Who is the current longest surviving person with ALS?

Stephen Hawking at a photo call for a gala screening of the documentary ‘Hawking’

Stephen Hawking, who died Wednesday at the age of 76, had lived with the crippling disease ALS for 55 years. How did he do it?

Probably in no small part because he was rich, famous and extremely well cared for, experts said.

Hawking was one of the best-known scientists of modern times, as famous for his motorized wheelchair and computer-generated voice as he was for his user-friendly explanations of esoteric physics and cosmology.

His intellectual strengths were the stuff of awe, but so was his ability to lead not simply a normal life, but an extraordinary one, while suffering with a tremendously debilitating condition.

Amyotrophic lateral sclerosis or ALS is one of several types of motor neurone diseases. It gradually and inexorably paralyzes patients, usually killing within about four years.

Hawking was diagnosed in 1963, when he was just 21 years old. He survived for 55 years with the incurable condition.

“His survival is longer than most,” said Dr. Jeffrey Elliott, chief of the neuromuscular disorders section at the University of Texas Southwestern Medical Center. “I think part of his longevity may have been because he had a slowly progressive form. Probably it was also due to the exclusive nursing and medical care that he received.”

Hawking received round-the-clock medical care, at first from a wife who gave up her career ambitions to tend to him, and later from a team of nurses. He was told when diagnosed that he likely would not live long — but he beat the odds.

According to the ALS Association, half of all people affected with ALS live at least three or more years after diagnosis. Twenty percent live five years or more; up to 10 percent will live more than 10 years.

People diagnosed when they are young, as Hawking was, live for longer for reasons that are not well understood. It may be that a different cause of the disease shows up in young adults.

“One type of ALS is caused by a change in gene A, another by gene B. There are different causes, also, for sporadic ALS,” said Elliott.

Over the years there was speculation about whether Hawking had an unusual form of ALS.

Elliott said in his experience, people who get better care tend to live longer. “Survival really depends on the type of medical and nursing care that they get,” he said. The longest any of his patients have survived is about 20 years, he said.

The paralysis caused by ALS puts people at risk of choking, pneumonia and digestive blockages, as well as other infections.

Most eventually require a ventilator and that requires constant maintenance and monitoring to prevent infections and to make sure the patient has good oxygen levels.

Many patients opt out of the expensive and time-consuming treatment needed to stay alive and healthy, Elliott said.

‘Mental attitude makes a difference’

Hawking’s needs took a toll on his marriages. He divorced his first wife, Jane Wilde, after 30 years and she’s written about the challenges of being married to such a single-minded man in need of so much attention —medical and otherwise.

He married one of his nurses, Elaine Mason, in 1995, and they later divorced in 2006.

Could Hawking’s devotion to his career have helped keep him alive? “Mental attitude makes a difference, for sure,” Elliott said.

Hawking said so, also.

“When you are faced with the possibility of an early death, it makes you realize that life is worth living and that there are a lot of things you want to do,” Hawking was quoted often as saying.

There is no cure for ALS, although two drugs are approved to help treat some of its symptoms. Patients progressively lose the use of their muscles, often becoming completely paralyzed except for their eyes.

The Centers for Disease Control and Prevention reports that 12,187 people in the United States have ALS. It can’t tell how many new diagnoses are made every year yet, but a new registry shows that four in every 100,000 people has ALS