Pain reduction by electrical brain stimulation in man. Part 1: Acute administration in periaqueductal and periventricular sites.

Acute studies performed in five patients indicate that electrical stimulation of the brain could be a powerful tool for the reduction or control of intractable pain. While chronic or spontaneous pain could be relieved by stimulation of the periaqueductal gray matter, the accompanying side effects render it impossible to stimulate this site regularly. On the other hand, stimulation of medial thalamic sites, particularly medial to the nucleus parafascicularis, yielded good relief of chronic pain at parameters which did not cause many undesirable side effects. The same parameters also produced inhibition of acute pain in two of the five patients.