pTau181 biomarker linked to memory concerns at age 45

University of Otago researchers found elevated plasma pTau181 in 45-year-olds from the Dunedin Study who reported memory and thinking concerns, despite MRI showing no structural brain changes. The result suggests Alzheimer's-related biology may appear decades before symptoms.

• pTau181 was elevated in 45-year-olds with subjective cognitive concerns
• MRI scans showed no detectable structural brain changes
• The biomarker indicates risk, not a diagnosis of Alzheimer's
• The test remains research-only and unavailable in NZ clinics