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

Therapeutic Plasma Exchange in AChR-Ab Positive Generalized Myasthenia Gravis: A Real World Study About Its Early Response

Background

Since there is no clear priority or selection principle in the guidelines for myasthenia crisis, therapeutic plasma exchange (TPE) and intravenous immunoglobulin are often administered randomly. However, it should be more prudent in taking TPE due to its higher cost and risk. Studying its early response factors is crucial for managing myasthenia crisis and can improve medical and economic benefits.

Methods

A prospective observational study was conducted, and patients classified as having "impending myasthenia crisis" or experiencing a myasthenia crisis and treated by TPE were included. The primary endpoint was the response after TPE. Univariate logistic regression analysis and repeated measurement were performed to analyze factors related to TPE efficacy.

Results

A total of 30 patients who treated with TPE as their fast-acting treatments were enrolled. After TPE, those whose QMGs and/or MGCs decreased by ≥5 points or ≥30% of the baseline were judged as "response group", accounting for 66.67% (20/30). Respiratory symptoms had a response rate of 72.00% (18/25), showing the most remarkable improvement. Meanwhile, extraocular symptoms were the least sensitive, with only 8.00% (2/25) showing efficacy. Thymoma (100.00% vs 50.00%, P=0.002) and a high concentration of AChR-Ab (37.37 nmol/L vs 25.4 nmol/L, P=0.039) were common in the early response group. Repeated measures showed significant changes in AChR-Ab and CD19+ B cells before and after TPE (all with P < 0.05). After treatment, the CD19+ B cells tended to decrease in the response group.

Discussion

These results indicated that, for AChR-Ab positive generalized MG, TPE can quickly improve respiratory symptoms. Thymoma and a high concentration of AChR-Ab before TPE predict an early better response. Additionally, TPE may work by decreasing AChR-Ab levels and inducing immune regulation. Future prospective and randomized controlled studies are needed.

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.

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.

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.

Nomogram for the acute exacerbation of acetylcholine receptor antibody-positive generalized myasthenia gravis

BACKGROUND AND OBJECTIVE

An acute exacerbation of myasthenia gravis (MG) can lead to the life-threatening myasthenia crisis which can increase the in-hospital mortality. This study aimed to clarify the correlative factor of the severity and activity of MG and the predictors of its exacerbation.

METHODS

A prospective study was conducted to compare the clinical characteristics of acetylcholine receptor antibody (AChR-Ab)-positive generalized MG during acute exacerbation (AE) and in a stable state (SS). Logistic regression was used to determine risk factors, and a nomogram was developed.

RESULTS

A total of 97 AChR-Ab MG patients were enrolled, of whom 44 had AE and 53 were in SS. The concentrations of AChR-Ab were 35.24 (23.26, 42.52) nmol/L and 19.51 (8.30, 36.93) nmol/L in the AE and SS groups (P = 0.005), respectively. The receiver operating characteristic curve showed that a single AChR-Ab predicted severity and acute exacerbation, with an area under the curve (AUC) of 0.679. Logistic regression analysis showed that, in addition to AChR-Ab (P = 0.018), bulbar symptoms (P = 0.001), interleukin (IL)-6 (P = 0.025), CD4⁺/CD8⁺ T cell ratio (P = 0.031), and CD19⁺ B cell proportion (P = 0.019) were independent risk factors for acute exacerbation of MG. The developed nomogram had an AUC of 0.878. The Hosmer and Lemeshow chi-square test was 4.37 (P = 0.929).

CONCLUSION

AChR-Ab concentration was positively correlated with the severity and activity of MG. AChR-Ab concentration, alongside bulbar symptoms, IL-6 concentration, CD4⁺/CD8⁺ T cell ratio, and CD19⁺ B cell proportion can predict the acute exacerbation of MG.

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.

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.

Hemogram parameters can predict in-hospital mortality of patients with Myasthenic crisis

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disease involving the neuromuscular junction. Myasthenic crisis (MC), which is characterized by respiratory failure and the requirement of mechanical ventilation in patients with MG, is still a medical emergency despite the decrease in mortality with the advances in acute management. Hemogram is a cost-effective test for evaluating hematological complications and systemic inflammation, and hemogram data have been used to predict various clinical outcomes of several diseases. The relationship between hemogram and MG has been discussed, but the role of hemogram data in predicting the prognosis of MC patients has not been established.

METHODS

To identify whether hemogram data can predict in-hospital mortality in patients with MC, we retrospectively investigated 188 myasthenic crisis events from the Chang Gung Research Database between April 2001 and March 2019. Demographic and clinical characteristics were collected, as well as hemogram data before intubation and extubation. The endpoints were mortality during mechanical ventilation and mortality after extubation.

RESULTS

The overall in-hospital mortality rate was 22%. Multivariate logistic regression analysis for predicting mortality during mechanical ventilation showed that old age at MC onset (OR = 1.039, p = 0.022), moderate-to-severe anemia (OR = 5.851, p = 0.001), and extreme leukocytosis (OR = 5.659, p = 0.022) before intubation were strong predictors of mortality, while acute management with plasma exchange or double-filtration plasmapheresis (PE/DFPP) significantly decreased mortality (OR = 0.236, p = 0.012). For predicting mortality after extubation, moderate-to-severe anemia before extubation (OR = 8.452, p = 0.017) and non-treated with disease-modifying therapy before MC (OR = 5.459, p = 0.031) were crucial predictive factors.

CONCLUSION

This study demonstrated that both old age at MC onset and moderate-to-severe anemia are important predictors of in-hospital mortality in patients with MC, and extreme leukocytosis is another crucial predictor of mortality during mechanical ventilation. The suggested mechanism is that anemia-induced hypoxia may enhance the release of proinflammatory cytokines, exacerbate systemic inflammation, and lead to multiple organ dysfunction syndrome and, finally, mortality.

Neuromuscular Disorders in the Intensive Care Unit

PURPOSE OF REVIEW

This article discusses the pathophysiology, presentation, diagnosis, treatment, and prognosis of common neuromuscular disorders seen in the intensive care unit, including Guillain-Barré syndrome, myasthenia gravis, and intensive care unit-acquired weakness.

RECENT FINDINGS

Guillain-Barré syndrome can have an excellent prognosis if patients are diagnosed early, appropriately treated, and monitored for complications, including respiratory failure and dysautonomia. Intensive care unit-acquired weakness increases overall mortality in patients who are critically ill, and distinguishing between critical illness myopathy and critical illness polyneuropathy may have important prognostic implications.

SUMMARY

Neuromuscular disorders are not rare in the intensive care unit setting, and precise identification and treatment of these conditions can greatly impact long-term outcomes.