The 3 Types of Primary Progressive Aphasia

Primary progressive aphasia, or PPA, is a neurological syndrome that causes people to slowly lose their ability to read, write, speak, and understand language. PPA is not the same as Alzheimer's disease (AD), although AD is thought to cause PPA in 30% to 40% of cases.

PPA happens when tissues in the frontal, parietal, and temporal regions (lobes) of the brain gradually deteriorate over time, usually on the left side of the brain. This is where several speech, language, and memory "control centers" are located.

Scientists have identified three types of PPA, based on the distinct symptom profiles the condition can cause. This article covers the similarities and differences between each type.

Overview

PPA is caused by neurodegenerative diseases, which shrink and destroy brain tissues. The most common of these are Alzheimer's disease, and a group of brain-damaging diseases known as frontotemporal lobar degeneration (FTD).

How a person is affected by neurodegenerative disease depends on which brain tissues are damaged. In someone with PPA, most damage occurs in areas of the brain that allow you to use and comprehend language in spoken and written form.

Along with language impairments, people with PPA may develop behavior and personality changes. They may become confused or disoriented as people and objects become less familiar. Some people may become depressed, anxious, or apathetic.

Doctors do not have a way to reverse the brain damage caused by neurodegenerative diseases, and they cannot stop these diseases from leading to PPA either. Although there is no cure for PPA, it can be managed and sometimes slowed with speech therapy.

Types of Primary Progressive Aphasia

There are three main PPA variants: logopenic, nonfluent, and semantic. Not everyone will fit the exact criteria for one specific variant. Individuals who don't are diagnosed as having unclassifiable PPA.

These three variants are similar in that they each cause progressive brain damage and language difficulties. But they can be distinguished by the specific symptom profiles they cause, which correspond to the parts of the brain most damaged by neurodegenerative disease.

Knowing whether or not you have a certain PPA variant can help you manage your symptoms and prepare for what problems you might encounter as your condition progresses.

Logopenic Variant PPA (lvPPA)

Logopenic variant PPA is the most common of the three main variants, affecting an estimated 42% of people with a PPA variant.

People with lvPPA have the motor and grammar skills to articulate their words, however, they tend to produce fragmented sentences because they often can't find the right words to say. In fact, the word “logopenia,” derived from Greek, means “lack of words.”

Someone with the logopenic PPA variant may also:

• Speak slowly, often halting mid-speech to search for a word
• Struggle to speak concisely or come across as long-winded
• Have trouble repeating sentences back to someone

The most notable distinction in individuals with lvPPA is their impaired working memory. They may be able to recognize a person or object without any problem, but they will regularly find themselves unable to retrieve the right word for that object or person from their memory.

Nonfluent Variant PPA (nfvPPA)

Nonfluent variant PPA (nfvPPA), also known as agrammatic variant PPA, is the second most common variant, affecting an estimated 36% of people with a PPA variant.

This variant is distinct in how it impairs a person's grammar skills along with the motor skills needed to pronounce words.

A person with the nonfluent variant may need to talk very slowly, as it is more difficult for them to configure sentences in their mind then form the words with their mouth.

They may also have trouble with:

• Moving their jaw, lips, or tongue to pronounce words correctly
• Producing complete sentences without halting mid-speech
• Speaking or comprehending syntactically complex sentences

Some people with nfvPPA describe a feeling of knowing what they want to say, but being unable to control their lips, jaw, or tongue to actually say it.

Semantic Variant PPA (svPPA)

Semantic variant PPA is the least common variant of the three, affecting an estimated 22% of people with a PPA variant.

The notable features of svPPA are difficulty recalling the names of everyday objects and comprehending the meaning of words. For example, someone with this variant may be having a normal conversation when suddenly a once familiar word like "watermelon" sounds completely foreign to them.

Someone with svPPA may also:

• Have a hard time making sense of a conversation
• Experience surface dyslexia, in which they have trouble reading words that are spelled differently than they sound
• Experience dysgraphia, in which they will read or write words just like they sound, for example, writing "yat" rather than “yacht”

Despite these impairments, a person with svPPA will often have most other cognitive abilities intact; they may remember life events easily, engage in complex hobbies, or find their way around without difficulty.

Summary

All people with PPA have trouble expressing themselves with language, but not everyone with PPA meets the criteria for a single variant. The three main PPA variants can be distinguished by the specific brain regions and language skills that are affected.

Whereas someone with nonfluent PPA may have trouble pronouncing words and stringing sentences together, someone with logopenic PPA may find it difficult to retrieve words from memory. Meanwhile, someone with semantic PPA may get lost in conversations, unable to comprehend what words mean.

A Word From Verywell

Learning that you have been diagnosed with primary progressive aphasia can be frightening. Although expressing yourself and your needs will become more challenging as time passes, your diagnosis also presents an opportunity to get creative with how you communicate your thoughts and feelings. In fact, some people find that art therapy is an excellent way to supplement speech therapy, while others reinvent themselves through forms of expression they never thought to try before.