[Electromyoneurographic study in inflammatory and noninflammatory myopathies]

Electromyoneurographic (EMNG) study is very useful in diagnosis of myopathy. Motor unit action potentials are low-amplitude, polyphasic and short duration and can be present to variable degree in different type of myopathies. Four components of needle EMG provide important information; morphology of motor unit action potentials, spontaneus activity, insertional activity and recruitment. Myopathy associtaed with fibrillations ussualy have components of inflammation and necrosis. Although there are no EMG findings for a specific disorders or couse, the combined patterns of findings may be characteristic of certain types of myopathy.