Dystonia Management: What to Expect From the Future? The Perspectives of Patients and Clinicians Within DystoniaNet Europe

Epidemiological study on pediatric-onset dystonia in Japan: A questionnaire-based survey

OBJECTIVE

This study aimed to investigate the clinical characteristics of pediatric-onset dystonia in Japan, addressing the diagnostic challenges arising from symptom variations and etiological diversity.

METHODS

From 2020 to 2022, questionnaires were distributed to 1218 board certified child neurologists (BCCNs) by Japanese Society of Child Neurology. In the primary survey, participants were asked to report the number of patients with pediatric-onset dystonia under their care. Subsequently, the follow-up secondary survey sought additional information on the clinical characteristics of these patients.

RESULTS

The primary survey obtained 550 responses (response rate: 45 %) from BCCNs for their 736 patients with dystonia. The predominant etiologies included inherited cases (with DYT10   being the most prevalent, followed by DYT5 and ATP1A3-related neurologic disorders), acquired cases (with perinatal abnormalities being the most common), and idiopathic cases. The secondary survey provided clinical insights into 308 cases from 82 BCCNs. Infancy-onset dystonia presented as persistent and generalized with diverse symptoms, primarily linked to ATP1A3-related neurologic disorders and other genetic disorders resembling acquired dystonia. Conversely, childhood/adolescent-onset dystonia showed paroxysmal, fluctuating courses, predominantly affecting limbs. The most common etiologies were DYT5 and DYT10 , leading to therapeutic diagnoses.

CONCLUSION

Pediatric-onset dystonia in Japan was treated by 28 % of BCCNs. The majority of cases were inherited, with high prevalence rates of DYT5 and DYT10 . Infancy-onset dystonia exhibits diverse etiologies and symptoms, emphasizing the utility of various examinations, including genetic testing. These findings significantly contribute to our understanding of pediatric-onset dystonia in Japan, although this study has the limitation of questionnaire survey.

Social Cognition, Executive Functioning, Mood, and Disability in Cervical Dystonia

BACKGROUND

Individuals with idiopathic adult-onset isolated cervical dystonia (CD) may have cognitive difficulties and increased mood challenges. Social cognition and executive functioning may be particularly affected.

OBJECTIVE

To explore social cognition and executive functioning performance in individuals with CD, using the Cambridge Neuropsychological Test Automated Battery (CANTAB), as previous research has used traditional, nondigital neuropsychological assessments. We sought to investigate the relationships between social cognition, executive functioning, mood, and disability in individuals with CD.

METHODS

We recruited 37 individuals with CD, including 26 women with an age range of 33 to 69 years (M = 56.64, SD = 8.31) from a dystonia clinic in a hospital neurology department. The individuals completed selected tasks from the CANTAB measuring social cognition and executive functioning. We compared the individuals' performance with CANTAB normative data. Depression, anxiety, disease severity, and disability were measured.

RESULTS

The individuals with CD had significantly lower scores than the CANTAB normative data in both social cognition and executive functioning tasks, with the largest differences evident in problem-solving, attention, and positive emotion bias tasks. Poorer emotion recognition was associated with increased difficulties in problem-solving tasks. The individuals demonstrated a bias toward identifying happiness in facial affect, which was related to a poorer recognition of emotions. Cognitive performance was not related to CD severity or disability or to current mood symptoms.

CONCLUSION

Difficulties with both social cognition and executive functioning were identified in the individuals with CD, and are likely important targets for clinical interventions.

Duration of botulinum toxin efficacy in cervical dystonia clinical trials: A scoping review

INTRODUCTION

Botulinum toxin (BoNT) is first-line treatment for cervical dystonia (CD). Treatment of CD with BoNT usually requires injections every 3-4 months for as long as symptoms persist, which can be for the lifetime of the individual. Duration of BoNT effect can impact quality of life since it is important that efficacy is maintained throughout an injection cycle to avoid fluctuations of effect after each injection. There is currently no consensus on how to assess duration of BoNT effect in patients with CD.

METHODS

A scoping review was conducted to summarize the available evidence from phase 3 clinical trials of BoNT in CD and on the interpretation of the reported duration of effect. The available evidence was analyzed in the context of clinical experience and real-world treatment practices of CD.

