The diagnostic yield of quantified electromyography and quantified muscle biopsy in neuromuscular disorders

Buchthal, Fritz; Kamieniecka, Z

doi:10.1002/mus.880050403

Cited by 190 publications

(91 citation statements)

References 67 publications

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“…The semiquantitative assessment used in this study allows easy comparison with routine daily practice in which semiquantitative techniques are most frequently used. The present study confirms several findings reported previously on EMG abnormalities in myositis [10, 11,16,17,18,19,20,21]. Several conclusions can be drawn that add to the present knowledge on EMG in myositis, keeping the retrospective nature of the study in mind.…”

Section: Discussionsupporting

confidence: 81%

Needle Electromyographic Findings in 98 Patients with Myositis

Blijham¹,

Hengstman

Hama-Amin³

et al. 2006

Eur Neurol

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Background/Aims: Little is known about the distribution of electromyographic (EMG) abnormalities in myositis even though this is relevant in daily practice. Methods: A retrospective semiquantitative analysis of needle EMG findings was performed in a group of 98 patients with myositis. The frequency, type, and distribution of abnormalities were studied. The influence of the use of corticosteroids and the stage of the disease were evaluated. Results: In most patients, a myopathic pattern with spontaneous activity was found, although several clinically relevant exceptions were noted. Long-duration motor unit potentials were found in all three diagnostic groups and were not associated with disease duration. In the lower extremity a distal to proximal gradient was present, adding to the diagnostic confusion with neurogenic diseases, and spontaneous activity was absent in a relatively large group although none of the patients in the acute stage of the disease had a normal EMG. The use of corticosteroids reduced the number of abnormal findings in dermatomyositis and polymyositis, but not in inclusion body myositis. Conclusion: A myopathic pattern with spontaneous activity was most frequently found, although several clinically relevant exceptions were noted. These results illustrate the spectrum of EMG findings in myositis, and may aid the clinician in the interpretation of the EMG in these patients.

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Section: Discussionsupporting

confidence: 81%

Needle Electromyographic Findings in 98 Patients with Myositis

Blijham¹,

Hengstman

Hama-Amin³

et al. 2006

Eur Neurol

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“…The scope of this work was the study of the involvement of the anterior tibial muscle in leprosy and for this reason we did not study other muscles with EMG, even knowing that we could find abnormalities in other muscles, if a complete examination was done. Also, even studying only one muscle, as in this paper, a good correlation can be obtained, according previously published papers 21,32 .…”

Section: Resul Resul Resul Resul Results Ts Ts Ts Tssupporting

confidence: 75%

Muscle involvement in leprosy: study of the anterior tibial muscle in 40 patients

Werneck

Teive

Scola

1999

Arq. Neuro-Psiquiatr.

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-The involvement of skeletal striated muscle in leprosy is considered secondary due to peripheral neuropathy, but some studies point it to a primary muscle lesion. In order to investigate the muscle involvement in leprosy, we studied 40 patients (lepromatous 23, tuberculoid 13, borderline 2 and indeterminate 2). The motor nerve conduction of the peroneal nerves had a reduction of the velocity, decreased compound muscle action potential and sometimes absence of potentials. The electromyographic study of the anterior tibial muscle showed signs of recent and chronic denervation in 77.5% of the cases and no myopathic potentials. The anterior tibial muscle biopsy revealed denervation in 45% of the cases, interstitial inflammatory myopathy in 30% and mixed (myopathic and neuropathic) pattern in 12.5%. Acid fast bacillus was detected in 25% of the cases, always in the interstitial tissue. Inflammatory reaction was present in the interstitial space and in patients with the lepromatous type. The histological findings clearly defined the presence of the so-called "Leprous Interstitial Myositis" on the top of denervation signs.KEY WORDS: leprosy, skeletal muscle, muscle biopsy, myositis.Alterações musculares na lepra: estudo do músculo tibial anterior em 40 pacientes RESUMO -O envolvimento do músculo estriado na lepra é considerado secundário à lesão dos nervos periféricos, mas alguns estudos relataram acometimento muscular primário. A fim de verificar esta controvérsia estudamos 40 pacientes com lepra, sendo 23 da forma lepromatosa, 13 da tuberculoide, 2 borderline e 2 indeterminada. Realizamos a neurocondução do nervo peroneiro, junto com eletromiografia e biópsia do músculo tibial anterior. Encontramos redução de velocidade de condução, da amplitude e algumas vezes ausência de potenciais no nervo peroneiro. A eletromiografia do tibial anterior mostrou sinais de desinervação recente e crônica em 77,5% dos casos e não foi encontrada evidência de padrão "miopático". A biópsia do músculo tibial anterior revelou desinervação em 45% dos casos, miopatia inflamatória intersticial em 30% e padrão misto (miopático e neuropático) em 12,5%. Bacilos alcool-ácido resistentes foram encontrados em 25% dos casos, sempre localizados no perimisio e endomisio. Na forma lepromatosa, a reação inflamatória estava presente no espaço intersticial. Os dados histológicos claramente definiram a presença de "Miosite Lepromatosa Intersticial" sobreposta às alterações histológicas encontradas em desinervação. PALAVRAS-CHAVES: lepra, músculo esquelético, biópsia muscular, miosite.Leprosy is a chronic infection illness caused by the Myobacterium leprae (M.leprae) that preferably attacks peripheral nerves. This disease is endemic all over the world, specifically in Brazil, and it is considered the commonest cause of treatable peripheral neuropathy [1][2][3] .

