Researchers at the University of Oslo report that the brain changes of Alzheimer's disease can be spotted on imaging more than seven years earlier than previously assumed. The study, led by the Department of Psychology and published in Nature Neuroscience, found structural alterations in the brain well before amyloid plaques reached levels visible on a PET scan.
That matters because amyloid-PET is currently treated as the gold standard for catching the disease early. The Oslo team's findings suggest the technique is not sensitive enough to pick up the earliest disease-related processes in the brain, including the buildup of amyloid itself. "We found that structural changes in the brain occur many years before high levels of plaque are seen on PET scans, which is the brain scan currently used to identify the earliest signs of Alzheimer's disease," said James Michael Roe, who led the research while a postdoctoral fellow at the Center for Lifespan Changes in Brain and Cognition.
A seven-year head start on detection is significant for a disease in which damage accumulates silently long before memory problems surface. If structural imaging can flag risk at a stage when amyloid scans still read as clean, it would widen the window in which people could be identified for monitoring or enrolled in trials of treatments aimed at the earliest phase of the disease - the period researchers increasingly believe offers the best chance of altering its course.
Roe, now International Scientific Lead at Cercare Medical, conducted the work at Oslo's LCBC center. The findings point to a gap in what a single imaging biomarker can reveal, rather than a ready-made clinical test, and further work would be needed to establish how these early structural signals perform as a practical tool for diagnosis.