RESULTS

Methods for estimating duration of effect varied across publications; most were based on artificial constructs developed for clinical trials (time until a pre-specified efficacy endpoint was reached) and are not appropriate to apply in clinical practice. Clinical trial outcomes in CD were not objectively evaluated, and did not prioritize patients' needs or focus on factors that impact patients' daily living activities and quality of life.

CONCLUSION

Better evidence and consistency of reporting for duration of effect for BoNT in CD is needed to help guide clinicians on when reinjection is likely to be required. The goal should be to keep patients as symptom-free as possible with flexible reinjection intervals tailored to individual needs.

Health-Related Quality of Life in Romanian Patients with Dystonia: An Exploratory Study

Background/Objectives: Dystonia is a neurological movement disorder characterized by involuntary muscle contractions that lead to abnormal movements and postures; it has a major impact on patients' health-related quality of life (HRQoL). The aim of this study was to examine the HRQoL of Romanian patients with dystonia using the EQ-5D-5L instrument. Methods: Responses to the EQ-5D-5L and the visual analogue scale (VAS) were collected alongside demographic and clinical characteristics. Health profiles were analyzed via the metrics of the EQ-5D-5L, severity levels, and age groups. Using Shannon's indexes, we calculated informativity both for patients' health profile as a whole and each individual dimension. Level sum scores (LSS) of the EQ-5D-5L were calculated and compared with scores from the EQ-5D-5L index and VAS. The HRQoL measures were analyzed through demographic and clinical characteristics. Descriptive statistics, Spearman correlation, and non-parametric tests (Mann-Whitney U or Kruskall-Wallis H) were used. The level of agreement between HRQoL measures was assessed using their intraclass correlation coefficient (ICC) and Bland-Altman plots. Results: A sample of 90 patients was used, around 75.6% of whom were female patients, and the mean age at the beginning of the survey was 58.7 years. The proportion of patients reporting "no problems" in all five dimensions was 10%. The highest frequency reported was "no problems" in self-care (66%), followed by "no problems" in mobility (41%). Shannon index and Shannon evenness index values showed higher informativity for pain/discomfort (2.07 and 0.89, respectively) and minimal informativity for self-care (1.59 and 0.68, respectively). The mean EQ-5D-5L index, LSS, and VAS scores were 0.74 (SD = 0.26), 0.70 (SD = 0.24), and 0.61 (SD = 0.21), respectively. The Spearman correlations between HRQoL measures were higher than 0.60. The agreement between the EQ-5D-5L index and LSS values was excellent (ICC = 0.970, 95% CI = 0.934-0.984); the agreement was poor-to-good between the EQ-5D-5L index and VAS scores (ICC = 683, 95% CI = 0.388-0.820), and moderate-to-good between the LSS and VAS scores (ICC = 0.789, 95% CI = 0.593-0.862). Conclusions: Our results support the utilization of the EQ-5D-5L instrument in assessing the HRQoL of dystonia patients, and empirical results suggest that the EQ-5D-5L index and LSS measure may be used interchangeably. The findings from this study highlight that HRQoL is complex in patients with dystonia, particularly across different age groups.

Intraventricular baclofen for palliative management of acquired generalized dystonia in pediatric patients: a case series and literature review

Dystonia represents a significant source of disability in children. Generalized dystonia, which involves multiple body regions, leads to impaired mobility and motor function, resulting in substantial challenges in daily activities. Surgical treatments are used when medical treatments fail. Intrathecal baclofen (ITB) or deep brain stimulations (DBS) are the most employed surgical therapies. When these options are not feasible or ineffective, some authors have explored the use of intraventricular baclofen (IVB). In this report, we present four cases of pediatric patients with generalized dystonia who underwent treatment with IVB, resulting in notable improvements. To further explore the potential of this treatment modality, we conducted a comprehensive literature review. The findings from our study provide a comprehensive overview that can guide palliative management in similar cases.

