Journal of neuromuscular diseases最新文献

Background: Bulbar dysfunction is a well-recognized burden experienced by individuals with spinal muscular atrophy (SMA). Metrics that capture the impact of these problems are lacking. Objectives: To develop and validate an SMA-Bulbar Scale that captures and quantifies patient-reported experiences with bulbar dysfunction. Methods: Cure SMA database members were invited to complete online surveys and a 31-item Bulbar Scale developed by the authors with reference to both bulbar dysfunction in the literature and consultations with SMA-dedicated health care providers, pharmaceutical companies, and persons affected by SMA. Results: 166 adults with SMA reported a range of bulbar dysfunctions. The most common problems, occurring more than 80% of the time, were prolonged meal times, difficulty with mouth opening, and swallowing pills. In addition, 10% of the respondents reported a worsening feeding function over the course of their lives. Across the diverse array of bulbar functions, exploratory and confirmatory factor analyses of responses identified three coherent dimensions of bulbar dysfunction: Swallowing; Mealtimes and Communication; and Breath Sounds, Speech, Voice, and Secretion Management. Higher scores of overall bulbar dysfunction, (p < .001) and each factor (p < .001), were reported by respondents with any degree of feeding restrictions. Sex, age, or use of SMA disease-modifying treatment did not correlate with bulbar scores. Conclusions: This patient-reported scale of bulbar function in adults with a wide range of SMA severity captures and quantifies the variable manifestations of experienced bulbar impairment. With preliminary evidence of validity, the scale supports efforts to standardize accurate identification of bulbar dysfunction, incorporate the perspectives of people with SMA on key areas of their daily functioning, provide metrics essential for meaningful endpoints in clinical trials, inform practice guidelines, and promote advancement of the regulatory science needed for the evaluation and development of therapeutic interventions. Identification of three coherent dimensions of bulbar dysfunction may improve further investigations.

Duchenne muscular dystrophy (DMD) is caused by loss-of-function mutations to the gene encoding dystrophin. Restoring the reading frame of dystrophin by removing internal out-of-frame exons may address symptoms of DMD. Therefore, the principle of exon skipping has been at the center stage in drug development for Duchenne muscular dystrophy (DMD) over the past two decades. Antisense oligonucleotides (AONs) have proven effective in modulating splicing sites for exon skipping, resulting in the FDA approval of several drugs using this technique in recent years. However, due to the temporary nature of AON, researchers are actively exploring genome editing as a potential long-term, single-administration treatment. The advancements in genome-editing technology over the last decade have boosted this transition. While no clinical trials for exon skipping in DMD via genome editing have been conducted as of this writing, preclinical studies show encouraging results. This review describes the preclinical landscape of genome editing for exon skipping in DMD treatment. Along with highlighting the adaptability of genome editing in exon skipping, this review also describes delivery challenges and outlines future research directions that could set a new stage for enhanced therapeutic development in DMD.

In Duchenne muscular dystrophy (DMD), age at symptom onset and rate of decline thereafter vary considerably. This study contrasted disease progression over time using the North Star Ambulatory Assessment (NSAA) in an overall sample of patients with DMD (mean age 7.1 years; baseline total NSAA score 22.2) with that of a centrally representative subgroup (mean age 6.9 years; NSAA score 24.0) defined according to median age at loss of ambulation. The average disease trajectory in the overall sample understated the more rapid rates of decline experienced by patients in the centrally representative subgroup.

Background: In the Netherlands a centralised approach to respiratory care for patients with Amyotrophic Lateral Sclerosis is used based on national guidelines. Patients with Amyotrophic Lateral Sclerosis are referred to one of 4 centres for Home Mechanical Ventilation.

Objective: Our aim was to evaluate the respiratory care according to the Dutch guideline by evaluation of reasons for starting non-invasive ventilation, timing of initiating and survival in patients with Amyotrophic Lateral Sclerosis using non-invasive ventilation.

Method: A retrospective chart-review was performed of 323 patients, who had been referred to centres for Home Mechanical Ventilation in 2016-2018. Data collected included symptoms of hypoventilation, forced vital capacity, blood gasses, criteria for (not) initiating non-invasive ventilation, and survival. Kaplan-Meyer curves and Multivariate Cox proportional hazard regression were used in the analysis.

Results: The main criteria used for initiating non-invasive ventilation were hypercapnia (77%) and the presence of orthopnea and/or dyspnoea (25%). Median survival after starting non-invasive ventilation was 11 months, and was shorter for patients with bulbar disease onset and older age. The proportion of the total disease duration that was spent on non-invasive ventilation was not significantly affected by age, sex or site of disease. Seventy nine percent of the patients who didn't start non-invasive ventilation had reached a joint decision with their caregivers and/or physicians.