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“…values proposed by Buchthal (10), being considered increased if the deviation was over 20% and diminished if it was under 20%. S) Average voltage of voluntary potentials: identical analysis to the previous potentials was made, but the only potentials considered were those which the positive deflexion peak to highest negative was not above 2C3us; there are no agreement in the literature about the normal values3GCuV to 5uV (32), 1C0..V to 2mV (39), higher than 2mV and lower than 4mV (13), 100 to 2000uV (53), important when it exceeds 60C0uV(S5), some hundreds of uV to under 3mV (56) -• we use the voltages found in normal individuals from our laboratory, which vary from 500 to 3000uV (unpublished data); they were considered increased if above SOOOuV and diminished if under 5C0uV.…”

Section: Methodsmentioning

confidence: 99%

Muscle biopsy correlated with electromyography: study of 100 cases

Werneck

Souza-Lima

1988

Arq. Neuro-Psiquiatr.

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SUMMARY -To find what the correlation is and verify if is possible to avoid extensive electromyographic examination, studying only one muscle, 100 patients with neuromuscular disorders (58 primary myopathies, 32 neurogenic disorders and 10 myotonic dystrophies) were submited to quantified electromyography (EMG) and muscle biopsy (MB) with fresh-¬ -frozen section plus histochemistry in the same muscle, but on the opposite side. The EMG was abnormal in 98% and MB in 93% of the cases. EMG and MB had a concordance of 84.3% in the neurogenic disorders and 84.77% in the primary myopathies. A correlation of 80% was obtained between all MB and EMG (including the cases of myotonic dystrophies), regarding the origin of the pathogenic process (p<0.01).The EMG had 5% inconsistences and the MB 11%, with respect to the pathogenic process. When the myotonic dystrophy was separated from the primary myopathies and from the denervation disorders, a complete concordance was found in all MB and had only 3.4% inconsistences in the denervation disorders and 3.1% in the primary myopathies.Correlação entre biópsia muscular e eletromiografia: estudo de 100 casos.RESUMO -A fim de verificar qual a correlação entre uma biópsia muscular e a eletro-¬ miografia quando um único músculo é estudado, bem como verificar a possibilidade de evitar eletromiografias extensivas e dolorosas em determinadas doenças, foram investigados 100 pacientes com doenças neuromusculares (58 com miopatias primárias, 32 doenças que determinam desinervação e 10 distrofias miotônicas). Todos os casos foram submetidos a eletromiografia quantificada (EMG) e a biópsia muscular (BM), utilizando técnicas de colorações a fresco e pela histoquímica, realizadas no mesmo músculo, mas em lados opostos do paciente. A EMG foi anormal em 98% e a BM in 93% dos casos. A EMG e a BM tiveram concordância de 84,3% nas doenças neurogênicas e 84,77% nas miopatias primárias. Foi obtida correlação de 80% entre a EMG e a BM em todos os casos, com relação à patogenia do processo (p<0,01).A EMG teve 5% de inconsistências e a BM 11%, em relação ao diagnóstico patogênico. Quando a distrofia miotônica foi separada das miopatias primárias e dos processos que determinam desinervação, uma concordância completa foi encontrada entre todas as BM e a EMG mostrou inconsistências somente em 3,4% das doenças que determinam desinervação e 3,1% das miopatias primárias, sugerindo que a distrofia miotônica deva ser classificada em um grupo separado (neuromiopatias). Os autores discutem os dados encontrados em relação à literatura existente e concluem que, dependendo da avaliação clínica, é possível submeter os pacientes a somente um dos procedimentos (geralmente a BM), utilizando ambos os procedimentos somente nos casos em que não foi possível chegar a um diagnóstico, sendo então examinados diversos músculos na EMG.

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The diagnostic yield of quantified electromyography and quantified muscle biopsy in neuromuscular disorders

Cited by 190 publications

References 67 publications

Needle Electromyographic Findings in 98 Patients with Myositis

Needle Electromyographic Findings in 98 Patients with Myositis

Muscle involvement in leprosy: study of the anterior tibial muscle in 40 patients

Muscle biopsy correlated with electromyography: study of 100 cases

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