Miopatias com padrão distal: descrição clínica de pacientes do Estado da Bahia / Distal myopathies: clinical description of patients from the State of Bahia

INTRODUÇÃO: As miopatias são doenças cuja etiologia decorre de alterações estruturais e/ou funcionais no músculo esquelético. As miopatias distais são doenças musculares primárias em que fraqueza e, frequentemente atrofia, tem início nas mãos, antebraços, pés e segmento distal das pernas. Apesar de terem sido divididas como um grupo restrito de doenças, outras miopatias podem se manifestar com um padrão distal, como a miopatia nemalínica e as distrofias musculares cintura-membros. Devido à escassez de trabalhos que descrevem clinicamente as miopatias distais, este trabalho visou contribuir com essa caracterização. METODOLOGIA: Os pacientes foram selecionados no ambulatório de doenças neuromusculares do Hospital Universitário Professor Edgar Santos, em seguida avaliados clinicamente, através de exame físico e também com exames complementares: eletroneuromiografia, exames laboratoriais, estudo molecular e histopatológico. RESULTADOS: Quinze pacientes com padrão distal foram analisados, sendo 40% do sexo feminino, média de idade de 29,8 anos, seis (40|%) pacientes naturais da capital, Salvador-Bahia. Quanto ao padrão de distribuição de fraqueza, sete apresentavam padrão distal, enquanto oito, padrão distal-proximal. Os pacientes foram agrupados de acordo com a idade de início dos sintomas, sendo 11 iniciados na infância e adolescência (T em homozigose), um com sarcoglicanopatia (mutação c.229C>T em homozigose) e um com miopatia nemalínica (histopatológico com presença de corpos nemalínicos). DISCUSSÃO: Os achados identificados nos pacientes com diagnósticos firmados foram compatíveis com o que é visto na literatura, como apresentação clínica e mutações identificadas previamente. Destaca-se o componente distal pronunciado da paciente com sarcoglicanopatia, considerado incomum. Além disso, a descrição da ressonância magnética realizada nos indivíduos demonstrou um padrão típico. Na maior parte dos pacientes não se chegou a um diagnóstico etiológico, a despeito da investigação realizada com os exames complementares e clínicos. CONCLUSÃO: O presente estudo caracterizou uma amostra de pacientes com miopatias distais, corroborando que essas doenças se manifestam clinicamente de forma heterogênea. A caracterização e divisão entre grupos visa tornar mais fácil a investigação, devendo ser feita com exames complementares, considerados imprescindíveis para se estabelecer o diagnóstico etiológico dessas doenças

INTRODUCTION: Myopathies are diseases which etiology results from structural and/or functional changes in skeletal muscle. Distal myopathies are a group of muscular pathologies in which weakness and atrophy begins and predominates in distal limbs, like hands and feet. Although it has been divided as a restrict group of diseases, other myopathies can manifest with that pattern of weakness, such nemaline myopathy and limb-girdle muscular dystrophies. Due to the scarcity of studies that described clinically the distal myopathies, this study focuses on clinical characterization of myopathies with distal pattern of weakness. METHODOLOGY: The patients were selected in the outpatient clinic for neuromuscular diseases at Professor Edgar Santos University Hospital. Those subjects were clinically evaluated through physical examination, laboratory tests, electroneuromyography, magnetic resonance (MRI) and histopathological study. RESULTS: Fifteen patients with distal pattern were analyzed, being 40% female, mean age 29.8 years, six (40 %) patients were born in the capital, Salvador-Bahia. As for the pattern of weakness distribution, seven had an exclusive distal pattern, while eight had a distal-proximal pattern. Patients were grouped according to the age of onset of symptoms, of which 11 were initiated in childhood and adolescence ( T in homozygous in exon 53 in another and one patient were diagnosed by biopsy), one with sarcoglicanopathy (mutation c.229C> T in homozygous) and one with nemaline myopathy (histopathological with the presence of nemalinic bodies). DISCUSSION: The findings identified in patients with established diagnoses were compatible with what is seen in the literature, such as clinical presentation and previously identified mutations. We highlight the pronounced distal component of the patient with sarcoglicanopathy, considered to be uncommon. In addition, the description of MRI performed in the individuals demonstrated a typical pattern. Most of the patients were not diagnosed, despite the research done with the complementary and clinical exams. CONCLUSION: The present study characterized a sample of patients with distal myopathies, corroborating that these diseases manifest themselves clinically heterogeneously. The characterization and division between groups aims to make the investigation easier, and should be done with complementary tests, considered essential to establish the etiological diagnosis of these diseases

Síndrome Antisintetasa / Antisynthetase syndrome

El síndrome antisintetasa es una entidad poco frecuente, incluida dentro del grupo de las miopatías inflamatorias idiopáticas. Se caracteriza por la presencia de anticuerpos antisintetasa, fiebre, miositis, enfermedad pulmonar intersticial, poliartritis, fenómeno de Raynaud y manos de mecánico.

The antisynthetase syndrome is a rare condition that has been included in the group of idiopatic inflammatory skeletal muscle disease. The presence of antisynthetase autoantibody, fever, myositis, intersticial lung disease, polyarthritis, Raynaud´s phenomenon and “mechanic´s hands” represent the main characteristics of antisynthetase syndrome.

Immunofluorescence on skeletal muscle and skin biopsy specimens in muscle diseases

A series of 110 muscle and 40 skin biopsy speciemens were examined using direct immunofluorescence aiming identify features that may differentiate the myopathy of connective tissue disease from other muscle diseases. The skeletal muscle fluorescence was positive in 75 per cents of the patients with muscle diseases. The sarcolemmal staining was higher in mitochondrial encephalomyopathy. Fiber and vascular staining occured in all muscle diseases, except in cases of myasthenia. Our results showed that 42 per cents of patients with polymyositis and 43 per cents of patients with peripheral motor neuron diseases have vascular deposits of immune complexes suggesting that these two deseases could result from an immune complex-induced vasculopathy. The IF test in skin specimens was positive in 60 per cents of the patients with muscular diseases. The absence of immunoglobulin deposit at the dermoepidermal junction and at epidermal nuclei in cases of peripheral motor neuron disease suggest that this skin test may be useful in the differentiation of muscle diseases