Recent developments in dystonia

Efficacy of the Hegab temporomandibular joint splint in treating patients diagnosed with dystonia with or without systemic involvement: A report of 14 cases

Dystonia is a neurological motor disorder characterised by involuntary and uncontrollable muscle contractions, tension, twisting, and tremors. The aim of the present study was to analyse the improvement in dystonic contractions in patients with dystonia following the use of a Hegab temporomandibular joint splint (HTS). The Fahn-Marsden Dystonia Movement Scale (DMS) and Disability Scale were used in the current study to evaluate dystonia. An HTS with a thickness ranging from 4 to 6 mm was used to treat the patients enrolled in the study. The final sample comprised 14 patients (10 female and four male) with mean (range) ages of 35.64 (18 to 55) years. Pre-treatment DMS ranged from 6.5 to 57 mean (SD) 18.21 (13.38). At the end of the study, DMS ranged from 0 to 15 mean (SD) 3.14 (3.86). Statistical analysis of the differences between pre-treatment and post-treatment DMS showed a significant decrease in DMS at the end of the treatment period (p = 0.0001). Regarding the disability scale, pre-treatment disability scale ranged from 7 to 18 mean (SD) 9.46 (3.02). At the end of the study, DMS ranged from 0 to 3 mean (SD) 1.46 (1.13). There was a statistically highly significant decrease in the Disability Scale at the end of the treatment period (p value ≤ 0.0001). This study suggests that the HTS can be considered an effective treatment modality for dystonia, as it significantly decreases both the DMS and the Disability scale.

Aberrant Splicing Caused by a Novel VPS16 Variant Linked to Dystonia Type 30

Dystonia is a hyperkinetic movement disorder characterized by sustained or intermittent involuntary muscle contractions, causing abnormal postures and/or repetitive movements. In this report, we identified a novel heterozygous splice-site variant in VPS16 (NM_022575.4:c.240+3G>C) in a patient with cervical and upper limb dystonia without other neurological or extra-neurological features. Analysis of patient's blood mRNA showed disruption of exon 3/intron 3 donor splice-site, leading to exon 3 skipping, which predictably results in a frameshift [p.(Ala48Valfs*14)]. Despite the scarcity of splice-affecting variants described in VPS16-related dystonia, our report contributes with the first fully characterized variant at the mRNA level.

Exploring the Psychosocial Impact of Botulinum Toxin Type A Injections for Individuals With Oromandibular Dystonia: A Qualitative Study of Patients' Experiences

Purpose The purpose of this study was to explore the psychosocial impact of botulinum toxin (BoNT) injections for oromandibular dystonia (OMD) and to gain a better understanding of how participants judge the success of this treatment. Method Eight individuals with OMD and dysarthria participated in one face-to-face, semistructured interview. Interviews were audio-recorded and transcribed verbatim. Qualitative, phenomenological methods of coding, immersion, and emergence were used in the analysis of interview data. Results Two major themes and six subthemes emerged from the analysis of interview data. The first theme, Botox has changed me and my experiences, explored the participants' perspective of receiving BoNT injections and its psychosocial impact. The second theme, What communication is like for me, explored the psychosocial impact of BoNT on speech production and participation. Conclusions Our results suggest that BoNT has a variable impact on domains related to quality of life, satisfaction with treatment, speech production, and communicative participation. This study adds novel information related to the psychosocial consequences of BoNT treatment in the management of OMD and builds on a literature that studies the consequences and experiences of living with OMD.

