Myasthenic crisis demanding mechanical ventilation: A multicenter analysis of 250 cases

Frequency and Severity of Myasthenia Gravis Exacerbations Associated With the Use of Ciprofloxacin, Levofloxacin, and Azithromycin

INTRODUCTION/AIMS

The true frequency and severity of myasthenia gravis (MG) exacerbation associated with the usage of fluoroquinolone and macrolide antibiotics remain unknown. We aimed to investigate the association between ciprofloxacin, levofloxacin, azithromycin, and MG exacerbation.

METHODS

A retrospective review was performed on MG patients seen at a single institution between 2002 and 2022, who received ciprofloxacin, levofloxacin, or azithromycin. Amoxicillin usage was chosen for comparison. The strength of association between antibiotic usage and MG exacerbation was scored using the Adverse Drug Reactions Probability Scale. A mixed-effects logistic regression model was constructed to evaluate predictors of antibiotic-associated MG exacerbation (AAMGE).

RESULTS

365 patients had a total of 918 episodes of antibiotic usage (n = 339 for ciprofloxacin, n = 187 for levofloxacin, n = 392 for azithromycin). Frequencies of MG exacerbation following antibiotic use were: 8 (2.4%) for ciprofloxacin, 3 (1.6%) for levofloxacin, 6 (1.5%) for azithromycin, and 17 (1.9%) for all. Six patients had impending crisis/crisis, and 9 required rescue therapy. MG exacerbation was associated with MG-related hospitalization or ED visit in the preceding 6 months (p = 0.012), female sex (p = 0.023) and diabetes (p = 0.032). Infection was the most common confounder in exacerbations (88.2%). MG exacerbation was seen in 8/603 (1.3%) episodes of amoxicillin use, without a significant difference in frequencies of AAMGE among the four antibiotics (p = 0.68).

DISCUSSION

Usage of ciprofloxacin, levofloxacin, or azithromycin was associated with MG exacerbation in less than 2.5% of episodes of antibiotic use. Underlying infection may play a role in AAMGE. As AAMGE can be severe, decision-making regarding the use of these antibiotics should be individualized.

Clinical outcome and peripheral CD4+ T profile in impending myasthenic crisis: A prospective cohort study

Impending Myasthenic Crisis (MC) is defined as a rapid worsening of myasthenia gravis (MG) that can progress to respiratory failure within days to weeks. The clinical data regarding the outcome and peripheral immune profile is limited. This multicenter cohort enrolled 37 patients with impending MC who were given timely rescue therapies from six university hospitals (n = 272). The transformation rate in the impending MC cohort to manifest MC was 24.32 % (9/37). Compared with those who have transformed to MC, the untransformed patients manifested a shorter hospital stay (13.98 ± 15.22 vs. 22.00 ± 16.03 days, P = 0.004), a lower baseline MG Quality of Life 15 (QOL-15) (23.42 ± 14.32 vs. 38.44 ± 13.56, P = 0.006), and shorter disease duration (29.30 ± 46.05 vs. 88.00 ± 71.43 months, P = 0.003). Peripheral CD4+ T profiling revealed an elevated Th17 proportion in impending crisis compared with healthy controls (22.33 ± 6.58 vs. 15.06 ± 4.35, P = 0.0006). Impending MC can be effectively prevented from transforming into manifest MC with rescue therapies.

Rapid response of eculizumab: a rescue therapy for ventilator-dependent refractory myasthenic crisis

Myasthenic crisis (MC) represents the most severe and life-threatening complication of myasthenia gravis (MG). Some patients exhibit refractory responses to conventional immunotherapies, including intravenous immunoglobulin and plasma exchange. This report describes a patient with MC refractory to repetitive high-dose steroids and intravenous immunoglobulin, requiring ventilator support. Within 2 days of eculizumab administration, significant improvement enabled ventilator discontinuation. Subsequent doses further ameliorated limb and pharyngeal weakness, leading to independence. A literature review that identified ten cases reported across five publications highlighted the favorable outcomes achieved with eculizumab in refractory MC, while concomitant respiratory infection was shown to complicate the recovery from MG-related respiratory failure. Although the randomized controlled trials have excluded MC cases, eculizumab has emerged as a promising option for rescue therapy in refractory MC. Larger studies that specifically include MC cases are warranted.

Very Late-Onset Myasthenia Gravis Presenting With Dysphagia and Gradual Decrease in Laryngeal Elevation During Repeated Swallowing: A Case Report

Very late-onset myasthenia gravis (VLOMG) is rare myasthenia gravis (MG) that begins after the age of 65 years. Here, we describe a 72-year-old patient who presented with dysphagia. Upper gastrointestinal radiography revealed delayed initiation of swallowing in the pharynx and inadequate opening of the upper esophageal sphincter. Notably, there was a gradual decrease in laryngeal elevation, which strongly suggested MG. Additionally, the frequency of swallowing was reduced, and anti-acetylcholine receptor (anti-AChR) antibodies were positive. Due to type I respiratory failure, the patient required a tracheotomy and ventilator support. By the time of hospital discharge, the patient was able to walk out independently with a stomach tube and tracheotomy cannula. In conclusion, VLOMG should be considered in patients over 65 years old who present with sudden, isolated dysphagia or dysarthria, particularly when there is a gradual decrease in laryngeal elevation during swallowing as observed on upper gastrointestinal radiography.

Fast-acting treatment of myasthenic crisis with efgartigimod from the perspective of the neonatal intensive care unit

BACKGROUND

Myasthenic crisis (MC) refers to rapid deterioration of myasthenia gravis (MG), affecting lung and bulbar muscles and causing breathing difficulties. Currently, efgartigimod has shown good therapeutic effects in patients with generalized myasthenia gravis (GMG). This retrospective real-world study explored the effectiveness of efgartigimod in patients with MC.

METHOD

Reviewing the clinical data of five patients (including four patients with refractory MC) with MC who received efgartigimod at the First Affiliated Hospital of Sun Yat-sen University, all of these patients were admitted from September 2023 to December 2023.

RESULTS

Each patient received 20 mg/kg of efgartigimod on the first and fifth day. After discharge, all patients showed a clinically meaningful decrease in Myasthenia Gravis Activities of Daily Living (MG-ADL) scale (a decrease of ≥ 2 points) and an improvement in their lung function. Additionally, all patients had a decrease in IgG levels (58.59 ± 18.48% after one cycle of efgartigimod). We also explored the ICU stay and mechanical ventilation (MV) duration for these five patients, and found no significant improvement compared to a large sample data. In terms of safety, four patients experienced adverse events (AEs), all of which were mild. At the last follow-up, four patients achieved the minimal symptom expression (MSE) status (an MG-ADL score of 0 or 1) after 6.25 ± 3.30 weeks. Only one patient experienced a worsening of symptoms in the second week after discharge, but she also achieved the MSE status after receiving a second cycle of efgartigimod treatment.

CONCLUSIONS

Given the conclusion that intravenous efgartigimod is a non-invasive fast-acting treatment with fewer AEs, this may provide NICU workers with another option for managing patients with MC.

Management of mechanical ventilation and weaning in critically ill patients with neuromuscular disorders

PURPOSE

Myasthenia-gravis and Guillain-Barre-syndrome are two of the most common causes of acute and reversible neuromuscular-respiratory-failure(ARNRF), both may worsen respiratory-failure and need for invasive-mechanical-ventilation(IMV) for long-periods due to muscle-weakness. However, approitive IMV-mode for ARNRF patients that better gas-exchange and weaning in ARNRF remain unclear.

MATERIALS AND METHODS

Critically-ill-patiens with IMV due to ARNRF, who could meet the weaning-criterias (after intubation for more than 7-days; difficult-weaning), between 2013, and 2023 were included in the study. IMV-settings, simultaneous arterial-blood-gas (ABG) analyses, and prognosis were recorded for each patient on relevant days.

RESULTS

Sixty-critically-ill-patients with ARNRF who defined as difficult-weaning were included in the study. When different IMV-modes were used in the same patient, simultaneous ABG results were compared for each ventilation-mode. It was determined that the partial-pressure-of-oxygen/fraction of inspired-oxygen-ratios were significantly higher and partial-carbon-dioxide-levels were significantly lower when critically-ill-patients were ventilated with the biphasic-positive-airway-pressure-ventilation(BIPAP) (95 % CI: [0.641-1.41]; p < .001; 95 % CI: [-1.05-.351]; p < .001, respectively). Length-of-time-until-weaning was significantly shorter in BIPAP-mode for each patient in the study group(95 % CI: [0.717-0.188]; p < .001). Moreover, weaning-success was statistically higher in patients with ARNRF were ventilated with BIPAP one-week-before spontenous-breathing-trial (95 % CI [1.026-21.65]; p = .046) than with all other IMV-modes.

