Prevalence of dystonia in Akita Prefecture in Northern Japan.

We investigated the prevalence of dystonia in Akita Prefecture (population was 1,166,967 as of 1 November 2004). The prevalence of primary generalized and focal dystonia is estimated to be 0.68 and 14.4 per 100,000 persons, respectively. Blepharospasm is the most common primary dystonia in this area.     

Prevalence of tardive dystonia

Tardive dystonia is a rare late-onset side effect of neuroleptics. This paper presents a prevalence study of 351 inpatients conducted in our hospital. Seven patients (2%) were found to suffer from this condition. The majority were found to be young and had received neuroleptics for a variable number of years before the onset of the dystonia. In general, treatment of this condition is disappointing.     

Community survey of primary dystonia in the city of Kolkata, India.

An epidemiological study on dystonia has not been reported from India. As part of a major study to find out the prevalence of major neurological disorders in the large urban city of Kolkata, Eastern India, we planned to determine the prevalence of primary dystonia. The study design was a cross-sectional study of a sample population obtained through stratified random selection and conducted in a two-stage procedure of screening by a nonprofessional team followed by confirmation of screened positive cases by the study neurologist. A total population of 52,377 was screened, and 29 subjects with dystonia were diagnosed. Out of them 23 subjects had primary dystonias [crude prevalence rate (CPR), 43.91/100,000; 95% confidence interval (CI), 28.41-64.81; age-standardized rates to world standard population, 49.06 (95% CI,31.74-72.41)] and all cases were focal type and predominantly of limb dystonia variety. Mean onset of dystonias were earlier in women (43.5 years) as compared to men (46.6 years). Thus our study on primary dystonia shows higher prevalence when compared with that of many studies globally, predominantly of focal type, earlier onset among women, and more cases of limb dystonias when compared with more prominent blepharospasm and cervical dystonias in western reports.     

Executive cognitive deficits in primary dystonia.

Primary dystonia is a disorder of movement for which no consistent pathophysiology has been identified; in the absence of evidence to the contrary, it is assumed to be cognitively benign. We have studied a clinically heterogeneous group of 14 patients with primary dystonia on a battery of neuropsychological tests. Despite well-preserved speed of information processing, language, spatial, memory and general intellectual skills relative to normal controls, we have identified a constellation of attentional-executive cognitive deficits on the Cambridge Neuropsychological Test Automated Battery (CANTAB). Specifically, patients demonstrated significant difficulties negotiating the extra-dimensional set-shifting phase of the IED task. The implications of these findings for the pathophysiology of primary dystonia are discussed. This is, to the best of our knowledge, the first report of a significant cognitive deficit in patients with primary dystonia.     

Spread of primary dystonia in relation to initially affected region

Abstract Not only childhoodonset, but also adult-onset primary dystonia may spread to multiple body parts. The relative risk of spread by site of onset of dystonia, important for clinical prognosis and approach, has not been well characterized. The aim of this study was to prospectively follow the spread of dystonia in 132 consecutive patients and to estimate the risk of spread by the site of onset of dystonia. The patients were included in the study if primary focal dystonia was the only sign of neurological disease other than tremor; i.e. in all patients a single body part could be identified as affected at the onset. At the end of the followup (mean duration 7.5 years; range 5.2–13.4 years), 96 patients (73%) remained focal, while 26 (20%) and 10 (7%) progressed to segmental and generalized dystonia, respectively. The highest likelihood for further spread was observed in patients with initial blepharospasm (10 out of 30 patients; 33.3%), followed by dystonia of upper extremities (32.3%), torticollis (19.6%), and laryngeal dystonia (6.7%). In addition to the highest risk for further spread of dystonia, blepharospasm was associated with the fastest rate of spread (the second region affected on average after 1.2 years). Our results demonstrated that the initial site of primary dystonia was relevant for the risk of spread.     

Facial recognition in primary focal dystonia.

