INTRODUCTION: Limb-girdle muscular dystrophy presents with heterogeneous clinical and molecular features. The primary characteristic of this disorder is proximal muscular weakness with variable age of onset, speed of progression, and intensity of symptoms. Sarcoglycanopathies, which are a subgroup of the limb-girdle muscular dystrophies, are caused by mutations in sarcoglycan genes. Mutations in these genes cause secondary deficiencies in other proteins, due to the instability of the dystrophin-glycoprotein complex. Therefore, determining the etiology of a given sarcoglycanopathy requires costly and occasionally inaccessible molecular methods. OBJECTIVE: The aim of this study was to identify phenotypic differences among limb-girdle muscular dystrophy patients who were grouped according to the immunohistochemical phenotypes for the four sarcoglycans. METHODS: To identify phenotypic differences among patients with different types of sarcoglycanopathies, a questionnaire was used and the muscle strength and range of motion of nine joints in 45 patients recruited from the Department of Neurology - HC-FMUSP (Clinics Hospital of the Faculty of Medicine of the University of São Paulo) were evaluated. The findings obtained from these analyses were compared with the results of the immunohistochemical findings. RESULTS: The patients were divided into the following groups based on the immunohistochemical findings: a-sarcoglycanopathies (16 patients), b-sarcoglycanopathies (1 patient), y-sarcoglycanopathies (5 patients), and nonsarcoglycanopathies (23 patients). The muscle strength analysis revealed significant differences for both upper and lower limb muscles, particularly the shoulder and hip muscles, as expected. No pattern of joint contractures was found among the four groups analyzed, even within the same family. However, a high frequency of tiptoe gait was observed in patients with a-sarcoglycanopathies, while calf pseudo-hypertrophy was most common in patients with non-sarcoglycanopathies. The a-sarcoglycanopathy patients presented with more severe muscle weakness than did y-sarcoglycanopathy patients. CONCLUSION: The clinical differences observed in this study, which were associated with the immunohistochemical findings, may help to prioritize the mutational investigation of sarcoglycan genes.

Apresentamos o caso de um menino de 8 anos com quadro de síndrome de Kearns-Sayre (SKS), caracterizada por oftlamoparesia, ptose palpebral, miopatia mitocondrial, retinite pigmentosa, associada a baixa estatura, quadro cerebelar, distúrbio de condução cardíaca, diabetes mellitus, hiperproteinorraquia e distonia focal em mãos e pés. A biópsia muscular demonstrou a presença de fibras tipo "ragged-red", citocromo C oxidase negativas e succinato deidrogenase positivas. A ressonância magnética de cabeça mostrou alterações de sinal simétricas no tegmento das estruturas do tronco cerebral, globo pálido e tálamo. A análise do DNA mitocondrial do músculo esquelético mostrou a presença de deleção em condição heteroplásmica. A associação com distonia, descrita pela primeira vez neste caso de SKS com confirmação molecular, é ressaltada, sendo discutida a importância dos defeitos da fosforilação oxidativa na fisiopatogênese desta desordem de movimento.

We present a boy of eight years of age with symptoms of Kearns-Sayre syndrome (KSS) characterised by ophthalmoparesis, palpebral ptosis, mitochondrial myopathy, pigmentous retinitis, associated to short stature, cerebellar signs, cardiac blockade, diabetes mellitus, elevated cerebrospinal fluid protein concentration, and focal hand and foot dystonia. The skeletal muscle biopsy demonstrated ragged red fibers, cytochrome C oxidase-negative and succinate dehydrogenase-positive fibers. The magnetic resonance imaging showed symmetrical signal alteration in tegmentum of brain stem, pallidum and thalamus. Mitochondrial DNA analysis from skeletal muscle showed a deletion in heteroplasmic condition. The association of dystonia to KSS, confirmed by molecular analysis, is first described in this case, and the importance of oxidative phosphorylation defects in the physiopathogenesis of this type of movement disorder is stressed.

OBJETIVO: Analisar o teste de esforço cardiopulmonar (TECP) no diagnóstico de miopatias. MÉTODOS: 27 pacientes com miopatia realizaram TECP (protocolo de bicicleta em rampa, máximo, interrompido por sintoma). RESULTADOS: Pacientes distróficos e pacientes com mitocondriopatias mostraram diferenças significativas em relação aos controles para as variáveis potência do trabalho desenvolvido (watt) e pico do consumo de oxigênio (VO2 máx). Pacientes com mitocondriopatias mostraram diminuição significativa do limiar anaeróbio em relação aos controles, além de elevação dos valores do quociente respiratório (QR) do pico do exercício em relação aos demais grupos. CONCLUSÕES: TECP pode ser útil na avaliação evolutiva do grau de limitação física dos pacientes com miopatia. As variáveis potência do trabalho desenvolvido, VO2 máx, limiar anaeróbio e QR do pico do exercício podem sugerir o diagnóstico de miopatia e seus subtipos, excluindo quadros psicológicos.

PURPOSE: To evaluate the cardiopulmonary exercise testing (CPX) for the diagnosis of myopathies. METHODS: 27 patients with myopathy were submitted to CPX testing (symptom limited bike protocol). RESULTS: Dystrophic patients and patients with mitochondrial disease, compared with controls, showed significant differences for the power of work perfomed (watt) and the maximum oxygen consumption (VO2 max). Patients with mitochondrial disease presented significantly lower values of anaerobic threshold when compared to controls and elevation of exercise peak respiratory exchange ratio (RER) values when compared to the others groups. CONCLUSIONS: CPX testing may be useful in evaluating degree of physical limitation of patients with myopathy at inicial stage as well on follow-up examinations. Power of work performed, VO2 max, anaerobic threshold and RER at exercise peak may suggest the diagnosis of myopathy and its sub-types and therefore exclude psychologic causes of limitation.

