Deposits of amyloid beta, an abnormal protein associated with the development of Alzheimer's disease, can be detected in the brain decades before the onset of the disease, according to results of a study published recently in the journal Lancet Neurology.
In the study, researchers from Melbourne's Austin Hospital in Australia followed 200 seniors, including 19 with Alzheimer's disease and 36 with mild cognitive impairment, in order to chart brain atrophy and cognitive decline against the rate of amyloid beta deposition.
The participants underwent neurospsychological examinations, as well as MRI and PET-CT scans of their brains every 18 months for at least three years. By extrapolating data, the researchers found that beta amyloid deposits leads to dementia in as few as 10 years, with an average of 19 years.
"It's now quite clear that it's a very slow, gradual process over a couple of decades," Christopher Rowe, M.D., Austin Hospital's director of nuclear medicine, told Bloomberg, adding that the brain needs to accumulate large amounts of amyloid beta in order for Alzheimer's to develop. "[Y]ou need it there for a long time," he said.
Since the rate at which amyloid beta deposits develop in the brain is slow and protracted, the authors said, it provides an opportunity to "facilitate the design and timing of therapeutic interventions aimed at modifying the course of this illness."
Rowe told Bloomberg that this research demonstrates the need to develop therapies that can curtail the build up of amyloid beta before it has a chance to damage the brain. "You have a much greater chance of stopping a disease than trying to repair a brain that's severely damaged," he said. "This is the great hope now."