Approaching Darkness: One Man Blogs His Descent Into Alzheimer's

I ring the bell for Apartment #2. But before I have time to flatten the creases in my skirt, a gray-haired man wearing no shoes appears at the door and lets me inside. Retired physician David Hilfiker, 68, has invited me to his Washington, D.C. home to discuss the blog he's operated for the past 10 months. David has Alzheimer's disease, a type of dementia that causes memory deficits and difficulty performing everyday tasks. This cognitive disorder manifests variably across patients, and its symp...