The earliest changes in Alzheimer disease begin with small protein clumps forming between and inside brain cells. The two main proteins involved are beta amyloid and tau. Beta amyloid is normally cleared away by the brain, but when this process slows down, the protein begins to collect in small sticky pieces. These pieces join together and form tiny clusters. At first they are so small that they do not disturb brain function, but as they increase they begin to interfere with communication betwee