Neurosurgery: Electrical Relief of Pain

When pain becomes so severe that doctors call it “intractable,” they mean that it cannot be controlled by any safe and simple dosage of drugs. Even the most severe pain can usually be alleviated by cutting the appropriate nerve fibers in the spinal cord, but this in itself is considered major surgery, and too drastic an operation for some patients. The cord-cutting procedure has an added disadvantage: when the patient recovers, he will have suffered permanent loss of feeling in the affected part of his body. Now an imaginative University of Chicago neurosurgeon has devised a way to achieve the desired relief of pain by a relatively minor operation under a local anesthetic. His method also permits the numbed area to regain sensation after about six months.

Dr. Sean F. Mullan begins with a simple injection of anesthetic into the side of the neck, just below the skull—one place where the spinal cord and its multiplex nerve cables are not completely encased in bone. Then he inserts a hollow, stainless-steel needle, only one hundredth of an inch in diameter, and guides the needle toward the nerves he wants to deaden with the aid of instant X rays that an assistant hands to him every ten seconds. One group of nerve fibers in the spinal cord serves the legs, another the trunk, and a third the arms. When the tip of the hollow needle is in about the right place, Neurosurgeon Mullan blows in a little air, then a radiopaque dye, so that the final, precise positioning will show on the X rays.

Satisfied that the needle’s tip has found its mark, Dr. Mullan sends a weak, 4-volt current through it for about ten minutes. During this time he checks the painful areas with repeated pinpricks, and the still-conscious patient reports to the surgeon when he can no longer feel the pin.

Although none of the spinal cord is literally cut, the effect is temporarily the same: some nerve fibers are killed, and others are so damaged by the electric current that they take months to revive. More than half of the first 250 patients treated by Dr. Mullan with his new technique have been in the final stages of cancer. For others, suffering from shingles, some forms of arthritis, and nerve damage resulting from injuries, relief has lasted an average of six months. If and when the pain returns, the operation can be repeated.