The basal ganglia seem to be involved in emotional processing. Primary dystonia is a movement disorder considered to result from basal ganglia dysfunction, and the aim of the present study was to investigate emotion recognition in patients with primary focal dystonia. Thirty-two patients with primary cranial (n=12) and cervical (n=20) dystonia were compared to 32 healthy controls matched for age, sex, and educational level on the facially expressed emotion labeling (FEEL) test, a computer-based tool measuring a person's ability to recognize facially expressed emotions. Patients with cognitive impairment or depression were excluded. None of the patients received medication with a possible cognitive side effect profile and only those with mild to moderate dystonia were included. Patients with primary dystonia showed isolated deficits in the recognition of disgust (P=0.007), while no differences between patients and controls were found with regard to the other emotions (fear, happiness, surprise, sadness, and anger). The findings of the present study add further evidence to the conception that dystonia is not only a motor but a complex basal ganglia disorder including selective emotion recognition disturbances.     

The entity of young onset primary cervical dystonia.

Primary cervical dystonia is typically an adult onset condition with symptom onset usually in the fifth and sixth decade. Young onset (<28 years) is uncommon. We report 76 patients with cervical dystonia as a presenting or predominant feature, with disease onset before the age of 28. Male to female ratio was 1.24:1 and the mean onset age was 21 (3-28) years. A family history of tremor and/or dystonia was noted in 26.3%. Depression and anxiety attacks were present in 23.7%.Prior injury or surgery involving the neck was noted in 17.1%. 23 (30.3%) experienced spontaneous partial or complete remissions within the first 5 years of onset, but all relapsed. Cervical dystonia was predominantly rotational torticollis. 30% developed extra-nuchal dystonia and tremor affecting contiguous parts but in only one there was spread to affect the legs. All 15 patients tested for the DYT1 gene were negative. 74% responded favorably to botulinum toxin injections, whereas none of the 13 patients treated with L-Dopa preparations had a beneficial response. The distinctive features of this entity are discussed.     

Epidemiology of primary dystonias in Japan: comparison with Western countries.

We performed epidemiological studies of primary dystonia in the city of Kyoto. The prevalence was at least 10.1 per 100,000 persons, which was similar to that in Western countries. Facial dystonia was more common than other types, which contrasts with that reported in Europe. Age of onset for both genders was in agreement with that in other countries.     

Prevalence of primary late-onset focal dystonia in the Belgrade population.

The aim of this cross-sectional study was to estimate the prevalence of different subtypes of idiopathic focal dystonia in the population of Belgrade (Serbia), Yugoslavia. On December 31, 2001, the crude prevalence of all studied types of dystonia (focal, segmental, and multifocal) in Belgrade was 13.6 per 100,000 population (11.8 per 100,000 for men and 15.2 per 100,000 for women). Type-specific prevalence for focal dystonia was 11.2 per 100,000. The prevalence for cervical dystonia, blepharospasm, writer's cramp and laryngeal dystonia were 5.9 per 100,000, 1.9 per 100,000, 1.9 per 100,000, and 1.1 per 100,000, respectively.     

Adult-onset primary lower limb dystonia.

The lower extremity is affected infrequently in adult-onset primary dystonia in contrast to childhood-onset dystonia, which typically begins in the foot. When dystonia affects the foot in an adult, it is usually on a secondary basis. We present findings on 17 patients (11 women, 6 men; average age of onset 48.4 years; average time to diagnosis 2.7 years) with adult-onset primary foot dystonia. Prior to diagnosis, most patients underwent extensive testing and treatment, including unnecessary surgeries. Only the left lower extremity was involved in 8 patients, only the right in 7, and both in 2. The most common patterns were plantar flexion of all toes and inversion of the foot, typically activated with standing or walking. Only 2 patients had dystonia elsewhere. There was a family history of possible dystonia in 2 patients. One of five tested for DYT1 was positive, in the absence of a family history. One of eight patients treated with levodopa experienced mild improvement. Six of eight treated with botulinum toxin improved. No patient has been observed to have a secondary cause of dystonia. The prognosis, with regard to progression or spread to other body parts, has been favorable. Although uncommon, foot dystonia on a primary basis, not due to DYT1, can begin in adulthood. In this series of patients, the diagnosis was often not recognized, leading to extensive and unnecessary testing and treatment and emphasizing the need for wider recognition.     

