Amyotrophic lateral sclerosis is a terminal neurological disorder characterized by progressive degeneration of nerve cells in the spinal cord and brain. Often referred to as Lou Gehrig's disease, named for a famous baseball player who died from the disease in 1941, it is one of the most devastating of the disorders that affects the function of nerves and muscles.
ALS does not affect mental functioning or the senses (such as seeing or hearing), and it is not contagious. Currently, there is no cure for amyotrophic lateral sclerosis.
The first symptom of ALS usually is unexplained muscle weakness in an arm or leg.
According to the ALS Association:
- Most people who develop ALS are between the ages of 40 and 70, although the disease can occur at a younger age.
- The average age for the onset of ALS is 55.
- ALS occurs throughout the world with no racial, ethnic or socioeconomic boundaries.
- ALS affects as many as 30,000 Americans, with 5,000 new cases diagnosed in the U.S. each year.
There are three known classifications of ALS:
This is the most common form of ALS in the U.S., involving 90 to 95 percent of all cases. These cases occur randomly, without any known cause, and there is no association with persons in the family with the disease.
Familial ALS is inherited and accounts for a very small number of cases in the U.S., about 5 to 10 percent.
An extremely high incidence of ALS was observed in Guam and the Trust Territories of the Pacific in the 1950s.