Disease Progression
Alzheimer's Disease is caused by degeneration of various parts of the brain, due to death in brain cells known as "neurons". As seen in the picture above, the overall size of an Alzheimer's-diseased brain is significantly smaller than a healthy brain. Specifically, an area of the brain called the "hippocampus" is particularly susceptible to neuronal cell death. This is the part of the brain that is notoriously important for the formation of new memories, which explains the memory loss that results during the progression of Alzheimer's disease. However, the disease ultimately progresses and affects the entirety of the brain, resulting in various cognitive symptoms on top of the memory loss.