What is primary progressive aphasia (PPA)?

Primary progressive aphasia (PPA) is a condition that results from damage to areas of the brain that control speech and language. Persons with PPA experience a gradual loss in their ability to speak, write, read, and/or understand what others are saying.

There are three subtypes of PPA, each defined by the language skills most affected:

  • Progressive nonfluent/agrammatic aphasia. People with this subtype have difficulty speaking – have difficulty planning how “speech muscles” will form words -- but still know the meaning of words. Grammar problems are a key feature of this subtype. Several common mistakes are made while speaking, including mixing up the order of words in a sentence, leaving out small grammatical words (for example, to, from, or the), or using incorrect word endings, pronouns, and verb tenses. Speech takes effort and becomes shortened to simple, incomplete phrases. Such a person may say, “Today. . . go dinner. . .ah. . .brother,” instead of, “Today, I’m going to go to dinner with my brother.”
  • Semantic variant primary progressive aphasia. People with this subtype lose the meaning of words (comprehension). A person with this type of PPA can speak fluently, but things they say might not make sense, and they might have trouble understanding what others are saying. Some examples: the person cannot recall the meaning of words that are not frequently used and may ask, “what is an airplane?” He or she may not remember what a toothbrush is or how to use it.
  • Logopenic aphasia (also called progressive fluent aphasia). People with this subtype have difficulty finding the right words when they are speaking, but they usually still know the meanings of words. Speech is fluent (flows/does not take a lot of effort to speak) during small talk, but slows, pauses or stops if the person needs to search for a specific or unfamiliar word).

The speed of decline and type of PPA varies from person to person. Language and speech are affected early in the course of PPA; however, other brain functions and behavior may change later on. Examples of cognitive functions that that are initially spared include memory, focus and attention, and visuospatial skills (ability to understand what we see around us and the dimensions and location of our surroundings.

Who gets primary progressive aphasia (PPA)?

Primary progressive aphasia (PPA) can occur in people as young as 35, but it is most often seen beginning in patients in their 50s and only rarely is seen after age 75.

Patients usually have some language problem for about 4 ½ years before going to the doctor.

How is the language loss from stroke different from that seen in primary progressive aphasia (PPA)?

The language loss from stroke is sudden and does not progress. Language problems seen in patients with PPA develop and worsen slowly over time. In the most severe stage, people with PPA may not be able to speak at all.

What causes primary progressive aphasia (PPA)?

Primary progressive aphasia (PPA) is the result of deterioration of brain cells, resulting in shrinkage (atrophy) of brain tissue important for speech and language. Damage is usually to the left side of the brain.

The destruction in brain tissue seen in PPA is caused by two types of neurodegenerative diseases (slow, ongoing death of the brain’s nerve cells) -- frontotemporal lobar degeneration (most cases of nonfluent or semantic PPA) and Alzheimer’s disease (associated with the logopenic variant). In most cases of PPA, there is no specific cause, however, sometimes it runs in families.

What are the symptoms of primary progressive aphasia (PPA)?

Early-stage symptoms include:

  • Slowing down, pausing, or stopping of speech
  • Word-finding difficulty
  • Written or spoken sentences with abnormal word order
  • Substitution of words
  • Mispronouncing words
  • Talking around a word
  • Using abnormally short phrases
  • Trouble understanding conversation
  • Trouble understanding simple words
  • Difficulty writing
  • Difficulty reading
  • Problems with spelling
  • Problems with arithmetic
  • Inability to remember familiar objects or how they are used
  • Mistakenly writing words that sound alike
  • Substituting a similar letter sound – for example, “t” for a “d”
  • Substituting a non-word that sounds similar to a real word – for example, lelephone for telephone

Late-stage symptoms. Language and speech skills will continue to worsen over time. The rate of decline is different from person to person. In the later stages of PPA, other thinking skills including memory and behavior may begin to decline.

Last reviewed by a Cleveland Clinic medical professional on 01/03/2019.


  • The Association for Frontotemporal Degeneration. Nonfluent/Agrammatic PPA. Accessed 1/7/2019.
  • The Association for Frontotemporal Degeneration. Logopenic Variant PPA. Accessed 1/7/2019.
  • The Association for Frontotemporal Degeneration. Semantic Variant PPA. Accessed 1/7/2019.
  • Gorno-Tempini, M.L. MD, PhD; Hillis, A.E. MD; Weintraub, S. PhD; et al. Classification of primary progressive aphasia and its variants. Neurology 2011 Mar 15;76(11):1006-14.
  • Kanter SJ, Factora RM, Suh TT. Does this patient have primary progressive aphasia? Cleve Clinic J Med 2006;73(11):1025-1027.
  • National Aphasia Association. What is Primary Progressive Aphasia (PPA)? Accessed 1/7/2019.

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