On the operating table the young man quivers silently, a grotesque tangle of limbs. One arm is crooked back across his shoulder, and gnarled fingers are clamped into a fist. The other arm coils about his head. His left leg is doubled back toward his buttocks; the other is rigid, immobilized, toes curled misshapenly under the sole of his foot.

The paralysis has frozen his face, too. He stares unblinkingly at the team of doctors gathered around him. One of them, an imposing six-footer in green gown and surgical mask, tries again gently to straighten the young man's contorted leg. The limb remains locked, and the surgeon can feel the trembling in the patient. "We're ready now, Rod," the doctor says to him.

The chief neurosurgeon of New York City's St. Barnabas Hospital, Dr. Irving Spencer Cooper, has begun to operate on a spastic paralytic. It is as desperate a case as he has seen in a quarter century of trying to help the victims of this cruel disease.

A few centuries ago, Cooper recalls, spastics were burned at the stake as witches whose bodies were possessed by demons. Those demons, it is now understood, reside not in the spastic's body but in the brain, the control system for all human senses and movement.

At 53 perhaps the most innovative brain surgeon working today, Cooper has been able to peer into the dark world of the spastic—a prison of humiliation to its victims who are helpless to control their violent spasms and often unable to communicate except through grunts.

When Cooper, as a freshman medical student in the early 1940s, became fascinated by the human brain, surgery to aid spastics could relieve tremors only at the cost of partial paralysis. Not until a decade later, when Cooper pioneered deep brain surgery, did a spastic's chances of gaining control of his limbs improve dramatically.

Cooper seemed destined for success long before he was named at 40 as one of the most important young men in America. He is the author of a critically acclaimed book, The Victim Is Always the Same, in which he describes the problems of two spastic children and their families. He will publish Living with Chronic Neurologic Disease next month and has written his first novel, about a doctor who stops a paralyzed patient's respirator, out next year. Cooper is fluent in five languages and once kept a Berlitz specialist at the hospital to coach him in Russian between operations.

Yet his remarkable medical discoveries owe much to chance, as he himself admits. In 1951, Cooper, then a 29-year-old neurosurgeon, inadvertently severed—and then repaired—a small artery in the brain of a palsied truck driver. The accident halted the truck driver's spasms without paralyzing him. Two years later Cooper discovered, again by chance, that arterial surgery could reverse even the limb-twisting symptoms of dystonia (disordered muscle tone), always believed to be hopelessly untreatable.

From that time on, Cooper worked steadily to refine his surgical techniques. One Christmas he received an unusual wine-bottle opener, a kind of syringe which pressed cold carbon dioxide through the cork and popped it out. The gadget caught the doctor's imagination and led to his development of a new surgical process called cryosurgery (from the Greek kryos for cold or frost). It helps not only spastics but also victims of deep-seated brain tumors, glaucoma and breast and prostate cancer as well.

In November 1961 Cooper first performed cryosurgery. Using the cryoprobe, or "ice scalpel," he penetrated deep into the brain and destroyed by freezing the diseased cells that create severe muscle tension. Since then he has freed more than 75 percent of his spastic or tremulous patients of symptoms with no subsequent ill effects. Fewer than 2 percent have died from the operation.

Cooper's techniques are now used in more than 1,000 hospitals in the U.S. and 15 other countries. They have brought him worldwide renown and spacious homes in Florida and New York, a weekend retreat in the Catskill Mountains and a private library of 10,000 volumes ranging from medical tracts to Camus, his favorite author. The doctor plows back 20 percent of his six-figure income into research.

His virtuosity has also brought predictable criticism from within the medical establishment. A leading New York surgeon says, "None of us likes him—he's a loner. But scientifically he's tops, better than the rest of us." Cooper explains, "For a lot of doctors who had spent 50 years trying to find a breakthrough in this field, my invention was hard to believe. A new idea is very upsetting."

Although Cooper carefully points out that he does not cure muscular paralysis—"It's the symptoms, not the disease, we're relieving"—St. Barnabas has become a sort of shrine for thousands of spastics seeking last-resort help. When the drug L-dopa and all other treatments fail, the afflicted are brought to the red brick hospital in a desolate section of the Bronx. A successful operation on one side of the brain which results in dramatic improvement may encourage the doctor, and convince the patient, to treat the other side.

In the more than 8,000 operations he has performed himself, Cooper has also relieved the shaking palsies of Parkinson's disease and helped ease the plight of some patients crippled by strokes.

