After a referral to the University of Michigan and further tests, doctors diagnosed Scott with amyotrophic lateral sclerosis (ALS), a rapidly progressive, invariably fatal neurological disease that attacks the nerve (neurons) responsible for controlling voluntary muscles. Unable to function, the muscles gradually weaken and waste away (atrophy). Eventually, the ability of the brain to start and control voluntary movement is lost. Most people with ALS die due to respiratory failure, typically within three to five years from the onset of symptoms. The cause of ALS is unknown and there is no cure.