Clinical effect of different immunosuppressive treatment regimens in children with ocular myasthenia gravis: a retrospective analysis / 中国当代儿科杂志

OBJECTIVES@#To investigate the clinical effect of different immunosuppressive treatment regimens in children with ocular myasthenia gravis (OMG).@*METHODS@#A retrospective analysis was conducted on 130 children with OMG who were treated in the Department of Neurology, Jiangxi Children's Hospital, from February 2018 to February 2023. According to the treatment regimen, they were divided into four groups: glucocorticoid (GC) group (n=29), mycophenolate mofetil (MMF) group (GC+MMF; n=33), methotrexate (MTX) group (GC+MTX; n=30), and tacrolimus (FK506) group (GC+FK506; n=38). Treatment outcomes and adverse reactions were compared among the groups.@*RESULTS@#After 3 months of treatment, the FK506 group had significantly lower scores of Myasthenia Gravis Quantitative Scale and Myasthenia Gravis-Specific Activities of Daily Living than the other three groups (P<0.05). After 3 months of treatment, the FK506 group had a significantly lower dose of prednisone than the GC group, and after 6 and 9 months of treatment, the MMF, MTX, and FK506 groups had a significantly lower dose of prednisone than the GC group (P<0.05). After 12 months of treatment, the MMF, MTX, and FK506 groups had a significantly lower incidence rate of GC-related adverse reactions than the GC group (P<0.05).@*CONCLUSIONS@#For children with OMG, the addition of various immunosuppressants can reduce the dosage of GC and adverse reactions. Among them, FK506 shows superior efficacy compared to other immunosuppressants in the early treatment of OMG.

Acupuncture combined with western medication for ocular myasthenia gravis: a randomized controlled trial / 中国针灸

OBJECTIVE@#To compare the clinical efficacy between acupuncture combined with western medication and simple western medication for ocular myasthenia gravis (OMG), and to explore its possible mechanism.@*METHODS@#A total of 60 patients of ocular myasthenia gravis were randomized into an acupuncture combined with western medication group (30 cases, 1 case dropped off) and a western medication group (30 cases, 2 cases dropped off). Oral pyridostigmine bromide tablet and prednisone acetate tablet were given in the western medication group. On the basis of the treatment in the western medication group, Tongdu Tiaoqi acupuncture (acupuncture for unblocking the governor vessel and regulating qi ) was applied at Baihui (GV 20), Fengfu (GV 16), Hegu (LI 4), Zusanli (ST 36), etc. in the acupuncture combined with western medication group, once a day, 6 days a week. The treatment was given 8 weeks in both groups. Before and after treatment, the OMG clinical absolute score was observed, electrophysiological indexes of orbicularis oculi (value of mean jitter, percentage of jitter >55 μs and percentage of blocks) were measured by single-fiber electromyography (SFEMG), serum levels of acetylcholine receptor antibody (AChR-Ab), interferon-gamma (IFN-γ) and interleukin-4 (IL-4) were detected by ELISA method.@*RESULTS@#After treatment, the OMG clinical absolute scores, values of mean jitter, percentages of jitter >55 μs, percentages of blocks and serum levels of AChR-Ab, IFN-γ and IL-4 were decreased compared before treatment in both groups (P<0.05), and those in the acupuncture combined with western medication group were lower than the western medication group (P<0.05).@*CONCLUSION@#Acupuncture combined with western medication can effectively improve ptosis, palpebra superior fatigability, eye movement disorder and neuromuscular junction dysfunction in patients with ocular myasthenia gravis, the therapeutic effect is superior to simple western medication. Its mechanism may be related to down-regulating serum levels of AChR-Ab, IFN-γ and IL-4 and promoting the recovery of orbicularis oculi function.

