Can the type of ALS you have change?

Amyotrophic lateral sclerosis (ALS) is a progressive disorder marked by muscle weakness and atrophy (wasting), which usually is mild to start and affects only one body part, then becomes more severe and gradually spreads to impact the whole body. It is classified based on the presence or absence of a family history, as well as based on the first symptoms that develop. Because these are descriptors of the disease at its onset, ALS classifications generally do not change over time.