Primary progressive aphasia (uh-FAY-zhuh) is a rare nervous system (neurological) syndrome that affects your ability to communicate. People who have it can have trouble expressing their thoughts and understanding or finding words.

Symptoms begin gradually, often before age 65, and worsen over time. People with primary progressive aphasia can lose the ability to speak and write and, eventually, to understand written or spoken language.

This condition progresses slowly, so you may continue caring for yourself and participating in daily life activities for several years after the disorder's onset.

Primary progressive aphasia is a type of frontotemporal dementia, a cluster of related disorders that results from the degeneration of the frontal or temporal lobes of the brain, which include brain tissue involved in speech and language.


Primary progressive aphasia symptoms vary, depending on which portion of the brain's language areas are involved. The condition has three types, which cause different symptoms.

Semantic variant primary progressive aphasia

Signs and symptoms include:

  • Difficulty comprehending spoken or written language, particularly single words
  • Trouble comprehending word meanings
  • Struggling to name objects

Logopenic variant primary progressive aphasia

Signs and symptoms include:

  • Difficulty retrieving words and word substitutions
  • Frequently pausing in speech while searching for words
  • Difficulty repeating phrases or sentences

Nonfluent-agrammatic variant primary progressive aphasia

Signs and symptoms include:

  • Poor grammar in written and spoken form
  • Trouble understanding complex sentences
  • Using grammar incorrectly
  • May be accompanied by speaking problems such as errors in speech sounds (known as apraxia of speech)


Primary progressive aphasia is caused by a shrinking (atrophy) of certain sections (lobes) of the brain responsible for speech and language. In this case, the frontal, temporal or parietal lobes, primarily on the left side of the brain, are affected.

Atrophy is associated with the presence of abnormal proteins, and brain activity or function in affected areas might be reduced.

Risk factors

Risk factors for primary progressive aphasia include:

  • Learning disabilities. If you had a childhood learning disability, particularly developmental dyslexia, you might be at somewhat higher risk of primary progressive aphasia.
  • Certain gene mutations. Rare gene mutations have been linked to the disorder. If other members of your family have had primary progressive aphasia, you might be more likely to develop it.


People with primary progressive aphasia eventually lose the ability to speak and write, and to understand written and spoken language. Some people develop substantial difficulty forming sounds to speak (a problem called apraxia of speech), even when their ability to write and comprehend are not significantly impaired.

As the disease progresses, other mental skills, such as memory, can become impaired. Some people develop other neurological symptoms such as problems with movement. With these complications, the affected person eventually will need help with day-to-day care.

People with primary progressive aphasia can also develop depression or behavioral or social problems as the disease progresses. Other problems might include blunted emotions such as unconcern, poor judgment or inappropriate social behavior.

Primary progressive aphasia care at Mayo Clinic

Dec. 27, 2018
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