IL-6 levels are associated with clinical status in patients with Myasthenia Gravis / Os níveis de IL-6 estão associados com o status clínico de pacientes com Miastenia Gravis

BACKGROUND: Myasthenia gravis (MG) is an autoimmune disease marked by fluctuating course of muscle weakness. OBJECTIVES: The current study was designed to evaluate plasma levels of cytokines (IL-2, IL-4, IL-6, IL-10, TNF, IFN-γ, and IL17A) in patients with MG and controls and to investigate whether cytokines levels are associated with clinical parameters. This study was conducted at the Neuromuscular Diseases Outpatient Clinic, Hospital das Clínicas, Universidade Federal de Minas Gerais (UFMG), Brazil. METHODS: Peripheral blood was drawn, and plasma levels of cytokines were measured by cytometric bead array (CBA) in 80 treated patients with MG and 50 controls. The MG Composite (MGC) was used to evaluate muscle weakness and severity of typical motor symptoms of MG. RESULTS: Patients with MG undergoing treatment exhibit lower levels of all evaluated cytokines compared to controls. There was a negative correlation between IL-6 levels and the MG Composite score, indicating that higher levels of IL-6 were associated with better control of the disease. CONCLUSION: This exploratory study suggests that IL-6 is associated with MG clinical status, as assessed by the MGC.

INTRODUÇÃO: A Miastenia Gravis (MG) é uma doença autoimune caracterizada por fraqueza muscular flutuante. OBJETIVOS: avaliar os níveis plasmáticos de citocinas (IL-2, IL-4, IL-6, IL-10, TNF, IFN-γ, e IL-17A) em pacientes com MG e controles e investigar se essas citocinas estão associadas com parâmetros clínicos. Este estudo foi conduzido no ambulatório de doenças neuromusculares do Hospital das Clínicas, Universidade Federal de Minas Gerais (UFMG), Brasil. MÉTODOS: Foi coletado sangue periféricos e os níveis plasmáticos das citocinas foram medidos por citometria em 80 pacientes com MG tratados e em 50 controles. O MG composite (MGC) foi utilizado para avaliar a fraqueza muscular e a gravidade dos sintomas motores típicos da MG. RESULTADOS: Os pacientes com MG em tratamento apresentaram menores níveis de todas as citocinas avaliadas comparados ao controle. Houve uma correlação negativa entre os níveis de IL-6 e o MGC, indicando que altos níveis de IL-6 estão associados com melhor controle da doença. CONCLUSÃO: este estudo exploratório sugere que a IL-6 está associada com o status clínico da MG, quando avaliado pelo MGC.

Protocolo Clínico e Diretrizes Terapêuticas da miastenia gravis / Clinical Protocol and Therapeutic Guidelines for myasthenia gravis