Sensory Alterations in Patients with Isolated Idiopathic Dystonia: An Exploratory Quantitative Sensory Testing Analysis

Abnormalities in the somatosensory system are increasingly being recognized in patients with dystonia. The aim of this study was to investigate whether sensory abnormalities are confined to the dystonic body segments or whether there is a wider involvement in patients with idiopathic dystonia. For this purpose, we recruited 20 patients, 8 had generalized, 5 had segmental dystonia with upper extremity involvement, and 7 had cervical dystonia. In total, there were 13 patients with upper extremity involvement. We used Quantitative Sensory Testing (QST) at the back of the hand in all patients and at the shoulder in patients with cervical dystonia. The main finding on the hand QST was impaired cold detection threshold (CDT), dynamic mechanical allodynia (DMA), and thermal sensory limen (TSL). The alterations were present on both hands, but more pronounced on the side more affected with dystonia. Patients with cervical dystonia showed a reduced CDT and hot detection threshold (HDT), enhanced TSL and DMA at the back of the hand, whereas the shoulder QST only revealed increased cold pain threshold and DMA. In summary, QST clearly shows distinct sensory abnormalities in patients with idiopathic dystonia, which may also manifest in body regions without evident dystonia. Further studies with larger groups of dystonia patients are needed to prove the consistency of these findings.

Occupational Health and the Performing Arts: An Introduction

OBJECTIVE

Workplace hazards in the performing arts cause injuries, disabilities, and deaths every year. Occupational health professionals are familiar with most of these hazards and are particularly qualified to contribute to efforts to reduce them. This article reviews current health issues in the performing arts and highlights opportunities for occupational health contributions.

METHODS

Recognized experts in performing arts medicine were consulted and articles illustrating performing arts health issues were reviewed. Literature sources included medical databases, unindexed art-health publications, and popular press articles.

RESULTS

Resources discussing hazards and health issues in theater, dance, voice, and instrumental musicians were located and reviewed.

CONCLUSIONS

Treatment providers have a history of involvement with segments of the performing arts. The occupational health approach to workplace health issues can effectively complement these efforts. Sources of further information on performing arts health concerns are available.

Etiology, Diagnosis and Management of Oromandibular Dystonia: an Update for Stomatologists

Oromandibular dystonia (OMD) is a rare focal neurological disorder that affects mouth, face, and jaws. This comprehensive literature review aimed to summarize the current evidence for etiology, diagnosis, and management of OMD and assess the possibility of dental origin of the disease and dental treatment plans for these patients. Different online databases namely PubMed, Google scholar, and Scopus were searched. The keywords "oromandibular dystonia", "orofaciomandibular dystonia", "orofacial-buccal dystonia", "lingual dystonia", "jaw dystonia", "cranial dystonia", and "adult-onset facial dystonia" were searched in the title and abstract of publications from 1970 to 2016. The inclusion criterion was the dental etiology and/or dental treatment. Out of 1260 articles, only 37 articles met the inclusion criteria. OMD can be caused or exacerbated through different dental treatments within which anyone is likely to be involved due to various reasons. Some novel methods employed to relieve this syndrome have led to certain cure or improvement of symptoms in several cases. OMD patients may refer to dentists with involuntary jaw movements and intraoral presentations. Thus, the dentists should be aware of the symptoms and signs and refer the suspicious cases. Dentists should also be familiar with special considerations when managing OMD patients.

The Burke-Fahn-Marsden Dystonia Rating Scale is Age-Dependent in Healthy Children

Background

The Burke-Fahn-Marsden Dystonia Rating Scale is a universally applied instrument for the quantitative assessment of dystonia in both children and adults. However, immature movements by healthy young children may also show "dystonic characteristics" as a consequence of physiologically incomplete brain maturation. This could implicate that Burke-Fahn-Marsden scale scores are confounded by pediatric age.

Objective

In healthy young children, we aimed to determine whether physiologically immature movements and postures can induce an age-related effect on Burke-Fahn-Marsden movement and disability scale scores.

Methods

Nine assessors specializied in movement disorders (3 adult neurologists, 3 pediatric neurologists, and 3 MD/PhD students) independently scored the Burke-Fahn-Marsden movement scale in 52 healthy children (4-16 years of age; 2 boys and 2 girls per year of age). Independent of that, parents scored their children's functional motor development according to the Burke-Fahn-Marsden disability scale in another 52 healthy children (4-16 years of age; 2 boys and 2 girls per year of age). By regression analysis, we determined the association between Burke-Fahn-Marsden movement and disability scales outcomes and pediatric age.

