Fatigue in patients with myasthenia gravis. A systematic review of the literature

Longitudinal relationships between free-living activities, fatigue, and symptom severity in myasthenia gravis using cohort and individualized models

INTRODUCTION/AIMS

Fluctuating symptoms and fatigue are common issues in myasthenia gravis (MG), but it is unclear if these symptoms are related to physical activity or sleep patterns. This study sought to determine the day-to-day relationship between patient-reported symptoms and physical activity and sleep over 12 weeks.

METHODS

Sixteen participants with generalized MG wore a wrist-mounted accelerometer continuously for the study duration and reported their symptoms and fatigue each evening. Cumulative link mixed models were used to analyze whether clinical and demographic characteristics, physical activity, and sleep were related to symptom severity and fatigue over the study period. Three types of models were constructed: a cohort model, a model in which data was scaled to each participant, and individual models.

RESULTS

The cohort model indicated that higher disease severity, female sex, more comorbidities, less physical activity, more inactive time, and lower quantity of sleep were significantly associated with increased symptom severity and fatigue (p < .05). However, in the within-participant scaled model, there were almost no significant associations with physical activity or sleep. In the individual models, some participants showed similar results to the cohort model, but others showed no associations or the opposite response in some variables.

DISCUSSION

While physical activity and sleep were associated with self-reported symptoms and fatigue within this population, this was not necessarily applicable to individuals. This demonstrates the importance of an individualized analysis for determining how physical activity and sleep may impact outcomes in MG, with implications for clinical and self-management.

SPOON: an observational, cross-sectional study of perceptions and expectations of adults with generalised myasthenia gravis in France

OBJECTIVES

To capture patient perceptions about living with myasthenia gravis (MG) with respect to aspirations and ways to improve treatment.

DESIGN

Online patient survey.

SETTING

Patients recruited by MG patient associations or at MG reference treatment centres.

PARTICIPANTS

Adults with physician-diagnosed generalised MG, living in France for ≥12 months, who had received ≥1 MG treatment were eligible. 291 patients opened the questionnaire, 255 were eligible and 246 completed the survey (age range 41-67 years; 187 women and 59 men).

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary: free-text response to the question 'Living with your disease, what would you like to do that you currently find difficult or impossible to do?' Secondary: free-text response to the question 'What improvements do you think could be made to treatments for MG?' Themes from replies to these questions were analysed using grounded theory and cluster analysis.

RESULTS

For the disease aspirations question, 617 citations were provided by 238 participants, which were grouped into 45 dimensions and six high-level domains (physical activity, activities of daily living, psychological burden, social activities, work/school and other). The most frequently cited dimensions were sport (82 citations), greater mobility (56 citations), being less tired (46 citations) and greater endurance (37 citations). Younger age, female gender, recent diagnosis and poorer quality of life were associated with citing more themes. For the treatment amelioration question, 263 citations were provided by 195 participants, which were grouped into 60 dimensions and three high-level domains (medication characteristics, safety and care paradigm). The most cited treatment-related dimensions were fewer side effects (40 citations), fewer daily medication intakes (21 citations) and fewer digestive side effects (20 citations).

CONCLUSIONS

These findings could help healthcare professionals to understand and better address patients' aspirations about living with MG, notably concerning the importance of physical activity, and their expectations for improved treatments.

275th ENMC international workshop: Seronegative myasthenia gravis: An update paradigm for diagnosis and management, 9-11 February 2024, Hoofddorp, the Netherlands

The 275th ENMC workshop on the diagnosis and management of seronegative myasthenia gravis (SNMG) was held on February 9-11, 2024. The participants included experts in the field of adult and pediatric MG together with patient representatives. This workshop aimed to redefine SNMG in view of recent diagnostic and therapeutic updates and to identify patient unmet needs. The workshop has highlighted considerable challenges in the SNMG diagnostic work-up. To date, SNMG confirmation is often controversial, given the absence of specific diagnostic tests; no recommendations from international panels of experts are available in literature; myopathies, congenital myasthenic syndromes and functional disorders are the commonest misdiagnoses. Improving the disease diagnosis is crucial to avoid long delays in receiving appropriate treatment. To this purpose, a comprehensive diagnostic algorithm achieved consensus. Moreover, a remarkable variability in SNMG response to therapy and long-term prognosis has also been highlighted.

Relationship between fatigue and quantitative electromyography findings in patients with myasthenia gravis

Background

Fatigue is a common complaint among patients with myasthenia gravis (MG). In this study, we investigated the alterations in muscle morphology in patients with MG experiencing fatigue using quantitative electromyography (QEMG), and explored the relationship between electrophysiological findings and the severity of both fatigue and disease.

Methods

We performed QEMG of the biceps brachii muscle using the peak ratio method and multi-motor unit potential (MUP) analysis across three groups: 18 MG patients with fatigue, 34 MG patients without fatigue, and 33 healthy subjects. Stimulated single-fiber EMG was performed on the frontalis muscle. The severity of perceived fatigue and disease was subsequently assessed using the quantitative myasthenia gravis (QMG) score, the MG-activities of daily living (MG-ADL) profile, self-reported fatigue questionnaires, and handgrip strength measurements.

Results

The QEMG study revealed a reduced mean MUP duration and size index (SI), in addition to an increased peak ratio in patients with MG (p < 0.05), which tended to be more pronounced in those experiencing fatigue. Compared to healthy subjects, MG patients with fatigue displayed a myopathic pattern characterised by a high peak ratio, short duration, and small-amplitude MUPs, without any increase in the number of phases or small time intervals. The mean peak ratio was positively correlated with the QMG, MG-ADL, and Fatigue Impact Scale total and physical subscores (p < 0.05). Further, MG patients with fatigue exhibited reduced maximum grip strength, which was positively correlated with the mean MUP duration, amplitude, SI, and thickness, and negatively correlated with the mean peak ratio (p < 0.05). No significant differences were observed in the jitter or block measurements (p > 0.05).

Conclusions

The present study investigated electrophysiological findings that were not considered or theorised in prior studies on patients with MG experiencing fatigue. The results of this study suggest that myopathic changes may be a critical pathophysiological component underlying the fatigue associated with MG.

The association between myasthenia gravis and risk of fracture: a systematic review and meta-analysis

Patients with myasthenia gravis (MG), because of their muscle weakness and exposure to corticosteroids treatment, are generally considered to be at increased risk for osteoporosis or fracture. However, clinical evidence of this issue is lacking. In this review, we systematically searched databases, including Cochrane Library, PubMed, Embase, and Airiti library from inception to the end of November 2023 for cohort studies that compared participants with MG and participants without MG for incidence of osteoporosis or fracture. We used the Newcastle-Ottawa Scale for quality assessment. In total, we included 3 studies with 34,865 participants. The pooled meta-analysis using the random effect model demonstrated no significant difference in risk of fracture in the MG group (odds ratio = 1.52; 95% confidence interval = 0.74 to 3.12; I2 = 93%; between-study variance [τ2] = 0.32) compared with that for the non-MG group. Due to limited studies, we could not perform a quantitative analysis for risk of osteoporosis. In conclusion, we found no robust evidence to support the proposition that patients with MG are at higher risk for fracture than general comparators. The explanations and underlying mechanisms of this finding remain unclear, we therefore conclude that additional studies are warranted.

