New Alzheimer's Test Could Detect Signs of Disease Decades Before Symptoms Show

A study detailed a blood test that can diagnose brain changes related to Alzheimer's with 94 percent accuracy, reports Newsweek . The test measured beta-amyloid levels, in conjunction with cerebrospinal fluid analysis and positron-emission tomography (PET) scans of the brain. One hundred out of 158 participants older than 50 underwent a second PET scan, and those who tested negative for beta-amyloid in first scan had a 15-fold risk of later testing positive if beta-amyloid 42/beta-amyloid 40 turned up in their blood. "The blood test, especially in combination with age and APOE e4 status, is very accurate in diagnosing the brain changes of Alzheimer's disease," says Washington University School of Medicine Professor Suzanne Schindler. "It also suggests that some results thought to be false positive positive blood test, negative amyloid PET scan, are actually indicating very early disease." Washington University Professor Randall J. Bateman suggests the blood test will likely be used for screening in trials within 12 months, and potentially available in clinics in one to two years.