Objective: To develop formal consensus-based guidance for the management of myasthenia gravis (MG). Methods: In October 2013, the Myasthenia Gravis Foundation of America appointed a Task Force to develop treatment guidance for MG, and a panel of 15 international experts was convened. The RAND/UCLA appropriateness methodology was used to develop consensus guidance statements. Definitions were developed for goals of treatment, minimal manifestations, remission, ocular MG, impending crisis, crisis, and refractory MG. An in-person panel meeting then determined 7 treatment topics to be addressed. Initial guidance statements were developed from literature summaries. Three rounds of anonymous e-mail votes were used to attain consensus on guidance statements modified on the basis of panel input. Results: Guidance statements were developed for symptomatic and immunosuppressive treatments, IV immunoglobulin and plasma exchange, management of impending and manifest myasthenic crisis, thymectomy, juvenile MG, MG associated with antibodies to muscle-specific tyrosine kinase, and MG in pregnancy. Conclusion: This is an international formal consensus of MG experts intended to be a guide for clinicians caring for patients with MG worldwide.
Serum antibodies to muscle-specific receptor tyrosine kinase were detected in 12 of 32 patients with generalized seronegative MG. All were women, with onset between ages 21 and 59 years. Seven had prominent neck, shoulder, or respiratory muscle weakness and little or delayed ocular muscle involvement. The response to cholinesterase inhibitors was variable, and electromyographic findings suggested myopathy in several. None improved after thymectomy. All patients improved after plasma exchange, and most had a good response to selected immunotherapy. MuSK antibody status should help diagnose MG with atypical presentations and ensure appropriate patient treatment.
Background: This prospective, randomized, double-blind, placebo-controlled, phase III trial assessed the efficacy, safety, and tolerability of mycophenolate mofetil (MMF) as a steroid-sparing agent in patients with myasthenia gravis (MG).
Immunosuppression is the mainstay of treatment for myasthenia gravis (MG). In this paper, we review the mechanisms of action and clinical application of corticosteroids and different classes of immunosuppressive drugs that are currently used in MG patients, and present the results of their use in more than 1000 patients with MG seen at our two centers. Immunosuppressive treatment was considered along with, or as an alternative to thymectomy in MG patients with disabling weakness, not adequately controlled with anticholinesterase drugs. Overall, 82% of our patients received immunosuppressants for at least 1 year, with frequencies varying according to disease severity, from 93-95% of those with thymoma or MuSK antibodies to 72% in ocular myasthenia. Prednisone was used in the great majority of patients, azathioprine was the first-choice immunosuppressant; mycophenolate mofetil and cyclosporine were used as second-choice agents. All clinical forms of MG benefited from immunosuppression: the rate of remission or minimal manifestations ranged from 85% in ocular myasthenia to 47% in thymoma-associated disease. Treatment was ultimately withdrawn in nearly 20% of anti-AChR positive early-onset patients, but in only 7% of thymoma cases. The risk of complications appears to depend on drug dosage, treatment duration, and patient characteristics, the highest rate of serious side effects (20%) having been found in late-onset MG and the lowest (4%) in early-onset disease. Although nonspecific, current immunosuppressive treatment is highly effective in most MG patients. Lack of randomized evidence, the need for prolonged administration, and unwanted effects are still relevant limitations to its use.
This document is the consensus of international experts on the current status of Single Fiber EMG (SFEMG) and the measurement of neuromuscular jitter with concentric needle electrodes (CNE - CN-jitter). The panel of authors was chosen based on their particular interests and previous publications within a specific area of SFEMG or CN-jitter. Each member of the panel was asked to submit a section on their particular area of interest and these submissions were circulated among the panel members for edits and comments. This process continued until a consensus was reached. Donald Sanders and Erik Stålberg then edited the final document.