ABSTRACT
INTRODUCTION: The conventional electromyography contribute to differentiation of myopatic and neuropatic patterns in neuromuscular disorders, however, the classical patterns related to myopatic changes can result in neurogenic components, this confusion could be due to denervation and reinervation changes involved at the different stages of those diseases. OBJECTIVE: Demonstrate the importance of quantitative electromyographic techniques, as the interference pattern analysis (IPA), for a better differentiation of muscular dystrophies. PATIENTS AND METHODS: IPA was done in 95 patients with 3 different muscular dystrophies: 52 Duchenne muscular dystrophy (DMD), 33 limb girdle muscular dystrophy (LGMD) and 10 myotonic muscular dystrophy (MD) individuals and in a control group of 25 individuals. The left braquial biceps and right anterior tibial muscles were evaluated; the variables analyzed were turns/seconds (t/s), amplitude/turns (a/t), ratio turns/amplitude mean and root squared mean (RSM). RESULTS: We found statistical significant differences in all variables in both braquial biceps and right anterior tibial muscles (p < 0.05) in DMD patients. In LGMD we only found differences in a/t in braquial biceps. In MD the differences were observed in a/t, ratio and RSM in braquial biceps, and in a/t (in anterior tibial). CONCLUSIONS: All the DMD patients show differences in IPA values in relation to control group, MD only in biceps, However there were not important changes in LGMD probably because the diversity and lack of homogeneity in affected muscles in this group.
Subject(s)
Electromyography/methods , Muscle, Skeletal/physiology , Muscular Dystrophies/physiopathology , Adolescent , Adult , Child , Child, Preschool , Data Interpretation, Statistical , Female , Humans , Male , Muscular Dystrophies/classification , Muscular Dystrophies/diagnosis , Neural Conduction/physiologyABSTRACT
Introducción. La electromiografía convencional contribuye a la distinción entre alteraciones miopáticas y neuropáticas en las enfermedades neuromusculares. Sin embargo, los patrones clásicamente miopáticos pueden, ocasionalmente, resultar en componentes neurogénicos; esta confusión puede ser por la denervación y la reinervación involucradas en estas enfermedades, de acuerdo a la etapa en que se encuentren. Objetivo. Utilizar técnicas de electromiografía cuantitativa, como el análisis del patrón de interferencia (API) para diferenciar estas enfermedades. Pacientes y métodos. Se realizó un API a 95 pacientes con distrofia muscular -52 de Duchenne (DMD), 33 de cinturas (DMC) y 10 miotónica (DM)- y se compararon con un grupo control de 25 sujetos normales. Se valoraron los músculos bíceps braquial (BB) izquierdo y tibial anterior derecho, y se estudiaron las siguientes variables: giros/segundo (G/S), amplitud/giros (A/G), relación entre número de giros y promedio de amplitud (NG/PA), potencia, percentil y raíz cuadrada de la media de la amplitud (RCMA). Resultados. En la DMD se encontraron diferencias significativas en todas las variables, tanto en el BB como en el tibial anterior (p < 0,05); en la DMC se encontraron diferencias en A/G y potencia en el BB, pero en el tibial anterior sólo en la potencia; en la DM las diferencias se observaron en A/G, NG/PA y RCMA del BB, pero en el tibial anterior, sólo en A/G. Conclusión. Todos los pacientes con DMD mostraron diferencias, pero en la DM sólo en el bíceps; sin embargo, no hubo cambios importantes en la DMC, probablemente por la diversidad y falta de homogeneidad de los músculos afectados de este grupo (AU)
Introduction. The conventional electromyography contribute to differentiation of myopatic and neuropatic patterns in neuromuscular disorders, however, the classical patterns related to myopatic changes can result in neurogenic components, this confusion could be due to denervation and reinervation changes involved at the different stages of those diseases. Objective. Demonstrate the importance of quantitative electromyographic techniques, as the interference pattern analysis (IPA), for a better differentiation of muscular dystrophies. Patients and methods. IPA was done in 95 patients with 3 different muscular dystrophies: 52 Duchenne muscular dystrophy (DMD), 33 limb girdle muscular dystrophy (LGMD) and 10 myotonic muscular dystrophy (MD) individuals and in a control group of 25 individuals. The left braquial biceps and right anterior tibial muscles were evaluated; the variables analyzed were turns/seconds (t/s), amplitude/turns (a/t), ratio turns/amplitude mean and root squared mean (RSM). Results. We found statistical significant differences in all variables in both braquial biceps and right anterior tibial muscles (p < 0.05) in DMD patients. In LGMD we only found differences in a/t in braquial biceps. In MD the differences were observed in a/t, ratio and RSM in braquial biceps, and in a/t (in anterior tibial). Conclusions. All the DMD patients show differences in IPA values in relation to control group, MD only in biceps, However there were not important changes in LGMD probably because the diversity and lack of homogeneity in affected muscles in this group (AU)
