (N = 4, 2.5%), autism (N = 3, 1.9%), and Savant's syndrome (N = 1, 0.6%), also may be associated with tics, as noted in 21 of the 155 patients (13.5%). Genetic and chromosomal disorders, such as Down's syndrome 5 (3.2%), neuroacanthocytosis (N = 2, 1.2%), and Huntington's disease (N = 1, 0.6%), were associated with tics in 16 patients (10.3%). We have also examined the co-existence of tics and other movement disorders such as dystonia (N = 31, 20.0%) and essential tremor (N = 17, 10.9%). Sixteen (10.3%) patients presented psychogenic tics, and one (0.6%) psychogenic tics and dystonia; conversely, Tourette syndrome preceded the onset of psychogenic dystonia (N = 1, 0.6%), and psychogenic tremor (N = 1, 0.6%) in two patients. Finally, 12 (7.7%) patients had tics in association with non-movement related neurological disorders, such as static encephalopathy (N = 2, 1.2%) and seizures (N = 3, 1.9%). To understand the physiopathology of tics and Tourette syndrome, it is important to recognize that these may be caused or associated with other disorders.

Dyskinesias and associated psychiatric disorders following streptococcal infections

BACKGROUND

The classical extrapyramidal movement disorder following beta haemolytic streptococcus (BHS) infection is Sydenham's chorea (SC). Recently, other post-streptococcal movement disorders have been described, including motor tics and dystonia. Associated emotional and behavioural alteration is characteristic.

AIMS

To describe experience of post-streptococcal dyskinesias and associated co-morbid psychiatric features presenting to a tertiary referral centre 1999-2002.

METHODS

In all patients, dyskinetic movement disorders followed BHS pharyngeal infection. BHS infection was defined by pharyngeal culture of the organism, or paired streptococcal serology. Movement disorders were classified according to international criteria, and validated by experienced child neurologists. Psychiatric complications were defined using ICD-10 criteria using a validated psychiatric interview.

RESULTS

In the 40 patients, the following dyskinetic movement disorders were present: chorea (n = 20), motor tics (n = 16), dystonia (n = 5), tremor (n = 3), stereotypies (n = 2), opsoclonus (n = 2), and myoclonus (n = 1). Sixty five per cent of the chorea patients were female, whereas 69% of the tic patients were male. ICD-10 psychiatric diagnoses were made in 62.5%. Using the same psychiatric instrument, only 8.9% of UK children would be expected to have an ICD-10 psychiatric diagnosis. Emotional disorders occurred in 47.5%, including obsessive-compulsive disorder (27.5%), generalised anxiety (25%), and depressive episode (17.5%). Additional psychiatric morbidity included conduct disorders (27.5%) and hyperkinetic disorders (15%). Psychiatric, movement, and post-streptococcal autoimmune disorders were commonly observed in family members. At a mean follow up of 2.7 years, 72.5% had continuing movement and psychiatric disorders.

CONCLUSION

Post-streptococcal dyskinesias occur with significant and disabling psychiatric co-morbidity and are potential autoimmune models of common "idiopathic" movement and psychiatric disorders in children. Multiple factors may be involved in disease expression including genetic predisposition, developmental status, and the patient's sex.

Tourettism and dystonia after subcortical stroke

The term "tourettism" has been used to describe Tourette syndrome (TS)-like symptoms secondary to some specific cause. Tics associated with attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), or both, are commonly present in TS, but this constellation of symptoms has been rarely attributed to stroke. We describe two boys who suffered a subcortical stroke and subsequently developed hemidystonia, tics, and behavioral comorbidities. Both had right hemispheric stroke involving the basal ganglia at 8 years of age, and in both the latency from the stroke to the onset of left hemidystonia was 2 weeks. In addition to ADHD and OCD, both exhibited cranial-cervical motor tics but no phonic tics. The temporal relationship between the stroke and subsequent TS-like symptoms, as well as the absence of phonic tics and family history of TS symptoms in our patients, argues in favor of a cause and effect relationship, and the observed association provides evidence for an anatomic substrate for TS and related symptoms.

Immediate and long term outcome after infrathalamic and thalamic lesioning for intractable Tourette's syndrome

OBJECTIVE

The surgical treatment of intractable Tourette's syndrome is controversial. Experience with 17 consecutive patients treated between 1970 and 1998 is reviewed and the efficacy and safety of surgical treatment is assessed.