Prevalence of Autism in Iceland

This clinic-based study estimated the prevalence of autism in Iceland in two consecutive birth cohorts, subjects born in 1974-1983 and in 1984-1993. In the older cohort classification was based on the ICD-9 in 72% of cases while in the younger cohort 89% of cases were classified according to the ICD-10. Estimated prevalence rates for Infantile autism/Childhood autism were 3.8 per 10,000 in the older cohort and 8.6 per 10,000 in the younger cohort. The characteristics of the autistic groups are presented in terms of level of intelligence, male:female ratio, and age at diagnosis. For the younger cohort scores on the Autism Diagnostic Interview-Revised and the Childhood Autism Rating Scale are reported as well. Results are compared with a previous Icelandic study and recent population-based studies in other countries based on the ICD-10 classification system. Methodological issues are discussed as well as implications for future research and service delivery.     

Epidemiology of primary focal dystonias in the western area of Tottori prefecture in Japan: Comparison with prevalence evaluated in 1993.

An epidemiological survey of primary focal dystonias in the western area of Tottori Prefecture in Japan was conducted in 2003, and the results were compared with those of a previous survey in 1993. The service-based prevalence of primary focal dystonia was 13.7 per 100,000 population, representing an increase from that found in the 1993 survey. In 1997, botulinum toxin type A was approved for use in Japan to treat blepharospasm, and the increased number of patients now being evaluated and diagnosed with focal dystonias at medical centers throughout Japan may be responsible for this increased prevalence. Prevalence by subtype per 100,000 population was as follows: facial dystonia, 6.5; spasmodic torticollis, 2.0; writer's cramp, 4.4; and other focal dystonias; 0.8. Facial dystonia showed the most marked increase in service-based prevalence among these subtypes.     

Novel Italian family supports clinical and genetic heterogeneity of primary adult-onset torsion dystonia.

We report on an Italian kindred with adult-onset primary torsion dystonia (PTD). A detailed clinical examination of the six definitely affected family members revealed a mild, purely focal phenotype. The disease involved only one body part (eyes, neck, or arm). PTD in this family was not linked to the known disease loci (DYT1, DYT6, DYT7, and DYT13), and the 3-bp deletion in the DYT1 gene was also excluded. These findings support genetic heterogeneity of PTD and indicate that a novel unassigned gene is responsible for focal dystonia in this family.     

Genetic classification and molecular mechanisms of primary dystonia*★

BACKGROUND： Primary dystonia is a heterogeneous disease, with a complex genetic basis. In previous studies, primary dystonia was classified according to age of onset, involved regions, and other clinical characteristics. With the development of molecular genetics, new virulence genes and sites have been discovered. Therefore, there is a gradual understanding of the various forms of dystonia, based on new viewpoints. There are 15 subtypes of dystonia, based on the molecular level, i.e., DYT1 to DYT15. OBJECTIVE： To analyze the genetic development of dystonia in detail, and to further investigate molecular mechanisms of dystonia. RETRIEVAL STRATEGY： A computer-based online search was conducted in PubMed for English language publications containing the keywords ＂dystonia and genetic＂ from January 1980 to March 2007. There were 105 articles in total. Inclusion criteria： ① the contents of the articles should closely address genetic classification and molecular mechanisms of primary dystonia; ② the articles published in recent years or in high-impact journals took preference. Exclusion criteria： duplicated articles. LITERATURE EVALUATION： The selected articles were on genetic classification and molecular genetics mechanism of primary dystonia. Of those, 27 were basic or clinical studies. DATA SYNTHESlS： ① Dystonia is a heterogeneous disease, with a complex genetic basis. According to the classification of the Human Genome Organization, there are 15 dystonia subtypes, based on genetics, i.e., DYT1-DYT15, including primary dystonia, dystonia plus syndrome, degeneration plus dystonia, and paroxysmal dyskinesia plus dystonia.② To date, the chromosomes of 13 subtypes have been localized; however, DYT2 and DYT4 remain unclear. Six subtypes have been located within virulence genes. Specifically, torsinA gene expression results in the DYTI genotype; autosomal dominant GTP cyclohydrolase 1 gene expression and recessive tyrosine hydroxylase expression result in the DYT5 genotype, respectively; the epsil     

Clinical characterization and evaluation of DYT1 gene in Indian primary dystonia patients