Conclusion: Key outcomes of the Dutch centralised respiratory care approach have shown that most patients were initiated on non-invasive ventilation due to presence of hypercapnia and/or dyspnoea/orthopnea, which is according to the Dutch guidelines. Half of patients spent at least 33% of their disease duration on non-invasive ventilation. To help find the optimal criteria and timing for non-invasive ventilation it would be useful for other countries to share their key outcomes as well.

Background: Glycogenosis type 11 or deficiency in lactate dehydrogenase A (LDHA) (OMIM: 612933) is an ultra-rare condition of perturbed glycogen metabolism, first described in 1980 in a Japanese patient, and quite rare outside Japan. There are very few cases described in the literature and there is limited awareness of this condition that can easily be misdiagnosed or remain undiagnosed.

Objective: To report on an ultra-rare form of glycogenosis stressing the association with cutaneous features and raise awareness for this rare condition. We report a novel pathogenic variant and aim to contribute to the understanding of the myopathophysiological mechanisms of disease by proteomics.

Methods: We report the clinical, histopathological, magnetic resonance, genetic and proteomic features of a 19-year-old male of North African background that presented from infancy episodes of muscle pain, contractures and high CK levels immediately after moderate to high-intensity exercise. The patient was followed for several years prior to our observation due to severe acne that involved mostly the back and was resistant to treatment.

Results: The phenotype of this patient is similar to the ones previously described with muscle and skin involvement. The MRI functional studies, interrupted at 2'30'' due to muscle pain, allowed us to confirm the presence of a metabolic disturbance of the muscles. The histological features of the muscle were quite subtle consisting mainly in rare subsarcolemmal vacuoles also identified at ultra-structural level. Immunostaining with the antibody targeting LDHA showed intracytoplasmic aggregates of the protein unlike the normal control that presented a diffuse staining. Exome analysis revealed a novel bi-allelic frameshifting deletion in exon 7 of the LDHA gene; c.766_767delGT. Proteomic findings accord with loss of functional LDHA and provide significant insights into the pathobiochemistry of the disease.

Conclusions: Our combined data expand the current genetic landscape of LDHA-related disease, confirms the concept of a metabolic-driven vacuolar myopathy and provides insights into the biochemical nature of myopathology.

X-linked myopathy with excessive autophagy (XMEA) is a rare neuromuscular disorder caused by mutations in the VMA21 gene, encoding a chaperone protein present in the endoplasmic reticulum (ER). In yeast and human, VMA21 has been shown to chaperone the assembly of the vacuolar (v)-ATPase proton pump required for the acidification of lysosomes and other organelles. In line with this, VMA21 deficiency in XMEA impairs autophagic degradation steps, which would be key in XMEA pathogenesis. Recent years have witnessed a surge of interest in VMA21, with the identification of novel mutations causing a congenital disorder of glycosylation (CDG) with liver affection, and its potent implication in cancer predisposition. With this, VMA21 deficiency has been further linked to defective glycosylation, lipid metabolism dysregulation and ER stress. Moreover, the identification of two VMA21 isoforms, namely VMA21-101 and VMA21-120, has opened novel avenues regarding the pathomechanisms leading to XMEA and VMA21-CDG. In this review, we discuss recent advances on the clinical spectrum associated with VMA21 deficiency and on the pathophysiological roles of VMA21.

Objective: Wheelchair users with neuromuscular disorders have symptoms related to the disease and complications to the sedentary lifestyle, such as constipation and lower back pain. Physical training might be beneficial. This systematic review investigates the potential benefits and harms of physical training for wheelchair users with neuromuscular disorders.

Methods: We systematically searched PubMed including studies published until July 2024. Inclusion criteria: 1) participants with a neuromuscular disorder, 2) at least 60% of participants in a study were wheelchair users, 3) physical training and its effects were investigated, 4) studies were prospective, and 5) English language was used. Non-peer-reviewed articles were excluded. Search results were screened by title, abstract, and full text. Two independent authors assessed the quality with the Downs and Black Quality Index.

Results: We included 14 studies of 140 patients from 5 types of neuromuscular disorders (Duchenne muscular atrophy, spinal muscular atrophy, limb-girdle muscular atrophy, facioscapulohumeral muscular dystrophy, and amyotrophic lateral sclerosis). The mean quality was low (16/32) due to flaws in study design, selection bias, and power. Even though many were of low quality and lacked descriptions of adverse events, they all showed positive effects. Most studies investigated physical training of mastication or respiration with improvements in both. Other findings were improvements in endurance, extremity strength, and range of motion.

