What is ALS?

ALS, or amyotrophic lateral sclerosis, is a progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord.

”Amyotrophic” comes from the Greek language. "A" means no. "Myo" refers to muscle.  "Trophic" means nourishment. So, amyotrophic means "no muscle nourishment,” and when a muscle has no nourishment, it "atrophies" or wastes away.

"Lateral" identifies the areas in a person's spinal cord where portions of the nerve cells that signal and control the muscles are located.

As this area degenerates, it leads to scarring or hardening ("sclerosis") in the region.

man in wheelchair painting

Motor neurons reach from the brain to the spinal cord and from the spinal cord to the muscles throughout the body. The progressive degeneration of the motor neurons in ALS eventually leads to their demise.

When the motor neurons die, the ability of the brain to initiate and control muscle movement is lost. When voluntary muscle action is progressively affected, people may lose the ability to speak, eat, move and breathe.

The motor nerves affected when you have ALS are the motor neurons that provide voluntary movements and muscle control. Examples of voluntary movements are making the effort to reach for a smartphone or step off a curb. These actions are controlled by the muscles in the arms and legs.

French neurologist Jean-Martin Charcot discovered ALS in 1869. While ALS can affect anyone, anywhere, at any time, there are two different ways cases are categorized.

  • For about 90% of all cases, there’s no known family history of the disease or presence of a genetic mutation linked to ALS.
  • For 5-10% of all cases, there’s a known family history of the disease. This is often called familial ALS.

In families with familial ALS, there is a 50% chance each offspring will inherit the gene mutation and may develop the disease.

For unknown reasons, military veterans are more likely to be diagnosed with the disease than the general public.

A wealth of new scientific understanding about the physiology ALS has occurred in recent years. There are currently seven drugs approved by the U.S. Food and Drug Administration (FDA) to treat ALS and its symptoms: Qalsody, RELYVRIO, Radicava, Rilutek, Tiglutik, Exservan and Nuedexta.

UPDATE – APRIL 2024: Relyvrio was voluntarily withdrawn from the market by Amylyx following a phase 3 trial that failed to show it was effective. The ALS Association stands by its decision to push for early approval of Relyvrio given the promising phase 2 trial data and the safety of the treatment. At the time, we said that if it turns out to be ineffective, at worst, people living with ALS would have taken an ineffective therapy without risk of harm. If it was indeed effective, delaying access would have meant that people living with ALS would have lost two years of being able to take a life-extending therapy. In the interests of transparency and education, we are leaving this information up for future reference. People living with ALS need life-saving treatments and we are working as urgently as possible to advance the many more potential treatments in clinical trials.

Studies to develop more treatments and a cure for ALS, many funded by The ALS Association, are ongoing around the world. Scientists have made significant progress in understanding how the disease works, identifying biological indicators that can help diagnose and treat the disease, and learning ways to prevent cases of ALS. Learn more about ALS research.

In addition, people living with ALS may experience a better quality of life by participating in support groups and attending one of The ALS Association’s Certified Treatment Centers of Excellence or a Recognized Treatment Center. Such Centers provide a national standard of best-practice multidisciplinary care to help manage the symptoms of the disease and help people living with ALS live on their own terms for as long as possible.

According to the American Academy of Neurology’s Practice Parameter Update, studies have shown that participation in a multidisciplinary ALS clinic may prolong survival and improve quality of life.

Click here to find a Center near you.

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