Myasthenic crisis patients who require intensive care unit management

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.

Detection of Antibodies against the Acetylcholine Receptor in Patients with Myasthenia Gravis: A Comparison of Two Enzyme Immunoassays and a Fixed Cell-Based Assay

The detection of serum anti-acetylcholine receptor (AChR) antibodies is currently an important tool for diagnosing myasthenia gravis (MG) since they are present in about 85% of MG patients. Many serological tests are now available. Nevertheless, results from these tests can be different in some patients. The aim of this study is to compare the sensitivity of a commercially available fixed cell-based assay (F-CBA) to that of enzyme-linked immunosorbent assay (ELISA) kits for anti-AChR detection in patients with a diagnosis of MG. Overall, 143 patients with a confirmed MG diagnosis were included in the study. The detection and measurement of serum anti-AChR antibodies were performed by three analytical methods, namely, a competitive ELISA (cELISA), an indirect ELISA (iELISA), and an F-CBA, according to the manufacturers' instructions. Anti-AChR antibody titers were positive in 94/143 (66%) using the cELISA, in 75/143 (52%) using the iELISA and in 61/143 (43%) using the F-CBA (adult and/or fetal). Method agreement, evaluated by concordant pairs and Cohen's kappa, was as follows: cELISA-iELISA: 110/143 (77%), k = 0.53 (95%CI 0.40-0.66); cELISA-F-CBA: 108/143 (76%), k = 0.53 (95%CI 0.41-0.66); iELISA-F-CBA: 121/143 (85%), k = 0.70 (95%CI 0.57-0.80). Our findings show that the cELISA has better analytical performance than the iELISA and F-CBA. However, the iELISA and F-CBA show the highest concordance.

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.

Risk Prediction Models for Early ICU Admission in Patients With Autoimmune Encephalitis: Integrating Scale-Based Assessments of the Disease Severity

Background

In patients with autoimmune encephalitis (AE), the prediction of progression to a critically ill status is challenging but essential. However, there is currently no standard prediction model that comprehensively integrates the disease severity and other clinical features. The clinical assessment scale in autoimmune encephalitis (CASE) and the modified Rankin Scale (mRS) have both been applied for evaluating the severity of AE. Here, by combining the two scales and other clinical characteristics, we aimed to investigate risk factors and construct prediction models for early critical care needs of AE patients.

Methods

Definite and probable AE patients who were admitted to the neurology department of Tongji Hospital between 2013 and 2021 were consecutively enrolled. The CASE and mRS scores were used to evaluate the overall symptom severity at the time of hospital admission. Using logistic regression analysis, we analyzed the association between the total scores of the two scales and critical illness individually and then we evaluated this association in combination with other clinical features to predict early intensive care unit (ICU) admission. Finally, we constructed four prediction models and compared their performances.

Results

Of 234 patients enrolled, forty developed critical illness and were early admitted to the ICU (within 14 days of hospitalization). Four prediction models were generated; the models were named CASE, CASE-plus (CASE + prodromal symptoms + elevated fasting blood glucose + elevated cerebrospinal fluid (CSF) white blood cell (WBC) count), mRS and mRS-plus (mRS + prodromal symptoms + abnormal EEG results + elevated fasting blood glucose + elevated CSF WBC count) and had areas under the ROC curve of 0.850, 0.897, 0.695 and 0.833, respectively. All four models had good calibrations. In general, the models containing “CASE” performed better than those including “mRS”, and the CASE-plus model demonstrated the best performance.

Conclusion

Overall, the symptom severity at hospital admission, as defined by CASE or mRS, could predict early ICU admission, especially when assessed by CASE. Adding other clinical findings, such as prodromal symptoms, an increased fasting blood glucose level and an increased CSF WBC count, could improve the predictive efficacy.

Myasthenia gravis-treatment and severity in nationwide cohort

INTRODUCTION

Myasthenia gravis (MG) is a rare autoimmune disorder of neuromuscular junction. MG healthcare burden has not been studied in Poland before.

METHODS

Data were drawn from the National Health Fund database; MG patient was defined as a person who received at least once medical service with ICD-10 code MG (G70) and at least two reimbursed prescriptions for pyridostigmine bromide or ambenonium chloride in two consecutive years. We have analyzed treatment: immunosuppression, intravenous immunoglobulins (IVIg), plasma exchange (PE), the number and length of hospitalizations (LOS), intensive care unit (ICU) care, and deaths between 2013 and 2018.

RESULTS

In 2018, there were 9012 MG patients (F:M 1.62:1), and 30.6% had early -onset MG (<50 years). 66.3% received symptomatic treatment only, 33.7%-glucocorticoids (CS) and/or other immunosuppressants (IS), 64.6%-CS only, 17.5%-azathioprine plus CS, 11%-azathioprine only, 4.6%-CS plus other IS (methotrexate, mycophenolate mofetil, cyclosporine, or tacrolimus), and 2%-other IS only. In 2018, 42.3% of patients were hospitalized at least once (mean 2.05/year), 13.7% due to MG (1.47/year). In 2018, 1.63% patients received PE, 2.33% IVIg. In 2013-2018, 2.7%-3.2% of MG patients required hospitalization in ICU. ICU mean LOS 2013-2018 was 11.5-15.0 days/per patient/year. 2.1% of all MG patients had myasthenic crisis. Mean age at death was 75.7 years for MG and 73.9 for general population (p = .006). All-cause mortality was higher for men (4.1%-5.1%) than for women (2.5%-3.1%), p < .01.

CONCLUSIONS

Our findings confirm significant healthcare burden of MG, comprising a tool to plan resources needed for MG patients.

Utilization of Decision Tree Algorithms for Supporting the Prediction of Intensive Care Unit Admission of Myasthenia Gravis: A Machine Learning-Based Approach

Myasthenia gravis (MG), an acquired autoimmune-related neuromuscular disorder that causes muscle weakness, presents with varying severity, including myasthenic crisis (MC). Although MC can cause significant morbidity and mortality, specialized neuro-intensive care can produce a good long-term prognosis. Considering the outcomes of MG during hospitalization, it is critical to conduct risk assessments to predict the need for intensive care. Evidence and valid tools for the screening of critical patients with MG are lacking. We used three machine learning-based decision tree algorithms, including a classification and regression tree, C4.5, and C5.0, for predicting intensive care unit (ICU) admission of patients with MG. We included 228 MG patients admitted between 2015 and 2018. Among them, 88.2% were anti-acetylcholine receptors antibody positive and 4.7% were anti-muscle-specific kinase antibody positive. Twenty clinical variables were used as predictive variables. The C5.0 decision tree outperformed the other two decision tree and logistic regression models. The decision rules constructed by the best C5.0 model showed that the Myasthenia Gravis Foundation of America clinical classification at admission, thymoma history, azathioprine treatment history, disease duration, sex, and onset age were significant risk factors for the development of decision rules for ICU admission prediction. The developed machine learning-based decision tree can be a supportive tool for alerting clinicians regarding patients with MG who require intensive care, thereby improving the quality of care.

Patients With Myasthenia Gravis With Acute Onset of Dyspnea: Predictors of Progression to Myasthenic Crisis and Prognosis

Background: Life-threatening myasthenic crisis (MC) occurs in 10–20% of the patients with myasthenia gravis (MG). It is important to identify the predictors of progression to MC and prognosis in the patients with MG with acute exacerbations.

Objective: This study aimed to explore the predictors of progression to MC in the patients with MG with acute onset of dyspnea and their short-term and long-term prognosis.

Methods: This study is a retrospective cohort study. We collected and analyzed data on all the patients with MG with acute dyspnea over a 10-year period in a single center using the univariate and multivariate analysis.

Results: Eighty-six patients with MG were included. In their first acute dyspnea episodes, 36 (41.9%) episodes eventually progressed to MC. A multivariate analysis showed that the early-onset MG (adjusted OR: 3.079, 95% CI 1.052–9.012) and respiratory infection as a trigger (adjusted OR: 3.926, 95% CI 1.141–13.510) were independent risk factors for the progression to MC, while intravenous immunoglobulin (IVIg) treatment prior to the mechanical ventilation (adjusted OR: 0.253, 95% CI 0.087–0.732) was a protective factor. The prognosis did not significantly differ between the patients with and without MC during the MG course, with a total of 45 (52.3%) patients reaching post-intervention status better than minimal manifestations at the last follow-up.

Conclusion: When treating the patients with MG with acute dyspnea, the clinicians should be aware of the risk factors of progression to MC, such as early-onset MG and respiratory infection. IVIg is an effective treatment. With proper immunosuppressive therapy, this group of patients had an overall good long-term prognosis.