OBJECTIVES: Dystonia is a common movement disorder. The purpose of this study is to examine the relative distribution of the primary dystonia subtypes and identify mutation (s) in the DYT1 gene in Indian patients. MATERIALS AND METHODS: Primary dystonia patients (n = 178) and controls (n = 63), lacking any symptoms of the disease, were recruited for the study from eastern India. The nucleotide variants in the DYT1 gene were identified by carrying out polymerase chain reaction, single stranded conformation polymorphism, and DNA sequencing. RESULTS: Unlike other reports, pain and/or tremor was more common in our sporadic patients than in familial cases. Three reported and two novel changes were identified in this gene. The homozygous genotype (G,G) for a missense variant (c.646G > C; Asp216His) was significantly over-represented in the patients compared with controls (P < 0.05). However, the commonly reported 3 bp deletion (904-906delGAG) was not detected. CONCLUSION: Our results suggest that the DYT1 gene might have a limited role in causation of dystonia in the Indian population.     

Phenotypic characterization of DYT13 primary torsion dystonia.

We describe the phenotype of DYT13 primary torsion dystonia (PTD) in a family first examined in 1994. A complete neurological evaluation was performed on all available family members: 8 individuals were definitely affected by dystonia. The family was re-evaluated in March 2000: at that time, 3 more individuals had developed symptoms of dystonia. Inheritance of PTD was autosomal dominant, with affected individuals spanning three consecutive generations and male-to-male transmission. Age at onset ranged from 5 to 43 years. Onset occurred either in the craniocervical region or in upper limbs. Progression was mild, and the disease course was benign in most affected individuals; generalization occurred only in 2 cases. We did not find anticipation of age at onset or of disease severity through generations. Most subjects presented with jerky, myoclonic-like dystonic movements of the neck or shoulders. DYT13-PTD is an autosomal dominant disease, with incomplete penetrance (58%). Clinical presentation and age at onset were more variable than in DYT1-PTD, and the neck was involved in most of those affected. Moreover, the individuals with generalised dystonia were not severely disabled and were able to lead independent lives. To date, this is the only family with DYT13-PTD.     

Morphine in tardive and idiopathic dystonia

Summary. Opioids have been shown to improve L-Dopa induced dyskinesias in patients with Parkinson's disease. In this pilot trial of five patients with tardive and four patients with idiopathic dystonia we tested the effect of morphinsulfate in a retarded form with a dosage of 20–60 mg per day. A substantial improvement of dystonic movements could be observed in four patients with tardive and one patient with idiopathic dystonia. The effect was only transient in tardive dystonia while pain relief mediated by morphine overlasted the effect on involuntary movements. Received February 9, 2001; accepted April 27, 2001     

The prevalence of primary dystonia: A systematic review and meta‐analysis

Dystonia is a hyperkinetic movement disorder characterized by sustained muscle contractions that produce repetitive movements and abnormal postures. Specific information on the prevalence of dystonia has been difficult to establish because the existing epidemiological studies of the condition have adopted different methodologies for case ascertainment, resulting in widely differing reported prevalence. Medline and Embase databases were searched using terms specific to dystonia for studies of incidence, prevalence, and epidemiology. All population‐based studies reporting an incidence and/or prevalence of primary dystonia were included. Sixteen original studies were included in our systematic review. Fifteen studies reported the prevalence of dystonia, including 12 service‐based and three population‐based studies. We performed a meta‐analysis on the results of the service‐based studies, and were able to combine data on the prevalence of several dystonia subtypes. From these studies, we calculated an overall prevalence of primary dystonia of 16.43 per 100,000 (95% confidence interval [CI]: 12.09–22.32). The prevalence of dystonia reported in the three population‐based studies appears higher than that reported in the service‐based studies. Only 1 of the 16 studies reported an incidence of cervical dystonia. This corresponded to a corrected incidence estimate of 1.07 per 100,000 person‐years (95% CI: 0.86–1.32). Despite numerous studies on the epidemiology of dystonia, attempting to determine an accurate prevalence of the condition for health services planning remains a significant challenge. Given the methodological limitations of the existing studies, our own prevalence estimate of primary dystonia likely underestimates the true prevalence of the condition. © 2012 Movement Disorder Society