Miotonia é o fenômeno da diminuição da velocidade de relaxamento muscular após contração, estímulo mecânico ou elétrico. As miotonias congênitas são afecções hereditárias e não apresentam distrofia muscular. Atualmente, a tendência é agrupá-las como doenças de canais iônicos, juntamente com as paralisias periódicas. Foram acompanhados sete pacientes, seis do sexo masculino e um do sexo feminino, com idade entre 16 e 48 anos (média 27 anos) e início dos sintomas entre 1 e 10 anos (média S anos), que apresentavam fenômeno miotônico desencadeado por contração intensa e hipertrofia muscular global. Três pacientes foram diagnosticados como miotonia generalizada tipo Becker por apresentarem herança autossômica recessiva e/ou episódios transitórios de fraqueza muscular. Dois pacientes correspondiam à miotonia congênita de Thomsen, com padrão de herança autossômica dominante e/ou ausência de episódios de fraqueza ou fatores de piora. Dois pacientes apresentavam miotonia flutuante, piorando com o frio e/ou ingestão de potássio. O diagnóstico clínico foi confirmado através de exames complementares (eletroneuromiografia, biópsia muscular e estudo do DNA). Cada paciente fez uso de diferentes drogas, no sentido de procurar o máximo de melhora da miotonia. Houve cinco relatos de melhora com difenil-hidantoína, um com carbamazepina, três com acetazolamida, um com bloqueador de canal de cálcio, um com beta-adrenérgico, um com tiazídico e nenhum com quinidina/procainamida.

Myotonia is the phenomenon of decrease of muscular relaxation rate, after either a contraction or a mechanical or electrical stimulus. Congenital myotonias are hereditary affections and do not present muscular dystrophy. The current trend is to group them as ionic channels diseases, together with the periodic paralysis.The authors accompanied the cases of seven patients, six males and one female, with ages ranging from 16 to 48 years (average 27 years) and onset of symptons between 1 and 10 years (average 5 years). These patients presented a myotonic phenomenon unleashed by intensive contraction and global muscular hypertrophy. Three patients were diagnosed as cases of Becker type generalized myotonia because they presented a recessive autosomic heredity and/or transient episodes of muscular weakness. Two patients fitted the description of Thomsen congenital myotonia, with a pattern of dominating autosomic heredity and/or absence of weakness episodes or worsening factors for their condition.Two patients presented fluctuating myotonia, which became worse in cold weather or at potassium intake. The clinical diagnosis was confirmed through complementary tests (electroneuromyography, muscle biopsy and DNA study). Each of the patients made use of different drugs, in the search of optimal lessening of their myotonia. There were five reports of amelioration with the use of diphenilhydantoine; one report with the use of carbamazepine; three reports with the use of acetazolamide; one report with the use of a calcium channel blocker; one report with the use of a beta-adrenergic; one report with the use of thiazide; and none with the use of quinidine/procainamide.

Os autores relatam o caso de paciente do sexo feminino de 18 anos de idade com fraqueza lentamente progressiva nos quatro membros desde a infância, sem antecedentes relevantes. O exame neurológico mostrou déficit motor discreto proximal e distal com retração muscular leve ao nível de ombros, cotovelos, articulações coxo-femurais, joelhos e tornozelos; hipotrofia muscular nas pernas e pés: reflexos presentes e sensibilidade normal. Creatinofosfoquinase com aumento de uma vez e meia o valor normal. Eletroneuromiografia: diminuição de amplitude e duração dos potenciais de ação e traçado de interferência paradoxal, compatíveis com afecção muscular primária. Biópsia muscular em congelação (HE, Gomori, PAS, ATPases, NADH, SDH, fosfatases ácida e alcalina, citocromo-c-oxidase e Oil-red-O) revelou afecção muscular primária caracterizada pela presença de corpos nemalínicos e corpos intracitoplasmáticos esferóides. Os corpos nemalínicos podem ser encontrados com diferentes alterações das fibras musculares, porém essa associação é rara. Este é o segundo relato da associação entre corpos nemalínicos e esferóides.

The authors report the case of a female patient, 18 years of age, with slowly progressing weakness in upper and lower limbs since childhood. There were no significant antecedents. The neurologic examination showed mild proximal and distal motor deficit with a slight muscular retraction at the level of shoulders, elbows, coxofemural joints, knees and ankles; muscular hypotrophy in the legs and feet; reflexes were present and sensitivity was normal. Creatinephosphokinase showed an increase of one and a half times the normal value. Electroneuromyography: decrease in the amplitude and duration of action potentials and excessive recruitment of motor units, compatible with a primary muscular disease. A muscle biopsy with frozen sections (HE, Gomori, PAS, ATPases, NADH, SDH, acid and alcaline phosphatases, cytochrome oxidase and Oil-red-o) revealed a primary muscular disease characterized by the presence of nemalinic and intracytoplasmic spheroid bodies. Nemalinic bodies have been described with different structural abnormalities of muscle fibers; however, such association is rare. This is the second case report of concomitant occurrence of nemalinic and spheroid bodies.