His brash attitude a factor.

It's a shame, he did everything that was asked of him this year, ... He's had an amazing career, but if you ask him, he's flat-out not interested in retiring. He still has a good three, four years in him.

They've all been validated, so that a certain score is indicative of Alzheimer's disease.

Research shows learning about Alzheimer's disease is one of the best ways to help patients and their families.