According to the ALS Association, amyotrophic lateral sclerosis is a progressive, neurodegenerative disease that destroys motor neurons in the brain and spinal cord, preventing signals from being sent to voluntary muscles. ALS is also commonly referred to as Lou Gehrig's Disease.
Early symptoms of ALS disease include muscle weakness or stiffness beginning in the hands and feet, according to the ALS Association. As the disease progresses, the muscles weaken and paralysis spreads to the trunk muscles. As the disease progresses, speech, swallowing, chewing and breathing are affected. In the final stages, a person with ALS needs a ventilator to survive.