Normal ageing and Alzheimer’s disease reshape the brain’s communication networks in fundamentally different ways, Lund University researchers have found. The study, published in Nature Neuroscience, could help doctors tell early disease apart from healthy ageing.

The team mapped how brain regions talk to each other. They found that ageing and Alzheimer’s drive coordinated connectivity shifts along distinct organisational axes in the brain. Crucially, the disease-specific pattern was already visible in people with low levels of Alzheimer’s pathology who were still cognitively unimpaired.

In participants with cognitive impairment, the connectivity patterns matched thinking ability more strongly than the build-up of amyloid-beta and tau proteins, the classic hallmarks of Alzheimer’s.

First author Jonathan Rittmo said the team was surprised the distinctive pattern appeared before any symptoms. Because brain function can be modified through stimulation, cognitive tasks or medication, the researchers say tracking connectivity could one day guide early intervention and measure how well treatments work.