Neuromodulation: spinal cord and peripheral nerve stimulation.

Spinal cord and peripheral nerve stimulation for relief of chronic intractable pain have been used since the mid-1960s. Multiple mechanisms of action have been theorized without a clear-cut winner. The early frustrations with patient selection criteria and equipment difficulties have diminished secondary to carefully controlled studies and improvements in equipment designs. Efficacy studies consistently show an overall 50% improvement in long-term pain control in patients who have failed conservative or other invasive modalities. With improvements in today's technology, one hopes that better analgesia will be attainable.