Frontotemporal dementia: Pick type

The status of Pick's disease within the concept of frontotemporal dementia (FTD) is unclear. Some researchers have defined Pick's disease as FTD with Pick bodies. Alternatively, the confusion may be clarified by using the term Pick body dementia (PBD) rather than by using the term Pick's disease in a narrow sense. Pick body dementia is characterized by a prominent frontotemporal lobar atrophy, gliosis, severe neuronal loss, ballooned neurons, and the presence of neuronal inclusions called Pick bodies. In recent years, studies of Pick body dementia have advanced from the standpoint of the tau pathology. Tau‐positive glial inclusions as well as neuronal inclusions have been observed in PBD and its related disorders. Various forms of FTD have been proposed based on the presence of neuronal or glial inclusions. We propose a new variant of FTD termed ‘glial tangle‐predominant type’. More research is required to understand the tau abnormalities in the various forms of FTD.