Alzheimer's disease. Conceptual computer artwork of a half-pixellated brain, representing the brain degeneration of Alzheimer's disease. The front of the brain is at bottom in this overhead view. The symptoms of Alzheimer's disease include memory loss, personality changes and extreme confusion. Many elderly people develop this disease. There is no cure and death occurs after several years of decline.
(c) ALFRED PASIEKA/SCIENCE PHOTO LIBRARY