CONCLUSION

According to our findings, when BIPAP was selected as the IMV-settings, gas exchange was improved,and weaning-success was higher in critically-ill-patients with ARNRF.

Data-driven explainable machine learning for personalized risk classification of myasthenic crisis

OBJECTIVE

Myasthenic crisis (MC) is a critical progression of Myasthenia gravis (MG), requiring intensive care treatment and invasive therapies. Classifying patients at high-risk for MC facilitates treatment decisions such as changes in medication or the need for mechanical ventilation and helps prevent disease progression by decreasing treatment-induced stress on the patient. Here, we investigated whether it is possible to reliably classify MG patients into groups at low or high risk of MC based entirely on routine medical data using explainable machine learning (ML).

METHODS

In this single-center pseudo-prospective cohort study, we investigated the precision of ML models trained with real-world routine clinical data to identify MG patients at risk for MC, and identified explainable distinctive features for the groups. 51 MG patients, including 13 MC, were used for model training based on real-world clinical data available from the hospital management system. Patients were classified to high or low risk for MC using Lasso regression or random forest ML models.

RESULTS

The mean cross-validated AUC classifying MG patients as high or low risk for MC based on simple or compound features derived from real-world clinical data showed a predictive accuracy of 68.8% for a regularized Lasso regression and 76.5% for a random forest model. Studying feature importance across 5100 model runs identified explainable features to distinguish MG patients at high or low risk for MC. Feature importance scores suggested that multimorbidity may play a role in risk classification.

CONCLUSION

This study establishes feasibility and proof-of-concept for risk classification of MC based on real-world routine clinical data using ML with explainable features and variance control at the point of care. Future research on ML-based prediction of MC should include multi-center, multinational data collection, more in-depth data per patient, more patients, and an attention-based ML model to include free-text.

Predictive modeling and interpretative analysis of risks of instability in patients with Myasthenia Gravis requiring intensive care unit admission

Objective

Myasthenia gravis (MG), a low-prevalence autoimmune disorder characterized by clinical heterogeneity and unpredictable disease fluctuations, presents significant risks of acute exacerbations requiring intensive care. These crises contribute substantially to patient morbidity and mortality. This study aimed to develop and validate machine-learning models for predicting intensive care unit (ICU) admission risk among patients with MG-related disease instability.

Methods

In this retrospective analysis of 314 MG patients hospitalized between 2015 and 2018, we implemented four machine learning algorithms, including logistic regression, support vector machine, extreme gradient boosting (XGBoost), and random forest, to predict ICU admission risk. The models incorporated fourteen clinical parameters as predictive features. The SHapley Additive exPlanations method was utilized to assess the importance of factors associated with ICU admission.

Results

Through 10-fold cross-validation, the XGBoost model demonstrated superior predictive performance (area under the receiver operating characteristic curve: 0.8943, accuracy: 0.8603, sensitivity: 0.7222, and specificity: 0.9125). Among the analyzed features, MG severity, as classified by the Myasthenia Gravis Foundation of America clinical classification, was identified as the most significant factor influencing ICU admission. Additionally, disease duration, a key continuous variable, was inversely correlated with the risk of ICU admission.

Conclusion

MG severity is the primary determinant of ICU admission, with shorter disease duration increasing the risk, possibly due to greater susceptibility to exacerbations. The XGBoost model exhibited excellent performance and accuracy, effectively identifying critical clinical factors for predicting ICU admission risk in MG patients. This novel, personalized approach to risk stratification elucidates crucial risk factors and has the potential to enhance clinical decision-making, optimize resource allocation, and ultimately improve patient outcomes.

Advances in Disease-Modifying Therapeutics for Chronic Neuromuscular Disorders

Neuromuscular disorders can cause respiratory impairment by affecting the muscle fibers, neuromuscular junction, or innervation of respiratory muscles, leading to significant morbidity and mortality. Over the past few years, new disease-modifying therapies have been developed and made available for treating different neuromuscular disorders. Some of these therapies have remarkable effectiveness, resulting in the prevention and reduction of respiratory complications. For myasthenia gravis (MG), efgartigimod, ravulizumab, rozanolixizumab, and zilucoplan have been Food and Drug Administration (FDA)-approved for the treatment of acetylcholine receptor (AChR) antibody-positive generalized MG in the past 2 years. Rozanolixiumab is also approved for treating MG caused by muscle-specific tyrosine kinase (MuSK) antibodies. The new MG therapeutics target the complement system or block the neonatal fragment crystallizable (Fc) receptors (FcRn), leading to significant clinical improvement. For spinal muscular atrophy (SMA), nusinersen (intrathecal route) and risdiplam (oral route) modify the splicing of the SMN2 gene, increasing the production of normal survival motor neuron (SMN) protein. Onasemnogene abeparvovec is a gene replacement therapy that encodes a functional SMN protein. All SMA medications, particularly onasemnogene abeparvovec, have led to clinically meaningful improvement. For late-onset Pompe disease (LOPD), avalglucosidase alfa has shown a greater improvement in respiratory function, ambulation, and functional outcomes in comparison to alglucosidase alfa, and cipaglucosidase alfa combined with miglustat has shown improvement in respiratory and motor function in a cohort of enzyme replacement therapy-experienced LOPD patients. Amyotrophic lateral sclerosis (ALS) remains a challenge. The two most recent FDA-approved medications, namely sodium phenylbutyrate and tofersen, may slow down the disease by a few months in a selected population but do not stop the progression of the disease.

Design of and Early Insights From a Generalized Myasthenia Gravis Patient Engagement Research Council

Background and Aims

An exploratory focus group study was conducted to better understand the needs of patients living with generalized myasthenia gravis (gMG).

Methods

US-based adults with gMG and caregivers of patients with gMG participated in a Patient Engagement Research Council between August 2022 and January 2023. The study consisted of a 15-min prework survey, followed by virtual focus groups facilitated using a semi-structured interview guide. Data concepts were identified using conversational analysis and by direct observation. All transcripts were coded based on concepts using a qualitative research analysis program (MaxQDA).

Results

16 participants (13 patients, three caregivers) were recruited. Participants reported impact on daily activities, fatigue, and psychosocial problems. Many participants experienced delayed diagnosis and difficulty accessing specialist care. Participants described multiple barriers related to their gMG, including barriers to treatment, access-related issues, and communication disconnect between patients and healthcare professionals. Achieving stable disease was the most important goal. There was a preference for the autonomy of self-administered medications at home versus infusions. Study insights led to recommendations to guide patient and healthcare professional education.

Conclusion

The study illustrates the need to improve access to specialist care, achieve earlier diagnosis, prioritize patients' preferences in disease management, and develop treatments that improve outcomes without additional burden.

Patient or Public Contribution

The data collected in this study was provided by the focus group participants, which included patients and caregivers of those with myasthenia gravis.

Intensive care due to myasthenia gravis: Risk factors and prognosis

BACKGROUND AND PURPOSE

Exacerbation of myasthenia gravis (MG) with respiratory failure requires intensive care. We aimed to study the risk factors for intensive care unit admission for MG exacerbation and myasthenic crisis (MC) and the prognosis of people with MG (pwMG) thereafter.

METHODS

This retrospective study investigated patients in the Helsinki and Uusimaa hospital district during the years 2008-2021. PwMG (International Classification of Diseases, 10th revision code G70.0) were identified through a data repository search, followed by a chart review of patient records. Risk factors for intensive care due to MG exacerbation were evaluated as compared with the patients only treated in the outpatient clinic and those treated in the neurological ward for MG exacerbation. The outcomes of patients in intensive care for any reason were also compared with those of patients in intensive care for exacerbation of bronchial asthma.

