Interpretation of electroneuromyographic studies in diseases of neuromuscular junction and myopathies

Electroneuromyography (ENMG) also called electrodiagnosis or at times simply (and erroneously) electromyography (EMG), has been used for the diagnosis of neuromuscular and muscle diseases. It consists of tests done serially and assessed collectively, to arrive at a diagnosis of neuromuscular weakness. The test should be treated as an extension of the clinical examination and not a replacement. When done adequately ENMG is the only test which gives information about the function of the peripheral nervous system and hence co-relates well with the clinical signs. This article reviews the role of ENMG in the evaluation of neuromuscular and muscle disease. We hope this will meet the requirements of both practicing neurologists and dedicated electromyographers.