Definition of Primary Progressive Aphasia (PPA)

  • Primary Progressive Aphasia (PPA) is a neurodegenerative disease which mainly affects language, ranging from subtle impairment to total incapacity to communicate.
  • PPA should be suspected in anyone who shows progressive language difficulties.
  • In their everyday life, people suffering from PPA show difficulty properly communicating their needs, for example, when speaking on the phone or ordering at a restaurant. Therefore, they tend to stand back and isolate themselves because of their language difficulties.
  • During the early stages of the disease, other cognitive functions such as memory and calculation abilities remain well preserved, but may decline over time.
  • Across the province of Quebec, PPA cases represent 3 people out of every 100 000 and they often present between the ages of 55 and 65.
  • There are three main variants of PPA: nonfluent/agrammatic, logopenic and semantic.
  • There is also a very rare form of communication disorder that specifically affects speech : the Primary Progressive Apraxia of Speech.

PPA diagnostic features

Inclusion criteria:
  1. The language impairment is the most prominent clinical feature and appears mainly as aphasia at the onset and during the early stages of the disease.


  2. The language deficits are the main cause of impaired daily living activites.
Exclusion criteria:

Cognitive deficits are better accounted for by another cause:

  • Neurological or medical disorders
  • Psychiatric disorders

Other neurological symptoms are more prominent in the early stages of the disease:

  • Episodic memory deficits
  • Visual memory deficits
  • Visuoperceptual deficits
  • Behavioral disturbances
  • PPA diagnoses are mostly based on a clinical assessment.
  • CT or MRI imaging is required to eliminate other potential causes or to support a diagnosis.
  • In some cases, imaging biomarkers (for example, a Positron Emission Tomography (PET) scan using fluorodeoxyglucose or amyloid compounds) or cerebrospinal fluid (CSF) biomarkers (collected through a lumbar puncture) can help confirm diagnosis.
  • Occasionally, genetic mutations (C9orf72, MAPT, PGRN) are associated with PPA, which makes investigating the family history important.

PPA diagnostic features based on Mesulam, 2001