The man on the operating table is a 28-year-old teacher from California. A once robust man who played high school football like Cooper, Rod has been bedridden since 1971—a speechless spastic since his brain was severely traumatized in an automobile accident.

In the gray-tiled O.R., Cooper moves swiftly. Into Rod's scalp, shaved and gleaming under the lamps, he injects a local anesthetic and then opens an inch-and-a-half-long incision on the right side. Within 30 seconds an electric drill has bored a dime-sized hole in the skull. No further anesthesia is needed because the skull bone and the gelatinous brain have no feeling.

The limbs on one side of the body are controlled by the opposite side of the brain. Thus, to relax Rod's twisted left arm and leg, Cooper must operate on the right hemisphere of the brain.

As Cooper deftly cauterizes the tiny blood vessels on the exposed brain surface, assistants ready the cryoprobe, a slim stainless steel tube with a refrigerated tip. The tube, connected to a console designed by the doctor that holds liquid nitrogen, is poised to penetrate the cortex of Rod's brain.

The operation is being filmed. Cooper's suburban New York mansion houses more than a million feet of filmed records of patients. There are 300 notebooks crammed with his research jottings.

Such exhaustive filing habits pay off. His most recent invention is a brain pacemaker to control spasms in cerebral palsy, which has also been used in the treatment of epileptics. While studying at the Mayo Clinic in 1950, Cooper read a report on reducing muscle spasms by electrical stimulation of the brain. He made notes and filed them away. Four years ago, while researching a lecture, he found the notes. As a result, he has devised an electronic instrument which sometimes permits patients to switch off an epileptic attack before it strikes. The epileptic, using a transmitter attached to his belt, can regulate battery-powered electrodes on the surface of his brain and connected by wires to a tiny receiver placed under the skin just below the collarbone. Eventually, because of the awkwardness of the belt equipment, Cooper hopes to conceal the transmitter under the patient's skin, too.

Cooper's governing philosophy is forthright—the patient supersedes all other considerations. "I'm not doing these things to advance science or to help my technique," Cooper says. "I'm doing them only to help the patient. If I'd had any other motivation I would never have lasted."

Some of his medical peers believe that Cooper's ample ego and a fondness for acclaim are what drive him. His 37-line bio in Who's Who is longer than President Ford's. Describing his work, Cooper says, "There is a vanity to it, a whole complex of gratifications. I identify with my technique the same as I would with my own child." But, he adds, if things go wrong "the agony is greater."

Cooper's enviable life-style, too, seems more sumptuous than that of most of his colleagues. He has a stunning young Norwegian wife (his second), four children and a white schnauzer, Odin. Their three-story home is decorated with surrealist art and has a private paddle-tennis court and a pool whose bathhouse is equipped with a bar.

A touch of the regal attends Cooper's periodic sweeps through St. Barnabas' sick wards, trailed by an entourage of aides. Yet his patients regard the surgeon as more saint than ruler, a man who is extraordinarily adept at conveying compassion. At meetings with patients and their families, Cooper soothes and gives hope even to those who have reached the outer limits of despair. Some patients plead for an operation, but he is firm in his refusal if a patient's condition does not warrant the risk. For those terrified at the thought of surgery, he has all the right words to reassure them. "The amazing thing," he says, "is how courageous most of them are."

Cooper has become close friends with many of the patients he's operated on and then examined regularly for years afterward. The fact that Cooper treats them with "my inventions," he says, "heightens my responsibility." And because his patients must remain awake throughout the operation—so he can consult with them on every step—Cooper says, "You're conscious every second of the risk."

How can he continue day after day under such emotional pressures, with such life-and-death responsibilities? "It's because of the enormous thrill in setting free someone who's been imprisoned in his own body. But I'm a reluctant surgeon. I really don't like to operate. I do it as a means toward an end—to make such operations, one day, obsolete."

Slowly Cooper maneuvers the tube through the cortex of the brain until the tip touches a part of the thalamus nearly two and a half inches below the surface. An aide starts the flow of liquid nitrogen into the tube. The surgical team pauses to check X rays that show Cooper the exact location of the tube's point. "Minus 10," Cooper snaps, as the first spurt of subfreezing fluid begins saturating a diseased area the size of a large pea. The temperature drops rapidly on the doctor's command. At minus 70° centigrade. Cooper turns to the patient. "Can you move the fingers of your left hand, Rod?"

Like a plant unfurling, Rod's gnarled fist opens.

"Lift your left leg, Rod."

The surgeon watches the limb uncoil and rise haltingly above the table. One hour and 45 minutes have passed since surgery began. Cooper smiles and grips Rod's hand in his. The operation is over.