Expert consensus recommendations for improving and standardising the assessment of patients with generalised myasthenia gravis

BACKGROUND

Regular and consistent disease assessment could provide a clearer picture of burden in generalised myasthenia gravis (gMG) and improve patient care; however, the use of assessment tools in practice lacks standardisation. This modified Delphi approach was taken to review current evidence on assessment tool use in gMG and develop expert-derived consensus recommendations for good practice.

METHODS

A European expert panel of 15 experienced gMG neurologists contributed to development of this consensus, four of whom formed a lead Sub-committee. The PICO (Population, Intervention, Control, Outcomes) framework was used to define six clinical questions on gMG assessment tools, a systematic literature review was conducted, and evidence-based statements were developed. According to a modified Delphi voting process, consensus was reached when ≥70% of the experts rated agreement with a statement as ≥8 on a scale of 1-10.

RESULTS

Eighteen expert- and evidence-based consensus statements based on six themes were developed. Key recommendations include: consistent use of the Myasthenia Gravis Activities of Daily Living score (MG-ADL) across clinical settings, followed by a simple question (e.g., Patient Acceptable Symptom State [PASS]) or scale to determine patient satisfaction in clinical practice; use of a Quantitative Myasthenia Gravis [QMG] or quality of life [QoL] assessment when the MG-ADL indicates disease worsening; and consideration of symptom state to determine the timing and frequency of recommended assessments. Expert panel consensus was reached on all 18 statements after two voting rounds.

CONCLUSIONS

This process provided evidence- and expert consensus-based recommendations for the use of objective and subjective assessment tools across gMG research and care to improve management and outcomes for patients.

Renshen Yangrong decoction for secondary malaise and fatigue: network pharmacology and Mendelian randomization study

Background

Renshen Yangrong decoction (RSYRD) has been shown therapeutic effects on secondary malaise and fatigue (SMF). However, to date, its bioactive ingredients and potential targets remain unclear.

Purpose

The purpose of this study is to assess the potential ingredients and targets of RSYRD on SMF through a comprehensive strategy integrating network pharmacology, Mendelian randomization as well as molecular docking verification.

Methods

Search for potential active ingredients and corresponding protein targets of RSYRD on TCMSP and BATMAN-TCM for network pharmacology analysis. Mendelian randomization (MR) was performed to find therapeutic targets for SMF. The eQTLGen Consortium (sample sizes: 31,684) provided data on cis-expression quantitative trait loci (cis-eQTL, exposure). The summary data on SMF (outcome) from genome-wide association studies (GWAS) were gathered from the MRC-IEU Consortium (sample sizes: 463,010). We built a target interaction network between the probable active ingredient targets of RSYRD and the therapeutic targets of SMF. We next used drug prediction and molecular docking to confirm the therapeutic value of the therapeutic targets.

Results

In RSYRD, network pharmacology investigations revealed 193 possible active compounds and 234 associated protein targets. The genetically predicted amounts of 176 proteins were related to SMF risk in the MR analysis. Thirty-seven overlapping targets for RSYRD in treating SMF, among which six (NOS3, GAA, IMPA1, P4HTM, RB1, and SLC16A1) were prioritized with the most convincing evidence. Finally, the 14 active ingredients of RSYRD were identified as potential drug molecules. The strong affinity between active components and putative protein targets was established by molecular docking.

Conclusion

This study revealed several active components and possible RSYRD protein targets for the therapy of SMF and provided novel insights into the feasibility of using Mendelian randomization for causal inference between Chinese medical formula and disease.

A Laing distal myopathy-associated proline substitution in the β-myosin rod perturbs myosin cross-bridging activity

Proline substitutions within the coiled-coil rod region of the β-myosin gene (MYH7) are the predominant mutations causing Laing distal myopathy (MPD1), an autosomal dominant disorder characterized by progressive weakness of distal/proximal muscles. We report that the MDP1 mutation R1500P, studied in what we believe to be the first mouse model for the disease, adversely affected myosin motor activity despite being in the structural rod domain that directs thick filament assembly. Contractility experiments carried out on isolated mutant muscles, myofibrils, and myofibers identified muscle fatigue and weakness phenotypes, an increased rate of actin-myosin detachment, and a conformational shift of the myosin heads toward the more reactive disordered relaxed (DRX) state, causing hypercontractility and greater ATP consumption. Similarly, molecular analysis of muscle biopsies from patients with MPD1 revealed a significant increase in sarcomeric DRX content, as observed in a subset of myosin motor domain mutations causing hypertrophic cardiomyopathy. Finally, oral administration of MYK-581, a small molecule that decreases the population of heads in the DRX configuration, significantly improved the limited running capacity of the R1500P-transgenic mice and corrected the increased DRX state of the myofibrils from patients. These studies provide evidence of the molecular pathogenesis of proline rod mutations and lay the groundwork for the therapeutic advancement of myosin modulators.

Improvement of fatigue in generalised myasthenia gravis with zilucoplan

BACKGROUND

Fatigue is a debilitating symptom of myasthenia gravis (MG). The impact of fatigue on MG can be assessed by Quality of Life in Neurological Disorders (Neuro-QoL) Short Form Fatigue scale. Transformation of raw Neuro-QoL fatigue scores to T-scores is a known approach for facilitating clinical interpretation of clinically meaningful and fatigue severity thresholds.

METHODS

In the Phase 3, double-blind, placebo-controlled RAISE study (NCT04115293), adults with acetylcholine receptor autoantibody-positive generalised MG (MG Foundation of America Disease Class II-IV) were randomised 1:1 to daily subcutaneous zilucoplan 0.3 mg/kg or placebo for 12 weeks. Patients completing RAISE could opt to receive zilucoplan 0.3 mg/kg in an ongoing, open-label extension study, RAISE-XT (NCT04225871). In this post-hoc analysis, we evaluated the long-term effect of zilucoplan on fatigue in RAISE patients who entered RAISE-XT. We report change in Neuro-QoL Short Form Fatigue T-scores and fatigue severity levels from RAISE baseline to Week 60.

RESULTS

Mean Neuro-QoL Short Form Fatigue T-scores improved from baseline to Week 12 in the zilucoplan group (n = 86) with a clinically meaningful difference versus placebo (n = 88; least squares mean difference: - 3.61 (nominal p-value = 0.0060]), and these improvements continued further to Week 60. At Week 12, more patients on zilucoplan (n = 34, 47.2%) experienced improvements in ≥ 1 fatigue severity level from baseline versus placebo (n = 23, 28.4%; p = 0.017). At Week 60, most (n = 55, 65.5%) patients had mild fatigue or none.

CONCLUSION

Treatment with zilucoplan demonstrated statistical and clinically meaningful improvements in fatigue scores and severity versus placebo during RAISE, which were sustained to Week 60 in RAISE-XT.

High-Performance Hydrogel Sensors Enabled Multimodal and Accurate Human-Machine Interaction System for Active Rehabilitation

Human-machine interaction (HMI) technology shows an important application prospect in rehabilitation medicine, but it is greatly limited by the unsatisfactory recognition accuracy and wearing comfort. Here, this work develops a fully flexible, conformable, and functionalized multimodal HMI interface consisting of hydrogel-based sensors and a self-designed flexible printed circuit board. Thanks to the component regulation and structural design of the hydrogel, both electromyogram (EMG) and forcemyography (FMG) signals can be collected accurately and stably, so that they are later decoded with the assistance of artificial intelligence (AI). Compared with traditional multichannel EMG signals, the multimodal human-machine interaction method based on the combination of EMG and FMG signals significantly improves the efficiency of human-machine interaction by increasing the information entropy of the interaction signals. The decoding accuracy of the interaction signals from only two channels for different gestures reaches 91.28%. The resulting AI-powered active rehabilitation system can control a pneumatic robotic glove to assist stroke patients in completing movements according to the recognized human motion intention. Moreover, this HMI interface is further generalized and applied to other remote sensing platforms, such as manipulators, intelligent cars, and drones, paving the way for the design of future intelligent robot systems.