Conclusions: Physical training of wheelchair users with neuromuscular disorders is not well investigated. Physical training seems safe and beneficial, but training of respiratory and masticatory muscles is the only well-documented exercise modality that can be advised in patients with Duchenne Muscular Dystrophy or Duchenne Muscular Dystrophy/Spinal Muscular Atrophy, respectively. Larger, high-quality trials, including other neuromuscular disorders, are needed to assess the effects and adverse events of physical training.

Background: Facioscapulohumeral muscular dystrophy (FSHD) is a hereditary muscle disease without an available cure. The first trials with potentially disease-modifying therapies have started, including a phase ll open-label study and a phase lll double-blind randomized placebo-controlled trial assessing the safety and efficacy of losmapimod. Having a more in-depth understanding of the patient's experience of these trials will further enhance the design and recruitment of future trials.

Objective: To explore the motivation, expectations, concerns, and experiences of FSHD patients in the first clinical trials in the Netherlands resulting in recommendations for future trials.

Methods: Semi-structured interviews with participants of phase II and III losmapimod trials were conducted. The interview guide was based on previous conducted literature reviews and consultation of a patient representative. Participants were selected through convenience sampling. Four main themes were discussed: motivation for participation, expectations regarding study drug and trial visits, trial participation experience, and recommendations for future trials. The interviews were transcribed, anonymized, and analyzed using Atlas.ti version 23.1.1 using a deductive approach.

Results: Thirteen participants were interviewed; six phase II participants and seven phase III participants. The primary motivations to participate concerned altruistic motives, contribute to science or improve their own health status. The participants had realistic expectations of the effect of the study drug before trial participation. Overall, participants were positive about their trial participation. Specifically, the personal and transparent communication within a trusting and dedicated trial team was appreciated. The phase III participants reported a higher than expected psychological burden on participating in a placebo-controlled trial. Recommendations consisted of more frequent updates on the overall progress and results of the trials.

Conclusions: This study presents the participants' perspective on FSHD trials, providing important key findings for future clinical trial design, study site practices and patient education.

Background: Myasthenia gravis (MG) is a chronic autoimmune disease causing fluctuating muscle weakness. The MycarinG study showed that rozanolixizumab, a neonatal Fc receptor inhibitor, provided clinically meaningful improvements in MG outcomes in patients with acetylcholine receptor (AChR) and muscle-specific tyrosine kinase (MuSK) autoantibody-positive generalized MG (gMG).

Objective: We assessed efficacy and safety of 6-week rozanolixizumab treatment cycles in patients with gMG.

Methods: Following MycarinG, eligible patients enrolled in the open-label extension Phase 3 studies MG0004 (NCT04124965) to receive up to 52 weekly rozanolixizumab infusions or MG0007 (NCT04650854) to receive cycles of 6 weekly rozanolixizumab infusions (initiated on symptom worsening at investigators' discretion). To assess the effect of repeated cyclical treatment, data were pooled across MycarinG, MG0004 (first 6 weeks) and MG0007 (interim analysis). Efficacy endpoints included change from baseline in Myasthenia Gravis Activities of Daily Living (MG-ADL), Myasthenia Gravis Composite (MGC) and Quantitative Myasthenia Gravis (QMG) assessed in patients who received ≥2 symptom-driven treatment cycles. Treatment-emergent adverse events (TEAEs) were assessed in patients who received ≥1 cycle and had an (up to) 8-week follow-up period.

Results: At data cut-off (July 8, 2022), 188/196 (95.9%) patients received ≥1 treatment cycle with a follow-up period (primary safety pool; MycarinG/MG0007) and 127 (64.8%) received ≥2 symptom-driven cycles (primary efficacy pool; MycarinG/MG0004 [first 6 weeks]/MG0007). Consistent and clinically meaningful improvements in MG-ADL, MGC and QMG scores, and high MG-ADL, MGC and QMG response rates, were observed at the end of the first symptom-driven cycle and subsequent cycles. TEAEs were experienced by 169/188 (89.9%) patients and were mostly mild to moderate. TEAEs did not increase with repeated cycles.

Conclusions: Repeated cycles of rozanolixizumab resulted in consistent, clinically meaningful improvements across cycles in MG-specific outcomes with an acceptable safety profile, supporting rozanolixizumab as a treatment option for adults with AChR and MuSK autoantibody-positive gMG.