Chronic thalamic and internal capsule stimulation for the control of central pain.

Thalamic electrical stimulation by means of chemically implanted electrodes and an externally placed transmitter was effected in patients with central pain. Good response was obtained in four patients with anesthesia dolorosa, four with thalamic syndrome, and one with paraplegic pain. Two patients with medullary syndrome experienced no relief. The mechanism of thalamic stimulation in the relief of pain is discussed and further clinical trials are anticipated.