Neurophysiologic evaluation of patients with low back pain.

1. Neurophysiologic testing is as accurate as CT scanning or myelography in the diagnosis of root compression due to disk disease. 2. The most reliable findings are abnormal H reflex, and positive sharp waves or fibrillations, or both, in the appropriate muscles. 3. Neurophysiologic testing may be more accurate than clinical examination or radiologic study in patients with canal stenosis. 4. Symptomatic post-laminectomy patients present a difficult diagnostic problem, even when all available methods are used.