In Awakenings, Robin Williams plays a shy, woolly, plant-loving neurologist named Dr. Malcolm Sayer—a fictionalized version of Dr. Oliver Sacks, the shy, woolly, plant-loving neurologist who lived through the astonishing, and heartbreaking, medical drama that is the basis for the acclaimed hit movie. The British-born Sacks, now 57, presided over what could be called the temporary rebirth of 80 patients who had been shut away for decades at Beth Abraham Hospital in Bronx, N.Y.

These patients were the victims of an epidemic of sleeping sickness—encephalitis lethargica—that broke out after World War I. Between 1916 and 1927, 5 million people contracted the illness worldwide; a third of them died. And thousands who survived later found themselves being attacked by a progressive form of parkinsonism so severe that they became, in effect, "frozen"—catatonic, locked in grotesque postures. In 1969, Sacks began to give his patients the drug L-dopa (short for laevodihydroxy-phenylalanine), touted at the time as a miracle treatment for Parkinson's disease. The results were indeed miraculous, and almost instantaneous, as previously unreachable patients began talking and walking again.

But within months, the miracle faded. The patients were overwhelmed by tics and manic behavior—side effects of L-dopa, perhaps, or the result of some deeper imbalance between the newly awakened and the world they had awakened to. For most of the patients, when the L-dopa experiment ended, a new ice age began.

In 1973, Sacks published Awakenings, a compassionate collection of case histories. Today he writes and continues to work in hospitals, including—until two weeks ago—the Bronx Psychiatric Center. He was pink-slipped, along with 1,200 other New York State health-care workers, for budgetary reasons. ("The cost in human terms," he said, "will be incalculable.") Recently Sacks, a bachelor who lives on City Island in a little red house with a white picket fence, met with writer-reporter Sue Carswell in his Greenwich Village office to talk about the true story behind Awakenings.

I got to Beth Abraham in 1966 as a young doctor, a year out of residency. Beth Abraham is a chronic hospital, an asylum. When I got there, I saw a melancholy scene of patients in wheelchairs, amputees, people with cerebral palsy, multiple sclerosis and strokes—as one sees in any chronic hospital. But there also were these "frozen" people who would often be standing up in a trance. I found these the strangest patients I had ever seen.

There were 80 of these patients at Beth Abraham in 1966. Sometimes they would come alive briefly. Once a patient brought a dog to the hospital. The poodle jumped up on a woman who was always frozen, and suddenly she belted out that she loved animals. She started stroking the dog and laughing. When the animal went away, once again she was frozen.

There were different degrees of this frozen state. One woman, Rosalie, would be frozen for hours, her fingers seemingly stuck to the lenses of her glasses. But she was extremely musical and could play the piano beautifully. Miriam knew all of Dickens by heart. Those who couldn't read had at least some freedom of the imagination. But some couldn't even imagine—they were the ones who were completely frozen.

Leonard [who inspired the Robert De Niro character in the movie] taught me more about parkinsonism, post-encephalitic illness, suffering and human nature than all my other patients combined. He was a very superior, educated man. He had gone to Harvard but was not able to complete a postgraduate degree because he became too frozen. He had started to become ill during his adolescence when his right hand grew stiff. When he was 27, his mother brought him to Beth Abraham.

When I saw him in 1966, he was 46 years old, a very stiff, motionless man. Despite his frozenness, he had very bright, mobile, mischievous eyes that really gave me a sign of intelligence. He was in charge of the hospital's library. He would read very slowly, but with great concentration and memory. His mother, who was with him 12 hours a day, would turn the pages. He would express himself by slowly using his index finger to tap on a letter board.

It didn't seem as though anything could be done for these patients. But when I had been at the hospital for six months, a famous paper by Dr. George Cotzias came out on the use of L-dopa for patients with Parkinson's. I had to think what L-dopa might be like for patients like mine. Their situation was much more complicated. Many of them had histories of having been "hyper," compulsive and volcanic in the past—I had to wonder what might leap out from within. And they had been dislocated from the world for so long.

I hesitated for two years because of these doubts. Then I decided I would start to use L-dopa. Leonard was the first patient I put on the drug. When he "awakened," his eyes became brighter, the stiffness melted, and he started to speak up. His voice became louder and louder. Things started to move inside for him. He kept talking about how he felt as if this was a resurrection. He was so lyrically happy. He would say, "If people felt as good as I did, nobody would make wars."

Leonard's mother's reaction was more complicated. At first she was delighted with the L-dopa. But then she became upset, especially when he said to her, "Why don't you take off to Florida for a while? I can manage alone." She would say to me, "You've taken away my baby with your darn 'L-dopey.' "

There were 80 patients who were awakened between March and July 1969. These vivid, idiosyncratic lives were sprouting. Some of the patients could be seen dancing together in the wards. But things started to go badly in July. For Leonard, physical things became tremendously accelerated. He had all sorts of tics. Reading became more and more difficult—his eyes would rush on ahead. He would repeat words. He wrote his autobiography during this time. This was a sizable thing—50,000 words. He wrote it in 10 days. As soon as he stopped typing, he would be ticcing frantically again. But it was when the book was completed that I think he didn't have anything left to hold him together.

Tensions started to come. Some of these began with a sort of falling in love that became too urgent. At first Leonard was mildly flirtatious. He liked exchanging kisses with the nurses. Then the erotic fantasies became more extreme. He wanted a brothel service to be set up. When he got rebuffed, he would start masturbating, getting angry, and then grandiose feelings appeared. He was the Messiah and other people were in the darkness. He wanted to go out and preach the gospel according to L-dopa. [Leonard was periodically administered L-dopa without any lasting success for another 12 years. He died in 1981.]

I think my patient Rose was perhaps the strangest and saddest of them all. When she came to, she had obsolete mannerisms and speech patterns—she was somewhat like a flapper come back to life. She would talk about Gershwin and other people who had been around back then as though they were still here. She said, "I know I'm 64, but I feel as though I'm 21. I know it's 1969, but I feel it's 1926." She had once been a vivacious woman in the swirl of things. Suddenly she found herself an aging woman, somewhat crippled, living in a hospital. She didn't like it. She said to me, "I don't like your Television Age. It's trash." Ten days later she went back into the trancelike stage. Nothing we could do would ever change this.

This had become a heaven-and-hell experience. But the patients would just have died without having even a glimpse of that life had they not been given L-dopa. What I did regret, and what many of the patients did as well, was that this was not available 10 or 20 years before, when they had not lost so many of their connections to the world. Maybe they would have had a better chance of coming to for a long time.

I think this film has been done rather eloquently. I spent a lot of time taking the actors to patients and showing them footage from 1969. Bob [De Niro] is a very deep observer. Nothing is real to him until he can feel it in his body and represent it. If he couldn't act it, then it couldn't be acted. I spent a lot of time with Robin. We hung out together and saw patients. I think he's a man of great curiosity and moral seriousness under his clowning.

Out of the original patients, only Lillian is still living. At 65, she's been on a modest dose of L-dopa for 21 years. [Her intellect remains sharp, but her motor functions have continued to deteriorate.] She was brought to the movie set one day. The actors just wanted to touch her in this purely magical way. In one scene, a frozen Leonard is being read to. Lillian herself was in one of these trancelike postures when Bob was brought in in a wheelchair. He took up that posture, and she shot a quick glance of approval at him. "He's got it," she was saying. "He understands us. It's okay."