CONTEXTO: Os PCDT são documentos que visam garantir o melhor cuidado de saúde diante do contexto brasileiro e dos recursos disponíveis no SUS. Podem ser utilizados como materiais educativos aos profissionais de saúde, auxílio administrativo aos gestores, regulamentação da conduta assistencial perante o Poder Judiciário e explicitação de direitos aos usuários do SUS. Os PCDT são os documentos oficiais do SUS que estabelecem critérios para o diagnóstico de uma doença ou agravo à saúde; tratamento preconizado, com os medicamentos e demais produtos apropriados, quando couber; posologias recomendadas; mecanismos de controle clínico; e acompanhamento e verificação dos resultados terapêuticos a serem seguidos pelos gestores do SUS. Os PCDT devem incluir recomendações de condutas, medicamentos ou produtos para as diferentes fases evolutivas da doença ou do agravo à saúde de que se tratam, bem como aqueles indicados em casos de perda de eficácia e de surgimento de intolerância ou reação adversa relevante, provocadas pelo medicamento, produto ou procedimento de primeira escolha. A lei reforçou a análise baseada em evidências científicas para a elaboração dos protocolos, destacando os critérios de eficácia, segurança, efetividade e custo-efetividade para a formulação das recomendações sobre intervenções em saúde. Para a constituição ou alteração dos PCDT, a Portaria GM n° 2.009 de 2012 instituiu na Conitec uma Subcomissão Técnica de Avaliação de PCDT, com as competências de definir os temas para novos protocolos, acompanhar sua elaboração, avaliar as recomendações propostas e as evidências científicas apresentadas, além da revisão periódica dos PCDT vigentes, em até dois anos. A Subcomissão Técnica de Avaliação de PCDT é composta por representantes de Secretarias do Ministério da Saúde interessadas na elaboração de diretrizes clínicas: Secretaria de Atenção Primária à Saúde, Secretaria de Atenção Especializada à Saúde, Secretaria de Vigilância em Saúde, Secretaria Especial de Saúde Indígena e Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos em Saúde. Após concluídas as etapas de definição do tema e escopo do PCDT, de busca, seleção e análise de evidências científicas e consequente definição das recomendações, a aprovação do texto é submetida à apreciação do Plenário da Conitec, com posterior disponibilização deste documento para contribuição de sociedade, por meio de consulta pública (CP) pelo prazo de 20 dias, antes da deliberação final e publicação. A consulta pública é uma importante etapa de revisão externa dos PCDT. O Plenário da Conitec é o fórum responsável pelas recomendações sobre a constituição ou alteração de PCDT, além dos assuntos relativos à incorporação, exclusão ou alteração das tecnologias no âmbito do SUS, bem como sobre a atualização da Relação Nacional de Medicamentos Essenciais (RENAME). É composto por treze membros, um representante de cada Secretaria do Ministério da Saúde ­ sendo o indicado pela Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos em Saúde (SCTIE) o presidente do Plenário ­ e um representante de cada uma das seguintes instituições: ANVISA, Agência Nacional de Saúde Suplementar - ANS, Conselho Nacional de Saúde - CNS, Conselho Nacional de Secretários de Saúde - CONASS, Conselho Nacional de Secretarias Municipais de Saúde - CONASEMS e Conselho Federal de Medicina - CFM. Cabe à Secretaria-Executiva, exercida pelo Departamento de Gestão e Incorporação de Tecnologias e Inovação em Saúde (DGITIS/SCTIE), a gestão e a coordenação das atividades da Conitec. Conforme o Decreto n° 7.646 de 2011, o Secretário de Ciência, Tecnologia, Inovação e Insumos Estratégicos em Saúde deverá submeter o PCDT à manifestação do titular da Secretaria responsável pelo programa ou ação a ele relacionado antes da sua publicação e disponibilização à sociedade. APRESENTAÇÃO: A proposta de atualização do PCDT de Miastenia Gravis é uma demanda que cumpre o Decreto nº 7.508 de 28 de junho de 2011 e as orientações previstas no artigo 26º e o parágrafo único, sobre a responsabilidade do Ministério da Saúde de atualizar os Protocolos Clínicos e Diretrizes Terapêuticas. Este PCDT apresenta a atualização da versão publicada em 2015, com inclusão do exame complementar de diagnóstico dosagem sérica de anticorpos de acetilcolina (anti-AChR). DELIBERAÇÃO INICIAL: Os membros da Conitec presentes na 88ª Reunião do Plenário, realizada nos dias 07, 08 e 09 de julho de 2020, deliberaram para que o tema fosse submetido à consulta pública com recomendação preliminar favorável à publicação deste Protocolo. CONSULTA PÚBLICA: A Consulta Pública nº 27/2020 foi realizada entre os dias 21 de julho a 10 de agosto de 2020. A seguir é apresentado o resumo da análise das contribuições recebidas, ressaltando-se que foram consideradas apenas as encaminhadas no período estipulado e por meio do sítio eletrônico da Conitec. Os dadosforam avaliados quantitativa e qualitativamente, considerando asseguintes etapas: a) leitura de todas as contribuições, b) identificação e categorização das ideias centrais, e c) discussão acerca das contribuições. Foram recebidas ao todo 34 contribuições. A grande maioria dos participantes (n= 33; 97%) classificou a proposta de PCDT como boa ou muito boa na avaliação geral.

