Changes Seen Long before Early Alzheimer’s

Changes in the brain and the fluid around it may occur as much as 25 years before symptoms of early-onset Alzheimer’s disease, a new study finds. The study focused on 128 people. All had a family history of early Alzheimer’s caused by a gene inherited from one parent. Symptoms start in the 30s, 40s or 50s. About half of those in the study carried the gene. Researchers gave everyone several tests. They determined when symptoms would be expected to start based on the parent’s age at diagnosis. About 25 years before symptoms were expected, those with the gene showed a drop in beta-amyloid in the fluid around the brain. This is a key component of Alzheimer’s plaques inside the brain. About 15 years before symptoms were expected, people with the gene had smaller brains, and plaques had appeared. Fluid around the brain also had more tau protein. This is another sign of Alzheimer’s.