Amyotrophic lateral sclerosis, or ALS, is a degenerative disease of nerve cells in the brain and spinal cord (central nervous system) that control voluntary muscle movement. ALS is also known as Lou Gehrig’s disease. In about 10% of cases, ALS is caused by a genetic defect. In the remaining cases, the cause is unknown.
In ALS, nerve cells (neurons) waste away or die and can no longer send messages to muscles. This eventually leads to muscle twitching, weakness, and the eventual inability to move the arms, legs and body. As the condition worsens, muscles in the chest stop working and it becomes hard or impossible to breathe on one’s own.
Worldwide, ALS affects approximately 5 out of every 100,000 people. There are no known risk factors outside having a family member with a hereditary form of the disease.
Symptoms usually do not develop until after age 50, but they can start in younger people. Persons with ALS have a loss of muscle strength and coordination that eventually worsens and makes it impossible to perform routine tasks such as going up steps, getting out of a chair or swallowing. Breathing or swallowing muscles are sometimes the first muscles affected. As the disease progresses, more muscle groups develop problems that impair function or ability. ALS does not affect the senses (sight, smell, taste, hearing, touch). It only rarely affects bladder and bowel function or a person’s ability to think or reason.
- Difficulty breathing
- Difficulty swallowing
- Choking easily
- Head drop due to weakness of the neck muscles
- Muscle cramps
- Muscle contractions called fasciculations
- Muscle weakness that slowly gets worse
- Commonly involves one part of the body first, such as the arm or hand
- Eventually leads to difficulty lifting, climbing stairs, and walking
- Speech problems, such as a slow or abnormal speech pattern (slurring of words)
- Voice changes, hoarseness
- Weight loss
Over time, people with ALS progressively lose the ability to function and care for themselves. Death often occurs within 3 – 5 years of diagnosis. About 25% of patients survive for more than 5 years after diagnosis.