Hopeful Brains Even the brain without symptoms (a) might eventually develop Alzheimer’s disease, but people with a certain dominant gene definitely will. They have no symptoms (b) in early adulthood, some symptoms (c) in middle adulthood, and stage five Alzheimer’s disease (d) before old age. Research has led to the discovery of early markers (such as those shown here) that predict the disease. As scientists detect early signs, they hope to determine a treatment to halt brain destruction before it starts.

TAMMIE BENZINGER, MD, PHD, TYLER BLAZEY, WASHINGTON UNIVERSITY SCHOOL OF MEDICINE IN ST. LOUIS