Amyotrophic lateral sclerosis (ALS), also called Lou Gehrig’s disease, is a classic motor neuron disease. ALS occurs when specific nerve cells in the brain and spinal cord that control voluntary movement gradually degenerate. The loss of these motor neurons causes the muscles under their control to weaken and waste away, leading to paralysis. Although progressive deterioration is characteristic of the disease, mental capacity or cognition is rarely affected. The cause of ALS is still unknown.

The most common forms of ALS are:

• Sporadic – accounts for 90-95% of all cases in the United States.
• Familial - approximately 5-10% of ALS is inherited.

• The disease affects 30,000 people per year just in the United States, with approximately 5,000 new cases diagnosed annually.
• Most people who develop ALS are adults over age 40, although there are cases of the disease starting at an earlier age.
• Men are more likely to develop ALS than women, however the incidence of ALS becomes more equal between men and women with increasing age.
• With currently available treatment, people with ALS can live more than five to ten years.

ALS can present and progress in different ways, depending on which muscles weaken first. Symptoms may include tripping and falling, loss of motor control in hands and arms, difficulty speaking, swallowing and/or breathing, persistent fatigue, and muscle twitching (fasciculations) and cramping.

The diagnosis of ALS is a "clinical diagnosis," meaning there is no specific test that gives a definitive answer. Instead, it requires a clinical examination and many tests to rule out illnesses with symptoms that may mimic ALS.

Not all individuals affected with ALS have speech and swallowing problems; however, in some cases slurred speech or difficulty swallowing is the first sign of ALS. For those who have these problems, there are professionals who are skilled in working with these patients and are able to provide access to a communication method, even when spoken output is no longer possible. These professionals can also assist in facilitating safe swallowing for longer periods of time. With the assistance of these professionals, those afflicted with ALS can maintain independence, decision making ability, and control over their lives.

There is no cure for ALS, however many of the symptoms of ALS are treatable. The Food and Drug Administration (FDA) has approved riluzole (RILUTEK), the first drug that has been shown to prolong the survival of ALS patients. The quality of life of patients with ALS can often be improved by various interventions, e.g. communication devices.