Amyotrophic lateral sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease and Charcot disease, is a specific disorder that involves the death of neurons. The cause is not known in 90% to 95% of cases. 

French neurologist Jean-Martin Charcot discovered the disease in 1869.

ALS, or amyotrophic lateral sclerosis, is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. 

A-myo-trophic comes from the Greek language. "A" means no. "Myo" refers to muscle, and "Trophic" means nourishment – "No muscle nourishment." When a muscle has no nourishment, it "atrophies" or wastes away. "Lateral" identifies the areas in a person's spinal cord where portions of the nerve cells that signal and control the muscles are located. As this area degenerates it leads to scarring or hardening ("sclerosis") in the region.

There are two different types of ALS, sporadic and familial:

1. Sporadic which is the most common form of the disease in the U.S., is 90 – 95 percent of all cases. It may affect anyone, anywhere. Familial ALS (FALS) accounts for 5 to 10 percent of all cases in the U.S. 

2. Familial ALS means the disease is inherited. In those families, there is a 50% chance each offspring will inherit the gene mutation and may develop the disease. 

ALS is found to be more
common in men than in women, affecting 1·2–1·5 men
for every woman. 

Survival is highly variable, but

respiratory failure usually leads to death about 3–4 years
after onset.

The mechanisms underlying neurodegeneration in ALS
are still not fully understood.