Brain stimulation for the suppression of the intractable pain.

Stimulation of the brain has been shown to effectively suppress the clinical pain states due to central nervous system lesions. The effective stimulation site is within the somatosensory system. Stimulation in the periventricular gray matter can produce profound analgesia and effective clinical relief of chronic pain states when they are due to lesions involving the peripheral structures. This system probably is effected by activating a descending tract in the dorsal lateral fasiculus of the spinal cord impinging upon neurons in lamina 5 and lamina 1 of the dorsal bone. Stimulation in this system has not been found to be effective in patients with central lesions, which might have been anticipated in view of the anatomical relationships presented.