Clinically normal (CN) adults with suspected non-Alzheimer disease pathophysiology (SNAP) did not exhibit evidence of elevated tau levels, which suggests that this biomarker construct does not represent amyloid-independent tauopathy, a recent study found. Researchers conducted a longitudinal observational study in an academic medical center that included 247 CN participants from the Harvard Aging Brain Study (142 women [57.5%]; 105 men [42.5%]; mean age, 74 years; 64 [25.9%] were classified as having SNAP). They found:

• At the group level, individuals with SNAP did not show cognitive decline but did show a diminished practice effect.

• SNAP is likely heterogeneous, with a subset of this group at elevated risk for short-term decline.

Citation: Mormino EC, Papp KV, Rentz DM, et al. Heterogeneity in suspected non-Alzheimer disease pathophysiology among clinically normal older individuals. [Published online ahead of print August 22, 2016]. JAMA Neurol. doi:10.1001/jamaneurol.2016.2237.