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PubMed1993

[Dystonia].

Dystonia is a persistent attitude or posture in one or other of the extremes of athetoid movement. It may take the form of an over-extension or over-flexion of the hand, torsion of the spine, with arching and twisting of the back or forceful closure of the eyes and a fixed grimace. Dystonia is classified into idiopathic and symptomatic dystonia. Idiopathic dystonia is further divided into generalized, focal and segmental dystonia. Generalized dystonia covers classical torsion dystonia, paradoxical dystonia, myoclonic dystonia, dystonia with diurnal variation and Dopa-responsive dystonia. Dystonic tic, paroxysmal dystonia and hypnotic dystonia show a dystonic posture, although they are also accompanied by various other involuntary movements such as athetosis or chorea. Torticollis, writer's cramp or blepharospasm is assigned to the focal dystonia and Meige syndrome to the segmental dystonia. Symptomatic dystonia is observed in various neurological disorders, including cerebrovascular diseases, Parkinson's disease and Wilson's disease.

Adolescent↗
PubMed2000

Dystonia-predominant adult-onset Huntington disease: association between motor phenotype and age of onset in adults.

BACKGROUND: In juvenile Huntington disease (HD), dystonia as well as parkinsonism and eye movement abnormalities may be the predominant motor signs rather than chorea. Several patients have come to our attention with adult-onset HD in whom there is prominent dystonia and minimal chorea (ie, an adult-onset form of HD that resembles juvenile HD). OBJECTIVES: To estimate the prevalence of these cases of dystonia-predominant HD in a clinic and to study the relationship between the motor phenotype and age of onset in HD. METHODS: The Unified Huntington's Disease Rating Scale (UHDRS) was administered to 127 subjects during their initial visit to the Huntington's Disease Center at the New York State Psychiatric Institute, where dystonia, chorea, bradykinesia, rigidity, and eye movements were rated. The dystonia score was the mean UHDRS rating of dystonia in 5 body regions; the chorea score, the mean rating of chorea in 7 regions; the bradykinesia score, the mean rating of axial and limb bradykinesia; the rigidity score, the mean rating of rigidity in both arms; and the eye movement score, the mean rating of ocular pursuit, saccade initiation, and velocity. Dystonia-predominant HD was defined by the severity of dystonia relative to the severity of chorea. RESULTS: Fifteen (11.8%) of 127 subjects had dystonia-predominant HD. Age of onset correlated negatively (r= -0. 22, P=.02) with the dystonia score divided by the chorea score and negatively (r= -0.28, P=.002) with the severity of dystonia, bradykinesia, and eye movement abnormalities relative to chorea (ie, [(dystonia score + bradykinesia score + eye movement score)/3] - chorea score), suggesting that subjects with younger ages of onset had more severe dystonia, bradykinesia, and eye movement abnormalities relative to chorea. CONCLUSIONS: Cases of adult-onset HD with prominent dystonia and a paucity of chorea may represent 1 in 8 cases in specialty clinics. Age of onset was clearly associated with the motor phenotype. A younger age of onset was associated with more severe dystonia, bradykinesia, and eye movement abnormalities relative to chorea, supporting the notion that in adult-onset HD, the motor phenotype forms a continuum with respect to age of onset.

Adult↗
PubMed2005

[Therapy of dystonia in Japan].

