Before diving in, it’s helpful to know that there are two proteins involved in the cognitive decline of Alzheimer’s disease: amyloid-beta and tau. The build up of these proteins are called aggregates, and are responsible for memory loss, personality changes, and ultimately the killing of brain cells.
Until now, researchers thought the disease progressed by spreading from one region of the brain to another “in a way that’s similar to many cancers,” lead study author Georg Meisl, Ph.D. said in a news release.
By using brain samples from deceased Alzheimer’s patients and PET scans from living patients with varying progressions of the disease, researchers were able to track how tau aggregates actually develop. What they discovered is that rather than spreading over time, tau aggregates already exist in multiple regions of the brain at the onset. “So trying to stop the spread between regions will do little to slow the disease,” Meisl explains.