RESULTS

Of 577 pwMG, 35 (6.1%) needed intensive care for MG within a median of 5.3 months from diagnosis. The mean (±SD) age at MG diagnosis was higher in the intensive care group (60.5 [±16.1] years) compared to the outpatient (48.3 [±20.9] years; p < 0.001) and neurological ward groups (53.4 [±20.8] years; p = 0.044). Thymoma (odds ratio [OR] 4.8, 95% confidence interval [CI] 1.19-19.43; p = 0.028) and female sex (OR 2.1, 95% CI 1.02-4.48; p = 0.045) were independent risk factors for intensive care. In-hospital mortality was 4% for MC patients. Six-month mortality after intensive care for MG exacerbation (14.3%) was twice that for asthma exacerbation (7.7%).

CONCLUSION

Our study shows an increased risk of intensive care treatment for patients with late-onset MG, female sex or thymoma, occurring usually within 6 months from diagnosis, which emphasises the importance of early treatment choices.

US Clinical Practice Experience with Eculizumab in Myasthenia Gravis: Acute Clinical Events and Healthcare Resource Utilization

BACKGROUND AND OBJECTIVE

The terminal complement inhibitor eculizumab is approved in the USA for the treatment of patients with acetylcholine receptor antibody-positive generalized myasthenia gravis (MG). The ELEVATE study aimed to examine clinical-practice outcome data on eculizumab effectiveness in US adults with MG (generalized or ocular). This paper reports the findings on MG exacerbations and crises and associated healthcare resource utilization, and the use of rescue therapy.

METHODS

A retrospective chart review was conducted of US adults with MG who initiated eculizumab. Outcomes assessed for up to 2 years before and after eculizumab initiation included percentages and rates per patient per year (PPPY) of exacerbations and crises (the latter defined as intubation/impending intubation), healthcare resource utilization, and rescue therapy administration.

RESULTS

A total of 119 patients diagnosed with MG were enrolled in the study; 92 patients had ≥ 3 months of data both before and during eculizumab therapy and were included in the analyses. The mean rate of MG exacerbations decreased from 0.385 PPPY before eculizumab initiation to 0.152 PPPY during eculizumab treatment (p = 0.0034); the mean rate of MG crises decreased from 0.411 to 0.056 PPPY (p = 0.0018). Rates of healthcare resource utilization and rescue therapy use also decreased significantly during eculizumab treatment.

CONCLUSIONS

This retrospective chart review analysis provides evidence for a beneficial impact of eculizumab treatment on the incidence of MG exacerbations and crises and associated healthcare resource utilization in clinical practice, and on rescue therapy use. These data further support the therapeutic benefits of eculizumab in patients with MG.

Efgartigimod treatment in patients with anti-MuSK-positive myasthenia gravis in exacerbation

Background

The prevalence of patients positive for muscle-specific kinase antibody (hereafter, MuSK-Ab) accounts for 5-8% of all myasthenia gravis (MG) cases. Currently, efgartigimod has shown good therapeutic effects in MUSK-Ab-positive MG patients in a phase III clinical trial. However, phase III clinical trials tend to exclude MG patients in exacerbation, and there are only few real-world studies on the efficacy of efgartigimod in MuSK-Ab-positive myasthenic crisis (MC) patients. This retrospective, real-world study aimed to explore the efficacy of efgartigimod in MuSK-Ab-positive MG with exacerbation.

Methods

We reviewed the clinical data of four MuSK-Ab-positive patients with exacerbation of MG who received efgartigimod at the First Affiliated Hospital of Sun Yat-sen University, including two patients with MC. All patients were admitted between September 2023 and May 2024. Most patients are simultaneously undergoing rituximab treatment.

Results

Each patient completed one cycle of efgartigimod. After the first administration, four patients showed a clinically meaningful decrease in the Myasthenia Gravis Activities of Daily Living (MG-ADL) score (a reduction of more than 4 points compared to baseline), and all patients showed a decrease in IgG levels after one cycle of efgartigimod. Regarding safety, none of the patients experienced any obvious adverse effects. At the final follow-up, all patients achieved the minimal symptom expression status (an MG-ADL score of 0 or 1) following the first administration of efgartigimod for 8.75 ± 5.56 weeks. This article presents a case involving a patient who exhibited prompt alleviation of symptoms following the administration of a high dose of efgartigimod (20 mg/kg, given on days 1 and 5), without the use of any other fast-acting treatment.

Conclusion

This retrospective real-world study demonstrates the effectiveness and safety of efgartigimod in these four MuSK-Ab-positive, female Asian patients with exacerbation of MG, as well as in patients experiencing MC. It is important to note that efgartigimod should not be viewed as a substitute for foundational immunotherapy; rather, it is intended as a rescue treatment during exacerbations and as an adjunctive therapy in the context of long-term immunotherapy. This non-invasive approach has the potential to become another treatment option for MuSK-Ab-positive MG patients.

Efgartigimod versus intravenous immunoglobulin in the treatment of patients with impending myasthenic crisis

Impending myasthenic crisis (IMC) is an emergent situation requiring aggressive management to prevent patients from developing myasthenic crisis (MC) in patients with myasthenia gravis (MG). Efgartigimod has been proved to be well tolerated and efficacious in MG patients. The present study aimed to compare the efficacy of efgartigimod and intravenous immunoglobulin (IVIg) in rescuing IMC. IMC patients treated with efgartigimod or IVIg were retrospectively enrolled. The primary outcome was determined as the mean change in MG activities of daily living (MG-ADL) score from baseline to week 1 and 4 after treatment, respectively. Safety was assessed based on medical records during the hospitalization to monitor the adverse events. A total of 9 patients treated with efgartigimod and 10 patients treated with IVIg were enrolled. There were no significant differences in the clinical characteristics at baseline between the two groups (P > 0.05). Compared with the IVIg group, the efgartigimod group had a greater reduction in the MG-ADL score at week 1 (P = 0.035) and week 4 (P = 0.005). One patient in the efgartigimod group had an upper respiratory infection. These findings suggest that efgartigimod is a treatment option for IMC in addition to IVIg and plasma exchange.

Risk Stratification and Management of Acute Respiratory Failure in Patients With Neuromuscular Disease

OBJECTIVES

Guillain-Barré syndrome (GBS) and myasthenia gravis (MG) are the most common causes of acute neuromuscular respiratory failure resulting in ICU admission. This synthetic narrative review summarizes the evidence for the prediction and management of acute neuromuscular respiratory failure due to GBS and MG.

DATA SOURCES

We searched PubMed for relevant literature and reviewed bibliographies of included articles for additional relevant studies.

STUDY SELECTION

English-language publications were reviewed.

DATA EXTRACTION

Data regarding study methodology, patient population, evaluation metrics, respiratory interventions, and clinical outcomes were qualitatively assessed.

DATA SYNTHESIS

No single tool has sufficient sensitivity and specificity for the prediction of acute neuromuscular respiratory failure requiring mechanical ventilation. Multimodal assessment, integrating history, examination maneuvers (single breath count, neck flexion strength, bulbar weakness, and paradoxical breathing) and pulmonary function testing are ideal for risk stratification. The Erasmus GBS Respiratory Insufficiency Score is a validated tool useful for GBS. Noninvasive ventilation can be effective in MG but may not be safe in early GBS. Airway management considerations are similar across both conditions, but dysautonomia in GBS requires specific attention. Extubation failure is common in MG, and early tracheostomy may be beneficial for MG. Prolonged ventilatory support is common, and good functional outcomes may occur even when prolonged ventilation is required.

CONCLUSIONS

Multimodal assessments integrating several bedside indicators of bulbar and respiratory muscle function can aid in evidence-based risk stratification for respiratory failure among those with neuromuscular disease. Serial evaluations may help establish a patient's trajectory and to determine timing of respiratory intervention.

Myasthenia gravis complicated with pulmonary infection by Nocardia cyriacigeorgica: a case report and literature review

Myasthenia gravis (MG) is an autoimmune disease. Patients with MG due to compromised autoimmune regulation, progressive muscle weakness, and prolonged use of immunosuppressants and glucocorticoid, often present with concomitant infections. However, cases of MG complicated by Nocardia infection are rare. In this case, we report MG complicated with pulmonary infection by Nocardia cyriacigeorgica. A 71-year-old male farmer who was admitted for management of MG. After 7 weeks of treatment of MG, the patient reported improvement. However, clinical presentation, inflammatory markers, and imaging findings supported a diagnosis of pulmonary infection. To further elucidate the etiology, Nocardia was identified in sputum smear microscopy and sputum culture, with 16S rRNA gene sequencing confirming N. cyriacigeorgica. The patient was prescribed trimethoprim-sulfamethoxazole. After 1 month of treatment, clinical symptoms of MG and pulmonary nocardiosis showed significant improvement. Additionally, we searched PubMed for case reports of Nocardia cyriacigeorgica pulmonary infection from 2010 to 2024 and conducted a statistical analysis of the case information. This report aims to highlights the increased risk of pulmonary Nocardia infection in MG patients after the use of steroids and immunosuppressants, thereby enhancing clinical awareness.