A questionnaire about the treatment of dystonia was sent out to 585 councilors of Societas Neurologica Japonica. One hundred and sixty-eight replies (28.7%) were collected, although some of them were excluded from the analysis because of inappropriateness. 1) The number of patients previously experienced was < 10; 37 respondents (22.7%), 10-50; 83 (50.9%), 50-100; 26 (16.0%), and > 100; 17 (10.4%). 2) Oral medication was most often the first line treatment in either of generalized dystonia, blapharospasm, cervical dystonia, and writer's cramp. Botulinum toxin injection was the first or the second line treatment in 147 (87.5%) and 116 (69.0%) respondents for blepharospasm and cervical dystonia, respectively. In these two conditions, the more experienced doctors tended to prefer botulinum toxin injection to the other treatments as the first choice (Cochran-Armitage analysis; p = 0.003 for blepharospasm and p = 0.002 for cervical dystonia). 3) Among the oral drugs, anticholinergics, especially trihexyphenidyl, were the most frequent choice in generalized dystonia, cervical dystonia, and writer's cramp. For blepharospasm, clonazepam was most favored. Sedatives, especially diazepam, were also often the drug of choice in either of these disorders. The favored drugs were not related to the respondent's experience. 4) The success rate of treatment, designated as the percentage of patients who improved through any treatment so much that the respondent was satisfied with it, was the highest in blepharospasm (65.4 +/- 24.1; mean +/- SD), followed by cervical dystonia (41.2 +/- 23.4), writer's cramp (32.9 +/- 22.5), and generalized dystonia (20.4 +/- 19.8). Only in cervical dystonia, the rate was significantly higher in more experienced respondents (regression analysis; p = 0.008). In blepharospasm (p < 0.001) and cervical dystonia (p = 0.002), regression analysis indicated that the success rate was higher in the group who preferred botulinum toxin injection to oral medication as the first line treatment. These results indicate that in Japan the treatment of choice for dystonia does not always follow the therapeutic guidelines for dystonia proposed in some foreign countries. Adopting more evidence-based rationale of treatment is encouraged, because the recent progress about the treatment of dystonia, e.g. botulinum toxin injection or the stereotaxic surgery, is reshaping dystonia from a devastating to a treatable disorder.

Anticonvulsants↗
PubMed2003

Secondary cervical dystonia associated with structural lesions of the central nervous system.

We tested the hypothesis that structural lesions of the central nervous system (CNS) associated with cervical dystonia more commonly involve the cerebellum and its primary afferent pathways than basal ganglia structures. Cervical dystonia is the most common focal dystonia, the majority of cases are idiopathic, and only a small percentage of patients have a family history of dystonia or other movement disorders. Pathophysiological mechanisms operative in solely or predominantly appendicular dystonias such as writer's cramp and Oppenheim's dystonia, respectively, may not be directly applicable to axial dystonias. The localization of structural lesions of the CNS associated with secondary cervical dystonia may provide some insight into the neural structures potentially involved in primary cervical dystonia. The National Library of Medicine Gateway (from 1960) and a clinical database maintained by the senior author (from 1999) were searched for cases of secondary cervical dystonia associated with structural lesions of the CNS. Search terms included one or more of the following: dystonia, torticollis, cervical, secondary, and symptomatic. Lesion localization and type, patient age, patient gender, head position, occurrence of sensory tricks, and associated neurological findings were tabulated for each case. Structural lesions associated with cervical dystonia were most commonly localized to the brainstem and cerebellum. The remaining cases were equally divided between the cervical spinal cord and basal ganglia. Although inconsistent, head rotation tended to be contralateral to lesion localization. Additional neurological abnormalities were present in the majority of patients with secondary cervical dystonia. The relative paucity of basal ganglia pathology and concentration of lesions in the brainstem, cerebellum, and cervical spinal cord in patients with secondary cervical dystonia suggests that dysfunction of cerebellar afferent pathways may be important to the pathophysiology of primary cervical dystonia.

Adult↗
PubMed2002

[The varied etiologies of childhood-onset dystonia].

