Primary progressive aphasia (
PPA) is a type of neurological syndrome in which language capabilities slowly and progressively become impaired while other mental functions remain intact. It was first described as a distinct syndrome by M.-Marsel Mesulam in 1982. Primary Progressive Aphasias have a clinical and pathological overlap with the
Frontotemporal Lobar Degeneration (FTLD) spectrum of disorders and
Alzheimer's disease.