Pitfalls in the Evaluation of Respiratory Failure in Myasthenia Gravis Patients: A Case Series

Objectives

To highlight the importance of recognizing different presentations of respiratory failure due to myasthenic and non-myasthenic etiologies in myasthenia gravis (MG) patients.

Methods

We describe 3 patients with different presentations of respiratory failure in MG.

Cases

Patient 1 is a 49-year-old female with longstanding MG who presented with lethargy and neck weakness without notable respiratory distress. She was found to be in hypercarbic respiratory failure, which improved with plasmapheresis treatment. Patient 2 is a 58-year-old female who presented with ptosis, dysphagia, and dyspnea requiring intubation. Her hypophonia and dyspnea persisted despite escalation in MG treatment, and further workup revealed glottal stenosis secondary to granulomatosis with polyangiitis. Patient 3 is an 85-year-old female with MG presenting with refractory hypoxia, which was secondary to a large patent foramen ovale resulting in right-to-left shunting.

Discussion

All 3 cases emphasize the role of clinical reasoning and careful analysis based on thorough history taking, detailed neurologic exam and comprehensive laboratory findings to determine the etiologies for respiratory dysfunction in MG and provide appropriate treatment.

Conclusion

A lack of overt signs of respiratory distress in MG does not rule out the presence of respiratory failure due to the sedating effect of hypercapnia. There is a need to consider alternative etiologies of hypoxia in MG patients if typical symptoms or signs of MG exacerbations are absent.

Efgartigimod as a promising add-on therapy for myasthenic crisis: a prospective case series

Introduction

Efgartigimod is effective and well-tolerated in patients with anti-acetylcholine receptor (AChR) antibody-positive generalized myasthenia gravis (MG). However, the therapeutic potential and the safety profile of efgartigimod in myasthenic crisis (MC) remained largely unknown.

Methods

This is an observational, prospective, multicenter, real-world study to follow 2 MC patients who initiated efgartigimod as a first-line rescue therapy and 8 cases who used it as an add-on therapy. Baseline demographic features and immunotherapies were collected, and the MG-activities of daily living (MG-ADL) scale was evaluated every week since efgartigimod treatment for 8 weeks. Additionally, serum IgG and anti-AChR antibody levels and the peripheral CD4+ T lymphocytes were measured before and after one cycle of treatment.

Results

Ten patients with MC were enrolled in the study, including 9 anti-AChR antibody positive and 1 anti-muscle-specific kinase (MuSK) positive. All patients were successfully weaned from the ventilation after receiving efgartigimod treatment, with a length of 10.44 ± 4.30 days. After one cycle of infusions, the MG-ADL score reduced from 15.6 ± 4.4 at the baseline to 3.4 ± 2.2, while the corticosteroid dose was tapered from 55.0 ± 20.7 mg to 26.0 ± 14.1 mg. The proportions of regulatory T cells and naïve T cells (% in CD4+ T) significantly decreased post-efgartigimod treatment (5.48 ± 1.23 vs. 6.90 ± 1.80, P=0.0313, and 34.98 ± 6.47 vs. 43.68 ± 6.54, P=0.0313, respectively).

Conclusion

These findings validated the rapid action of efgartigimod in facilitating the weaning process with a good safety profile in patients with MC.

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

Improving Outcome in Severe Myasthenia Gravis and Guillain-Barré Syndrome

When progressive and severe, myasthenia gravis and Guillain-Barré syndrome may have the potential for fatal and unfavorable clinical outcomes. Regardless of important differences in their clinical course, the development of weakness of oropharyngeal muscles and respiratory failure with requirement of mechanical ventilation is the main driver of poor prognosis in both conditions. The need for prolonged mechanical ventilation is particularly relevant because it immobilizes the patient and care becomes extraordinarily complex due to daily risks of systemic complications. Additionally, patients with myasthenia gravis often require long-term immunosuppressive treatments with associated toxicity and infectious risks. Unlike myasthenia gravis, the recovery period is prolonged in Guillain-Barré syndrome, but often favorable, even in the more severely affected patients. Outcome, for a large part, is determined by expert neurocritical care.

Generalized myasthenia gravis with acetylcholine receptor antibodies: A guidance for treatment

BACKGROUND

Generalized myasthenia gravis (MG) with antibodies against the acetylcholine receptor is a chronic disease causing muscle weakness. Access to novel treatments warrants authoritative treatment recommendations. The Nordic countries have similar, comprehensive health systems, mandatory health registers, and extensive MG research.

METHODS

MG experts and patient representatives from the five Nordic countries formed a working group to prepare treatment guidance for MG based on a systematic literature search and consensus meetings.

RESULTS

Pyridostigmine represents the first-line symptomatic treatment, while ambenonium and beta adrenergic agonists are second-line options. Early thymectomy should be undertaken if a thymoma, and in non-thymoma patients up to the age of 50-65 years if not obtaining remission on symptomatic treatment. Most patients need immunosuppressive drug treatment. Combining corticosteroids at the lowest possible dose with azathioprine is recommended, rituximab being an alternative first-line option. Mycophenolate, methotrexate, and tacrolimus represent second-line immunosuppression. Plasma exchange and intravenous immunoglobulin are used for myasthenic crises and acute exacerbations. Novel complement inhibitors and FcRn blockers are effective and fast-acting treatments with promising safety profiles. Their use depends on local availability, refunding policies, and cost-benefit analyses. Adapted physical training is recommended. Planning of pregnancies with optimal treatment, information, and awareness of neonatal MG is necessary. Social support and adaptation of work and daily life activities are recommended.

CONCLUSIONS

Successful treatment of MG rests on timely combination of different interventions. Due to spontaneous disease fluctuations, comorbidities, and changes in life conditions, regular long-term specialized follow-up is needed. Most patients do reasonably well but there is room for further improvement. Novel treatments are promising, though subject to restricted access due to costs.

[Myasthenia gravis-Gender aspects and family planning]

BACKGROUND

There is evidence that gender-specific differences can influence the diagnostics, treatment and long-term disease course of myasthenia gravis (MG). In women the diagnosis is often made during childbearing age.

OBJECTIVE

Gender-specific differences in MG and relevant aspects in routine clinical practice are presented. In addition, current studies on family planning, pregnancy and childbirth in MG are highlighted and treatment recommendations are derived.

MATERIAL AND METHODS

Narrative literature review.

RESULTS

In addition to sociodemographic data, gender-specific differences encompass clinical as well as paraclinical factors, such as disease severity and antibody status. With few exceptions pregnancy is possible with good maternal and neonatal outcome. During pregnancy and peripartum, children of MG patients should be closely monitored for early detection and treatment of potential syndromes caused by diaplacental transfer of maternal antibodies.

CONCLUSION

Gender-specific factors can influence the course of MG. Adequate medical counselling and multidisciplinary collaboration are essential for MG patients who wish to have children.

Identifying patients at risk for myasthenic crisis with hemogram and inflammation-related laboratory parameters - a pilot study

Background

Myasthenia gravis (MG) is a rare autoimmune disease characterized by fatigable weakness of the voluntary muscles and can exacerbate to life-threatening myasthenic crisis (MC), requiring intensive care treatment. Routine laboratory parameters are a cost-effective and widely available method for estimating the clinical outcomes of several diseases, but so far, such parameters have not been established to detect disease progression in MG.

Methods

We conducted a retrospective analysis of selected laboratory parameters related to inflammation and hemogram for MG patients with MC compared to MG patients without MC. To identify potential risk factors for MC, we applied time-varying Cox regression for time to MC and, as a sensitivity analysis, generalized estimating equations logistic regression for the occurrence of MC at the next patient visit.

Results

15 of the 58 examined MG patients suffered at least one MC. There was no notable difference in the occurrence of MC by antibody status or sex. Both regression models showed that higher counts of basophils (per 0.01 unit increase: HR = 1.32, 95% CI = 1.02-1.70), neutrophils (per 1 unit increase: HR = 1.40, 95% CI = 1.14-1.72), potentially leukocytes (per 1 unit increase: HR = 1.15, 95% CI = 0.99-1.34), and platelets (per 100 units increase: HR = 1.54, 95% CI = 0.99-2.38) may indicate increased risk for a myasthenic crisis.

