1. aphasia, primary progressive A progressive form of dementia characterized by the global loss of language abilities and initialpreservation of other cognitive functions. Fluent and nonfluent subtypes have been described. Eventually a pattern of global cognitive dysfunction, similar to ALZHEIMER DISEASE, emerges. Pathologically, there are no Alzheimer or PICKDISEASElike changes, however, spongiform changes of cortical layers II and III are present in the TEMPORALLOBE and FRONTALLOBE. (From Brain 1998 Jan;121(Pt 1):115-26)