Largest tau PET study confirms link to memory decline

Tau PET imaging has only recently been catching up to amyloid imaging in neurodegenerative disease and dementia research, but tau may be more of the culprit in cognitive decline than other naturally occurring proteins like amyloid. Finding tau deposition in the brain could be a way to verify Alzheimer's prior to the arrival of all the characteristic symptoms, according to a study presented during this week's Alzheimer's Association International Conference (AAIC) 2014.

Keith Johnson, MD, from Massachusetts General Hospital in Boston, and colleagues evaluated 56 normal adults with a median age of 72 in the largest tau PET study of its kind to date to assess whether tau deposits in the brains of healthy subjects are connected to declining memory. Every subject had already undergone three annual memory tests prior to tau imaging. In order to visualize tau, researchers administered an investigational tau agent, F-18 T807. The radiotracer, developed by Eli Lilly, binds to tau in the brain.

Results of the study showed that higher levels of tau were in fact associated with declining memory function. Poor memory performance was linked specifically to the entorhinal cortex and temporal neocortex.

“These preliminary data suggest that tau in these brain areas is related to memory decline in normal older individuals,” said Johnson in an official statement. “This study demonstrates the potential for PET technology to be used for early detection, and to help pick participants for prevention trials and treatment trials that target tau.”