Conclusion

This pilot study provides proof of the concept that increased counts of basophils, neutrophils, leukocytes, and platelets may be associated with a higher risk of developing MC in patients with MG.

Clinical outcome and peripheral immune profile of myasthenic crisis with omicron infections: A prospective cohort study

The impact of Omicron infections on the clinical outcome and immune responses of myasthenia gravis (MG) remained largely unknown. From a prospective multicenter MG cohort (n = 189) with 197 myasthenic crisis (MC), we finally included 41 independent MG patients to classify into two groups: the Omicron Group (n = 13) and the Control Group (n = 28). In this matched cohort study, all-cause mortality was 7.69% (1/13) in Omicron Group and 14.29% (4/28) in Control Group. A higher proportion of elevated serum IL-6 was identified in the Omicron Group (88.89% vs 52.38%, P = 0.049). In addition, the proportions of CD3+CD8+T in lymphocytes and Tregs in CD3+CD4+ T cells were significantly elevated in the Omicron Group (both P = 0.0101). After treatment, the Omicron Group exhibited a marked improvement in MG-ADL score (P = 0.026) and MG-QoL-15 (P = 0.0357). MCs with Omicron infections were associated with elevated serum IL-6 and CD3+CD8+T response. These patients tended to present a better therapeutic response after fast-acting therapies and anti-IL-6 treatment.

Hospitalizations and Mortality From Myasthenia Gravis: Trends From 2 US National Datasets

BACKGROUND AND OBJECTIVES

Myasthenia gravis (MG) is a rare neuromuscular disorder where IgG antibodies damage the communication between nerves and muscles, leading to muscle weakness that can be severe and have a significant impact on patients' lives. MG exacerbations include myasthenic crisis with respiratory failure, the most serious manifestation of MG. Recent studies have found MG prevalence increasing, especially in older patients. This study examined trends in hospital admissions and in-hospital mortality for adult patients with MG and readmissions and postdischarge mortality in older (65 years or older) adults with MG.

METHODS

Data from the Nationwide Inpatient Sample (NIS), an all-payer national database of hospital discharges, were used to characterize trends in hospitalizations and in-hospital mortality related to MG exacerbations and MG crisis among adult patients aged 18 years or older. The Medicare Limited Data Set, a deidentified, longitudinal research database with demographic, enrollment, and claims data was used to assess hospitalizations, length of stay (LOS), readmissions, and 30-day postdischarge mortality among fee-for-service Medicare beneficiaries aged 65 years or older. The study period was 2010-2019. Multinomial logit models and Poisson regression were used to test for significance of trends.

RESULTS

Hospitalization rates for 19,715 unique adult patients and 56,822 admissions increased from 2010 to 2019 at an average annualized rate of 4.9% (MG noncrisis: 4.4%; MG crisis: 6.8%; all p < 0.001). Readmission rates were approximately 20% in each study year for both crisis and noncrisis hospitalizations; the in-hospital mortality rate averaged 1.8%. Among patients aged 65 years or older, annualized increases in hospitalizations were estimated at 5.2%, 4.2%, and 7.7% for all, noncrisis, and crisis hospitalizations, respectively (all p < 0.001). The average LOS was stable over the study period, ranging from 11.3 to 13.1 days, but was consistently longer for MG crisis admissions. Mortality among patients aged 65 years or older was higher compared with that in all patients, averaging 5.0% across each of the study years.

DISCUSSION

Increasing hospitalization rates suggest a growing burden associated with MG, especially among older adults. While readmission and mortality rates have remained stable, the increasing hospitalization rates indicate that the raw numbers of readmissions-and deaths-are also increasing. Mortality rates are considerably higher in older patients hospitalized with MG.

Case report: Recovery from refractory myasthenic crisis to minimal symptom expression after add-on treatment with efgartigimod

Myasthenic crisis, a life-threatening exacerbation of myasthenia gravis, is a significant clinical challenge, particularly when refractory to standard therapies. Here, we described a case of myasthenic crisis in which the patient transitioned from refractory myasthenic crisis to minimal symptom expression after receiving add-on treatment with efgartigimod, a novel neonatal Fc receptor antagonist. A 54 years-old woman who was diagnosed with anti-acetylcholine receptor antibody-positive myasthenia gravis experienced respiratory failure necessitating mechanical ventilation. Despite aggressive treatment with plasmapheresis, intravenous immunoglobulins, and high-dose corticosteroids, her condition continued to deteriorate, culminating in persistent myasthenic crisis. Efgartigimod was administered as salvage therapy. Remarkable improvement in neuromuscular function was observed within days, allowing for successful weaning from mechanical ventilation. Over the subsequent weeks, the patient's symptoms continued to ameliorate, ultimately reaching a state of minimal symptom expression. Serial assessments of her serum anti-acetylcholine receptor antibody titer showed a consistent decline in parallel with this clinical improvement. This case highlights efgartigimod's potential as an effective therapeutic option for refractory myasthenic crisis, offering new hope for patients facing this life-threatening condition.

Weaning and extubation failure in myasthenic crisis: a multicenter analysis

Myasthenic crisis (MC) requiring mechanical ventilation is a serious complication of myasthenia gravis (MG). Here we analyze the frequency and risk factors of weaning- and extubation failure as well as its impact on the clinical course in a large cohort. We performed a retrospective chart review on patients treated for MC in 12 German neurological departments between 2006 and 2015. Weaning failure (WF) was defined as negative spontaneous breathing trial, primary tracheostomy, or extubation failure (EF) (reintubation or death). WF occurred in 138 episodes (64.2%). Older Age (p = 0.039), multiple comorbidities (≥ 3) (p = 0.007, OR = 4.04), late-onset MG (p = 0.004, OR = 2.84), complications like atelectasis (p = 0.008, OR = 3.40), pneumonia (p < 0.0001, OR = 3.45), cardio-pulmonary resuscitation (p = 0.005, OR = 5.00) and sepsis (p = 0.02, OR = 2.57) were associated with WF. WF occurred often in patients treated with intravenous immungloblins (IVIG) (p = 0.002, OR = 2.53), whereas WF was less often under first-line therapy with plasma exchange or immunoadsorption (p = 0.07, OR = 0.57). EF was observed in 58 of 135 episodes (43.0%) after first extubation attempt and was related with prolonged mechanical ventilation, intensive care unit stay and hospital stay (p ≤ 0.0001 for all). Extubation success was most likely in a time window for extubation between day 7 and 12 after intubation (p = 0.06, OR = 2.12). We conclude that WF and EF occur very often in MC and are associated with poor outcome. Older age, multiple comorbidities and development of cardiac and pulmonary complications are associated with a higher risk of WF and EF. Our data suggest that WF occurs less frequently under first-line plasma exchange/immunoadsorption compared with first-line use of IVIG.

Depression: A Contributing Factor to the Clinical Course in Myasthenia Gravis Patients

