Before Jack got Alzheimer’s disease, he was a college professor. He could talk for hours about a wide variety of topics.

Then, as Alzheimer’s ravaged his brain, he lost his ability to speak. So he had to write everything down on paper in order to communicate-even something as simple as letting his wife know he needed a drink of water.

As the disease got worse, Jack couldn’t remember how to spell certain words, and then he couldn’t even recall …