Predicting Alzheimes dementia in oldest of the old

A new study indicates that severity of amyloid deposition in the brain-not just age-may be key to determining who will benefit from new anti-amyloid therapies to delay the progression of Alzheimer’s disease.

University of Pittsburgh clinicians and scientists report that the accumulation of toxic amyloid beta clumps that signal Alzheimer’s disease pathology accelerates in old age but the baseline amyloid burden and the overall brain health going into this acceleration are more powerful predictors of who is most likely to progress to Alzheimer’s. The paper was published today in Neurology, the medical journal of the American Academy of Neurology.

The presence and the overall quantity and distribution of amyloid beta, or A-beta, clumps in the brain are some of the most common neuropathologies associated with Alzheimer’s. Yet, while people who are 80 and older have the highest prevalence of Alzheimer’s-associated dementias, most studies that measured A-beta burden in the brain using imaging techniques have focused on younger populations. As such, the connection between A-beta and dementia in the oldest of the old have remained unclear.

“Our findings are consistent with studies showing that the amyloid accumulation in the brain takes decades to develop, and occurs in the context of other brain pathologies, specifically small vessel disease,” said Lopez, who also directs Pitt’s Alzheimer's Disease Research Center. “Whether there is a vascular process that occurs in parallel to the A-beta deposition could not be examined in this study. However, understanding of the timing of the presence of these pathologies will be critical for the implementation of future primary prevention therapies.”

Reference: Predicting Alzheimer’s dementia in oldest of the old, UNIVERSITY OF PITTSBURGH, Neurology