The influence of symptom severity and fatigue on sleep quality in patients with myasthenia gravis

INTRODUCTION

Myasthenia gravis is a rare and chronic autoimmune disease. The study aimed to evaluate the influence of symptom severity and fatigue on sleep quality in patients with myasthenia gravis.

METHODS

This was a cross-sectional study, and the population consisted of patients with MG throughout Turkey. The study was completed with 163 patients on 1 April and 31 July 2022.

RESULTS

 It was found that the mean Myasthenia Gravis-Activities of Daily Living Scale score was 6.32 ± 3.9, the Fatigue Severity Scale score was 37.01 ± 23.26, and the total Pittsburgh Sleep Quality Index score was 9.04 ± 2.69. The variables affecting the Pittsburgh Sleep Quality Index scores were age, Body Mass Index, Fatigue Severity Scale ≥ 4, Myasthenia Gravis-Activities of Daily Living Scale ≥ 5.5, duration of diagnosis, and income level; a multiple regression model was created with these variables, and the variables in the resulting model explained 26.4% of the Pittsburgh Sleep Quality Index scores. In addition, those with clinically significant symptom severity (MG-ADL ≥5.5) in daily living and those with severe fatigue (FSS ≥4) explained 17.2% of the PSQI scores, and the model was statistically significant (p < 0.001).

CONCLUSION

The study determined that the participants had clinically significant symptom severity in daily living, severe fatigue, and poor sleep quality. The participants with clinically significant severe symptoms in daily living and fatigue had higher sleep disturbances, daytime dysfunction, and poor sleep quality.

Transcranial direct current stimulation for fatigue in neurological conditions: A systematic scoping review

BACKGROUND AND PURPOSE

Fatigue following neurological conditions negatively impacts daily activities, reducing overall quality of life. Transcranial direct current stimulation (tDCS) for fatigue management is still underexplored. This scoping review explores its use in managing fatigue among various neurological conditions.

METHODS

A thorough literature search was carried out using PubMed, Scopus, CINAHL, Web of Science, Embase, ProQuest, and the Cochrane Library. Google Scholar and clinicaltrials.gov were manually searched for gray literature and ongoing trials, respectively. Regardless of the study design, all studies utilizing tDCS for the management of fatigue in various neurological conditions were considered. Two reviewers independently screened all the studies, following which the data were retrieved.

RESULTS

Studies employing tDCS for fatigue management across neurological conditions is as follows: Multiple sclerosis (MS) (n = 28, 66%), stroke (n = 5, 12%), Parkinson's disease (PD) (n = 4, 10%), post-polio syndrome (PPS) (n = 2, 5%), traumatic brain injury (TBI) (n = 2, 5%), and amyotrophic lateral sclerosis (n = 1, 2%). All the studies used anodal stimulation, with the common stimulation site being the left dorsolateral prefrontal cortex for MS, stroke, and PD. A stimulation intensity of 1.0-4.0 mA with a duration ranging from 15 to 30 min in 1 to 24 sessions were commonly reported. The Fatigue Severity Scale (n = 21) and Modified Fatigue Impact Scale (n = 17) were frequently implemented outcome measures. Regardless of the study design, 36/42 (85.7%) studies reported an improvement in fatigue scores in the tDCS group. The common adverse events noted were tingling (n = 8, 35%), headache (n = 6, 26%), and itching (n = 6, 26%).

DISCUSSION

Application of tDCS for fatigue was explored in individuals with stroke, PD, PPS, and TBI after MS. Even though a wide range of treatment parameters and outcome measures were adopted to assess and target fatigue, tDCS proves to have a promising role in alleviating this symptom.

Correlation of fatigue on walking ability in myasthenia gravis patients: a cross-sectional study

Introduction

Myasthenia gravis (MG) is a neuromuscular junction autoimmune disease characterised of intermittent muscle weakness that increases with activity and recovers with rest.

Objective

Analysing the correlation of fatigue on walking ability in MG patients.

Methods

This study used a cross-sectional design with consecutive sampling. Participants MG patients took in this trial. Data collection encompasses fatigue and walking ability, with fatigue being assessed using the fatigue severity scale (FSS) and walking ability being assessed using the 10-metre walking test. The 10-metre walking test assessment contains three components: comfortable walking speed (CWS), maximum walking speed (MWS), and natural cadence. The statistical analysis used in this study includes the Pearson correlation and Spearman rank tests with P<0.05.

Results

The number of participants was 23 MG patients, and most of the participant was female (69.6%). The participant's fatigue value was 5.46±1.13, including MGFA 1=5.32±1.15, MGFA 2A=5.5±1.11, and MGFA 2B=5.61±1.30. Meanwhile, the participant's walking abilities included CWS of 1.10±0.11 m/s, MWS of 1.31±0.15 m/s, and natural cadence of 110.91±7.74 steps/min. No significant correlation of fatigue on walking ability including FSS vs. CWS (r=-0.141; P=0.520), FSS vs MWS (r=-0.169; P=0.442), and FSS vs. natural cadence (r=-0.050; P=0.822).

Conclusion

There was no significant correlation between fatigue and walking ability in MG patients who had MGFA 1, MGFA 2A, and MGFA 2B.

Myasthenia gravis-Pathophysiology, diagnosis, and treatment

Myasthenia gravis (MG) is an autoimmune disease characterized by dysfunction of the neuromuscular junction resulting in skeletal muscle weakness. It is equally prevalent in males and females, but debuts at a younger age in females and at an older age in males. Ptosis, diplopia, facial bulbar weakness, and limb weakness are the most common symptoms. MG can be classified based on the presence of serum autoantibodies. Acetylcholine receptor (AChR) antibodies are found in 80%-85% of patients, muscle-specific kinase (MuSK) antibodies in 5%-8%, and <1% may have low-density lipoprotein receptor-related protein 4 (Lrp4) antibodies. Approximately 10% of patients are seronegative for antibodies binding the known disease-related antigens. In patients with AChR MG, 10%-20% have a thymoma, which is usually detected at the onset of the disease. Important differences between clinical presentation, treatment responsiveness, and disease mechanisms have been observed between these different serologic MG classes. Besides the typical clinical features and serologic testing, the diagnosis can be established with additional tests, including repetitive nerve stimulation, single fiber EMG, and the ice pack test. Treatment options for MG consist of symptomatic treatment (such as pyridostigmine), immunosuppressive treatment, or thymectomy. Despite the treatment with symptomatic drugs, steroid-sparing immunosuppressants, intravenous immunoglobulins, plasmapheresis, and thymectomy, a large proportion of patients remain chronically dependent on corticosteroids (CS). In the past decade, the number of treatment options for MG has considerably increased. Advances in the understanding of the pathophysiology have led to new treatment options targeting B or T cells, the complement cascade, the neonatal Fc receptor or cytokines. In the future, these new treatments are likely to reduce the chronic use of CS, diminish side effects, and decrease the number of patients with refractory disease.