Miastenia gravis refractaria con buena respuesta a rituximab: caso clínico / Refractory myasthenia gravis with good response to rituximab: report of one case

Myasthenia gravis (MG) is a heterogeneous disease, and there is no unique therapeutic approach for all patients. In 2013 the Myasthenia Gravis American Foundation (MGFA) panel of experts defined refractory MG as the lack of change or deterioration after the use of corticosteroids and two immunosuppressive agents, in adequate doses and time. We report a 51-years-old female with MG of bulbar predominance, who presented four myasthenic crises in 17 months despite the use of corticosteroids, azathioprine and mycophenolate. The high costs associated with her hospitalizations, as well as severe caloric - protein malnutrition, the need for tracheostomy and gastrostomy support, led us to use rituximab. The patient evolved with an excellent response, free of crises after 30 months. She gained 12 kg of weight, without tracheostomy and gastrostomy, only using pyridostigmine support 4 times a day.

Celebrating the 70 years of pyridostigmine on therapy of Myasthenia Gravis: historical aspects of the preliminary trials / Celebrando os 70 anos da piridostigmina no tratamento da Miastenia Gravis: aspectos históricos dos ensaios clínicos preliminares

Abstract Currently, pyridostigmine bromide is an indispensable anticholinesterase agent used worldwide to treat patients with Myasthenia Gravis (MG). However, pyridostigmine bromide was unsuccessful in its "pioneering trials" to treat a series of MG patients. There are important historical landmarks before pyridostigmine bromide becomes useful, safe and indispensable for MG therapy. After 70 years of these "pioneering trials", this article reviews some historical aspects related to them, as well as other preliminary trials using pyridostigmine bromide as therapy for MG patients.

Resumo Atualmente, o brometo de piridostigmina é um indispensável agente anticolinesterásico usado em todo o mundo no tratamento de pacientes com Miastenia Gravis (MG). Contudo, o brometo de piridostigmina não foi bem-sucedido, em seus "ensaios clínicos pioneiros", no tratamento de uma série de pacientes com MG. Existem importantes marcos históricos antes do brometo de piridostigmina se tornar útil, seguro e indispensável no tratamento da MG. Após 70 anos desses "ensaios clínicos pioneiros", este artigo revisa alguns aspectos históricos a eles relacionados, bem como a outros estudos preliminares que usaram o brometo de piridostigmina como um tratamento para pacientes com MG.

Miastenia Gravis: reporte de dos casos y revisión de la literatura / Myasthenia Gravis: two case reports and review

Myasthenia gravis is an acquired autoimmune disorder of the neuromuscular junction characterized by fluctuating weakness and fatigability of skeletal muscles. The diagnosis can be established by clinical and serologic testing, with predominance of autoantibodies against the acetylcholine receptor, and Muscle-specific kinase antibodies. We report two cases of Myasthenia gravis, the first one is a 31 year old patient with a debut of the disease, mainly with bulbar symptoms, and the second one is a 29 year old patient diagnosed with generalized Miasthenia Gravis also mainly with bulbar symptoms with worsening of symptomatology. In this report treatments alternatives and management approaches are discused

Enfermedades inmunomediadas del sistema nervioso periférico / Peripheral nervous system immunological disorder

Las enfermedades autoinmunes del sistema nervioso periférico son frecuentes en pediatría. Las más importantes son el síndrome de Guillain-Barré, la miastenia gravis juvenil y la dermatomiositis juvenil. Tienen en común ser causadas por acción de anticuerpos específicos que producen la signología clínica, reacción que puede ser gatillada por un cuadro viral o bacteriano, como ocurre principalmente en SGB. La polineuropatía aguda inflamatoria desmielinizante es más frecuente. Existe también la forma axonal motora. Ambas tienen clínica progresiva ascendente. El tratamiento específico es la inmunoglobulina 2 g/ kg. La miastenia gravis juvenil se expresa por signos oculares, generalizados y fatigabilidad fluctuante. Puede comprometer la función respiratoria desencadenando crisis miasténica. Se trata con anticolinesterásicos, corticoides, inmunoglobulinas e inmunosupresores. La timectomía ha mostrado recientemente su efectividad. La dermatomiositis juvenil se expresa por signos cutáneos y musculares. Se diagnostica por elevación de enzimas musculares, biopsia y resonancia musculares y se trata con corticoides, inmunoglobulinas e inmunosupresores. Tanto el síndrome de Guiilain-Barré, como la miastenia gravis y la dermatomiositis juvenil, tienen buen pronóstico.

