[Pick's disease].

Pick's disease is a type of frontotemporal lobar degeneration(FTLD) with circumscribed atrophy in the frontotemporal lobe. The terminology for Pick's disease has evolved over time. Pick's disease was a term formerly used to define a disorder with symptoms caused by frontal and temporal lobe dysfunction. Therefore, the diagnosis was previously based on clinical features and the distribution of brain atrophy. Pick's disease is currently defined by the presence of tau-positive Pick bodies, and thus can be diagnosed only pathologically. The clinical phenotypes of Pick's disease include behavioral variant FTD (bvFTD), progressive nonfluent aphasia (PNFA) and semantic dementia (SD).