Experience of Daily Life with Generalized Myasthenia Gravis: A Qualitative Investigation and Assessment of Instrument Content Validity

INTRODUCTION

Generalized myasthenia gravis (gMG) is a rare autoimmune disease. Symptoms of gMG are diverse, and understanding of their impact on patients is limited. This qualitative study aimed to provide an in-depth exploration of patients' daily experiences of gMG.

METHODS

Published qualitative studies were reviewed to identify the most important signs, symptoms, and functional impacts related to the patient experience in gMG. Semi-structured hybrid concept elicitation interviews (allowing spontaneous generation of disease concepts) and cognitive debriefing interviews (assessing the validity of existing disease assessments) were conducted with clinicians and adult patients with gMG. Signs, symptoms, and impacts were reviewed to understand which were most salient (i.e., reported by at least 50% of patients, with disturbance rating 5 or higher [10-point numeric scale]); concept saturation was also assessed. The disease conceptual model was updated. Existing clinical outcomes assessments (COAs) that capture how patients feel, function, and survive were assessed.

RESULTS

Interviews with patients (n = 24) identified seven new signs and symptoms and 37 new impacts compared with the literature. Concept saturation was reached. Signs and symptoms identified by patients as most important (salient) were shortness of breath, general fatigue, muscle weakness of arms, legs, and neck, dysphonia, dysarthria, trouble swallowing liquids, choking, and heat sensitivity. Patient-identified salient impacts were work life, depression, difficulty walking, grooming hair, showering, and brushing teeth, eating, personal relationships, family life, and participating in social activities. Clinicians considered ocular, respiratory, swallowing, speech/talking, and extremity function as key clinical manifestations of gMG. Patients and clinicians found clinical outcome assessments (COAs) to be conceptually relevant and comprehensive.

CONCLUSION

This research provides a holistic understanding of gMG signs, symptoms, and impacts experienced by patients, as observed by patients and clinicians. The conceptual model of gMG highlights the range of signs, symptoms, and impacts that adult patients with gMG experience in their everyday lives, emphasizing the humanistic impact and unmet needs.

Measuring Overall Severity of Myasthenia Gravis (MG): Evidence for the Added Value of the MG Symptoms PRO

INTRODUCTION

Accurate measurement of myasthenia gravis (MG) severity is required for appropriate clinical monitoring of patients with MG and assessment of the benefit of new treatments in clinical trials. Our objective was to explore how MG severity can be measured and to determine how the newly developed MG Symptoms Patient-Reported Outcome (PRO) instrument complements the available measures of MG severity.

METHODS

The conceptual coverage of the Quantitative MG (QMG), MG Composite (MGC), MG-Activities of Daily Living (MG-ADL), and MG Symptoms PRO was scrutinized against core symptoms of MG: muscle weakness in three muscle groups (ocular, bulbar, and respiratory), muscle weakness fatigability, and physical fatigue. Post hoc analyses of the MG0002 study, a Phase 2a clinical trial of rozanolixizumab in adults with moderate to severe generalized MG, included correlation and Rasch model analyses.

RESULTS

The qualitative appraisal highlighted that only the MG Symptoms PRO captured physical fatigue. Data from 541 assessments (43 unique patients) were used for the analyses. Correlations ranged between 0.56 and 0.74 for the MG-ADL, QMG, MGC, and MG Symptoms PRO Muscle Weakness Fatigability score, and between 0.20 and 0.71 for the MG Symptoms PRO scores focusing on independent muscle groups. Analyses with the Rasch model estimated a meaningful continuum of severity of MG, including all items, except ocular muscles, from the four instruments. The QMG and MG Symptoms PRO had the broadest coverage of the MG severity continuum. Muscle fatigability and physical fatigue were more characteristic of low severity while bulbar weakness indicated more severe MG.

CONCLUSION

The severity of MG can be reflected in a meaningful continuum underpinned by the MG-specific outcome measures. Only ocular muscle manifestations were shown to reflect a possibly different facet of MG severity. With its modular nature and comprehensive content, the MG Symptoms PRO provides complementary information to the outcome measures widely used in MG.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03052751.

Myasthenia gravis, respiratory function, and respiratory tract disease

Myasthenia gravis (MG) is characterized by muscle weakness caused by autoantibodies that bind to the postsynaptic membrane at the neuromuscular junction and impair acetylcholine receptor function. Weakness of respiratory muscles represents the most severe MG manifestation, and 10-15% of all patients experience an MG crisis with the need of mechanical ventilatory support at least once in their life. MG patients with respiratory muscle weakness need active immunosuppressive drug treatment long term, and they need regular specialist follow-up. Comorbidities affecting respiratory function need attention and optimal treatment. Respiratory tract infections can lead to MG exacerbations and precipitate an MG crisis. Intravenous immunoglobulin and plasma exchange are the core treatments for severe MG exacerbations. High-dose corticosteroids, complement inhibitors, and FcRn blockers represent fast-acting treatments that are effective in most MG patients. Neonatal myasthenia is a transient condition with muscle weakness in the newborn caused by mother's muscle antibodies. In rare cases, treatment of respiratory muscle weakness in the baby is required.

Exploring impairments and allied health professional utilisation in people with myasthenia gravis: A cross-sectional study

This study aimed to explore how people with myasthenia gravis experience impairments in vision, dizziness, hearing, and fatigue, and how these relate to balance confidence, community participation, and health-related quality of life. Additionally, this study investigated the utilisation and perception of the allied health role in managing these impairments in the Australian context. Visual and hearing impairments, along with fatigue, were found to be correlated with health-related quality of life and community participation to varying degrees, while visual impairment and dizziness were correlated with balance confidence. Perception and utilisation of allied health professionals was variable; common barriers to better utilisation included participant perception of clinicians having poor knowledge around myasthenia gravis, previous poor experiences with clinicians, uncertainty about the clinicians' role, and lack of awareness that symptoms were associated with myasthenia gravis. Further research exploring clinicians' knowledge of myasthenia gravis is recommended, along with education for people with the disease about symptoms associated and how to appropriately access care.

Evaluation of the quality of patient involvement in a patient-led analysis of the lived experience of a rare disease

BACKGROUND

Patients themselves are best placed to provide insights on the lived experience and to lead the analysis of such insights to bring the patient voice into peer-reviewed literature. In doing so, they can meet the authorship criteria for subsequent research publications. It is important to evaluate patient engagement to identify ways to improve future collaborations. Here, we describe the approach taken during a patient-led and patient co-authored analysis of the lived experience of generalized myasthenia gravis, which may be applicable to other indications. We also assessed the quality of patient engagement throughout the research project.

METHODS

We used self-reported experience surveys based on the Patient Focused Medicines Development Patient Engagement Quality Guidance criteria for assessing patient engagement. The surveys were adapted to focus on individual projects and assessed eight domains using a five-point Likert scale. In September 2020, we invited eight patient council members to complete a self-reported experience survey following qualitative lived experience data generation. We calculated the average experience score as a percentage of the maximum possible score. Patient authors (n = 1) and non-patient authors (n = 3) were invited to complete a similar survey in November 2021, with questions customized for relevance, to evaluate the authorship experience following publication of the research.

