Why did Stephen Hawking live so long?
Stephen Hawking was just 21 years old when he was told he’d only have two years to live. But it wasn’t until earlier this week that he died at the age of 76.
The world-renowned physicist, cosmologist and author of A Brief History of Time, defied incredible odds by living with amyotrophic lateral sclerosis (ALS) for over five decades.
The average survival rate for people with the motor-neuron disease is two to five years from the time of diagnosis, making Hawking’s long life a mystery of medicine.
Prof Tissa Wijeratne, who leads the neuroscience research unit at Melbourne’s Western Hospital, told news.com.au neurology and disorders affecting the brain and nerves is a “fascinating specialty”.
“On average many folks with ALS live a few years from the diagnosis,” he said.
“There are people who live for a long long time too. This is due to the amazing variability of how this disorder affects different human bodies.”
He added: “There are variants of ALS that progress very, very slowly: PMA or progressive muscular atrophy is one such example.”
“These patients can live for a long long time.”
Leo McCluskey, an associate professor of neurology and medical director of the ALS Center at the University of Pennsylvania, told the Scientific American that life expectancy was down to two things.
“The first thing is motor neurons running the diaphragm — the breathing muscles,” he said.
“So the common way people die is of respiratory failure. And the other thing is the deterioration of swallowing muscles, and that can lead to malnutrition and dehydration.
“If you don’t have these two things, you could potentially live for a long time — even though you’re getting worse.
“What happened to him is just astounding. He was certainly an outlier.”
Dr. Lucie Bruijn, the ALS Association's chief scientist in the US, said, "We wish we knew because that would give us clues to treatment.”
"His lifespan is exceptional. I think there are few — I certainly don't know of any others — that have had such a long lifespan,” he added.