Results

In healthy children, assessment of physiologically immature motor performances by the Burke-Fahn-Marsden movement and disability scales showed an association between the outcomes of both scales and age (until 16 years and 12 years of age, β = -0.72 and β = -0.60, for Burke-Fahn-Marsden movement and disability scale, respectively [both P < 0.001]).

Conclusions

The Burke-Fahn-Marsden movement and disability scales are influenced by the age of the child. For accurate interpretation of longitudinal Burke-Fahn-Marsden Dystonia Rating Scale scores in young dystonic children, consideration of pediatric age-relatedness appears advisory.

Association Analysis of NALCN Polymorphisms rs1338041 and rs61973742 in a Chinese Population with Isolated Cervical Dystonia

Background. A genome-wide association study (GWAS) demonstrated a possible association between cervical dystonia (CD) and a sodium leak channel, nonselective (NALCN) gene. However, the association between NALCN and CD was largely unknown in Asian population. The present study was carried out to examine the associations between the two single nucleotide polymorphisms (SNPs) rs1338041 and rs61973742 in the NALCN gene and CD in a Chinese population. Methods. In a cohort of 201 patients with isolated CD, we genotyped the two SNPs rs1338041 and rs61973742 using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). We also included 289 unrelated, age- and sex-matched healthy controls (HCs) from the same region. Result. No significant differences were observed in either the genotype distributions or the minor allele frequencies (MAFs) of the two SNPs between the CD patients and the HCs. There were no significant differences between early-onset and late-onset CD patients, between patients with and without a positive family history of dystonia, or between patients with and without tremor or sensory tricks. Conclusion. Lack of association between the SNPs of NALCN and CD suggests that the SNPs of NALCN do not play a role in CD in a Chinese population.

Association analysis of TOR1A polymorphisms rs2296793 and rs3842225 in a Chinese population with cervical dystonia

BACKGROUND

TOR1A (torsinA, DYT1) is the leading cause of early-onset generalized dystonia, however, the associations between common TOR1A single nucleotide polymorphisms (SNPs) and primary adult-onset focal dystonia are controversial.

METHODS

In a cohort of 201 focal cervical dystonia (CD) patients, we genotyped rs2296793 and rs3842225 SNPs in TOR1A using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. We also included 289 unrelated, age- and sex-matched healthy controls (HCs) from the same region.

RESULT

No significant differences were found in either the genotype distributions or minor allele frequencies (MAFs) of rs2296793 and rs3842225 between CD patients and HCs. There were no significant differences between early-onset and late-onset CD patients, between patients with and without a positive family history of dystonia, or between patients with and without tremor or sensory tricks.

CONCLUSION

Our study suggests that the common rs2296793 and rs3842225 SNPs of TOR1A do not play a major role in CD in a Chinese population.

Clinical and scientific perspectives on movement disorders: Stanley Fahn's contributions

Dr. Stanley Fahn, the H. Houston Merritt Professor of Neurology and Director Emeritus of the Center for Parkinson's Disease and Other Movement Disorders at Columbia University, one of the founders of the field of movement disorders, was the first president of the Movement Disorders Society (subsequently renamed as the International Parkinson and Movement Disorder Society). Together with his friend and colleague, Professor David Marsden, he also served as the first co-editor of the journal Movement Disorders. By emphasizing phenomenology as the key element in differentiating various hypokinetic and hyperkinetic movement disorders, Dr. Fahn drew attention to the clinical history and the power of observation in the diagnosis of movement disorders. Dr. Fahn had major influence on the development of classifications and assessments of various movement disorders and in organizing various research groups such as the Parkinson Study Group. As the founder and president of the World Parkinson Coalition and an organizer of the initial three World Parkinson Congresses, he has demonstrated his long-standing commitment to the cause of including patients as partners. The primary goal and objective of this invited review is to highlight some of Dr. Fahn's most impactful scientific and clinical contributions to the understanding and treatment of Parkinson's disease, dystonia, and other movement disorders.