RESULTS

Overall, patient council members had a positive experience of taking part in this study, with an average experience score of 90% (71.6/80.0; n = 8). The patient author and non-patient authors rated their authorship experience highly, with average experience scores of 92% (78.0/85.0) and 97% (63.3/65.0), respectively. There were key aspects that contributed to the overall project success (e.g., ensuring that all participants were aligned on the project objectives at the outset and understood their roles and responsibilities). We also identified elements of the approach that could be improved in future collaborations.

CONCLUSION

In this patient-led analysis, patient council members, patient authors and non-patient authors had a positive experience of being involved in the project. We gained useful insights into elements that contributed to the project's success and ways to improve future patient-led projects on the lived experience.

Safety and efficacy of zilucoplan in patients with generalised myasthenia gravis (RAISE): a randomised, double-blind, placebo-controlled, phase 3 study

BACKGROUND

Generalised myasthenia gravis is a chronic, unpredictable, and debilitating rare disease, often accompanied by high treatment burden and with an unmet need for more efficacious and well tolerated treatments. Zilucoplan is a subcutaneous, self-administered macrocyclic peptide complement C5 inhibitor. We aimed to assess safety, efficacy, and tolerability of zilucoplan in patients with acetylcholine receptor autoantibody (AChR)-positive generalised myasthenia gravis.

METHODS

RAISE was a randomised, double-blind, placebo-controlled, phase 3 trial that was done at 75 sites in Europe, Japan, and North America. We enrolled patients (aged 18-74 years) with AChR-positive generalised myasthenia gravis (Myasthenia Gravis Foundation of America disease class II-IV), a myasthenia gravis activities of daily living (MG-ADL) score of least 6, and a quantitative myasthenia gravis score of at least 12. Participants were randomly assigned (1:1) to receive subcutaneous zilucoplan 0·3 mg/kg once daily by self-injection, or matched placebo, for 12 weeks. The primary efficacy endpoint was change from baseline to week 12 in MG-ADL score in the modified intention-to-treat population (all randomly assigned patients who received at least one dose of study drug and had at least one post-dosing MG-ADL score). Safety was mainly assessed by the incidence of treatment-emergent adverse events (TEAEs) in all patients who had received at least one dose of zilucoplan or placebo. This trial is registered at ClinicalTrials.gov, NCT04115293. An open-label extension study is ongoing (NCT04225871).

FINDINGS

Between Sept 17, 2019, and Sept 10, 2021, 239 patients were screened for the study, of whom 174 (73%) were eligible. 86 (49%) patients were randomly assigned to zilucoplan 0·3 mg/kg and 88 (51%) were assigned to placebo. Patients assigned to zilucoplan showed a greater reduction in MG-ADL score from baseline to week 12, compared with those assigned to placebo (least squares mean change -4·39 [95% CI -5·28 to -3·50] vs -2·30 [-3·17 to -1·43]; least squares mean difference -2·09 [-3·24 to -0·95]; p=0·0004). TEAEs occurred in 66 (77%) patients in the zilucoplan group and in 62 (70%) patients in the placebo group. The most common TEAE was injection-site bruising (n=14 [16%] in the zilucoplan group and n=8 [9%] in the placebo group). Incidences of serious TEAEs and serious infections were similar in both groups. One patient died in each group; neither death (COVID-19 [zilucoplan] and cerebral haemorrhage [placebo]) was considered related to the study drug.

INTERPRETATION

Zilucoplan treatment showed rapid and clinically meaningful improvements in myasthenia gravis-specific efficacy outcomes, had a favourable safety profile, and was well tolerated, with no major safety findings. Zilucoplan is a new potential treatment option for a broad population of patients with AChR-positive generalised myasthenia gravis. The long-term safety and efficacy of zilucoplan is being assessed in an ongoing open-label extension study.

FUNDING

UCB Pharma.

Characterization of Muscle Weakness Due to Myasthenia Gravis Using Shear Wave Elastography

Myasthenia gravis (MG) is often accompanied with muscle weakness; however, little is known about mechanical adaptions of the affected muscles. As the latter can be assessed using ultrasound shear wave elastography (SWE), this study characterizes the biceps brachii muscle of 11 patients with MG and compares them with that of 14 healthy volunteers. Simultaneous SWE, elbow torque and surface electromyography measurements were performed during rest, maximal voluntary contraction (MVC) and submaximal isometric contractions (up to 25%, 50% and 75% MVC) at different elbow angles from flexion to extension. We found that, with increasing elbow angle, maximum elbow torque decreased (p < 0.001), whereas muscle stiffness increased during rest (p = 0.001), MVC (p = 0.004) and submaximal contractions (p < 0.001). Muscle stiffness increased with increasing contraction intensities during submaximal contractions (p < 0.001). In comparison to the healthy cohort, muscle stiffness of MG patients was 2.1 times higher at rest (p < 0.001) but 8.93% lower in active state (75% MVC, p = 0.044). We conclude that (i) increased muscle stiffness shown by SWE during rest might be an indicator of MG, (ii) SWE reflects muscle weakness and (iii) SWE can be used to characterize MG muscle.

A Symptoms and Signs Approach to the Patient With Neuromuscular Weakness

PURPOSE OF REVIEW

Muscle weakness is a common feature of many neuromuscular disorders. This article outlines a symptoms and signs approach to the patient presenting with neuromuscular weakness, highlighting key aspects of the clinical history and examination.

RECENT FINDINGS

The past several years have seen a dramatic increase in the ability to test for many inherited and autoimmune neuromuscular disorders more reliably and accurately. Similarly, numerous targeted therapies have been recently approved to treat previously untreatable disorders. Therefore, timely and accurate diagnosis is essential so that patients can receive appropriate therapy, ultimately leading to better clinical outcomes.

SUMMARY

Muscle weakness is a common symptom resulting from dysfunction that can occur at any level of the neuraxis and is a cardinal feature of many neuromuscular disorders. An accurate and meticulous history and a thorough neurologic examination are paramount in localizing the lesion in order to generate a differential diagnosis and guide appropriate ancillary testing. The patient's age at symptom onset, any identified inciting factors, tempo of symptom progression, pattern of weakness, and associated symptoms and signs are all important diagnostic clues in the evaluation of a patient presenting with muscle weakness.

Diagnosis and Management of Myasthenia Gravis

PURPOSE OF REVIEW

This article reviews updated diagnostic procedures and currently available treatment modalities for myasthenia gravis (MG).

RECENT FINDINGS

Patients with MG can be classified based on antibody status and their clinical presentation; treatment responses may differ based on disease subtypes. Improved diagnostic methods and recognition of new antigenic targets such as lipoprotein-related protein 4 have led to improved diagnostic efficiencies. Corticosteroids remain the first-line immunotherapy, but there is a trend toward minimizing their use at high doses and for long durations. Oral immunosuppressants such as mycophenolate mofetil, azathioprine, and tacrolimus remain useful. An international, multicenter randomized trial comparing thymectomy plus prednisone with prednisone alone demonstrated that thymectomy improves clinical outcomes in selected patients with nonthymomatous MG. Eculizumab, efgartigimod, and ravulizumab have recently been approved by the US Food and Drug Administration (FDA) for adult patients with generalized MG who are acetylcholine receptor-antibody positive. These drugs take advantage of novel mechanisms of action and expand treatment options for patients with MG. Data on rituximab suggest that it can be a good option, especially for patients with MG who are positive for antibodies against muscle-specific tyrosine kinase (MuSK). The number of clinical trials and drugs in development for MG is steadily increasing.

