An Alzheimer's Warning 25 Years Before Symptoms Show | MIT Technology Review Early onset: Brain scans show evidence of Alzheimer’s disease 20 years before symptoms arise (far left), 10 years before (middle), and after the onset of symptoms (right). Beta amyloid, a protein associated with the disease, is more visible in people who develop the disease (top row) than in those who don’t. The more color in the scan, the more beta amyloid is present in the brain.
The image on the left is a side view of the outside of the brain, showing the major lobes (frontal, parietal, temporal and occipital) and the brain stem structures (pons, medulla oblongata and cerebellum). The image on the right is a side view showing the location of the limbic system inside the brain. The limbic system consists of a number of structures, including the fornix, hippocampus, cingulate gyrus, amygdala, the parahippocampal gyrus and parts of the thalamus.