Background and Objectives: The association between myasthenia gravis (MG) and depression is intricate and characterized by bidirectional causality. In this regard, MG can be a contributing factor to depression and, conversely, depression may worsen the symptoms of MG. This study aimed to identify any differences in the progression of the disease among patients with MG who were also diagnosed with depression as compared to those without depression. Our hypothesis focused on the theory that patients with more severe MG symptoms may have a higher likelihood of suffering depression at the same time. Materials and Methods: One hundred twenty-two male and female patients (N = 122) aged over 18 with a confirmed diagnosis of autoimmune MG who were admitted to the Neurology II department of Myasthenia Gravis, Clinical Institute Fundeni in Bucharest between January 2019 and December 2020, were included in the study. Patients were assessed at baseline and after six months. The psychiatric assessment of the patients included the Hamilton Depression Rating Scale-17 items (HAM-D), and neurological status was determined with two outcome measures: Quantitative Myasthenia Gravis (QMG) and Myasthenia Gravis Activities of Daily Life (MG-ADL). The patients were divided into two distinct groups as follows: group MG w/dep, which comprised 49 MG patients diagnosed with depressive disorder who were also currently receiving antidepressant medication, and group MG w/o dep, which consisted of 73 patients who did not have depression. Results: In our study, 40.16% of the myasthenia gravis (MG) patients exhibited a comorbid diagnosis of depression. Among the MG patients receiving antidepressant treatment, baseline assessments revealed a mean MG-ADL score of 7.73 (SD = 5.05), an average QMG score of 18.40 (SD = 8.61), and a mean Ham-D score of 21.53 (SD = 7.49). After a six-month period, a statistically significant decrease was observed in the MG-ADL (2.92, SD = 1.82), QMG (7.15, SD = 4.46), and Ham-D scores (11.16, SD = 7.49) (p < 0.0001). These results suggest a significant correlation between MG severity and elevated HAM-D depression scores. Regarding the MG treatment in the group with depression, at baseline, the mean dose of oral corticosteroids was 45.10 mg (SD = 16.60). Regarding the treatment with pyridostigmine, patients with depression and undergoing antidepressant treatment remained with an increased need for pyridostigmine, 144.49 mg (SD = 51.84), compared to those in the group without depression, 107.67 mg (SD = 55.64, p < 0.001). Conclusions: Our investigation confirms that the occurrence of depressive symptoms is significantly widespread among individuals diagnosed with MG. Disease severity, along with younger age and higher doses of cortisone, is a significant factor associated with depression in patients with MG. Substantial reductions in MG-ADL and QMG scores were observed within each group after six months, highlighting the effectiveness of MG management. The findings suggest that addressing depressive symptoms in MG patients, in addition to standard MG management, can lead to improved clinical outcomes.

Neuroinflammation and Neurodegenerative Diseases: How Much Do We Still Not Know?

The term "neuroinflammation" defines the typical inflammatory response of the brain closely related to the onset of many neurodegenerative diseases (NDs). Neuroinflammation is well known, but its mechanisms and pathways are not entirely comprehended. Some progresses have been achieved through many efforts and research. Consequently, new cellular and molecular mechanisms, diverse and conventional, are emerging. In listing some of those that will be the subject of our description and discussion, essential are the important roles of peripheral and infiltrated monocytes and clonotypic cells, alterations in the gut-brain axis, dysregulation of the apelinergic system, alterations in the endothelial glycocalyx of the endothelial component of neuronal vascular units, variations in expression of some genes and levels of the encoding molecules by the action of microRNAs (miRNAs), or other epigenetic factors and distinctive transcriptional factors, as well as the role of autophagy, ferroptosis, sex differences, and modifications in the circadian cycle. Such mechanisms can add significantly to understanding the complex etiological puzzle of neuroinflammation and ND. In addition, they could represent biomarkers and targets of ND, which is increasing in the elderly.

Identification and Management of Acute Neuromuscular Respiratory Failure in the ICU

Respiratory failure is a common and potentially life-threatening complication of neuromuscular diseases. Prompt recognition and accurate diagnosis of new or worsening chronic neuromuscular disease have important clinical management and prognostic implications. In this article, we present an approach to the acute presentation of undifferentiated neuromuscular respiratory failure in the ICU and guidance for determination and respiratory management of the underlying disorder.

Myasthenic crisis in thymoma-associated myasthenia gravis: a multicenter retrospective cohort study

Thymoma-associated myasthenia gravis (TMG) had more severe symptoms and worse prognoses in comparison to non-thymoma-associated MG. Thymoma recurrence was frequently associated with transient worsening of MG and even acute respiratory failure, namely myasthenic crisis (MC). However, little is known about the clinical features and outcomes of MC in thymoma-associated MG patients. We performed a retrospective cohort study in MG patients recruited from 9 independent tertiary neuromuscular centers in China from Jan 2015, through Oct 2022. Overall, 156 MC from 149 MG patients with positive anti-acetylcholine receptor (AChR) antibodies were finally analyzed. Next, these patients were divided into two subgroups: the TMG group (n = 60 MCs, 58 patients) and the non-thymoma-associated MG group (n = 96 MCs, 91 patients). Compared with non-thymoma-associated MG, TMG patients had a significantly shorter disease duration from symptom onset to the crisis (17.95±40.9 vs 51.31±60.61 months, P<0.0001), a larger proportion of MGFA IVa as the initial onset clinical classification (6.67% vs 0, P = 0.0205), and a longer hospital stay (39.24±22.09 [6-111] vs. 33.2 ± 23.42 days [7-120]; P = 0.0317) during the crisis. Within the TMG group, the hospital stay was significantly longer in patients with unresected thymoma compared to that in postoperative myasthenic crisis (POMC) (47.68±24.9 [6-111] vs. 34.21±18.87 days [12-82]; P = 0.0257). Early identification of the MG categories may provide some hints in tailoring therapeutic strategies to improve the prognosis.

Disease-Based Prognostication: Myasthenia Gravis

Myasthenia gravis (MG) is an acquired autoimmune neuromuscular junction transmission disorder that clinically presents as fluctuating or persistent weakness in various skeletal muscle groups. Neuroprognostication in MG begins with some basic observations on the natural history of the disease and known treatment outcomes. Our objective is to provide a framework that can assist a clinician who encounters the MG patient for the first time and attempts to prognosticate probable outcomes in individual patients. In this review article, we explore clinical type, age of onset, antibody status, severity of disease, thymus pathology, autoimmune, and other comorbidities as prognostic factors in MG.

Peripheral immune landscape for hypercytokinemia in myasthenic crisis utilizing single-cell transcriptomics

BACKGROUND

Myasthenia gravis (MG) is the most prevalent autoimmune disorder affecting the neuromuscular junction. A rapid deterioration in respiratory muscle can lead to a myasthenic crisis (MC), which represents a life-threatening condition with high mortality in MG. Multiple CD4+ T subsets and hypercytokinemia have been identified in the peripheral pro-inflammatory milieu during the crisis. However, the pathogenesis is complicated due to the many types of cells involved, leaving the underlying mechanism largely unexplored.

METHODS

We conducted single-cell transcriptomic and immune repertoire sequencing on 33,577 peripheral blood mononuclear cells (PBMCs) from two acetylcholine receptor antibody-positive (AChR +) MG patients during MC and again three months post-MC. We followed the Scanpy workflow for quality control, dimension reduction, and clustering of the single-cell data. Subsequently, we annotated high-resolution cell types utilizing transfer-learning models derived from publicly available single-cell immune datasets. RNA velocity calculations from unspliced and spliced mRNAs were applied to infer cellular state progression. We analyzed cell communication and MG-relevant cytokines and chemokines to identify potential inflammation initiators.

RESULTS

We identified a unique subset of monocytes, termed monocytes 3 (FCGR3B+ monocytes), which exhibited significant differential expression of pro-inflammatory signaling pathways during and after the crisis. In line with the activated innate immune state indicated by MC, a high neutrophil-lymphocyte ratio (NLR) was confirmed in an additional 22 AChR + MC patients in subsequent hemogram analysis and was associated with MG-relevant clinical scores. Furthermore, oligoclonal expansions were identified in age-associated B cells exhibiting high autoimmune activity, and in CD4+ and CD8+ T cells demonstrating persistent T exhaustion.

CONCLUSIONS

In summary, our integrated analysis of single-cell transcriptomics and TCR/BCR sequencing has underscored the role of innate immune activation which is associated with hypercytokinemia in MC. The identification of a specific monocyte cluster that dominates the peripheral immune profile may provide some hints into the etiology and pathology of MC. However, future functional studies are required to explore causality.

Clinical features and outcomes of patients with myasthenia gravis admitted to an intensive care unit: A 20-year retrospective study

Background

There are limited data on the clinical characteristics and outcomes of patients with myasthenia gravis (MG) admitted to the intensive care unit (ICU) at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH).

Objectives

The aim was to study the clinical characteristics and outcomes of patients with MG admitted to the CMJAH over two decades.

Methods

A retrospective study was undertaken of patients with MG admitted to the multidisciplinary ICU of CMJAH over a 20-year period, from 1998 to 2017. Demographic data, clinical features, management and outcomes of patients were assessed and reviewed from the case records.

