What is ALS, the disease Stephen Hawking lived with for 50 years?

(CNN) — Amyotrophic Lateral Sclerosis (ALS) is a progressive and neurodegenerative disease. It affects the nerve cells in the brain and spinal cord that make the muscles of the body move.

With disease, these nerve cells lose their ability to initiate and control muscle movement, leading to paralysis and later death. People with this disease lose control of the movement of their muscles, and sometimes they also lose the ability to eat, speak, walk and, ultimately, breathe.

The most famous patient with the condition was physicist Stephen Hawking, who died on Wednesday at the age of 76.

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ALS (ALS) is also known as Lou Gherig’s disease, named for a baseball player who retired because of the disease. Other known sufferers include actor David Niven, NBA player George Yardley, and jazz musician Charles Mingus.

Little is known about the causes of this disease, and there is currently no cure. Slightly more men than women suffer from it.

Unusually long duration

Hawking, diagnosed with the disease in 1963, lived with it for more than 50 years – an unusually long duration for an ALS patient.

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The ailment left him completely paralyzed and dependent on others and technology for everything: bathing, dressing, eating, moving and talking. He was only able to move a few fingers on one of his hands.

In 1963, Hawking was diagnosed with amyotrophic lateral sclerosis. Three years later he completed his doctoral work in physical theory. His thesis was on black holes. (Credit: MENAHEM KAHANA / AFP / Getty Images)

“I try to have as normal a life as possible and not think about my condition or regret the things that it prevents me from doing, which are not many,” he wrote on his website.

“I have been fortunate because my condition has evolved more slowly than it usually does. But still it is necessary not to lose hope,” he added.

Hawking’s life, including his battle with ALS, was made into a movie in 2014: in the movie ‘The Theory of Everything’, starring Eddie Redmayne.

LOOK: What are the signs and symptoms of amyotrophic lateral sclerosis?

17 million people joined the popular ‘Ice Bucket Challenge’ in 2014, including Italy’s national soccer team, pictured in September of that year. (Credit: ALBERTO PIZZOLI / AFP / Getty Images)

El reto ‘ice bucket challenge’

The US Centers for Disease Control (CDC) estimate that between 20,000 and 30,000 people in the country suffer from ALS, with about 5,000 new cases each year. The diagnosis usually comes when patients are between 55 and 75 years old. On average, patients live between two and five years after symptoms begin.

There are two types of ALS: sporadic, which is more common, and familial. The latter is hereditary: the children of the sick have a 50% chance of inheriting the condition, and people with familial ALS live on average only between one and two years after symptoms appear. However, this is much rarer: 90% of cases are sporadic ALS.

The disease became well known in 2014, when Pete Frates, a former Boston College basketball player who had lived with ALS since 2012, began the ice bucket challenge. The challenge went viral and greatly improved awareness of this disease, as well as generating a huge increase in donations to the ALS Association.

“We have never seen anything like this in the history of the disease,” said Barbara Newhouse, president and CEO of the association, in a press release at the time.

LOOK: They discover the gene responsible for amyotrophic lateral sclerosis thanks to the challenge of the ice bucket

Unknown cause

No one knows what causes this disease, and for reasons still unknown, military veterans are twice as likely to be diagnosed with ALS, according to the ALS Association.

Scientists have been studying many factors that could be linked to ALS, such as genetics and environmental exposures, “says the CDC.

“Other scientists have studied diet or injury. No cause has been found for most cases of ALS. In the future, scientists may find that many factors together cause ALS.”

Until last year, there was only one drug approved by the Food and Drug Administration (FDA) for ALS. This only prolonged survival for a few months. In May 2017, the FDA approved the first new drug in more than 20 years to treat the condition.