MAPT and argyrophilic grain disease: AGD was first reported in 1987, by Braak and co-workers as a progressive, late-onsetneurodegenerative disease characterized by small spindle- or comma-shaped, silverstain positive lesions in neuronal processes, referred to as argyrophilic grains(AG).12 Subsequently,studies revealed hyperphosphorylated-tau protein as a major AG component.