Diagnostic utility of DNA methylation episignature analysis for early diagnosis of KMT2B-related disorders: case report

The lysine methyltransferase 2B (KMT2B) gene product is important for epigenetic modifications associated with active gene transcription in normal development and in maintaining proper neural function. Pathogenic variants in KMT2B have been associated with childhood-onset Dystonia-28 and Intellectual developmental disorder, autosomal dominant 68 (MRD 68) for cases of neurodevelopmental impairment without dystonia (DYT28; OMIM 617284 and MRD68; OMIM 619934, respectively). Since its first description in 2016, approximately one hundred KMT2B genetic variants have been reported with heterogeneous phenotypes, including atypical patterns of dystonia evolution and non-dystonic neurodevelopmental phenotypes. KMT2B-related disorders share many overlapping phenotypic characteristics with other neurodevelopmental disorders and delayed dystonia, that can appear later in childhood, often delaying clinical diagnosis. Furthermore, conventional genetic testing may not always provide actionable information (e.g., gene panel selection based on early clinical presentation or variants of uncertain significance), which prevents patients and families from obtaining early access to treatments and support. Herein, we describe the early diagnosis of KMT2B-related neurodevelopmental disorder by DNA methylation episignature testing in a 4-year-old patient without features of dystonia at diagnosis, which is reported to develop in more than 80% of KMT2B-related disorder cases. The proband, a 4-year-old female of Jewish-Israeli descent, presented with speech delay, microcephaly, poor weight gain, attention-deficit and hyperactivity disorder, dysmorphism, intellectual disabilities and joint hyperlaxity, but presented no signs of dystonia at initial evaluation. Episignature screening in this pre-symptomatic patient enabled accurate genetic diagnosis and timely and actionable intervention earlier in the natural history of Childhood-onset Dystonia-28.

Electrophysiological insights into deep brain stimulation of the network disorder dystonia

Deep brain stimulation (DBS), a treatment for modulating the abnormal central neuronal circuitry, has become the standard of care nowadays and is sometimes the only option to reduce symptoms of movement disorders such as dystonia. However, on the one hand, there are still open questions regarding the pathomechanisms of dystonia and, on the other hand, the mechanisms of DBS on neuronal circuitry. That lack of knowledge limits the therapeutic effect and makes it hard to predict the outcome of DBS for individual dystonia patients. Finding electrophysiological biomarkers seems to be a promising option to enable adapted individualised DBS treatment. However, biomarker search studies cannot be conducted on patients on a large scale and experimental approaches with animal models of dystonia are needed. In this review, physiological findings of deep brain stimulation studies in humans and animal models of dystonia are summarised and the current pathophysiological concepts of dystonia are discussed.

Non-Motor Symptoms and Quality of Life in Patients with PRRT2-Related Paroxysmal Kinesigenic Dyskinesia

Background

Monoallelic pathogenic variants of PRRT2 often result in paroxysmal kinesigenic dyskinesia (PKD). Little is known about health-related quality of life (HrQoL), non-motor manifestations, self-esteem, and stigma in patients with PKD.

Objectives

We investigated non-motor symptoms and how they related to HrQoL in a genetically homogeneous group of PRRT2-PKD patients. We paid special attention to perceived stigmatization and self-esteem.

Methods

We prospectively enrolled 21 consecutive PKD patients with a pathogenic variant of PRRT2, and 21 healthy controls matched for age and sex. They were evaluated with dedicated standardized tests for non-motor symptoms, HrQoL, anxiety, depression, stigma, self-esteem, sleep, fatigue, pain, and psychological well-being.

Results

Patients reported an alteration of the physical aspects of HrQoL, regardless of the presence of residual paroxysmal episodes. Non-motor manifestations were frequent, and were an important determinant of the alteration of HrQoL. In addition, patients perceived a higher level of stigmatization which positively correlated with a delay in diagnosis (ρ = 0.615, P = 0.003) and the fear of being judged (ρ = 0.452, P = 0.04), but not with the presence of paroxysmal episodes (ρ = 0.203, P = 0.379).

Conclusions

Our findings have important implications for care givers concerning patient management and medical education about paroxysmal dyskinesia. PRRT2-PKD patients should be screened for non-motor disorders in routine care. A long history of misdiagnosis may play a role in the high level of perceived stigmatization. Improving knowledge about diagnostic clues suggestive of PKD is mandatory.