Autoimmune diseases of the peripheral nervous system are common in pediatrics. Guillain-Barré syndrome, juvenile myasthenia gravis, and juvenile dermatomyositis are the most important. Their common pathogenesis involves the action of specific autoantibodies which are frequently triggered by viral or bacterial infection. Acute inflammatory demyelinating polyneuropathy is the most frequent pathological feature. There is also a motor axonal form. Both have a progressive ascending clinical course. The specific treatment is immunoglobulin 2 g/kg. Juvenile myasthenia gravis is expressed by ocular signs and generalized and fluctuating fatigability. It can involve respiratory functions triggering a myasthenic crisis. It is treated with anticholinesterase agents, corticosteroids, immunoglobulins, and immunosuppressants. Thymectomy has recently shown effectiveness. Juvenile dermatomyositis is expressed by skin and muscle signs. Elevated muscle enzymes, muscle biopsy, and magnetic resonance imaging contribute to the diagnosis. It is treated with corticosteroids, immunoglobulins, and immunosuppressants. All three disorders, Guillain-Barré, juvenile myasthenia gravis, and juvenile dermatomyositis have a good prognosis.

Miastenia gravis y su asociación con trastornos linfoproliferativos: casos clínicos / Myasthenia gravis and its association with lymphoproliferative disorders: a case series

Myasthenia gravis (MG) is a rare autoimmune disease of the neuromuscular junction. It is characterized by variable weakness and excessive fatigability of skeletal muscles. In the last few years, numerous reports have been published showing the association between autoimmune diseases, such as systemic erythematous lupus or rheumatoid arthritis, with lymphoid neoplasias. The association between MG and lymphoid neoplasia seems to be less frequent. To analyze this association we reviewed the MG patients in the Department of Neurology, Hospital Salvador of Santiago, Chile. During a three-year period we identified four patients who developed different lymphoproliferative disorders: two with B-cell lymphoma, one with chronic lymphocytic leukaemia and one plasmacytoma with an associated amyloidosis. The MG was generalized but mild, all cases classified as type IIa according to the definition proposed by the MG Foundation of America. The neoplasia appeared two to 36 years after the onset of MG. These cases provide additional evidence of the association between MG and lymphoproliferative disorders.

Mary Broadfoot Walker: 83 years since a historical discovery / Mary Broadfoot Walker: 83 anos desde uma descoberta histórica

ABSTRACT Mary Broadfoot Walker was a Scottish physician who, in 1935, described in great detail the effect of an anticholinesterase drug (physostigmine) on the signs and symptoms of myasthenia gravis. An original five-minutes movie is available online and the skepticism of her contemporary British medical doctors is understandable when the drastic effect of the treatment is shown in this movie. What Mary Walker taught us, more than eight decades ago, about myasthenia gravis continues to be the basis of a pharmacological diagnostic test and treatment of this disease.

RESUMO Mary Broadfoot Walker foi uma médica escocesa que em 1935 descreveu em grande detalhe o efeito de uma droga anticolinesterásica (fisostigmina) nos sinais e sintomas da myasthenia gravis. Um filme original com cinco minutos de duração está disponível online e a reação cética dos colegas médicos contemporâneos de Mary é compreensível dado o drástico efeito terapêutico mostrado neste filme. O que Mary Walker nos ensinou mais de oito décadas atrás continua a ser a base de um teste diagnóstico farmacológico e do tratamento da myasthenia gravis.