Dystonia is not uncommon in childhood, and identification of its etiology is an ultimate aim in the clinical evaluation of dystonia. Advances in neuroimaging, recent identification of gene or loci implicated in dystonic syndromes, and characterisation of new pathological entities (creatine deficiency, biotin-responsive basal ganglia disease) enlarge our understanding of childhood dystonia, and expend its diagnosis spectrum. Awareness of the diverse etiologic categories of childhood-onset dystonia is necessary to accurate diagnosis approach. Clinical examination and cerebral magnetic resonance imaging are the keys of this diagnosis approach. Primary dystonia is defined as syndromes in which dystonia is the sole phenotypic manifestation (especially no cognitive deterioration is observed, and brain MRI is normal); DYT1 dystonia, in which the abnormal gene is located on chromosome 9, is the most frequent childhood-onset primary dystonia; progressive generalisation of the abnormal movements occur in 70p.cent of the patients. Dopa - Responsive Dystonia are characterized by marked diurnal fluctuations of the dystonic symptoms and by their marked and sustained response to dopaminergic therapy; associated parkinsonian signs are usually observed later in the course of the disease. Clinical presentation of DRD might be atypical (mimicking cerebral palsy or isolated limb pain without diurnal fluctuation). DRD is rare, but a trial of L-dopa should be performed on all patients with childhood-onset dystonia, lasting at least one month. Secondary dystonias or heredodegenerative diseases are the most frequent etiology of childhood-onset dystonic syndromes. Among a huge range of heredodegenerative disease, those that are amenable to a specific treatment, such as Wilson's disease or creatine deficiency, should be particularly investigated. The main objective of investigation of dystonia is to identify secondary dystonias or heredodegenerative diseases. Further investigations will be performed according to the clinical characteristics of the dystonia, to the presence of associated neurological or extraneurological symptoms, and according to brain imaging; this approach must be discussed for each single patient. The aim of the diagnosis strategy is the rapid identification of the etiology of dystonia which will lead to accurate treatment and pertinent genetic counselling.

Circadian Rhythm↗
PubMed2003

Abnormalities of spatial discrimination in focal and generalized dystonia.

Sensory processing is impaired in focal hand dystonia (FHD), with most previous studies having evaluated only the symptomatic limb. The purpose of this study was to establish whether the sensory system is affected in other types of dystonias and whether the contralateral hand is also involved in FHD. We used a spatial acuity measure (Johnson-Van Boven-Phillips domes) to evaluate sensory spatial discrimination in both hands of patients with different forms of dystonias including primary generalized DYT1 dystonia (associated with a unique deletion in the DYT1 gene) (n = 13), FHD (n = 15), benign essential blepharospasm (n = 9), cervical dystonia (n = 10) and in age-matched controls. Clinical evaluation included the Fahn dystonia scale for the focal dystonia groups and the Marsden-Burke-Fahn scale for the generalized dystonia group. Spatial discrimination was normal in patients with DYT1 dystonia, despite all of these patients having hand dystonia. However, spatial discrimination thresholds were significantly increased in both hands in the focal dystonia groups (thresholds were similar for each group) and did not correlate significantly with either severity or duration of dystonic symptoms. Thresholds were significantly increased in the dominant hand compared with the non-dominant hand only within the FHD group. Our observations demonstrate involvement of both the dominant and non-dominant somatosensory cortices, and suggest that abnormal sensory processing is a fundamental disturbance in patients with focal dystonia. These findings of altered sensory processing in idiopathic focal but not generalized DYT1 dystonia suggest both a primary pathophysiological role for the phenomenon in focal dystonia and divergent pathophysiological processes in the two conditions.

Adult↗
PubMed2002

Deep brain stimulation for dystonia in adults. Overview and developments.

The renaissance of functional neurosurgery in the treatment of Parkinson's disease has sparked also the interest in other movement disorders which are refractory to medical treatment. Deep brain stimulation (DBS) has been used only since a few years in dystonia patients. This review summarizes the available data on pallidal and thalamic DBS for various dystonic syndromes. The major advantage of DBS as compared to radiofrequency lesioning is that it allows performing contemporaneous bilateral surgery with relatively low morbidity in these patients. The posteroventral lateral globus pallidus internus (GPi) has been the preferred target in most instances, thus far. While phasic dystonic movements may improve early after surgery, the response of tonic dystonic movements to chronic stimulation may be delayed. The most beneficial results have been achieved in patients with primary genetic generalized and segmental dystonia, myoclonic dystonia, and complex cervical dystonia. Outcome has been varied in patients with other dystonic disorders, in particular those with secondary dystonia. Most studies have reported on relatively short follow-up periods, on single cases, or were retrospective. Pallidal DBS has been shown to be effective in complex cervical dystonia yielding both symptomatic and functional benefit for up to 2.5 years of follow-up. Dramatic improvement has been obtained in children and in adults with DYT1 positive dystonia. Also, patients with non DYT1 genetic dystonia achieved sustained benefit for up to 2 years of follow-up. Preliminary experience indicates that choreoathetosis in patients with cerebral palsy responds less well to pallidal DBS, and that it may not be effective at all in some patients. In single instances unilateral pallidal DBS has been shown to yield valuable benefit in patients with hemidystonia. The experience with DBS for treatment of Meige syndrome and other focal dystonias has been explored only recently. There is much less experience with thalamic DBS for dystonia. Thalamic DBS has been shown to be effective in single cases with posttraumatic dystonia, postanoxic dystonia and paroxysmal nonkinesigenic dystonia. Future perspectives of DBS for treatment of dystonia include the development of new technology, the evaluation of the possible role of other targets, and carefully planned studies to further establish the role of surgery.

