Myasthenia

INTRODUCTION: In this study we sought to clarify the effects of early fast-acting treatment (EFT) strategies on the time course for achieving the treatment target in generalized myasthenia gravis (MG). METHODS: This retrospective study of 923 consecutive MG patients analyzed 688 generalized MG patients who had received immunotherapy during the disease course. The time to first achieve minimal manifestations (MM) or better while receiving prednisolone at ≤5 mg/day for ≥6 months (MM-or-better-5mg) up to 120 months after starting immunotherapy was compared between EFT and non-EFT patients...

BACKGROUND: Myasthenic crisis is a rare, yet serious condition that carries a 3%-8% mortality rate. Although infection is a common cause of decompensation in myasthenia gravis, several antibiotics classes have also been associated with an exacerbation. Selecting antibiotics can be a daunting clinical task and, if chosen inappropriately, can carry significant deleterious consequences. Not only do clinicians have to focus on treating the underlying infection appropriately, but avoiding antibiotics that may potentiate a myasthenic crisis is also vital...

PURPOSE OF REVIEW: Myasthenic disorders are a well characterized group of diseases of the neuromuscular junction. Their pathogenesis is diverse, including genetic and autoimmune mechanisms. We review recent findings on risk factors, pathogenesis and treatment of autoimmune myasthenia gravis. RECENT FINDINGS: Better knowledge of congenital myasthenia has led to the development of efficient diagnostic algorithms that have therapeutic implications. New epidemiological and genetic risk factors have been identified and are considered to play a role in the development of myasthenia gravis...

INTRODUCTION: Complement activation at the neuromuscular junction is a primary cause of acetylcholine receptor loss and failure of neuromuscular transmission in myasthenia gravis (MG). Eculizumab, a humanized monoclonal antibody, blocks the formation of terminal complement complex by specifically preventing the enzymatic cleavage of complement 5 (C5). METHODS: This study was a randomized, double-blind, placebo-controlled, crossover trial involving 14 patients with severe, refractory generalized MG (gMG)...

Myasthenia gravis (MG) is usually caused by antibodies against the muscle acetylcholine receptor (AChR). Plasmapheresis and immunoadsorption are often used to treat non-responsive patients. Antigen-specific immunoadsorption would remove only the pathogenic autoantibodies reducing side-effects. We expressed AChR extracellular domain mutants for use as specific adsorbents, and characterized them. Antigenicity and capacity for autoantibody binding were improved compared to the wild-type proteins. Adsorption appeared to be fast, as high plasma flow-rates could be applied...

Myasthenia gravis is an autoimmune disorder of the neuromuscular junction caused by circulating antibodies specific for the post-synaptic acetylcholine receptor or, in a minority of cases, for the muscle-specific tyrosine-kinase and the low-density lipoprotein receptor-related protein 4. A wide range of symptomatic and immunosuppressive treatments is currently available for MG patients with variable outcome. However, most immunosuppressive treatments are characterized by delayed onset of action and in some cases are not sufficient to induce stable remission of the disease...

We report the case of a 44-year-old woman with Masaoka stage IV, World Health Organization type B1 thymoma associated with pure red cell aplasia, thrombocytopenia, and myasthenia gravis, which occurred during preoperative chemotherapy with high-dose methylprednisolone. Noninvasive positive-pressure ventilation, intravenous immunoglobulin infusion, and methylprednisolone pulse therapy were performed for the myasthenic crisis. Disseminated thymoma was markedly reduced after these treatments, and macroscopic complete resection was performed after achieving control of pure red cell aplasia, myasthenia gravis, and thrombocytopenia using cyclosporine A...

Myasthenia gravis is characterized by muscle weakness and abnormal fatigability. It is an autoimmune disease caused by the presence of antibodies against components of the muscle membrane localized at the neuromuscular junction. In most cases, the autoantibodies are against the acetylcholine receptor (AChR). Recently, other targets have been described such as the MuSK protein (muscle-specific kinase) or the LRP4 (lipoprotein related protein 4). Myasthenia gravis can be classified according to the profile of the autoantibodies, the location of the affected muscles (ocular versus generalized), the age of onset of symptoms and thymic abnormalities...

Myasthenia gravis (MG) is the most common disorder of the neuromuscular junction (NMJ), with an estimated prevalence between 25 and 142 per million. It characteristically presents with fatigable weakness, often initially involving the ocular muscles and manifesting as intermittent ptosis and diplopia. Ultimately, the disease generalizes in two-thirds of patients, leading to weakness of bulbar, neck, limb, and respiratory muscles. The majority of patients with generalized MG, and roughly half of patients with purely ocular disease, harbor antibodies to skeletal muscle nicotinic acetylcholine receptors...

Myasthenia gravis (MG) is the most common autoimmune disease affecting neuromuscular junction transmission. MG is characterized by muscle weakness that worsens with activity and fluctuates over the course of the day. Involvement of respiratory musculature can lead to life-threatening crisis requiring intensive care unit care. Antibody testing is positive in most patients with MG. Treatment of MG includes short-term symptomatic treatment, chronic immunosuppression, surgical intervention, and immunomodulatory therapies for severe disease or crisis...