SUMMARY

The diagnosis of MG can generally be made from the patient's history, a neurologic examination, and laboratory and electrodiagnostic testing. Carefully selected treatment improves outcomes in MG. Additional treatment options for MG will likely be available in the near future.

Long COVID and the Neuroendocrinology of Microbial Translocation Outside the GI Tract: Some Treatment Strategies

Similar to previous pandemics, COVID-19 has been succeeded by well-documented post-infectious sequelae, including chronic fatigue, cough, shortness of breath, myalgia, and concentration difficulties, which may last 5 to 12 weeks or longer after the acute phase of illness. Both the psychological stress of SARS-CoV-2 infection and being diagnosed with COVID-19 can upregulate cortisol, a stress hormone that disrupts the efferocytosis effectors, macrophages, and natural killer cells, leading to the excessive accumulation of senescent cells and disruption of biological barriers. This has been well-established in cancer patients who often experience unrelenting fatigue as well as gut and blood–brain barrier dysfunction upon treatment with senescence-inducing radiation or chemotherapy. In our previous research from 2020 and 2021, we linked COVID-19 to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) via angiotensin II upregulation, premature endothelial senescence, intestinal barrier dysfunction, and microbial translocation from the gastrointestinal tract into the systemic circulation. In 2021 and 2022, these hypotheses were validated and SARS-CoV-2-induced cellular senescence as well as microbial translocation were documented in both acute SARS-CoV-2 infection, long COVID, and ME/CFS, connecting intestinal barrier dysfunction to disabling fatigue and specific infectious events. The purpose of this narrative review is to summarize what is currently known about host immune responses to translocated gut microbes and how these responses relate to fatiguing illnesses, including long COVID. To accomplish this goal, we examine the role of intestinal and blood–brain barriers in long COVID and other illnesses typified by chronic fatigue, with a special emphasis on commensal microbes functioning as viral reservoirs. Furthermore, we discuss the role of SARS-CoV-2/Mycoplasma coinfection in dysfunctional efferocytosis, emphasizing some potential novel treatment strategies, including the use of senotherapeutic drugs, HMGB1 inhibitors, Toll-like receptor 4 (TLR4) blockers, and membrane lipid replacement.

The effectiveness and side effects of pyridostigmine in the treatment of myasthenia gravis: a cross-sectional study

Pyridostigmine is the most commonly used drug in the symptomatic treatment of myasthenia gravis (MG); however, research into its effectiveness and side effects is scarce. The aim of this study was to assess the effectiveness, prevalence of side effects and net benefit of pyridostigmine. All MG patients participating in the Dutch-Belgian myasthenia patient registry were included. A dynamic online questionnaire was developed to assess the effectiveness, side effects and net benefit of pyridostigmine. Out of 642 invited patients, 410 patients (64%) fully completed the questionnaire; 61% reported that they currently used pyridostigmine, 36% had discontinued pyridostigmine and 2% reported to never have used pyridostigmine. Patients reported a median effectiveness of 60, IQR 28-78 and net benefit of 65, IQR 45-84. Of all patients currently using pyridostigmine, 91% reported side effects (vs. 55% in the control group). Most frequently reported side effects were flatulence, urinary urgency, muscle cramps, blurred vision and hyperhidrosis. In the group of patients who discontinued pyridostigmine, side effects were the reason for discontinuation in 26%. Diarrhea, abdominal cramps and muscle twitching were the most frequently cited reasons to discontinue pyridostigmine. These results can be used to guide shared decision making prior to starting symptomatic treatment for MG.

Integrated proteomics and metabolomics analysis reveals hubs protein and network alterations in myasthenia gravis

Background: Thymoma-associated myasthenia gravis (TAMG) is a well-described subtype of Myasthenia gravis (MG). Nevertheless, the detailed proteins and bioprocess differentiating TAMG from TAMG (−) thymoma have remained unclear.

Methods: The proteomics and metabolomics were carried out on serum samples from thymoma group (n = 60, TNMG), TAMG (+) thymoma group (n = 70, TAMG (+)), and TAMG (−) thymomas group (n = 62, TAMG (−)), and controls (n = 159). groups. Proteomics and metabolomics analyses, including weighted gene co-expression network analysis (WGCNA), was conducted to detect the hub proteins and metabolomics processes that could differentiate TAMG (+) from TAMG (−) thymomas. MetaboAnalyst was used to examine the integration of proteomic and metabolomic analysis to differentiate TAMG (+) from TAMG (−) thymomas.

Results: The of module–trait correlation of WGCNA analysis identified KRT1, GSN, COL6A1, KRT10, FOLR2, KRT9, KRT2, TPI1, ARF3, LYZ, ADIPOQ, SEMA4B, IGKV1-27, MASP2, IGF2R was associated with TAMG (+) thymomas. In addition, organismal systems-immune system and metabolism-biosynthesis of other secondary metabolites were closely related to the mechanism of TAMG (+) pathogenesis.

Conclusion: Our integrated proteomics and metabolomics analysis supply a systems-level view of proteome changes in TAMG (+), TAMG (−) thymomas and exposes disease-associated protein network alterations involved in.

Academic and Employment Status in Patients With Generalized Myasthenia Gravis Treated With Eculizumab: A Case Series

OBJECTIVES

To evaluate the impact of treatment with eculizumab, a terminal complement inhibitor, on academic and employment status in patients with refractory generalized myasthenia gravis (MG).

METHODS

Case review of 7 US patients.

RESULTS

Six patients were aged ≤65 years; one was a full-time student and the remainder were in employment before MG diagnosis. After diagnosis, all patients gave up work (n = 3) or reduced their study/working hours (n = 4). In the 12 months after eculizumab initiation, patients who had stopped work resumed working in some capacity, whereas those who had changed their work/study hours returned to their original work/study pattern. Patients also experienced a reduction in the number of MG exacerbations, and a clinically significant improvement in MG-Activities of Daily Living scores, and were able to reduce other MG medications.

CONCLUSIONS

These results suggest that treatment with eculizumab may help maintain education/employment activity in patients with refractory generalized MG.

Does Cardiovascular Autonomic Dysfunction Contribute to Fatigue in Myasthenia Gravis?

Myasthenia gravis (MG) is an autoimmune disease characterized by fatigable muscle weakness. Despite full spontaneous or pharmacological remission some MG patients still complain of physical and mental fatigue. Fatigue has been related to autonomic dysregulation. The aim of this study was to assess autonomic responses in a group of MG patients in complete remission but complaining of persistent fatigue. Seventeen well-regulated but persistently fatigued MG patients and 17 individually matched controls underwent echocardiography assessing systolic and diastolic heart function. Beat to beat cardiovascular responses at rest and to 30o head-up tilt, tilt-back, and 2-min static handgrip contraction were recorded. Fatigued MG patients had a statistically significant higher resting HR than their matched controls (p=0.03). The difference in resting heart rate between MG patients not using acetylcholine esterase inhibitors (AChEi) and their matched controls was even more pronounced (p=0.007). The autonomic cardiovascular adjustments to head-up tilt, tilt-back and handgrip contraction were not statistically significant different between patients and controls. We found a higher resting heart rate in all well-regulated but fatigued MG patients compared with controls. The difference was more pronounced between patients not taking AChEi compared to their matched controls. This finding may reflect a disturbed resting sympathovagal balance and this might be a contributing factor to the fatigue symptoms.