Brain↗
PubMed2006

[The study and treatment of dystonias in childhood].

AIMS: Dystonia is after spasticity and tics the most common movement disorder in childhood. The etiology, diagnostic methods and treatment of childhood dystonia is reviewed. DEVELOPMENT: Children have generalized dystonia more often than adults. The most frequent secondary dystonia are due to cerebral palsy, and often it is associated with other movement disorders like spasticity. The study of dystonia must consider the diverse heredo-degenerative causes because the genetic counseling, natural evolution and treatment may be specific. Among the primary dystonias, torsion dystonia DYT1 and dopa responsive dystonias (DRD) are the more frequent. DRD can be produced by mutation of GCH1 (DYT5) or other enzymatic defects of the neurotransmitter formation pathway. The clinical features of DYT1, DYT5, DYT11, DYT12 and other primary dystonias presenting in childhood are described. The treatment of dystonias depends on the anatomic distribution. Focal dystonias are best treated with botulinum toxin type A. Most of generalized dystonias are improved by oral drugs (trihexiphenidil, baclofen, clonazepam, tizanidine, tetrabenazine, neuroleptics) in monotherapy or in associations. Intratecal baclofen and deep brain stimulation are the most useful treatments of severe childhood dystonias. CONCLUSION: The study of dystonias in children is complex, there are many disorders to consider as possible causes. Pharmacological and surgical treatments can be time-consuming and expensive but give a significant improvement of symptoms and quality of life to the patients.

Child↗
PubMed2000

[Genetics of dystonia].

To date, at least 12 types of primary dystonia can be distinguished on a genetic basis. A 3-bp deletion in the DYT1 gene causes early onset, generalized torsion dystonia (TD), and mutations in the GTP cyclohydrolase I and the tyrosine hydroxylase genes result in dopa-responsive dystonia (DYT5). A missense change in the D2 dopamine receptor in one large family (DYT11) has recently been implicated in myoclonus-dystonia. Furthermore, seven other loci for dystonia genes have been mapped to chromosomal regions, including a locus for a mixed dystonia phenotype (DYT6), one form of focal dystonia (DYT7), three types of paroxysmal dystonia (DYT8-10), X-linked dystonia-parkinsonism (DYT3), and rapid-onset dystonia-parkinsonism (DYT12). No positive linkage results have yet been obtained for autosomal recessive TD (DYT2) and several other families of different types of dominantly inherited TD (DYT4). In addition, hereditary secondary dystonia may occur as part of familial diseases of the basal ganglia, metabolic and storage disorders, and various X-linked and other familial neurodegenerative syndromes affecting the basal ganglia. It may be anticipated that the traditional clinical and etiological classifications of dystonia will increasingly be replaced by a genetic one and that the identification of more dystonia genes may lead to a better understanding of these largely nondegenerative disorders.

Dystonia↗
PubMed1998

Clinical and molecular genetics of primary dystonias.