Results

Thirty-four patients with MG were admitted to the ICU during this period: 24 female and 10 male. The mean age ± SD was 37.4 ± 13.0 years, with a range of 16 - 66 years. Four patients were human immunodeficiency virus (HIV)-positive. The mean length of stay (LOS) in ICU was 10.6 ± 20.1 days, ranging from 1 to 115 days. Two patients were diagnosed with MG in the ICU after failure to wean from the ventilator. Overall, 22 patients were intubated and ventilated on admission. Morbidities included self-extubation, aspiration pneumonia and iatrogenic pneumothorax. History of thymectomy was present in 12 patients. The treatments received for MG included pyridostigmine (73.5%), corticosteroids (55.9%), azathioprine (35.3%), plasmapheresis (26.5%) and intravenous immunoglobulin (8.8%). The overall mortality in the ICU was 5.9%.

Conclusion

MG is a serious disorder with considerable morbidity and mortality. It is, however, a potentially manageable disease, provided that appropriate ICU resources are available.

Contributions of the study

This study provides further insight into the characteristics and outcomes of myasthenia gravis patients in ICU, within a South African context.

Occurrence and severity of myasthenic crisis in an unselected Turkish cohort of patients with myasthenia gravis

Myasthenia gravis (MG) is a disorder of the neuromuscular junction that can deteriorate into myasthenic crisis, involving weakness of bulbar and respiratory muscles. In this study, we describe the clinical manifestations of myasthenic crisis, identify risk factors, and examine treatments and outcomes. All 95 patients with generalized MG treated at our center during the last 10 years were included in this retrospective study. We collected data from the patients' records, including clinical follow-ups, muscle antibodies, thymic status, and treatments. The characteristics of patients who did and did not experience myasthenic crisis were compared. Features of all myasthenic crises were also assessed. Twelve patients (13%) developed myasthenic crisis during the observation period. Men were more often affected at older ages. Seven patients experienced multiple myasthenic crises. Thymoma increased the risk of a crisis, whereas thymic hyperplasia decreased the risk. Myasthenic crises were more common in the summer months. No patients died during a myasthenic crisis. Risk factors for myasthenic crisis were thymoma, older age, MuSK antibodies, and previous crises. Individualized and active immunosuppressive treatment and optimal intensive care during crises provide a good outcome for patients with generalized MG.

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.

Greater Number of Plasma Exchanges Does Not Improve Outcome in Myasthenic Crisis

OBJECTIVES

To determine the relationship between the number of plasma exchanges and clinical outcome in patients experiencing myasthenic crisis.

METHODS

We retrospectively reviewed all episodes of myasthenia gravis exacerbation/crisis who received plasmapheresis in patients admitted to a single-center tertiary care referral center from July 2008 to July 2017. We performed statistical analyses to determine whether the increased number of plasma exchanges improves the primary outcome (hospital length of stay) and the secondary outcome (disposition to home, skilled nursing facility, long-term acute care hospital, or death).

RESULTS

There is neither clinically observable nor statistically significant improvement in length of stay or disposition on discharge in patients who received 6 or greater sessions of plasmapheresis.

CONCLUSIONS

This study provides class IV evidence that extending the number of plasma exchanges beyond 5 does not correlate with decreased hospital length of stay or improved discharge disposition in patients experiencing myasthenic crisis.

Emergency Tracheostomy Due to a Myasthenic Crisis in a Post-COVID Patient: Report of a Case

Myasthenia gravis is an autoimmune disorder caused by the production of antibodies that block either acetylcholine receptors or structural receptors of the neuromuscular junction. There is expanding evidence that novel coronavirus (2019-nCoV) disease can lead to the development of an autoimmune response. Myasthenic crisis, a life-threatening respiratory muscle weakness severe enough to necessitate intubation or tracheostomy, can be a potential complication of myasthenia gravis. In this report, we describe the case of a 57-year-old man with acute respiratory insufficiency requiring emergency tracheostomy. His health condition rapidly deteriorated 1 week after initiating systemic corticosteroid treatment for a suspected adult-onset asthma exacerbation. The patient had a history of COVID-19 infection and thymectomy, which were noted in his medical records. Serological testing and electrodiagnostic evaluation confirmed the diagnosis of myasthenia gravis. The patient was treated with plasma exchange, continuous neostigmine infusion, and prednisone. He was successfully decannulated and discharged with anticholinesterase inhibitors and long-term immunosuppression therapy. It is important to consider neurological disorders in the differential diagnosis for patients presenting with respiratory insufficiency, particularly during the COVID-19 pandemic.

Myasthenic crisis

Myasthenic crisis (MC) is a life-threatening manifestation of myasthenia gravis (MG) defined by respiratory insufficiency that requires the use of invasive or non-invasive ventilation. This is often the result of respiratory muscle weakness but can also be due to bulbar weakness with upper airway collapse. MC occurs in approximately 15%-20% of patients with MG usually within the first 2 to 3 y of the disease course. Many crises have a specific trigger with respiratory infections being most common; however, no specific trigger is found in 30%-40% of patients. MG patients with a history of MC, severe disease, oropharyngeal weakness, muscle-specific kinase (MuSK) antibodies and thymoma appear to be at higher risk. Most episodes of MC do not occur suddenly, providing a window of opportunity for prevention. Immediate treatment is directed toward airway management and removing any identified triggers. Plasmapheresis is preferred over intravenous immune globulin as the treatments of choice for MC. The majority of patients are able to be weaned from mechanical ventilation within 1 mo and the outcomes of MC are generally favorable. The mortality rate in United States cohorts is less than 5% and mortality in MC seems to be driven by age and other medical co-morbidities. MC does not appear to affect long-term prognosis as many patients are able to eventually achieve good MG control.

Outcomes of COVID-19 Infection and Vaccination Among Individuals With Myasthenia Gravis

Importance

There are limited data regarding COVID-19 outcomes and vaccine uptake and safety among people with myasthenia gravis (MG).

Objective

To investigate COVID-19-related outcomes and vaccine uptake among a population-based sample of adults with MG.

Design, Setting, and Participants

This population-based, matched cohort study in Ontario, Canada, used administrative health data from January 15, 2020, and August 31, 2021. Adults with MG were identified using a validated algorithm. Each patient was matched by age, sex, and geographic area of residence to 5 controls from the general population and from a cohort of individuals with rheumatoid arthritis (RA).

Exposure

Patients with MG and matched controls.

Main Outcomes and Measures

Main outcomes were COVID-19 infection and related hospitalizations, intensive care unit admissions, and 30-day mortality among patients with MG vs controls. Secondary outcomes were uptake of COVID-19 vaccination among patients with MG vs controls.

Results

Among 11 365 233 eligible Ontario residents, 4411 patients with MG (mean [SD] age, 67.7 [15.6] years; 2274 women [51.6%]) were matched to 22 055 general population controls (mean [SD] age, 67.7 [15.6] years; 11 370 women [51.6%]) and 22 055 controls with RA (mean [SD] age, 67.7 [15.6] years; 11 370 women [51.6%]). In the matched cohort, 38 861 of 44 110 individuals (88.1%) were urban residents; in the MG cohort, 3901 (88.4%) were urban residents. Between January 15, 2020, and May 17, 2021, 164 patients with MG (3.7%), 669 general population controls (3.0%), and 668 controls with RA (3.0%) contracted COVID-19. Compared with general population controls and controls with RA, patients with MG had higher rates of COVID-19-associated emergency department visits (36.6% [60 of 164] vs 24.4% [163 of 669] vs 29.9% [200 of 668]), hospital admissions (30.5% [50 of 164] vs 15.1% [101 of 669] vs 20.7% [138 of 668]), and 30-day mortality (14.6% [24 of 164] vs 8.5% [57 of 669] vs 9.9% [66 of 668]). By August 2021, 3540 patients with MG (80.3%) vs 17 913 general population controls (81.2%) had received 2 COVID-19 vaccine doses, and 137 (3.1%) vs 628 (2.8%), respectively had received 1 dose. Of 3461 first vaccine doses for patients with MG, fewer than 6 individuals were hospitalized for MG worsening within 30 days of vaccination. Vaccinated patients with MG had a lower risk than unvaccinated patients with MG of contracting COVID-19 (hazard ratio, 0.43; 95% CI, 0.30-0.60).

Conclusions and Relevance

This study suggests that adults with MG who contracted COVID-19 had a higher risk of hospitalization and death compared with matched controls. Vaccine uptake was high, with negligible risk of severe MG exacerbations after vaccination, as well as evidence of effectiveness. The findings support public health policies prioritizing people with MG for vaccination and new COVID-19 therapeutics.

