Peripheral Nerve Stimulator Implant for Treatment of RSD

Abstract

Injury to peripheral nerves may produce causalgia as described in detail in preceding chapters. Sweet and Wepsic (1,2) utilized electrical stimulation to treat causalgia involving the median and ulnar nerves, to produce a pleasant “tingling” and loss of the burning pain in many cases.

Subsequently, surgical techniques were developed for implanting two different types of peripheral nerve stimulating electrodes for treating causalgia (3,4). Varying success rates were reported with these electrodes; for instance, 58% (5) and 52.6% for upper extremity and 31% pain relief for lower extremity pain (4,6). However, foreign body reactions related to direct electrode contact with the nerve, was one limitation to the usefulness of this therapy. A surgical implantation technique was therefore developed, that creates a barrier between the nerve and the electrode, by covering the electrode with a thin fibrous membrane from intramuscular septa. The stimulator also has the capacity to be periodically cycled and to change pulse width.