Primary Progressive Aphasia Download PDF, 845KB, PDF Primary Progressive Aphasia (PPA) is a neurological condition in which language capabilities become slowly and progressively impaired. It is caused by degeneration of parts of the brain that are important for language. PPA is progressive and an individual may lose nearly their total ability to speak in the most severe stage. The type or pattern of language problems may differ for each individual. In view of the communication difficulties, individuals with PPA are often referred to a Communication Clinic. [Please download the PDF file if you are unable to view the image below.]