Effect of Two Different Rehabilitation Approaches on Pulmonary Functional Tests, Neuromuscular Functions and Quality of Life in Juvenile Myasthenia Gravis: A Randomized Controlled Trial Study

Background and Objectives: Children with juvenile myasthenia gravis have a variety of symptoms, ranging from isolated intermittent ocular complaints to overall muscle weakness with or without respiratory insufficiency. This study aimed to investigate the efficacy of a specialized physical therapy with or without partial body weight supported treadmill training on pulmonary functional tests, neuromuscular functions, and quality of life. Materials and Methods: Thirty children, ranging in age from 13 to 16 years, were distributed randomly into two study groups (A or B). Both groups underwent a designed physical therapy program. In addition, group A underwent the partial body weight supported treadmill training. The treatment was conducted three times a week for 12 weeks successively. Pulmonary functional tests (FVC, FEV1, PEFR, and MVV), neuromuscular function tests (compound motor action potential, isometric muscle force of biceps brachii and rectus femoris, balance, walking endurance, and fatigue), and quality of life were measured before and after 12 successive weeks. Results: A significant improvement in all investigated variables were recorded in both groups in favor of group A. Conclusions: Both a specialized physical therapy and partial body weight supported treadmill training are effective in terms of enhancing pulmonary functional tests, neuromuscular functions, and quality of life. Partial body weight supported treadmill training is an excellent adjunctive to the physical therapy program.

Mitochondrial dynamics and biogenesis indicators may serve as potential biomarkers for diagnosis of myasthenia gravis

Due to challenges in diagnosing myasthenia gravis (MG), identifying novel diagnostic biomarkers for this disease is essential. Mitochondria are key organelles that regulate multiple physiological functions, such as energy production, cell proliferation and cell death. In the present study, Mfn1/2, Opa1, Drp1, Fis1, AMPK, PGC-1α, NRF-1 and TFAM were compared between patients with MG and healthy subjects to identify potential diagnostic biomarkers for MG. Blood samples were collected from 50 patients with MG and 50 healthy subjects. The participants' demographic information and routine blood test results were recorded. Mitochondrial dynamics were evaluated and levels of Mfn1/2, Opa1, Drp1, Fis1, AMPK, PGC-1α, NRF-1 and TFAM were determined in peripheral blood mononuclear cells using western blotting and reverse transcription-quantitative PCR, respectively. Receiver operating characteristic curve analysis was used to evaluate the diagnostic accuracy of these indicators. The areas under the curve values of Mfn1/2, Opa1, Drp1, Fis1,AMPK, PGC-1α, NRF-1 and TFAM were 0.5408-0.8696. Compared with control subjects, mRNA expression levels of Mfn1/2, Opa1, AMPK, PGC-1α, NRF-1 and TFAM were lower, while those of Drp1 and Fis1 were higher in patients with MG. The protein expression levels of all these molecules were lower in patients with MG than in control subjects. These results suggested that mitochondrial dynamics and biogenesis indicators may be diagnostic biomarkers for MG.

Correlation between Fatigue and Ability to Perform Activities of Daily Living in Myasthenia Gravis Patients

BACKGROUND: Myasthenia Gravis (MG) is an autoimmune disease of the neuromuscular junction that has autoantibodies that can be found in most cases. Fatigue and skeletal muscle weakness are the pathognomonic symptoms of MG and can be severely disabling, interfering with a patient’s ability to pursue activities of daily living, limiting their work, family, and social lives. AIM: This study aimed to analyze the correlation between fatigue and the ability to perform activity of daily living (ADL) among patients with MG. METHOD: Fatigue severity scale (FSS) was used to measure the fatigue and MG-ADL scale was used to evaluate the patient’s ability to perform ADL. Rank-Spearman test was used to assess the correlation between fatigue and patient’s ability to perform daily activities. RESULTS: Thirty-one patients (nine males and 22 females) with MG were included and classified into three subgroups of fatigue: Non-fatigue (FSS <4), borderline (4 < FSS < 5), and fatigue (FSS >5). There was a significant correlation between fatigue and the patient’s ability to perform ADL (p = 0.005; p = 0.488) with CI 95%. CONCLUSION: Fatigue in patients with MG correlates with the ability to perform ADL.

The association between anti-acetylcholine receptor antibody level and clinical improvement in myasthenia gravis

BACKGROUND

Anti-AChR-antibodies in the serum are detected in most patients with generalized myasthenia gravis (MG) and used as a diagnostic tool. The aim of this study was to analyse a possible association between anti-AChR-antibody serum levels and clinical improvement of MG.

METHODS

The Maastricht University Medical Center is a centre of expertise for the treatment of MG. Between 1997 till 2020, more than 4.000 anti-AChR-antibodies were measured for clinical care using quantitative radioimmunoassay (RIA) technique. These results, in combination with the clinical status obtained from the patients' electronic patient files, were retrospectively analysed by a single blinded clinician. Symptoms of MG were classified by the Myasthenia Gravis Foundation of America (MGFA).

RESULTS

In total, 90 anti-AChR-antibody positive MG-patients with 837 blood samples were included. Median follow-up time was 72 months. The majority of the included patients were female (61.1%), on immunosuppressive drug therapy (88.9%), and did undergo a thymectomy (54.4%). Multilevel logistic regression analysis showed a significantly inverse association between change in anti-AChR-antibody level and the odds of MGFA improvement (per 10 percent decrease of anti-AChR-antibody level OR: 1.21, CI: 1.12-1.31, p <0.001).

CONCLUSIONS

A change in anti-AChR-antibody serum level is associated with the clinical status in patients with MG. Analyses of anti-AChR-antibody are not only useful for diagnostics but also in follow-up of adult symptomatic patients with MG. The use of repetitive anti-AChR-antibody serum levels might be valuable as a long-term monitor for clinical improvement in patients with MG, however, further research is required for specific recommendations.

The Lived Experience of Myasthenia Gravis: A Patient-Led Analysis

Introduction

A greater understanding of the reality of living with myasthenia gravis (MG) may improve management and outcomes for patients. However, there is little published data on the patient perspective of how MG impacts life. Our objective was to reveal the lived experience of MG from the patient perspective.

Methods

This analysis was led by an international Patient Council comprising nine individuals living with MG who serve as local/national patient advocates in seven countries (Europe and the United States). Insights into the lived experience of MG were consolidated from three sources (a qualitative research study of 54 people with MG or their carers from seven countries; a previous Patient Council meeting [September 2019]; and a literature review). Insights were prioritised by the Patient Council, discussed during a virtual workshop (August 2020) and articulated in a series of statements organised into domains. Overarching themes that describe the lived experience of MG were identified by the patient authors.

Results

From 114 patient insights and supporting quotes, the Patient Council defined 44 summary statements organised into nine domains. Five overarching themes were identified that describe the lived experience of MG. These themes include living with fluctuating and unpredictable symptoms; a constant state of adaptation, continual assessment and trade-offs in all aspects of life; treatment inertia, often resulting in under-treatment; a sense of disconnect with healthcare professionals; and feelings of anxiety, frustration, guilt, anger, loneliness and depression.

Conclusion

This patient-driven analysis enriches our understanding of the reality of living with MG from the patient perspective.

