Percutaneous central gray stimulation for cancer pain.

Electrical stimulation of the periventricular and periaqueductal gray matter via a percutaneous electrode appears to be a useful method for relieving cancer pain with midline and bilateral distribution. Due to the nondestructive character and the minor surgical risks involved in this procedure it may be tried before considering bilateral cordotomy or myelotomy. A possible mechanism of action or at least a contributive factor to the pain relief is the activation of endorphins.