MAPT and argyrophilic grain disease: According to the appearance, histologic localization, and anatomical distribution of the 4R-tau aggregates, 4R-tauopathies are classified into progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), argyrophilic grain disease, globular glial tauopathy and frontotemporal lobar degeneration due to MAPT mutations with 4R-tau pathology (Kovacs, 2015).