Predictors of outcome in patients with myasthenic crisis undergoing non-invasive mechanical ventilation: A retrospective 20 year longitudinal cohort study from a single Italian center

About 20% of patients with myasthenia gravis (MG) may develop myasthenic crisis (MC) requiring ventilation, either invasive (MV) or non-invasive (NIV) and intensive unit care (ICU). NIV failure in patients with MC can occur up to 60% of cases admitted to ICU. Moreover it is not known the outcome of MC receiving NIV. Purpose of this study was to identify predictors of outcome in MC who underwent non-invasive ventilator support outside ICU setting. We enrolled 90 patients, 53 females and 37 males admitted to University Hospital of Modena (Italy) between January 2000 and September 2020. Median age at MC was 65 years. Thirty-four patients (37.8%) required MV. Thymectomy was performed in 45 cases, associated with thymoma in 55%, with hyperplastic thymus in 33%. First-line treatment was plasmaexchange (38.8%) or intravenous immunoglobulins (45.6%). Males exhibited higher risk of MV than females .Patients in MV were treated with plasmaexchange as first-line therapy . Our in-hospital mortality rate was low. Nine patients underwent tracheostomy which was significantly related to male gender. Comorbidities had significant effect on length of ICU .Our study confirms as predictors of prognosis in our patients male gender, older age at onset, infections as trigger, pneumonia.

Feasibility study of respiratory function home monitoring for patients with Myasthenia Gravis

BACKGROUND

Myasthenia gravis (MG) is a rare and chronic autoimmune neuromuscular disease that causes weakness among skeletal muscles responsible for mobility and breathing. Individuals with MG who have difficulty breathing may need to schedule an emergent provider visit where a negative inspiratory force (NIF) measurement test is performed to measure respiratory strength.

PURPOSE

Examine the feasibility of individuals with MG to perform NIF respiratory function monitoring in the home setting and determine its impact on their perceived quality of life.

METHODS

This is a quantitative one-group pretest-posttest study of 30 individuals (18-75 years old) who carry the diagnosis of MG and have been stable with treatment for at least 30 days. Participants completed the Brunnsviken Brief Quality of Life Scale (BBQ-LS) and the System Usability Scale (SUS) prestudy. Participants were required to independently perform and record their NIF measurements twice daily for 14 days. After completing the 14 days, participants completed the BBQ-LS, SUS, and an end-of-study survey.

RESULTS

There was a significant difference in BBQ-LS scores at baseline (M = 62.97, SD = 17.84) and poststudy (M = 98.2, SD = 13.63) (t[29] = -5.39, p <.000). System Usability Scale scores were significantly different at baseline (M = 77.25, SD = 11.05) than at study completion (M = 94.42, SD = 5.64) (t[29], = -8.04, p = .000).

CONCLUSION

Study results indicate that it is feasible for individuals with MG to perform NIF readings in the home setting and demonstrated an increase in the perceived quality of life.

IMPLICATIONS

Future large-scale studies can help determine the adoption of handheld NIF monitoring at home for individuals with MG.

Myasthenia gravis at the crossroad of COVID-19: focus on immunological and respiratory interplay

Coronavirus disease 2019 (COVID-19), a disease caused by the novel betacoronavirus (SARS-CoV-2) has become a global pandemic threat. COVID-19 caused by SARS-CoV-2 is reported to originate in December 2019 in Wuhan, China and spreading rapidly around world. SARS-CoV-2 is structurally similar to the other coronaviruses, causing the severe respiratory syndrome (SARS-CoV) and the middle east respiratory syndrome (MERS-CoV), both binding to the angiotensin-converting enzyme 2 (ACE2) receptor to enter human cells. ACE 2 is widely expressed in several cells including, neural tissue. COVID-19 presents with fever and respiratory symptoms, possibly leading to acute respiratory distress (ARDS) but there are several published reports of acute cerebrovascular diseases, seizures, olfactory and gustatory dysfunctions, isolated involvement of cranial nerves, myositis/rabdhomyolisis as well myasthenic crisis (MC) and Guillain–Barré syndrome (GBS). The ARDS described during COVID-19 pandemic, coupled with respiratory muscle failure occurring in myasthenia gravis (MG), may result in a life-threatening condition, challenging for intensivists, pulmonologists and neurologists. Infections are recognized trigger of exacerbations and crisis in MG and patients with MG probably exhibit a mortality higher than the general population during this COVID-19 pandemic. We review the current state of knowledge on MG during the COVID-19 pandemic to focus the immunological and respiratory interplay between these two conditions.