The Role of Human Microbiota in Myasthenia Gravis: A Narrative Review

Myasthenia gravis (MG) is an autoimmune neuromuscular disease characterized by fluctuating weakness of the skeletal muscles. Although antibodies against the neuromuscular junction components are recognized, the MG pathogenesis remains unclear, even if with a well-known multifactorial character. However, the perturbations of human microbiota have been recently suggested to contribute to MG pathogenesis and clinical course. Accordingly, some products derived from commensal flora have been demonstrated to have anti-inflammatory effects, while other have been shown to possess pro-inflammatory properties. In addition, patients with MG when compared with age-matched controls showed a distinctive composition in the oral and gut microbiota, with a typical increase in Streptococcus and Bacteroides and a reduction in Clostridia as well as short-chain fatty acid reduction. Moreover, restoring the gut microbiota perturbation has been evidenced after the administration of probiotics followed by an improvement of symptoms in MG cases. To highlight the role of the oral and gut microbiota in MG pathogenesis and clinical course, here, the current evidence has been summarized and reviewed.

Short-term outcome prediction for myasthenia gravis: an explainable machine learning model

Background

Myasthenia gravis (MG) is an autoimmune disease characterized by muscle weakness and fatigability. The fluctuating nature of the disease course impedes the clinical management.

Objective

The purpose of the study was to establish and validate a machine learning (ML)-based model for predicting the short-term clinical outcome in MG patients with different antibody types.

Methods

We studied 890 MG patients who had regular follow-ups at 11 tertiary centers in China from 1 January 2015 to 31 July 2021 (653 patients for derivation and 237 for validation). The short-term outcome was the modified post-intervention status (PIS) at a 6-month visit. A two-step variable screening was used to determine the factors for model construction and 14 ML algorithms were used for model optimisation.

Results

The derivation cohort included 653 patients from Huashan hospital [age 44.24 (17.22) years, female 57.6%, generalized MG 73.5%], and the validation cohort included 237 patients from 10 independent centers [age 44.24 (17.22) years, female 55.0%, generalized MG 81.2%]. The ML model identified patients who were improved with an area under the receiver operating characteristic curve (AUC) of 0.91 [0.89-0.93], 'Unchanged' 0.89 [0.87-0.91], and 'Worse' 0.89 [0.85-0.92] in the derivation cohort, whereas identified patients who were improved with an AUC of 0.84 [0.79-0.89], 'Unchanged' 0.74 [0.67-0.82], and 'Worse' 0.79 [0.70-0.88] in the validation cohort. Both datasets presented a good calibration ability by fitting the expectation slopes. The model is finally explained by 25 simple predictors and transferred to a feasible web tool for an initial assessment.

Conclusion

The explainable, ML-based predictive model can aid in forecasting the short-term outcome for MG with good accuracy in clinical practice.

The diagnostic and prognostic utility of repetitive nerve stimulation in patients with myasthenia gravis

Repetitive nerve stimulation (RNS) is a standard test for the diagnosis of myasthenia gravis (MG), where decrement of compound muscle action potentials (CMAP) corresponds to clinical muscle fatigability. Our aim was to ascertain the diagnostic and prognostic utility of RNS in MG patients. This study included MG patients treated between 01/2000 and 12/2016, with an observational period of at least one year and a minimum of two neurological examinations. Clinical and electrophysiological data were retrospectively gathered from patient records, and CMAP decrement was correlated with autoantibody titers and clinical disease severity at different time points. Ninety-four patients were included, with 88.3% of the cohort testing positive for acetylcholine receptor autoantibodies (AChR-Abs). RNS sensitivity was higher in patients with generalized disease (71.6%) than in purely ocular MG (38.5%). CMAP decrement did not significantly correlate with AChR-Ab titers, nor with clinical symptom severity at the time of testing or last follow up. However, there was a significant correlation between CMAP decrement and the worst recorded clinical status on a group level. RNS testing is more sensitive in generalized disease and AChR-Ab positive patients, but our data do not support RNS as a tool for long-term outcome prediction. Future studies with a prospective study design could help to overcome a number of limiting factors discussed in our study.

Unexpected Myasthenic Crisis in Anesthesia for Magnetic Resonance Imaging - Diagnosis and Management

Myasthenic crisis (MC) is a rare and life-threatening manifestation of myasthenia gravis (MG) and is characterized by rapidly progressing weakness of respiratory and bulbar muscles leading to immobility, severe dyspnea, respiratory insufficiency, and possible aspiration. Early recognition and prompt treatment may prevent the development of further complications and the need for intubation, invasive mechanical ventilation, and ICU admission. Its diagnosis requires a high degree of clinical suspicion, and anesthesiologists, despite being prepared to deal with and provide anesthesia care to patients with MG, may not be immediately aware of the correct diagnosis and treatment of this medical emergency, and of the red flags that should prompt more invasive measures. Due to the very low incidence and possibly high morbidity of the condition, it is important to report cases of perioperative MC to raise awareness for early diagnosis and treatment. This case also emphasizes the importance of pre-anesthetic consultation and a multidisciplinary approach with appropriate communication and referral between medical specialties as the diagnosis of MG was not disclosed to the anesthetic team. The organizational, communication and safety gaps that occurred during the perioperative period could potentially have had a negative impact on patient outcomes. We report a case of MC in a patient who underwent general anesthesia for ambulatory magnetic resonance imaging and whose diagnosis of MG was not conveyed to the anesthesia care team.

Frequency and Correlates of Mild Cognitive Impairment in Myasthenia Gravis

BACKGROUND

Antibodies against acetylcholine receptors (AChRs) can also target nicotinic AChRs that are present throughout the central nervous system, thus leading to cognitive dysfunctions in patients with myasthenia gravis (MG). However, the presence of cognitive impairment in MG is controversial, and the factors that may influence this risk are almost completely unknown. In this study, the frequency of mild cognitive impairment (MCI) in MG, as well as the clinical, immunological, and behavioral correlates of MCI in MG were evaluated.

METHODS

A total of 52 patients with MG underwent a comprehensive assessment including motor and functional scales, serological testing, and neuropsychological and behavioral evaluation.

RESULTS

The frequency of MCI was 53.8%, and the most impaired cognitive domains were, in order, visuoconstructive/visuospatial skills, memory, and attention. After multivariate analysis, only pyridostigmine use was inversely associated with the presence of MCI, while a trend toward a positive association between MCI and disease severity and arms/legs hyposthenia was found. Correlation analyses showed that daily doses of prednisone and azathioprine significantly correlated with depressive symptomatology, while disease severity significantly correlated with depressive symptomatology and sleep disturbance.

CONCLUSIONS

The presence of MCI is rather frequent in MG and is characterized by multidomain amnestic impairment. Such preliminary data need further confirmation on larger case series.

Risk and course of COVID-19 in immunosuppressed patients with myasthenia gravis

BACKGROUND

Patients with myasthenia gravis (MG) are potentially prone for a severe COVID-19 course, but there are limited real-world data available on the risk associated with COVID-19 for patients with MG. Here, we investigate whether current immunosuppressive therapy (IST) influences the risk of SARS-CoV-2 infection and COVID-19 severity.

METHODS

Data from the German myasthenia gravis registry were analyzed from May 2020 until June 2021 and included patient demographics, MG disease duration, comorbidities, current IST use, COVID-19 characteristics, and outcomes. Propensity score matching was employed to match MG patients with IST to those without, and multivariable binary logistic regression models were used to determine associations between IST with (1) symptomatic SARS-CoV-2 infection and (2) severe COVID-19 course, as measured by hospitalization or death.

RESULTS

Of 1379 patients with MG, 95 (7%) patients (mean age 58 (standard deviation [SD] 18) presented with COVID-19, of which 76 (80%) received IST at time of infection. 32 patients (34%) were hospitalized due to COVID-19; a total of 11 patients (12%) died. IST was a risk factor for hospitalization or death in the group of COVID-19-affected MG patients (odds ratio [OR] 3.04, 95% confidence interval [CI] = 1.02-9.06, p = 0.046), but current IST was not associated with a higher risk for SARS-CoV-2 infection itself.

DISCUSSION

In this national MG cohort study, current IST use was a risk factor for a severe disease course of COVID-19 but not for SARS-CoV-2 infection itself. These data support the consequent implementation of effective strategies to prevent COVID-19 in this high-risk group.

TRIAL REGISTRATION INFORMATION

German clinical trial registry ( https://www.drks.de ), DRKS00024099, first patient enrolled: February 4th, 2019.