Somatosensory evoked potentials in lumbar stenosis.

The present findings suggest that, in patients with similar symptoms and findings, both physical and roentgenographic, the radiculopathy in those whose evoked potentials became abnormal after walking or change in posture had a mechanical cause. Consequently, operation designed to correct a mechanical problem was associated with a better result than in those patients in whom the evoked potentials were unaffected by these maneuvers. The recording of somatosensory evoked potentials is a noninvasive, painless, safe and relatively inexpensive procedure which appears to be a useful adjunct in the diagnosis and treatment of patients with lumbar stenosis and may help differentiate neurogenic from vascular claudication when these conditions cannot be clearly distinguished clinically.