Physical Activity and Sedentary Behaviour in People with Myasthenia Gravis: A Cross-Sectional Study

BACKGROUND

Despite improvements in the medical management of myasthenia gravis (MG) in recent years, patients continue to report poor health and wellbeing outcomes such as high levels of fatigue, reduced quality of life (QoL), walking limitation and lowered balance confidence. Physical activity has been shown to be associated with these outcomes in other populations, however, there has been limited research in adults with MG.

OBJECTIVE

To describe physical activity and sedentary behaviour in adults with MG and to explore associations between these behaviours and fatigue, QoL, balance confidence and walking limitation.

METHODS

A self-report online survey was used to assess physical activity, sedentary behaviour, fatigue, QoL, balance confidence and walking limitation in adults with MG. Multiple linear regression was used to examine associations and descriptive statistics were used to analyse participant characteristics, physical activity, and sedentary behaviour.

RESULTS

Eighty-five adults with MG were included (mean age 48±16 years). Over half of participants (n = 53, 62.4%) reported sufficient physical activity to meet public health guidelines. Participants reported an average of 9 h/day of sedentary time (mean 9.0±3.5). Physical activity and fatigue (R2 = 0.196), QoL (R2 = 0.330), walking limitation (R2 = 0.305) and balance confidence (R2 = 0.304) were significantly (p <  0.05) and positively correlated, with no associations found for sedentary behaviour. When patterns of physical activity and sedentary behaviour were combined, lower fatigue (R2 = 0.213), higher QoL (R2 = 0.364), reduced walking limitation (R2 = 0.341) and higher balance confidence (R2 = 0.279) was observed in patients who had greater physical activity levels (>  150 mins/week) and lower sedentary time (<  10 h/day).

CONCLUSIONS

Higher physical activity and lower sedentary behaviour is associated with favorable health and wellbeing outcomes in adults with MG. Further research is required to ascertain whether these behaviours may be an appropriate target intervention to improve outcomes in this population.

Timing and localization of myasthenia gravis-related gene expression

Myasthenia gravis (MG) is an acquired autoimmune disorder caused by autoantibodies binding acetylcholine receptors (AChR), muscle‐specific kinase (MuSK), agrin or low‐density lipoprotein receptor‐related protein 4 (Lrp4). These autoantibodies inhibit neuromuscular transmission by blocking the function of these proteins and thereby cause fluctuating skeletal muscle weakness. Several reports suggest that these autoantibodies might also affect the central nervous system (CNS) in MG patients. A comprehensive overview of the timing and localization of the expression of MG‐related antigens in other organs is currently lacking. To investigate the spatio‐temporal expression of MG‐related genes outside skeletal muscle, we used in silico tools to assess public expression databases. Acetylcholine esterase, nicotinic AChR α1 subunit, agrin, collagen Q, downstream of kinase‐7, Lrp4, MuSK and rapsyn were included as MG‐related genes because of their well‐known involvement in either congenital or autoimmune MG. We investigated expression of MG‐related genes in (1) all human tissues using GTEx data, (2) specific brain regions, (3) neurodevelopmental stages, and (4) cell types using datasets from the Allen Institute for Brain Sciences. MG‐related genes show heterogenous spatio‐temporal expression patterns in the human body as well as in the CNS. For each of these genes, several (new) tissues, brain areas and cortical cell types with (relatively) high expression were identified suggesting a potential role for these genes outside skeletal muscle. The possible presence of MG‐related antigens outside skeletal muscle suggests that autoimmune MG, congenital MG or treatments targeting the same proteins may affect MG‐related protein function in other organs.

Fatigue, physical activity and associated factors in 779 patients with myasthenia gravis

The objective of the study was to examine the association between fatigue (measured by the Multidimensional Fatigue Inventory; MFI-20) and physical activity (measured by the Saltin-Grimby Physical Activity Level Scale; SGPALS) in a large cohort of patients (≥18 years) with myasthenia gravis (MG) including relevant disease - and lifestyle-related factors. A total of 1463 persons, registered at the Danish National Registry of Patients with a MG diagnosis, according to the International Classification of Diseases, received a web-based survey. A total of 779 patients (53% women, mean [SD] age 60.8 [15.5]) responded. The remaining persons were either non-responders (n = 390) or could not confirm the MG diagnosis (n = 294). The most prominent MFI-20 fatigue domains were general fatigue (median [inter-quartile ranges, IQR], 13 [10-16]) and physical fatigue (median [IQR], 13 [9-15]), and 386 (53%) patients reported low levels of physical activity. All fatigue domains were associated with physical activity (p<.01). Higher level of physical activity was associated with lower levels of fatigue. Important factors for the association were myasthenia gravis disease severity (measured by the Myasthenia Gravis Activities of Daily Living profile), body mass index, insomnia (measured by the Insomnia Severity Index) job-status, comorbidity, and cohabitation.

Prevalence and associated factors of fatigue in autoimmune myasthenia gravis

Fatigue is usually defined as a subjective perception of lacking energy, mentally or physically, with a difficulty sustaining voluntary activities. It is a common symptom of many diseases and most likely has a multifactorial cause. In myasthenia gravis (MG), fatigue has a high prevalence and is correlated with female sex and disease severity. However, no large scale studies have been performed. Therefore, we aimed to evaluate fatigue in the Dutch participants (n = 420) of the Dutch-Belgian Myasthenia Patient Registry using an online survey. Additional information was obtained on mood, sleep, coping, quality of life, disease severity, physical activities and medication. Severe fatigue was present in 62% with a mean score of 37.1 ± 13.2 points. Fatigue severity and prevalence increased significantly with disease severity. A positive correlation was found for female gender, BMI, disease severity and depressive symptoms. A negative correlation was found for strenuous physical activities and older age. The strong association with disease severity suggests that fatigue should be recognized as an element of the symptomatology of MG. The observed association between strenuous activity and fatigue and differences in coping style between fatigued and non-fatigued patients warrant future clinical trials on exercise and cognitive behavioral therapy.

What Is in the Neuromuscular Junction Literature?

ABSTRACT

This update covers recommendations for myasthenia gravis (MG) in patients with coronavirus 2019 disease as well as reports of the clinical features of patients with MG and coronavirus 2019. Updated advisory committee recommendations for the use of thymectomy in generalized MG are also provided. Other MG topics include lipoprotein receptor-4 and agrin antibody associations, factors influencing conversion of ocular to generalized MG, the use of rituximab for more recent onset disease, immunoglobulins for maintenance therapy, and fatigue and depression.

Physical training and exercise in myasthenia gravis

Myasthenia gravis is characterized by muscle weakness and fatigue. As sustained muscle use increases the weakness, the value of physical training programs has previously been questioned. This is a review to clarify the safety and usefulness of systematic training in myasthenia gravis, based on a systematic search in available databases using the relevant key words. Ten intervention studies including 159 patients with generalized disease have been published regarding the effect of systematic physical training, three of them on respiratory muscles. Muscle strength improved, and in the majority of the studies also daily function and quality of life. The feeling of fatigue not directly related to actual muscle weakness was less influenced by physical training. Continuous training was necessary to maintain the improved function. Physical training and exercise are safe in myasthenia gravis. This can improve both muscle strength and daily function. Type and intensity of systematic training should be adapted in the individual patient. A minimum of 150 min of exercise per week is recommended for myasthenia gravis patients with mild and moderate disease.