Basic concepts of needle electromyography

Abstract

Korea Clinical evaluations, nerve conduction studies, and electromyography play major complementary roles in electrophysiologic diagnoses. Electromyography can be used to assess pathologic changes and localize lesions occurring in locations ranging from motor units to anterior-horn cells. Successfully performing electromyography requires knowledge of the anatomy, physiology, and pathology of the peripheral nervous system as well as sufficient skill and interpretation ability. Electromyography techniques include acquiring data from visual/ auditory signals and performing needle positioning, semiquantitation, and interpretation. Here we introduce the basic concepts of electromyography to guide clinicians in performing electromyography appropriately. Visual evoked potentials (VEPs) are frequently used to assess the anterior and posterior visual pathways. In particular, the use of VEPs have been increasing in various fields such as evaluation of the optic nerves in patients with multiple sclerosis. The performance of VEP test can be affected by various factors such as stimulus type and subject condition, and its interpretation is also difficult. However, there have been no guidelines for performing and interpreting VEPs in Korea. Therefore, we aimed to provide comprehensive information regarding basic requirement and interpretation for VEPs.