Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. 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 lead to their death. When the motor neurons die, the ability of the brain to initiate and control muscle movement is lost. With voluntary muscle action progressively affected, patients in the later stages of the disease may become totally paralyzed. ("About ALS". ALSA.org. June 18, 2011 <http://www.alsa.org/about-als/>)
Causes, Incidence, and Risk Factors
- 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 weakening, twitching, and an inability to move the arms, legs, and body. The condition slowly gets worse. When the muscles in the chest area stop working, it becomes hard or impossible to breathe on one's own.
- ALS affects approximately 5 out of every 100,000 people worldwide.
- There are no known risk factors, except for having a family member who has a hereditary form of the disease.
Facts You Should Know
- ALS is not contagious.
- It is estimated that ALS is responsible for nearly two deaths per hundred thousand population annually.
- Approximately 5,600 people in the U.S. are diagnosed with ALS each year. The incidence of ALS is two per 100,000 people, and it is estimated that as many as 30,000 Americans may have the disease at any given time.
- Although the life expectancy of an ALS patient averages about two to five years from the time of diagnosis, this disease is variable and many people live with quality for five years and more. More than half of all patients live more than three years after diagnosis.
- About twenty percent of people with ALS live five years or more and up to ten percent will survive more than ten years and five percent will live 20 years. There are people in whom ALS has stopped progressing and a small number of people in whom the symptoms of ALS reversed.
- ALS occurs throughout the world with no racial, ethnic or socioeconomic boundaries.
- ALS can strike anyone.
- The onset of ALS is insidious with muscle weakness or stiffness as early symptoms. Progression of weakness, wasting and paralysis of the muscles of the limbs and trunk as well as those that control vital functions such as speech, swallowing and later breathing generally follows.
("Facts You Should Know". ALSA.org. June 18, 2011 <http://www.alsa.org/about-als/facts-you-should-know.html>)
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