Pat Summitt's Death: Why Alzheimer's Disease Is Deadly

Hall of Fame women's basketball coach Pat Summitt died today (June 28) at age 64 after a five-year battle with early-onset Alzheimer's disease. Although Alzheimer's disease shortens people's life spans, it is usually not the direct cause of a person's death, according to the Alzheimer's Society, a charity in the United Kingdom for people with dementia. Alzheimer's is a progressive brain disease in which abnormal protein deposits build up in the brain, which causes brain cells to die.