Embarazada con miastenia grave ocular. Reporte de un caso / Pregnant woman with ocular myasthenia gravis. A case report

La miastenia grave es una enfermedad autoinmune de la placa motora del músculo estriado, caracterizada por fatiga y debilidad muscular fluctuante. La prevalencia es aproximadamente de 5 casos por cada 100 000 personas. La paciente reportada presentó síntomas que limitaban la musculatura cercana al ojo. Esta entidad se denomina miastenia grave ocular, su incidencia en el embarazo es infrecuente. Se reportó un caso de una paciente de 23 años de edad, atendida en la Consulta de Infertilidad del municipio Isla de la Juventud. Se consultó el caso con varias especialidades médicas. El nacimiento se produjo por cesárea de urgencia producto de estado fetal intranquilizante y aplicando anestesia regional. Se obtiene bebé sano, con buena puntuación de apgar y buen peso. Durante el puerperio la madre y el recién nacido evolucionaron satisfactoriamente (AU).

Myasthenia gravis is an autoimmune disease of the motor end-plate of the striated muscle, characterized by fluctuant muscular fatigue and weakness. Its prevalence is around 5 cases per 100 000 persons. The reported patient presented symptoms limiting the muscles near the eye. This entity is named ocular myasthenia gravis. Its incidence in pregnancy is infrequent. It is reported the case of a female patient, aged 23 years, attended in the Infertility Consultation of the municipality Isla de la Juventud. The case was consulted with several medical specialties. The delivery was produced by emergency cesarean section, applying regional anesthesia, due to the worrying fetal status. The newborn had good apgar score and weight. Mother and child showed satisfactory evolution during the postpartum period (AU).

Síntomas de miastenia grave en un paciente con antecedente de timectomía por timoma invasor / Symptoms of myasthenia gravis in a patient with a history of thymectomy for invasive thymoma

Introducción. La miastenia grave es una enfermedad autoinmunitaria mediada por anticuerpos. Entre 10 y 15 % de quienes la padecen tienen timoma y su presencia se asocia con una mayor gravedad de los síntomas, crisis miasténicas y fracaso del tratamiento de primera línea. La timectomía se recomienda en pacientes jóvenes con miastenia grave generalizada y en todos los pacientes con timoma. Caso clínico. Se presenta el caso de una mujer de 43 años que, en el 2005, presentó una primera crisis miasténica asociada con un timoma invasor que se trató con timectomía y radioterapia. Durante los siguientes tres años, presentó síntomas graves y dos crisis más, que obligaron a suministrarle respiración mecánica asistida e inmunoglobulina. Al cabo del tratamiento, no se evidenciaron signos de recurrencia en las tomografías de tórax con contraste. Entre el 2009 y el 2012, la gravedad de los síntomas fue menor. En el 2013, estos se exacerbaron y una resonancia magnética de tórax con contraste reveló una lesión en el mediastino anterior, ya observada en el 2011, sugestiva de tejido residual o fibrosis. Se inició el tratamiento usual con inmunoglobulina y se hizo una tomografía por emisión de positrones cuyos resultados no fueron concluyentes, por lo que se llevó a cabo una nueva resección y se constató que no había recurrencia del tumor. Conclusiones. Los pacientes con miastenia grave y aquellos con timoma asociado, deben someterse a la timectomía como parte del tratamiento. Sin embargo, la exacerbación de los síntomas o su reaparición después del procedimiento no necesariamente implica una nueva alteración en el timo.

Introduction: Myasthenia gravis is an antibody-mediated autoimmune disease. Approximately 10-15% of patients present with a thymoma, the presence of which is associated with greater severity of symptoms, myasthenic crisis, and irresponsiveness to front-line therapy. A thymectomy is recommended in young patients with generalized myasthenia gravis and in all patients presenting with thymoma. Clinical case: The patient was a 43-year-old woman, who first showed symptoms of myasthenic crisis in 2005 and presented with invasive thymoma managed with thymectomy and radiotherapy. In the subsequent three years, the patient presented with severe symptoms and two myasthenic crises that required mechanical ventilation and immunoglobulin treatment. Contrast chest computed tomography examinations showed no recurrence. Between 2009 and 2012, the patient experienced decreased symptom severity. In 2013, the patient presented with an exacerbation of symptoms; a contrast chest magnetic resonance scan showed a lesion in the anterior mediastinum, previously observed in 2011, suggestive of residual tissue as opposed to fibrosis. Regular management was started with immunoglobulins; a positron emission tomography scan was inconclusive, requiring a new resection, which showed no evidence of tumor recurrence. Conclusions: Patients with myasthenia gravis and those with myasthenia-related thymoma both share thymectomy as an element of treatment. However, following the procedure, exacerbation or reappearance of symptoms does not necessarily represent new alterations in the thymus.