Primary dystonias are movement disorders with dystonia as a major symptom. They are frequently inherited as Mendelian traits. There are at least eight clinically distinct autosomal dominant and two X-linked recessive forms. In addition, pedigree analyses suggest the occurrence of an autosomal recessive variant. The clinical classification is increasingly being replaced by a genetic one. To date gene loci have been identified in at least six autosomal dominant forms, i.e., in idiopathic torsion dystonia (9q34), focal dystonia (18p), adult-onset idiopathic torsion dystonia of mixed type (8p21-q22), dopa-responsive dystonia (14q22.1-q22.2), and paroxysmal dystonic choreoathetosis (2q25-q33; 1p21-p13.3). Gene loci in the X-linked recessive forms have been assigned to Xq13.1 in the X-linked dystonia parkinsonism syndrome and to Xq22 in X-linked sensorineural deafness, dystonia, and mental retardation. The disease genes have been identified in two autosomal dominant forms and in one X-linked recessive form. Mutations in a gene coding for an ATP-binding protein were detected in idiopathic torsion dystonia (DYT1), and the GTP cyclohydrolase 1 gene is mutated in dopa-responsive dystonia (DYT5). In sensorineural deafness, dystonia, and mental retardation, mutations were found in the gene DDP coding for a polypeptide of unknown function. This article reviews the clinical and molecular genetics of primary dystonias, critically discusses present findings, and proposes referring to the known forms, most of which can be distinguished by genetic criteria, as dystonias 1-12.

Carrier Proteins↗
PubMed1999

Genetics of primary dystonia.

Currently, at least 12 types of dystonia can be distinguished on a genetic basis. Advances in the molecular genetics of dystonia have led to the recent identification of a 3-bp deletion in the DYT1 gene, causing early-onset generalized torsion dystonia (TD), and to the detection of mutations in the GTP cyclohydrolase I and the tyrosine hydroxylase genes causing dopa-responsive dystonia (DYT5). A missense change in the D2 dopamine receptor has been shown to be associated with myoclonus-dystonia in one family. In addition, six other dystonia gene loci have been mapped to chromosomal regions, including a locus for a mixed dystonia phenotype (DYT6), one form of focal dystonia (DYT7), two types of paroxysmal dystonia (DYT8, DYT9), X-linked dystonia-parkinsonism (DYT3), and rapid-onset dystonia parkinsonism (DYT12). No positive linkage studies have as yet been reported for autosomal recessive TD (DYT2) and in several other large families with various types of dominantly inherited TD (DYT4). It may be anticipated that the traditional clinical and etiological classifications of dystonia will increasingly be replaced by a genetic one and that the identification of more dystonia genes may lead to a better understanding of these largely nondegenerative disorders.

Carrier Proteins↗
PubMed1999

[Genetic dystonia].

A NEW CLASSIFICATION: The advent of molecular genetics has led to a total revision of earlier classifications of primary dystonias. LOCUS DYT-1 PRIMARY DYSTONIA: Locus DYT1, situated on chromosome 9, is responsible for the most common phenotypic expression of generalized primary dystonia, Ziehen-Oppenheim disease. This autosomal dominant disease has variable penetration. It has long been recognized that some individuals in families with typical disease only have segmentary, multifocal or even focal dystonia. It has been proven by molecular genetics that the disease can be expressed simply by familial writers cramp with particularly early, and often bilateral, onset. The mutation concerns the torsine A gene, whose function remains to be elucidated. Torsine A is found in the central nervous system, particularly in the dopaminergic neurons of the locus niger. GENERALIZED PRIMARY DYSTONIA UNRELATED TO DYT-1: These dystonias are phenotypically different: younger and more variable age at onset, focal localization early in the disease course generally involving the cervical or cephalic pole, less severe course. Certain forms are linked to chromosome 8 (locus DYT 6). PRIMARY FOCAL OR SEGMENTARY DYSTONIAS: These primary dystonias cause functional or postural disorders and were long considered as sporadic despite rare familial cases suggesting a genetic factor. When searched for systematically, familial cases are found in 20 to 30% of the cases. The dystonia is transmitted by dominant autosomal heredity with reduced penetration. Phenotypically, expression is heterogeneous with a constant frequency of unrecognized or neglected forms and of postural forms. One form is known to be linked to chromosome 18 (locus DYT 7). DOPA-RESPONSIVE DYSTONIA: This class represents 5 to 10% of childhood dystonias. The phenotypic expression is polymorphous but symptoms always improve with very small doses of L-dopa. Both sporadic, and more frequently familial, cases are described. Some forms are recessive, caused by mutation of the gene coding for tyrosine hydroxylase, others are autosomal dominant, often linked to mutation of the gene coding for GTP cyclohydrolase. RAPID ONSET DYSTONIA SYNDROME-PARKINSONISM: This dominant autosomal dystonia is quite exceptional, ... and intriguing.

