Brain scans could help nip dementia in the bud

BRAIN screening to spot a rogue protein could be key to halting dementia, scientists believe.

Scans have shown high levels of amyloid in the brains of people not yet showing symptoms such as memory loss.

These people are likely to benefit most from cutting-edge drugs such as solanezumab, which removes excess amyloid, to delay the onset of dementia.

A study called A4 (AntiAmyloid Treatment in Asymptomatic Alzheimer’s Disease) found that large amounts of the protein were linked to a high risk of dementia.

Lead author Dr Reisa Sperling, at Brigham and Women’s Hospital in Boston, said: “Elevated amyloid was associated with lower test performance results and increased reports of subtle recent declines in daily cognitive function.

“These results support the hypothesis that elevated amyloid represents an early stage in the Alzheimer continuum and demonstrate the feasibility of enrolling these high-risk participants in secondary prevention trials aimed at slowing cognitive decline during the preclinical stages of Alzheimer’s disease.”

Previous checks identified a 10-15 year window in which people exhibit changes associated with Alzheimer’s but still manage to function normally.

Scans could become as common as cancer screening, allowing treatment to delay onset.

Screening of 4,486 people, aged 65 to 85, revealed 1,323 with raised amyloid who were clinically normal but were more likely to have a family history of dementia and carry the “dementia gene” APOE.

They also had lower cognitive test scores and worse declines in daily mental function.

Participants were followed from 2014 to 2017 and will continue in A4’s tests of solanezumab, with results due in late 2022. It is the largest study of pre-clinical dementia to date.

Dr Richard Hodes, director of the National Institute on Aging which is part-funding the study, said A4 addressed the problem of previous trials “intervening too late in the disease process to be effective”.

He said: “A4 is pioneering in the field because it targets amyloid accumulation in older adults at risk for developing dementia before the onset of symptoms.”

The results were published in JAMA Neurology.