Clinical neurophysiologic testing plays a critical role as a complement to the clinical assessment in patients who are being evaluated for a variety of neurologic symptoms. Many different techniques and methods of assessment can be used to evaluate the function of the nervous system, including electroencephalography, electromyography, evoked potentials, movement disorder studies, and sleep studies. An accurate understanding of the role of these tests and reliable technical performance and interpretation of these studies is critical in clinical practice. This new edition in the Contemporary Neurology Series remains an essential resource for physicians and technologists learning or utilizing clinical neurophysiology in their training or practice.