Test Spots Alzheimer's Decades Before Start of Symptoms Brain starts to change many years before problems surface By Rob Quinn, Newser Staff Posted Nov 6, 2012 3:34 AM CST 11 comments Comments Brain scans spotted telltale signs of the disease. (National Institutes of Health) (Newser) – Researchers have spotted very early signs of Alzheimer's disease in patients decades before symptoms usually appear, raising hopes that the disease can be treated before the brain degenerates badly, the BBC reports. Tests on people in their 20s destined to develop the inherited, early-onset form of the disease revealed telltale changes in the brain and spinal fluid. Researchers now hope to develop tests that can predict future Alzheimer's sufferers in the general population. Early treatment is vital to prevent damage to memory and thinking, but many patients have already lost a fifth of their brain cells by the time symptoms appear. "These findings suggest that brain changes begin many years before the clinical onset of Alzheimer's disease," one of the researchers says. "They raise new questions about the earliest brain changes involved in the predisposition to Alzheimer's and the extent to which they could be targeted by future prevention therapies."