In 1970, we began implanting electrodes for prolonged stimulation of
injured peripheral nerves to reduce chronic pain. Thirty-eight peripheral
nerves in thirty-five patients have been stimulated with electrodes for a
period ranging from four to nine years. Nineteen electrode systems were
implanted in the upper extremity (eleven on the median nerve, six on the
ulnar nerve, one on the median and ulnar nerves, and one on the median and
radial nerves), with successful relief of pain in 52..6 per cent of the
patients. Sixteen stimulators have been implanted on the sciatic nerve with
a success rate for pain relief of 31 per cent. Failures in the lower
extremity were found primarily in lesions of the posterior tibial nerve at
the ankle. We speculate that the stress of weight-bearing and the
anatomical position of the posterior tibial nerve may partially account for
this rate of failure. Use of the electrode-implant systems required careful
preoperative assessment by an experienced team, meticulous technique, and a
mechanical system that tolerates stress. The location and characteristics
of the lesion affect the response to electrical stimulation.