DIRECT INTRANEURAL SPINAL NERVE-STIMULATION

During 1982-93 17 patients with intractable pain and some motor dysfunction were treated with intraneural spinal nerve stimulation (ISNS) at the cervical or lumbar level. The study groups included one patient with post-herpetic pain of the trigeminal nerve with facialis paresis; in this patient, intraganglionic stimulation (IGS) of the gasserian ganglion was performed. During ISNS and IGS procedures, intensive physical therapy was performed, followed by 3-6 months of ambulatory physical therapy treatment. ISNS and IGS were repeated two to three times during 1 year. Duration of the total treatment lasted 12-36 months. The 17 patients were divided into groups: seven with laminectomy pain syndrome with reflex sympathetic dystrophy (RSD) in the lower limb; seven with post-traumatic RSD in the lower limb; two with post-stroke pain syndrome with hemiparesis; and one with post-herpetic neuralgia of the trigeminal nerve with facial paresis. In all patients, criteria for selection were based on the presence of an obvious sympathetic hyperactivity and sensory abnormalities. All patients were classified as having neuropathic(14) or deafferentation(3) pain syndrome. All patients had previously undergone a variety of different treatment regimens. The long-term results showed pain relief in 70.5 per cent of the patients; and an increase in motor function and mobility was observed in 76.4 per cent of the patients. In this preliminary report, the techniques of ISNS and IGS are described and the results are discussed. According to Devor's hypothesis of neuropathic pain mechanism, our clinical observations indicated that the combination of peripheral pathomechanism and its triggering influence on the central sensitization in the spinal column and spinothalamocortical pathways, plays in role in both of these pain syndromes.