Road to Alzheimer's disease begins in middle-age

Alzheimer's disease and other neurological ailments are well know to affect individuals later in life, but now a study by researchers at ANU and Brunel University, London, has found the precursors to neurological decline can be found in individuals in middle-age.

They found that some apparently healthy men and women aged between 44 and 48 show the early signs of lesions in white matter in the brain that is associated with cognitive impairment.

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While many studies have found such legions in individuals aged over 60, few have investigated the precursors in younger people.

This opens up the possibility of early testing well before the symptoms of neurological disease manifest, allowing for early treatment and perhaps prevention.

The study involved 428 middle-aged men and women, and found that lesions in white matter in different parts of the brain was associated with a range of minor cognitive impairments, including motor and facial recognition tasks.

Interestingly, the study also found no significant link between white matter lesions and vascular risk factors, which have previously been associated with neurological disorders.

The researchers suggest that early testing for white matter legions could be a good strategy to help detect the early signs of neurological disease and begin taking preventative measures.

"From a lifespan perspective, these findings are important as they add to evidence that the deleterious effects of neurobiological disturbance may manifest at an earlier age than is suggested by the broader literature," the study authors write.

"Not only is this of note theoretically as it points to a possible neuropathological basis for cognitive decline in middle age, but also practically, as it suggests that preventative programs and early intervention may benefit community-dwelling adults in their 40 s and upwards."

According to project lead, David Bunce, of the Centre for Mental Health Research at ANU, the study places an emphasis on early intervention for a range of diseases that are normally only treated later in life.

“Although we cannot be certain that these middle-aged people will go on to get dementia, the results are important for several reasons,” said Bunce.

“First, the study is one of the first to show that lesions in areas of the brain that deteriorate in dementia are present in some adults aged in their 40s.

“Second, although the presence of the lesions was confirmed through MRI scans, we were able to predict those persons who had them through very simple-to-administer tests that measure attention.

“Finally, if the findings are repeated in laboratories elsewhere, the study lays open possibilities for screening, early detection and intervention in healthcare settings. The earlier we can intervene with people vulnerable to eventual dementia, the greater the chances of preventing or delaying the disease onset.”

The study was published in the open access journal, PLoS One.