METHODS

These patients were retrospectively reclassified into subtypes according to the protocol of the Tourette's Syndrome Study Group. One patient was excluded from the study. Ventriculography based stereotactic zona incerta (ZI) and ventrolateral/ lamella medialis thalamotomy (VL/LM) were performed on all patients. The preoperative, postoperative, and late tic severities were assessed by the tic severity rating scale. The median follow up of 11 patients (65%) was 7 years (range 3.5-17 years) and six patients were lost to long term follow up.

RESULTS

Median age was 23 years (range 11-40) at the time of surgery. Median duration of illness was 14 years (range 3-33). The mean preoperative motor and vocal tic severities were estimated to be 4.44 (SD 0.63) and 3.81 (SD 0.66), respectively. Unilateral ZI lesioning and VL/LM lesioning selected by asymmetry of symptoms provide an effective control of tic severity (p motor and vocal<0.001). In attenuation of contralateral symptoms, a second surgical intervention in the relevant side could reduce tic severity sufficiently (p motor<0.01; p vocal<0.005). Transient complications occurred in 68% of patients. Only one permanent complication was registered in six patients followed up after unilateral surgery. Two out of five patients followed up after bilateral surgery had disabling side effects of surgery.

CONCLUSIONS

ZI and VL/LM lesioning provide a significant long term reduction of tic severity in intractable Tourette's syndrome. Adequate selection of the side of first intervention might prevent the patient from increased risk of bilateral surgery.

Atypical movement disorders in the early stages of Huntington's disease: clinical and genetic analysis

Huntington's disease (HD) is notably difficult to diagnose in the early stages. One reason is that the early clinical manifestations of HD vary widely and sometimes have an atypical onset. In this paper we primarily sought information on affected patients who initially presented with movement disorders other than chorea. We also investigated atypical motor presentations in relation to triplet CAG expansions. After reviewing the clinical records of two neurological centres, we identified patients with a final, documented diagnosis of HD and selected for study 205 patients according to their onset of motor manifestations. CAG repeats were analysed. Of the 205 patients studied, 15 had atypical motor symptoms at onset. In this group we identified three types of initial clinical manifestations other than chorea: parkinsonism, ataxia and dystonia. We conclude that HD patients may have different motor manifestations at the initiation of the illness. Patients with atypical movement disorders in the early stages have larger CAG expansions and an earlier age at onset than HD patients with typical onset chorea.

Do the same genes predispose to Gilles de la Tourette syndrome and dystonia? Report of a new family and review of the literature

Gilles de la Tourette syndrome (TS) and idiopathic focal torsion dystonia are both movement disorders in which the pathologic process is thought to arise within the basal ganglia. However, despite their possible functional links, they are clinically distinct and are generally considered to have different underlying etiologies. There are several reports in the literature that suggest a relationship between eye winking tics, excessive blinking, and blepharospasm and a report of the coexistence of tics and dystonia. We describe a three-generation family in which TS and dystonias cosegregate. In total, eight patients were affected, five with dystonia and three with TS/facial tics. One of the patients with historic evidence of dystonia subsequently died of motor neuron disease. The identification of this family further strengthens the evidence in favor of an etiologic relationship between some cases of Gilles de la Tourette syndrome and focal dystonia.

Tourettism as clinical presentation of Huntington's disease with onset in childhood

Infantile Huntington's disease (HD) shows a wide clinical heterogeneity. Here we describe the case of a child affected by HD who showed unusual neurological features consistent with tourettism. The absence of family history and persisting normal magnetic resonance imaging (MRI) results long after the onset of symptoms delayed the diagnosis of the disease. An MRI exam performed 26 months after disease onset disclosed bilateral atrophy in the putamen, suggesting HD. The diagnosis was confirmed by genetic analysis. The present report underlines the need to consider HD in childhood cases of unusual and even unfamiliar progressive movement disorders.