Management of rare movement diseases in different world regions

To evaluate the management of rare movement disorders (RMD) at the international level and identify care needs to be addressed, the Rare Movement Disorders Study Group of the International Parkinson and Movement Disorders Society (MDS) has conducted an exploratory survey. We sent an online survey to experts in Africa, Asia, Oceania and American continents following the classification of the MDS Regional Sections: Africa, Asia and Oceania (A&O), and Pan-America. We did not include Europe as the European Reference Network for Rare Neurological Diseases recently performed a similar care needs survey across European countries. We obtained responses from experts from 20 African, 26 A&O and 19 Pan-American countries. According to the respondents, only 55% of African countries had movement disorders experts, while these were present in 96% of A&O and 91% of Pan-American. Access to care for patients with RMD was stated difficult in 70% of African, 54% of A&O, and 65% of Pan-American countries. Africa was the region with greatest difficulties in accessing diagnostic tests. However, in Pan-America and A&O, large inequalities were observed between countries with quite variable access to therapeutic options such as deep brain stimulation. The survey results reflect wide variability in the management of RMD and provide evidence that a worldwide care-focused network is highly warranted. Scientific and medical organisations should raise awareness of deficits in managing RMD and care disparities among regions. The goals should be to facilitate the training of professionals, establish improvement strategies, and increase support and budgeting for these diseases.

Dystonia in Childhood: How Insights from Paediatric Research Enrich the Network Theory of Dystonia

Dystonia is now widely accepted as a network disorder, with multiple brain regions and their interconnections playing a potential role in the pathophysiology. This model reconciles what could previously have been viewed as conflicting findings regarding the neuroanatomical and neurophysiological characteristics of the disorder, but there are still significant gaps in scientific understanding of the underlying pathophysiology. One of the greatest unmet challenges is to understand the network model of dystonia in the context of the developing brain. This article outlines how research in childhood dystonia supports and contributes to the network theory and highlights aspects where data from paediatric studies has revealed novel and unique physiological insights, with important implications for understanding dystonia across the lifespan.

Dystonia management across Europe within ERN-RND: current state and future challenges

BACKGROUND

Since the first European-wide evaluation of dystonia management in 2016, several efforts have been made to improve dystonia-care. One of these was the development of the Dystonia Disease Group as a part of the European Reference Network for Rare Neurological Diseases (ERN-RND) that implemented several initiatives based on the recommendations made in 2016.

AIM

To evaluate the current state of dystonia management across Europe.

METHODS

Twenty-four countries were surveyed via 62 dystonia-experts from 44 ERN-RND-related centers.

RESULTS

Dystonia-experts for adult patients were available in all surveyed countries. However, almost half of the countries evaluated accessibility as merely 'satisfactory'. Access to genetic and neurophysiological testing was challenging to varying degrees in over half of countries. Main oral medications and botulinum toxin were available in all countries. Deep brain stimulation (DBS) was easily accessible in one-third of the countries. Dystonia research was conducted in 20/24 countries. Trainings on dystonia for general practitioners (GPs) were available in 11/24 countries. However, lack of trainings for other professionals was almost general. For pediatric dystonia, experts and specific training were available in over half of the countries.

CONCLUSIONS

In this overview, we present the current state of dystonia management within ERN-RND. Management has slightly improved since 2016 in several fields, including diagnostics, availability of DBS, and research. The results highlight that future challenges in dystonia management are accessibility of experts, and diagnostic tools and treatments, education on adult and childhood dystonia, and optimization of referral pathways. These findings are important for improving dystonia care across Europe.

Increased Knowledge of Adult-Onset Dystonia Amongst Medical Students via Brief Video Education: A Systematic Review and Cohort Study

Most doctors have limited knowledge of dystonia, a movement disorder that can affect people of all ages; this contributes to diagnostic delay and poor quality of life. We investigated whether a brief educational intervention could improve knowledge of dystonia amongst medical students. We conducted a systematic review on undergraduate knowledge of dystonia and created an eight-minute video on the condition. We invited medical students at the University of Leeds, UK, to answer 15 multiple choice questions before and immediately after watching the video, and again one month later. Only one previous study specifically assessed medical students’ knowledge of dystonia whilst five others tested their knowledge of movement disorders, or neurology generally, with some questions on dystonia. Of the University of Leeds medical students, 87 (100%), 77 (89%) and 40 (46%) completed the baseline, immediate-recall and delayed-recall questionnaires, respectively. The mean score for students who completed all three questionnaires increased from 7.7 (out of 15) to 12.5 on the immediate-recall questionnaire (p < 0.001), and to 10.1 on the delayed-recall questionnaire (p < 0.001). At baseline, 76% of students rated their confidence in recognising dystonia as low. After watching the video, 78% rated their confidence as a high, and none rated it low. A brief video improved their knowledge substantially, with sustained effects. This method could be incorporated into medical curricula to reduce diagnostic delays.