Amyotrophic Lateral Sclerosis (ALS)

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What is amyotrophic lateral sclerosis (ALS)?

ALS, sometimes called Lou Gehrig's disease, is a progressive brain disease that attacks the nerve cells that control muscles (motor neurons). It results in the gradual degeneration and death of motor neurons that are located in the brain, brainstem, and spinal cord. When these neurons die, the brain can no longer start or control muscle movements. Consequently, the muscles gradually waste away (atrophy). When the motor neurons in the brainstem are affected (bulbar ALS), the muscles used in speech and swallowing are impaired.

ALS only affects muscles that are moved voluntarily (such as those in the mouth or arm) and does not impact those muscles involved in involuntary movements, such as digestion. Because ALS affects only the motor neurons, it does not significantly impair a person's mind. Personality, intelligence, memory, and self-awareness remain the same. The senses of sight, smell, touch, hearing, and taste remain intact as well.

ALS is progressive, meaning that the symptoms gradually worsen over time. The rate of disease progression varies extensively from person to person. The average lifespan of the individual after diagnosis has been reported to be 2 to 5 years.

What causes ALS?

The specific causes and risk factors for ALS have not been identified. Though ALS is typically not hereditary, scientists have recently indicated that some genetic mutations may result in ALS.

How common is ALS?

More than 12,000 people in the United States have a diagnosis of ALS, for a prevalence of 3.9 cases per 100,000 persons in the U.S. general population, according to the National ALS Registry. According to the ALS Association, approximately 6,000 people are diagnosed with ALS each year.

What are some signs or symptoms of ALS?

The symptoms of ALS depend on the muscle groups affected. The earliest symptoms may include muscle twitches, tight and stiff muscles (spasticity), muscle weakness that may affect the limbs, slurred speech, and difficulty chewing or swallowing.

Degeneration of the motor neurons in the brainstem (bulbar ALS) first affects an individual's ability to speak loudly and clearly (dysarthria). Eventually, the condition completely prevents speaking and vocalizing. Some of the earliest speech-related symptoms of ALS may include:

  • nasal speech quality (talking out of your nose);
  • difficulty pronouncing words due to weak, tight, or stiff speech muscles;
  • reduced breath control with lengthy sentences or conversation.

As muscles for breathing weaken, it becomes more difficult for individuals to speak loudly enough to be understood.

Individuals with bulbar ALS may also experience difficulty chewing and swallowing (dysphagia). Initially, hard/solid food consistencies are difficult to manage, but over time it becomes difficult for the individual to swallow even pureed foods and saliva. People with ALS tire easily, and they may not have the energy to eat an entire meal. All of these factors make it difficult for the affected person to maintain adequate nutrition and weight. Eventually, doctors may decide that it is best to insert a feeding tube into the stomach to make sure the individual receives enough nutrition.

When the motor neurons in the spinal cord are affected (spinal ALS), initial symptoms may affect only one leg or arm. Individuals may have awkwardness and stumbling when walking or running. They may have difficulty lifting objects or performing tasks that require manual dexterity (e.g., buttoning a shirt, tying a shoe, turning a key). Eventually, the individual will not be able to stand or walk, get in and out of bed without help, or use hands and arms to perform activities of daily living, such as washing and dressing.

How is ALS diagnosed?

There is no specific laboratory test for ALS, making it hard to diagnose. The diagnosis of ALS is primarily based on the symptoms and signs the physician observes in the individual and a series of tests to rule out other diseases. 

What treatments are available for people with ALS?

Presently, there is no cure for ALS. Riluzole is the first drug approved by the U.S. Food and Drug Administration for the treatment of patients with ALS. Although Riluzole is not a cure, it has been found to slow the rate of progression of the disease in some individuals.

As with any incurable disease, the state of the art in treatment for ALS is symptom management (also referred to as palliative care). According to the World Health Organization, palliative care is active care of the whole individual. Individuals with ALS receive the best treatment from multidisciplinary clinical teams that specialize in neuromuscular disorders. Intervention deals with symptoms that occur over the course of the disease process.

What does a speech-language pathologist (SLP) do when working with individuals with ALS?

The role of the speech-language pathologist in treating people with ALS is to help them maintain functional communication and swallowing throughout the course of the disease. The SLP provides strategies to improve speech intelligibility and prevent fatigue during communication. The SLP may also help the individual use an augmentative and alternative communication device to effectively communicate when speech production may not be the best communication option.

The SLP also works closely with the health care team to help the individual with ALS reduce the risk of aspiration (getting food and liquid in the lungs) and provides recommendations to ensure that the individual with ALS receives safe and adequate nutritional intake.

What other organizations have information about ALS?

This list is not exhaustive, and inclusion does not imply endorsement of the organization or the content of the website by ASHA.

The following websites can provide information and support for people with ALS and their families: