Brain shrinkage biomarker may predict early-onset Alzheimer’s progression

In people diagnosed with early-onset Alzheimer's disease, a biomarker tool that detects shrinkage of the brain's gray matter may predict how quickly someone may progress from mild cognitive impairment (MCI) to dementia, according to a new study published August 26, 2026, in Neurology®, an official journal of the American Academy of Neurology.

Early-onset Alzheimer's disease develops before age 65, while people are still working or raising families. It begins with mild cognitive impairment, thinking and memory problems that are greater than normal aging but not severe enough to be diagnosed as dementia. It often progresses quickly to dementia, but the timeline varies widely from person to person.

This is a study driven by one of the most frequent questions we get from patients in the clinic: 'When will I lose my independence? There are limited ways to predict the transition from MCI to dementia, so we developed a brain scan biomarker called the early-onset Alzheimer's disease signature, a map that can be applied to brain scans to measure shrinkage in regions of the brain involved in thinking such as memory, language and reasoning. Our study found that brain shrinkage measured by our biomarker can act as a timer for predicting when dementia will start and how quickly someone progressed from MCI to dementia."

The early-onset Alzheimer's disease signature biomarker includes a set of brain regions that show greater atrophy in people with the disease than in people without the disease.