Amyotrophic lateral sclerosis (ALS), the disease that inspired the viral Ice Bucket Challenge, is a degenerative motor neuron disease with no known cure. Also known as Lou Gehrig’s disease, this rare and fatal condition is known for its rapid progression.

In this article, Ability Central dives a little deeper into the disease to answer the following questions:

• What is amyotrophic lateral sclerosis (ALS)?
• Why is ALS called “Lou Gehrig’s disease”?
• What are the two types of ALS?
• Who is most likely to be affected by ALS?
• What causes ALS?
• Is ALS a genetic disorder?
• How does ALS affect communication?
• Where can I get more information about ALS?

What is amyotrophic lateral sclerosis (ALS)?

Amyotrophic lateral sclerosis (ALS) is a rare and fatal nervous system disease. The disease is progressive, which means it gets worse over time. ALS affects nerve cells in the brain and spinal cord, which causes the loss of muscle control.

ALS attacks the motor neurons that control voluntary muscle movements like chewing, walking, and talking. Over time, the motor neurons degenerate and die. As the neurons stop sending messages to the muscles, the muscles begin to weaken, twitch, and waste away. 

ALS progresses so rapidly that it is typically fatal within 3 to 5 years after diagnosis, although some people—like astrophysicist Stephen Hawking—can live for years or decades after diagnosis. 

The most common cause of death in people with ALS is respiratory failure, as the nerves associated with breathing die off. 

In mid-2014, a viral Internet campaign called the Ice Bucket Challenge raised awareness about ALS and also raised approximately $135 million for ALS research. At this time, however, there is still no cure for the disease. For more information on the earliest signs and symptoms of ALS, see Symptoms and Stages of Amyotrophic Lateral Sclerosis (ALS).

Why is ALS called “Lou Gehrig’s disease”?

Lou Gehrig was a famous baseball player for the New York Yankees in the 1920s and 1930s. In 1938, at only 35 years old, Gehrig began exhibiting concerning symptoms that impacted both his ability to play baseball and his daily life. 

In 1939, Gehrig retired from the game in the same year that he was diagnosed with ALS. He passed away from ALS complications only two years later. 

Today, we often hear ALS called “Lou Gehrig’s disease” in honor of Gehrig’s life, both as a baseball player and as an advocate for medical research. Major League Baseball also hosts Lou Gehrig Day on June 2nd of each year to raise awareness and funds for ALS research.

What are the two types of ALS?

There are two types of ALS:

• Sporadic ALS. Most cases of ALS are considered sporadic, appearing with no clear risk factors and no family history of the disease. 
• Familial ALS. ALS is inherited in 5% to 10% of people. The disease is considered familial if two or more family members have ALS. Researchers have identified approximately 60% of the genes associated with familial ALS, but much more research is needed to identify their exact links to the disease.

Who is most likely to be affected by amyotrophic lateral sclerosis (ALS)?

ALS occurs in approximately 1 to 4 per 100,000 individuals. In the United States, approximately 30,000 people live with ALS, and about 6,400 Americans are diagnosed annually.

ALS affects people across all racial and ethnic groups, but people with Caucasian or non-Hispanic ancestry are most likely to develop the disease. 

Symptoms usually begin between the ages of 40 and 70, although they can occur at a younger age.

Before age 65, men are slightly more likely than women to develop ALS. This gender difference disappears after age 70.

Some studies suggest that military veterans are 1.5 to 2 times more likely to develop ALS, although more research is needed to confirm this link. Some researchers link this increased ALS prevalence to veterans’ exposure to lead, pesticides, and other environmental toxins in the course of duty.

What causes ALS?

While there is no singular known cause for ALS, scientists have identified several potential risk factors that may play a part in developing the disease. These include: 

• Exposure to toxic substances, like lead or pesticides. 
• Smoking, especially in post-menopausal women.
• Age. Most people with ALS develop symptoms between ages 55 and 75. 
• Biological sex. People assigned male at birth are slightly more likely to develop ALS than people assigned female at birth. 
• Genetics. Certain genetic variations may raise the risk of familial ALS. 
• Race and ethnicity. ALS affects people of Caucasian or non-Hispanic backgrounds slightly more than other backgrounds.
• Head trauma. Recent studies suggest there may be a link between traumatic brain injury and ALS, but much more research is needed to confirm the connection.

Is ALS a genetic disorder?

While the vast majority of ALS cases have no known cause, some studies have found genetic variations that might make people more susceptible to ALS. 

About 65% of individuals with familial ALS and 10% of people with sporadic ALS have a known ALS-associated genetic mutation. These mutations can be inherited from a parent who never had ALS, or they can have newly developed within the affected person.

The cause of sporadic ALS involves a combination of genetic and environmental factors. Gene mutations that are risk factors for ALS may add, delete, or change DNA building blocks. This leads to altered or reduced protein function. 

People with a gene variation that increases their risk of ALS require additional genetic and environmental triggers to develop the disorder.

For more information on the specifics of gene mutations, see research from the ALS Association.

How does ALS affect communication?

Someone with ALS can lose everyday functions like walking, talking, or chewing so suddenly that it can be extremely alarming for both the person with ALS and their loved ones. As ALS progresses, more and more practices of everyday care—feeding, bathing, etc.—become impossible for someone with ALS to do on their own. 

However, ALS does not impact someone’s cognitive abilities or intelligence. Someone with ALS is aware of these rapid changes but may suddenly find themselves unable to communicate the way they used to. 

Alternative communication innovations, like computer-based speech synthesizers, eye-tracking devices, and “voice banking” (recording one’s voice for future use in computer-generated speech) help people with ALS communicate after they’ve lost the ability to speak, write, or type. 

Many people with ALS find themselves very quickly reliant on their caregivers. This can be frustrating and overwhelming for both parties. It’s critical to make support services available to people with ALS and their caregivers, whether that’s through a support group, traditional talk therapy, or a local support organization. 

To see organizations near you that offer support for disabilities, visit Ability Central’s Service Locator tool. 

To learn more about long-term support options for people with ALS, see Amyotrophic Lateral Sclerosis (ALS): Financial Planning and Long-term Support. 

Where can I get more information about Amyotrophic Lateral Sclerosis (ALS)?

Ability Central has multiple resources to learn more about ALS, including:

• Symptoms and Stages of Amyotrophic Lateral Sclerosis (ALS)
• Amyotrophic Lateral Sclerosis (ALS) First Steps: What to Do After a Diagnosis
• Amyotrophic Lateral Sclerosis (ALS): Financial Planning and Long-term Support