American Physiological Society -- NEW ORLEANS—Amyotrophic lateral sclerosis (ALS) is a fatal disease that damages key neurons in the brain and spinal cord. The disease causes progressive paralysis of voluntary muscles and often death within five years of symptoms. Although ALS (Lou Gehrig’s disease) was discovered over a century ago, neither the cause nor a cure have been found, but several mechanisms seem to play a role in its development, including oxidative stress.