Adolescent↗
PubMed2006

Cortical and spinal abnormalities in psychogenic dystonia.

OBJECTIVE: The pathophysiology of psychogenic dystonia has not been examined, but a growing body of literature suggests that abnormal sensory input from repetitive movements can lead to plastic cortical changes. Reduced cortical and spinal inhibition is well documented in organic dystonia. We tested the hypothesis that aberrant sensory input associated with abnormal posture may cause similar abnormalities by testing patients with psychogenic dystonia. METHODS: We assessed cortical and spinal inhibitory circuits and cortical activity associated with voluntary movement in 10 patients with clinically definite psychogenic dystonia, 8 patients with organic dystonia, and 12 age-matched healthy control subjects. RESULTS: Three measures of cortical inhibition, resting short- and long-interval intracortical inhibition and cortical silent period, were reduced in both psychogenic dystonia and organic dystonia. Cutaneous silent period mediated by spinal circuitries was increased in psychogenic and organic dystonia. Forearm spinal reciprocal inhibition was reduced in psychogenic dystonia. INTERPRETATION: Psychogenic and organic dystonia share similar physiological abnormalities. Previous findings of abnormal cortical and spinal excitability in organic dystonia may, in part, be a consequence rather than a cause of dystonia. Alternatively, these findings may represent endophenotypic abnormalities that predispose to both types of dystonia.

Adult↗
PubMed2006

Runner's dystonia.

Adult-onset focal dystonia in the upper limbs is well characterized whereas such dystonia has been rarely reported in the lower limbs, especially in proximal parts. When such focal dystonia occurs in an athlete it is often wrongly attributed to an orthopedic disorder. We present five cases, three female and two male with mean age of 44.6+/-10.43 years, mean age at onset of 37.4+/-10.33 years, and mean duration of symptoms for 7.2+/-4.44 years, who initially noted dystonia of one leg during long-distance running. The clinical features of dystonia in these long-distance runners overlap with those of more recognizable forms of focal dystonia including relief with sensory or motor "tricks". They also share features with paroxysmal dyskinesia and carbamazepine markedly ameliorated the symptoms at least in one patient. One patient benefited from an oral anticholinergic, one from levodopa, and another two patients benefited from repeat botulinum toxin injections. Our patients differed from the typical childhood-onset leg dystonia, such as the DYT1 dystonia, in that there was no family history of dystonia and the leg dystonia remained focal without spreading to other body parts. Two of our patients had prior injury to the affected leg within 1 year prior to the onset of the dystonia, raising the possibility of peripherally-induced dystonia. We draw attention to this rare, disabling, adult-onset focal dystonia involving proximal lower limbs. When recognized early, it may be treated effectively with either anticholinergic drugs, anticonvulsants, levodopa, or botulinum toxin injections.

Adult↗
PubMed2002

The genetics of primary dystonias and related disorders.

Dystonias are a heterogeneous group of disorders which are known to have a strong inherited basis. This review details recent advances in our understanding of the genetic basis of dystonias, including the primary dystonias, the 'dystonia-plus' syndromes and heredodegenerative disorders. The review focuses particularly on clinical and genetic features and molecular mechanisms. Conditions discussed in detail include idiopathic torsion dystonia (DYT1), focal dystonias (DYT7) and mixed dystonias (DYT6 and DYT13), dopa-responsive dystonia, myoclonus dystonia, rapid-onset dystonia parkinsonism, Fahr disease, Aicardi-Goutieres syndrome, Hallervorden-Spatz syndrome, X-linked dystonia parkinsonism, deafness-dystonia syndrome, mitochondrial dystonias, neuroacanthocytosis and the paroxysmal dystonias/dyskinesias.