Enfermedad de graves en asociación con miastenia gravis: presentación de un caso y revisión de la literatura / Myasthenia gravis with concomitant hyperthyroidism: report of one case

Myasthenia gravis and Graves disease are autoimmune diseases that can coexist in the same patient. We report a 18 years old female with a history of myasthenia gravis diagnosed at the age of six, treated with neostigmine and prednisone. She starts with palpitations, dyspnea, proximal muscle weakness and exophthalmos appearing seven months after the onset of symptoms. She was admitted to the hospital due to her decompensated hyperthyroidism. After admission, she develops a myasthenic crisis, that requires mechanical ventilation. Afterwards, the patient is subjected to a thymectomy and thyroidectomy with a good postoperative evolution.

Miastenia grave en la adolescencia: a propósito de un caso / Myasthenia gravis in adolescence: apropos of a case

En este trabajo se presenta a un adolescente masculino que inició un cuadro de fatigabilidad muscular tras el ejercicio, que lo llevó a desaprobar la asignatura de preparación física. Posteriormente comienza a presentar dificultades para ingerir alimentos, para pronunciar palabras y asimetría en la fuerza muscular de ambos hemicuerpos. Es ingresado, y a los pocos días comienza a presentar alteraciones respiratorias, por lo que se decide su traslado a la sala de cuidados intensivos donde fue necesario acoplarlo a un ventilador mecánico. En esta oportunidad no hubo respuesta a la administración de anticolinesterásicos, sin embargo comenzó a mejorar con el tratamiento con esteroides. Evolucionó satisfactoriamente con recuperación lenta y progresiva de la fuerza muscular. Se restableció el tratamiento con anticolinesterásicos paulatinamente con buena respuesta en esta oportunidad.

A male adolescent that started with a picture of muscle weakness after doing exercises that led him to fail the physical education subject is presented in this paper. Later on, he began to have difficulties to eat and to pronounce words, and to show asymmetry in the muscular strength of both hemibodies. He was admitted and a few days after he had respiratory alterations and it was decided to transfer him to an intensive care unit and to couple him to a mechanical ventilator. In that opportunity, there was no response to the administration of anticholinesterase agents; however, he began to improve with steroids. His evolution was satisfactory with a slow and progressive recovery of the muscle strength. The treatment with anticholinesterase agents was gradually re-established with a good response this time.

Drug related crisis in myasthenia gravis.

Myasthenia gravis is an autoimmune disorder where antibodies against the nicotinic Ach receptor resulting in impaired transmission at the NM junction. A number of drugs have been reported to cause neuromuscular blockade and/or to increase weakness in myasthenia gravis. We report a case of myasthenia gravis in which the calcium channel blocker-nifedipine caused the worsening of the symptoms.

Myasthenia gravis accompanied with hypokalemic periodic paralysis.

Myasthenia gravis and hypokalemic periodic paralysis are commonly related with hyperthyroidism but rarely occur together. Here, the authors reported a case of hypokalemic periodic paralysis in a Northeastern Thai woman accompanied with myasthenia gravis. She had motor weakness despite a normal level of serum potassium. Prostigmine test was positive. She dramatically improved after pyridostigmine treatment. Autoantibodies to nicotinic AchR-Ab and dihydropyridine receptor or L-type voltage gated calcium channel were postulated to explain these associated diseases.