Electrophysiologic studies in the diagnosis and prognosis of motor neuron diseases.

The identification and characterization of motor neuron diseases, such as amyotrophic lateral sclerosis, can be much enhanced by electrodiagnostic testing. Combinations of needle electromyography, nerve conduction studies, and other techniques can not only confirm the diagnosis or identify the presence of unsuspected disease, but can also provide clues to the rate of progression and prognosis.