It has really been bothering me lately that the media (fiction and news) have be misusing the term "early onset" in reference to Alzheimer's. Early-onset Alzheimer's is not early STAGE Alzheimer's. Early-onset Alzheimer's (which my dad had) refers to cases where diagnosis was before age 65. (My dad was 63.)
Someone who is 80 and just got diagnosed doesn't have early onset Alzheimer's. They have early-stage Alzheimer's. There is a difference!