Imagine finding a glimmer of good news in a diagnosis of Alzheimer's. And imagine how that would change the outlook of the 5 million Americans who suffer from Alzheimer's disease and other dementias, not to mention their families, loved ones, and caretakers. A neurologist who's been specializing in dementia and memory loss for more than 20 years, Dr. Gayatri Devi rewrites the story of Alzheimer's by defining it as a spectrum disorder--like autism,...