PPA is a rare type of aphasia caused by a gradual loss of brain cells in the areas responsible for language. Unlike aphasia from a stroke or injury, PPA declines over time. It is not caused by a sudden event rather by a disease in the brain, like frontotemporal degeneration (FTD) or Alzheimer’s. PPA can begin in midlife and often affects speech before other thinking abilities. See our section on PPA and PPAOS for more information.