Practical Approach to Electromyography

Electromyography (EMG) is an extension of the neurologic examination, and it should be performed only after a focused history and examination. Every EMG should be individualized and based on the clinical scenario under which the EMG is being conducted. This book serves as a practical guide for clinicians for performing EMG. It is divided into three sections. Section I starts with a brief introduction to clinical EMG followed by several chapters that summarize the approach to different clinical problems encountered in the EMG laboratory. These problems include carpal tunnel syndrome and other entrapment neuropathies, radiculopathy, plexopathy, polyneuropathy, motor neuron diseases, and neuromuscular junction disorders. The second section highlights technical aspects and potential pitfalls of sensory and motor nerve conduction studies (NCSs). The proper placements of recording and stimulation electrodes for common NCSs are illustrated with black and white photographs. The section also includes instructions for performing cervical root stimulation to help guide more experienced electromyographers. Section III begins with an introduction to needle EMG examination, and is followed by a pictorial guide for the proper placement of needle electrodes into different muscles. The technique of muscle localization is emphasized by palpation while the patient alternately contracts and relaxes the target muscle. At times, lines were drawn on the patient’s skin to highlight anatomic landmarks or the borders of individual muscles.