ABSTRACT
The original studies utilizing spinal cord and peripheral nerve stimulation for pain were based upon the gate control theory developed by R. Melzack and P. D. Wall. It was proposed that the transmission of information related to noxious stimuli is controlled at spinal cord levels; the degree of transmission is determined by the balance of activity between large-and small-fiber peripheral systems. When pain is located in the perineum and lower limbs, our patients have reported greater relief of pain when currents are applied through electrodes placed anterior to the spinal cord. Patients underwent spinal cord stimulation using the subdural method described. Spinal cords were also otained from four patients who died of cancer, but had no evidence of metastases involving the CNS, and from four patients who died of nonneoplastic disorders. Epidural monopolar electrodes currently in use inject less current into the spinal cord than the alternate polarity arrays or the anterior to posterior array.