Adolescent↗
PubMed2006

A 9-year review of dystonia from a movement disorders clinic in Singapore.

The clinical features of dystonia have not been evaluated in Southeast Asia. We therefore investigated the clinical spectrum and characteristics of dystonia in Singapore, a multi-ethnic Southeast Asian country comprising 77% Chinese, 14% Malays, and 8% Indians. We identified all dystonia patients from the Movement Disorders database and Botulinum Toxin clinic between 1995 and November 2004. Their medical records were reviewed to verify the diagnosis of dystonia and obtain demographic and clinical data using a standardized data collection form. A total of 119 (73%) patients had primary dystonia whilst 45 (27%) had secondary dystonia. There were 77% Chinese, 9% Malays, and 8% Indians. The most common focal dystonia were cervical dystonia (47%), writer's cramp (32%), and blepharospasm (11%). There was no significant difference in the distribution of dystonia between the different races. Males were noted to have earlier onset of dystonia overall. There was a significant male predominance in primary dystonia overall (M:F 1.6:1, P=0.008) and in the subgroup of focal dystonia (M:F 1.6:1, P=0.037). This contrasts with previous studies that found a female predominance. The role of genetic, hormonal, and environmental factors and their interactions need to be investigated to better understand the gender differences in the occurrence of dystonia.

Dystonic Disorders↗
PubMed2003

[Primary focal dystonia: descriptive study of 205 patients].

OBJECTIVES: To describe the clinical and epidemiologic aspects of different types of focal dystonia. PATIENTS AND METHODS: A total of 205 patients with primary focal dystonia were studied retrospectively and the following variables were analyzed: gender, age of onset, age at examination, evolution time, history of trauma, association with other movement disorders, fluctuations of dystonic symptoms as well as a family history of dystonia, Parkinson's disease, tremor, and lefthandedness or stuttering. We compared these variables among the different clinical categories of focal dystonia. RESULTS: Those patients with cranial and laryngeal dystonia were significantly older at the onset of symptoms compared with patients with writer's cramp. Males were more prevalent than females in all categories of focal dystonia except for cranial dystonia. Prior history of trauma and association with tremor were more frequent in patients with cervical dystonia than in those with others dystonic categories. Most patients with cranial, cervical and laryngeal dystonia had fluctuations in the intensity of dystonic symptoms, unlike the patients with writer's cramp. CONCLUSIONS: There is a caudo-cranial gradient in age of onset and the age of onset increases as the cranial presentation becomes greater. Females are more prevalent in cranial dystonia and there is a preponderance of males in the dystonias with a lower location. The dystonias with cranial distribution frequently present fluctuations of symptoms during the day. Association with other movement disorders, such as tremor, and prior history of trauma, is common in patients with cervical dystonia.

Adolescent↗
PubMed2003

Dystonia: phenotypes and genotypes.

Despite clinical and genetic complexity of dystonia, knowledge of primary torsion dystonia and dystonia-plus syndromes was recently expanded. Part of the category of primary dystonia includes genetic forms (DYT1, DYT6, DYT13). The DYTI mutation, with predominant limbs (95p. 100) and neck and trunk (25-35p. 100) involvement accounts for about 80p. 100 of the early onset cases in the Ashkenazi population and of 16-53p. 100 in the non- Ashkenazi population. The dystonia-plus group is defined by the association of parkinsonism (dopa-responsive-dystonia and rapid-onset dystonia-parkinsonism) or myoclonus (myoclonus-dystonia). Dopa-responsive-dystonia is a heterogeneous group with several causes (GCH1 mutations, compound mutations in GCH1, mutations in TH gene, or in 6-PTS gene). Differential diagnosis could be juvenile parkinsonism (parkin mutations). Epsilon-sarcoglycan mutation accounts for a sub-group of myoclonus-dystonia, but other genes are still unidentified. The vast majority of dystonia are sporadic and still unexplained. Functional imaging may bring new insights in disease mechanisms. Because of phenotypic overlaps, within dystonia, new classifications based on functional markers may emerge.

Dystonia↗