Masdeu was the first to demonstrate in vivo that abnormal tau proteins spread throughout human brain networks using white matter tracts. The Journal of Nuclear Medicine study combined MRI and ¹⁸F-flortaucipir PET to study tau protein behavior in a tau-dependent progressive neurodegenerative disorder that affects the language-related syntactic neural network. In the study participants, tau accumulation likely began in the anterior frontal node and travelled to the spatially separate posterior temporal lobe. The acruate fasciculus white matter tract connecting these regions was most affected near the anterior frontal node, corresponding to a loss of neurons in the anterior node.

This discovery reveals a window of opportunity for treatment, because to jump from neuron to neuron, tau appears to become extracellular - and possibly amenable to immunotherapy using antibodies that target this abnormal protein to hamper the spread, thereby preserving neural networks. Three clinical trials are underway at the Nantz National Alzheimer Center using anti-tau antibodies from Abbvie, Biogen and Eli Lilly.