Nerve conduction studies (NCSs) and needle electromyography (EMG) should be considered extensions of the neurologic history and examination of the peripheral sensory and motor systems. NCSs assess large, myelinated sensory and motor nerve fibers. EMG assesses primarily type 1 muscle fibers. Because of the limitations of NCSs and EMG, small-fiber function (ie, small-fiber neuropathies) and, to an extent, type 2 muscle-fiber diseases (ie, steroid myopathy) cannot be excluded with these studies. The main goal of NCSs and EMG is to obtain objective evidence of disease within the peripheral nervous system and to assist with localization of the problem.
Potential risks of nerve conduction studies and needle electromyography
