Amyotrophic lateral sclerosis (also known as Lou Gehrig's disease) is a fatal neurodegenerative disease. People living with the disease become progressively paralyzed due to degeneration of the upper and lower motor neurons in the brain and spinal cord. Eighty per cent of people with ALS die within two to five years of diagnosis - unable to breathe or swallow. Ten per cent of those affected may live for 10 years or longer.