Reduced Brain Volume May Predict Progression to Early-Onset Dementia, Study Finds - Video

A new brain scan biomarker may help predict how quickly people with early-onset Alzheimer’s disease progress from mild cognitive impairment (MCI) to dementia, according to a study published August 26, 2026, in Neurology.

Early-onset Alzheimer’s develops before age 65 and can progress rapidly, although the timing varies considerably between individuals. Researchers at Harvard Medical School developed an early-onset Alzheimer’s disease signature, a brain imaging tool that measures shrinkage in regions involved in memory, language and reasoning.

The study included 130 people with MCI and 97 healthy participants, all aged 40 to 64. Participants underwent MRI brain scans at the beginning of the study and at least one annual follow-up. Researchers measured gray matter thickness across eight brain regions and combined the results into an overall atrophy score.

Participants were followed for an average of two years, during which about 65% of those with early-onset Alzheimer’s progressed from MCI to dementia.

Researchers found that people with greater gray matter shrinkage had a faster progression to dementia. For every one-standard-deviation increase in brain shrinkage, the risk of progressing from MCI to dementia was 1.24 times higher.

Importantly, the biomarker performed better at predicting progression than assessments based only on symptoms recorded at the start of the study.

Researchers say the tool could eventually help doctors provide patients and families with better estimates of disease progression and help identify people who may benefit from clinical trials at an earlier stage.

However, the findings remain preliminary. The biomarker was developed and tested in a single study group, which was predominantly non-Hispanic White. This means its accuracy in other racial and ethnic populations remains uncertain.

If validated in larger and more diverse groups, the researchers say the brain scan signature could become a useful tool for personalizing prognosis and monitoring early-onset Alzheimer’s disease.

REFERENCE: Paranhos, T., et al. (2026). EOAD-Signature Atrophy Predicts Dementia in Early-Onset MCI due to Alzheimer Disease. Neurology. DOI: 10.1212/WNL.0000000000218519.