We define late-onset myasthenia gravis (LOMG) when symptoms appear at ≥65 years of age. There has been a continuous increase in the incidence of LOMG with a clear male predominance. Commonly, patients present with focal (ocular or bulbar) weakness. A high index of suspicion required to achieve early diagnosis and to improve prognosis. Management options include acetylcholinesterase inhibitors, steroids, and immunosuppressants. The most controversial issue in treatment is thymectomy, because not enough data are available...

Intravenous immunoglobulin (IVIg) treatment for acute exacerbations of Myasthenia Gravis (MG) was shown in several open-label studies. There are only two studies demonstrating the efficiency of regular intermittent IVIg therapy on MG patients who are not in their acute attack periods. Thirteen patients who had displayed an inadequate clinical response to immunosuppressive treatments, or who were not appropriate for immunosuppressive treatment due to the age factor and thus were given regular IVIg therapy, were retrospectively investigated...

BACKGROUND: Anti-muscle specific kinase antibody positive myasthenia gravis (MuSK MG) is often characterized by a relatively severe and progressive course, refractoriness to standard myasthenia gravis (MG) medications, and an increased risk of myasthenic crisis. We report here successful management of three MuSK MG patients using maintenance therapeutic plasma exchange (TPE) treatment for up to 4.5 years. MATERIALS: The study was a 5-year retrospective review of all MG patients treated with TPE between 2008 and 2013 at University of Michigan...

Tirasemtiv is a fast skeletal troponin activator that sensitizes the sarcomere to calcium and increases muscle force following subtetanic nerve input. In an animal model of myasthenia gravis (MG), single oral doses of tirasemtiv improved muscle force and reduced fatigability. The purpose of this study was to determine the effect of single doses of tirasemtiv on skeletal muscle function and fatigability in patients with generalized MG. Thirty-two patients with acetylcholine receptor-antibody positive MG and muscle weakness received single doses of tirasemtiv (250 mg or 500 mg) or placebo in a double-blind, randomized treatment sequence with each treatment separated by at least 1 week...

INTRODUCTION: In cases of exacerbation or crisis, myasthenia gravis (MG) patients can be treated with intravenous immunoglobulin (IVIg), plasmapheresis, or immunoadsorption. However, IVIg efficacy data in maintenance treatment are sparse. METHODS: We prospectively observed 16 index patients with chronic and insufficiently controlled MG under standard immunosuppressant therapy and symptomatic treatment. The IVIg treatment response was measured using changes in quantitative myasthenia gravis (QMG) score and surrogates...

Disorders affecting the presynaptic, synaptic, and postsynaptic portions of the neuromuscular junction arise from various mechanisms in children and adults, including acquired autoimmune or toxic processes as well as genetic mutations. Disorders include autoimmune myasthenia gravis associated with acetylcholine receptor, muscle specific kinase or Lrp4 antibodies, Lambert-Eaton myasthenic syndrome, nerve terminal hyperexcitability syndromes, Guillain Barré syndrome, botulism, organophosphate poisoning and a number of congenital myasthenic syndromes...

INTRODUCTION: Myasthenia gravis (MG) can be refractory to conventional immunotherapy. We report on the efficacy and durability of intravenous (IV) remission-induction cyclophosphamide (CYC) followed by oral immunosuppression in refractory MG. METHODS: We identified 8 patients from our medical records with moderate or severe refractory MG who were treated with 6 cycles of IV CYC (0.75 g/m(2) ) every 4 weeks followed by oral immunosuppression. RESULTS: Six patients improved within 3 months of treatment...

The association of dermatomyositis with myasthenia gravis (MG) is uncommon, having been reported so far in only 26 cases. We report the case of a 69 year-old man diagnosed with MG two years ago and currently treated with piridostigmyne. The patient developed acute proximal weakness, shoulder pain and elevated creatine-kinase (CK). He also developed generalized facial erythema and Gottron's papules. Laboratory tests showed positive antinuclear and anti-Mi2 antibodies. Further analysis confirmed CK levels above 1000 U/l...

Many performance-enhancing supplements and/or drugs are increasing in popularity among professional and amateur athletes alike. Although the uncontrolled use of these agents can pose health risks in the general population, their clearly demonstrated benefits could prove helpful to the critically ill population in whom preservation and restoration of lean body mass and neuromuscular function are crucial. Post-intensive care unit weakness not only impairs post-intensive care unit quality of life but also correlates with intensive care unit mortality...

Intravenous immunoglobulin (IVIG) is increasingly recommended for many diseases apart from primary immunodeficiency diseases (PID). Although effective and safe, adverse reactions may occur. We conducted a 2-year prospective observational study in 117 patients with PID who received regular IVIG replacement therapy at a median dose of 600 mg/kg every 3 to 4 weeks to examine IVIG's adverse effects; 1765 infusions were performed (mean=15/patient) in 75 males and 42 females (aged 3 months to 77 years) in 3 groups: ≤ 9 years (34...