‘Silent Phase’ of Alzheimer’s Begins Decades Before Symptoms, NIH Study Suggests

Recent advancements in Alzheimer’s disease research show a promising shift in the understanding of the memory-robbing disorder, suggesting that crucial brain changes can occur decades before symptoms manifest.
Alzheimer’s disease has a long pre-symptomatic period, with related changes taking place in the brain “10, 15, even 20 years before the onset of memory and thinking symptoms,” Igor Camargo Fontana, Alzheimer’s Association director of scientific conference programming, told The Epoch Times.
This research could also open new avenues for earlier detection and targeted treatments.
Researchers have found that the initial phase of Alzheimer’s is insidious, unfolding slowly over time and occurring well before noticeable memory problems arise. During this phase, a gradual buildup of beta-amyloid plaques and tangles—hallmarks of Alzheimer’s—can be observed.
This early “quiet” phase is marked by subtle changes in brain cells, particularly inhibitory neurons, which may be among the first to become vulnerable, disrupting communication between brain cells, according to Fontana. These cells are mostly located in a brain region that is associated with memory, vision, and language.
The study suggests that in this later phase of the disease, other cells associated with inflammation—microglia and astrocytes—begin counteracting initial changes by releasing molecules or altering their structures, according to Fontana.
The results fundamentally alter scientists’ understanding of how Alzheimer’s harms the brain and will guide the development of new treatments for this devastating disorder, Hodes noted in a statement.
By recognizing distinct phases of the disease, researchers can better tailor diagnostics and therapeutics to the specific cellular changes taking place at various stages. This discovery may also facilitate earlier interventions and improve patient outcomes.
The “bigger picture” is that Alzheimer’s long pre-symptomatic period presents opportunities for early detection and intervention to prevent the onset of dementia symptoms, Fontana said. “If the findings in this new paper are confirmed by other labs,” he added, “it raises the question of whether effectively addressing the brain changes that happen in what the authors call the first ‘quiet’ phase can slow, delay or prevent the second, more destructive phase.”
Fontana stressed the importance of evaluating this “quiet” phase using a combination of diagnostic tools and investigating its associations with Alzheimer’s biomarkers, such as amyloid and tau.