Clinical Electromyography (Nerve Conduction Studies and Needle Electromyography)

Nerve conduction studies and needle electromyography are often crucial during the evaluation of patients with disorders of the anterior horn cells, spinal roots, sensory nerves, motor nerves, neuromuscular junctions, or muscles. The studies are performed with a guidance of the neurological examination, and the findings should be interpreted within the clinical context. In this chapter, basic principles of NCSs and needle EMG will be discussed, followed by a review of methodology, indications for performing NCS-EMG, and electrophysiologic findings in common neuromuscular disorders.