Premotor potentials.

The topic of this article is probably unfamiliar to most electromyographers. These potentials can be seen at high amplification immediately preceding the median or ulnar compound muscle action potential (CMAP) during standard motor nerve conduction studies. A chronological review of premotor potentials is provided. After longstanding debate, eventual determination of their electrophysiologic origin employed analysis of these potentials using volume conduction principles. The significance of premotor potentials is addressed.