PANDAS: the search for environmental triggers of pediatric neuropsychiatric disorders. Lessons from rheumatic fever

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) is a relatively new diagnostic construct applied to children or adolescents who develop, and have repeated exacerbations of, tic disorders and/or obsessive-compulsive disorder following group A beta-hemolytic streptococcal infections. The proposed pathophysiology is that the group A beta-hemolytic streptococcal bacteria trigger antibodies that cross-react with the basal ganglia of genetically susceptible hosts leading to obsessive-compulsive disorder and/or tics. This is similar to the etiologic mechanisms proposed for Sydenham's chorea, in which group A beta-hemolytic streptococcal antibodies cross-react with the basal ganglia and result in abnormal behavior and involuntary movements. When first proposed, there was much controversy about the idea that streptococcal infections were etiologically related to rheumatic fever. In a like manner, discussion has arisen about the concept of infection-triggered obsessive-compulsive disorder and tic disorders. We review the historical background to these controversies, give an update on the findings provided by research on PANDAS, and address areas of future study.

Genetic screening for Huntington's disease in Chinese patients with involuntary movements

The diagnosis of Huntington's disease (HD) can be confirmed by detecting the expanded CAG repeat in the IT15 gene. Besides chorea, patients with HD may present with a variety of bizarre involuntary movements, resulting in confusion in making the diagnosis. Under such conditions, genetic analysis is the final confirmatory test. To determine if any patient with involuntary movements of undetermined etiology might be related to HD, we did genetic analysis on 22 patients and identified three with expanded CAG repeat. We could not obtain family history of HD in these patients due to adoption, early death of parents, or a vague history. All three patients were among the group with generalized chorea, but one had additional marked dystonic posturing. Together with four clinically recognizable HD patients, the relative frequency of HD among the 103 patients with choreiform movements in this hospital is 6.8%.

Adult-onset tics associated with peripheral injury

We report the cases of two patients with adult-onset, simple, nonvarying tic disorder that commenced after a peripheral (non-CNS) injury. The first patient is a 38-year-old man who suffered a right facial injury when his car fell off its jack while he was working underneath. Bilateral facial twitching began hours after the trauma and was characterized as a sniffinglike gesture. The movements waxed and waned, were suppressible, and were associated with a premonitory sensation. The tics remitted after 9 months but still recur occasionally under stressful situations. The second patient is a 34-year-old man with a 3-year history of abrupt, rapid head-turning movements that began 12 months after a motor vehicle accident in which he injured his neck. The tics continue to wax and wane, are suppressible, and are associated with an urge. Neither patient suffered a head injury or had a family history of Tourette syndrome. Based on the clinical and historical features of these patients, the temporal relationship between the trauma and onset of tics, and the occurrence of tics only in the traumatized region, a causal relationship is possible. These may represent the first reported cases of tic disorder in association with peripheral injury. The mechanism by which the tic disorder resulted from the peripheral injury is unclear, but these patients might have been susceptible individuals and the trauma acted as a trigger.

Antiphospholipid antibodies: an epiphenomenon in Tourette syndrome

Antiphospholipids (aPLAs) have been previously identified in children with Tourette syndrome (TS), which has led to the speculation that these antibodies might have a pathophysiologic role in this disorder. Therefore, 21 healthy children and adolescents with TS, whose ages ranged from 7 to 17 years, underwent laboratory studies designed to diagnose the lupus anticoagulant, anticardiolipin (aCL) antibodies [immunoglobulin (Ig) G, IgA, and IgM], and antinuclear antibodies. Although five subjects had at least one value that differed from accepted laboratory standards, the changes were marginal in four of them. Lupus anticoagulant was identified in one patient, based on a minimal requirement of a prolonged dilute Russell viper venom time, clotting studies that did not correct after mixture with normal plasma, and an abnormal platelet neutralization procedure. A prolonged (but correctable) activated partial thromboplastin time was found in one individual, and aCL IgG was marginally increased in three subjects. Two (10%) of a control population of 20 same-age children also had low positive aCL IgG levels. There were no differences in tics (onset, type, frequency, severity, and family history) or comorbid features between children with normal or "abnormal" laboratory study results. Our data suggest that the presence of aPLAs in TS represents an epiphenomenon rather than a pathophysiologic mechanism.

Tourette syndrome. Secondary tic disorders

The putative relationship between a variety of neurologic and neuropsychiatric disorders, which have been reported in association with tics, is reviewed. Tics also may be increased or exacerbated by drugs affecting a variety of neurotransmitter systems. Recognition and study of these secondary tic disorders may further our understanding of basal ganglia physiology and the pathogenesis of Tourette syndrome.