Primary Progressive Aphasia
FTD syndromes characterized predominantly by the gradual loss of the ability to speak, read, write and understand what others are saying fall under the category of primary progressive aphasia, or PPA.
PPA is diagnosed when three criteria are met:
- There is a gradual impairment of language (not just speech).
- The language problem is initially the only impairment.
- The underlying cause is a neurodegenerative disease.
Experts further subdivide PPA into three clinical subtypes based on the specific language skills that are most affected. They are: