Click on image to play movie
Amyloid accumulation. Cross-sectional analysis using florbetapir PET shows that brain amyloid deposits ramp up steeply in AD mutation carriers between the ages of 28 and 38, several years before clinical symptoms appear. Movie courtesy of Adam Fleisher and Lancet Neurology
Evidence keeps building that the first signs of Alzheimer’s disease appear decades before symptoms. In two companion papers in the November 6 Lancet Neurology, theAlzheimer’s Prevention Initiative (API) formally published cross-sectional biomarker data from young adults who carry a presenilin 1 mutation and are destined to develop AD. Researchers led by Eric Reiman at Banner Alzheimer’s Institute, Phoenix, Arizona, and Francisco Lopera, University of Antioquia, Medellin, Colombia, report that mutation carriers show structural and functional brain abnormalities characteristic of AD more than two decades before they are expected to develop cognitive symptoms of the disease. Notably, the changes occur in the presence of high levels of Aβ42, but before there is evidence of amyloid accumulation in the brain. Although it is not yet proven that these results will generalize to late-onset AD, researchers noted the changes are consistent with brain imaging findings in young adults at increased risk for sporadic AD, suggesting the two forms of the disease progress similarly. The researchers saw the first evidence of amyloid deposits about 16 years before the expected symptom onset, in agreement with findings from the Dominantly Inherited Alzheimer Network (DIAN) cohort. Much of these data were previously presented at conferences.