Neurofilament Light Levels Correlate With Cognitive Decline 

In a study comparing potential biomarkers for cognitive decline in Alzheimer disease, neurofilament light (NfL) levels correlated more strongly with cognitive decline compared with total tau (T-tau) levels. Baseline plasma NfL also associated with neuroimaging biomarkers cortical thickness, hippocampal volume, white matter integrity, and white matter hyperintensity volume. 

Overall, plasma NfL at baseline had better utility as a prognostic marker of cognitive decline and neuroimaging changes and T-tau did not add prognostic value. The combination of elevated NfL and T-tau levels together at baseline, however, was more strongly associated with worse cognitive outcome after a 6.2-year period as well as reduced temporal cortex thickness and increased number of infarcts, adding cross-sectional value to the NfL measurement. 

In the Mayo Clinic Study on Aging, 995 individuals without dementia had concurrent plasma NfL and T-tau levels, cognitive status, and neuroimaging data collected every 15 months for a median 6.2 years. A linear mixed effects models was used to adjust for potential confounders of education, sex, and age. The analyses were replicated in the Alzheimer's Disease Neuroimaging Initiative (ADNI) among 387 participants without dementia followed for a median of 3.0 years.

These data were presented at the Emerging Science Session of the American Academy of Neurology Virtual Annual Meeting, April 17-22, 2021.