Amyotrophic Lateral Sclerosis (ALS), sometimes referred to as "Lou Gehrig's Disease," is a progressive fatal neuromuscular disease that attacks nerve cells and pathways in the brain and spinal cord. Motor neurons, among the largest of all nerve cells, reach from the brain to the spinal cord and from the spinal cord to muscles throughout the body with connections to the brain. When they die, the ability of the brain to start and control muscle movement dies with them. With all voluntary muscle action affected, ALS patients in the later stages are totally paralyzed; through it all, however, their minds remain unaffected. Amyotrophic comes from the Greek language.