Myasthenic crisis treated in a Chinese neurological intensive care unit: clinical features, mortality, outcomes, and predictors of survival

BACKGROUND

Myasthenic crisis (MC) often requires admission to an intensive care unit (ICU).

METHODS

We retrospectively investigated 113 consecutive patients with first MC admitted to the neurological ICU. Patients' demographic, clinical and other characteristics were examined, as well as therapeutic interventions, mortality and functional outcome.

RESULTS

MC patients at first onset admitted to neurological ICU had a mortality rate of 18.6%. PCO₂ level before intubation and score on Myasthenia Gravis-Activities of Daily Living (MG-ADL) scale at MC onset correlated with duration of ventilation and length of ICU stay. Compared with patients with good functional outcome, patients with intermediate or poor functional outcome were older at first MC onset, had lower pH and PO₂, and had higher PCO₂ before intubation. Multivariate logistic analysis identified pre-intubation PCO₂ level as an independent predictor of survival. Cox regression showed that age at first MC onset requiring ICU management was the factor which significantly influenced the mortality.

CONCLUSIONS

Our results suggest that PCO₂ before intubation and MG-ADL score at MC onset may be useful indicators of more severe disease likely to require extensive respiratory support and ICU management. Higher pre-intubation PCO₂ indicates chronic respiratory acidosis that can increase risk of severe disability and death, especially in patients with older age at first MC onset.

Neuromuscular complications of immune checkpoint inhibitor therapy

Immune checkpoint inhibitor (ICPI) therapy unleashes the body's natural immune system to fight cancer. ICPIs improve overall cancer survival, however, the unbridling of the immune system may induce a variety of immune-related adverse events. Neuromuscular immune complications are rare but they can be severe. Myasthenia gravis and inflammatory neuropathy are the most common neuromuscular adverse events but a variety of others including inflammatory myopathy are reported. The pathophysiologic mechanism of these autoimmune disorders may differ from that of non-ICPI-related immune diseases. Accordingly, while the optimal treatment for ICPI-related neuromuscular disorders generally follows a traditional paradigm, there are important novel considerations in selecting appropriate immunosuppressive therapy. This review presents 2 new cases, a summary of neuromuscular ICPI complications, and an approach to the diagnosis and treatment of these disorders. Muscle Nerve, 2018.

Myasthenia Gravis and Crisis: Evaluation and Management in the Emergency Department

BACKGROUND

Myasthenia gravis (MG) is an uncommon autoimmune disorder affecting the neuromuscular junction and manifesting as muscle weakness. A multitude of stressors can exacerbate MG. When symptoms are exacerbated, muscle weakness can be severe enough to result in respiratory failure, a condition known as myasthenic crisis (MC).

OBJECTIVE

This review discusses risk factors, diagnosis, management, and iatrogenic avoidance of MC.

DISCUSSION

MC can affect any age, ethnicity, or sex and can be precipitated with any stressor, infection being the most common. MC is a clinical diagnosis defined by respiratory failure caused by exacerbation of MG. Muscle weakness can involve any voluntary muscle. MC can be differentiated from other neuromuscular junction diseases by the presence of normal reflexes, normal sensation, lack of autonomic symptoms, lack of fasciculations, and worsening weakness with repetitive motion. Treatment should target the inciting event and airway support. All acetylcholinesterase inhibitors should be avoided in crisis, including edrophonium testing and corticosteroids initially. Respiratory support can begin with noninvasive positive-pressure ventilation, as this has been successful even in patients with bulbar weakness. If intubation is necessary, consider avoiding paralytics or use a reduced dose of nondepolarizing agents.

CONCLUSIONS

MC should be in the differential of any patient with muscular weakness and respiratory compromise. Emergency department management of MC should focus on ruling out infection and respiratory support. Strong consideration should be given to beginning with noninvasive positive-pressure ventilation for ventilatory support. Corticosteroids, depolarizing paralytics, and acetylcholinesterase inhibitors should be avoided in patients with MC in the emergency department.