Semantic variant PPA is a type of frontotemporal dementia that involves difficulties with word and object recognition. Over time, it can cause changes in behaviors and emotions.

Semantic variant primary progressive aphasia (svPPA) causes the gradual deterioration of language and communication skills.

In svPPA, you may experience difficulties in understanding word meanings, recognizing objects, and naming things.

svPPA is one of three types of primary progressive aphasia (PPA), a rare neurodegenerative group of conditions that primarily affects language and communication skills.

The other two types of PPA are:

  • nonfluent/agrammatic variant (nfvPPA), which involves difficulties in forming grammatically correct sentences as well as slowed production of speech
  • logopenic variant (lvPPA), marked by challenges in word-finding and sentence production

In svPPA, language comprehension and word knowledge are affected due to the deterioration of semantic memory, which involves understanding concepts and relationships between words. It’s estimated to account for one-third of all cases of frontotemporal dementia.

People with svPPA may find it challenging to comprehend word meanings, recognize familiar objects, and name things accurately.

As the condition progresses, they might begin to experience difficulties in other cognitive areas beyond language, including:

  • memory loss
  • problem-solving challenges
  • changes in behavior or personality

Is semantic dementia the same as svPPA?

Semantic dementia and svPPA are closely related terms, but they refer to slightly different concepts.

svPPA is a specific subtype of PPA and primarily centers around language-related challenges, including word meanings, object recognition, and naming.

Semantic dementia is a broader syndrome that not only involves language issues but also includes difficulties recognizing familiar faces, objects, and concepts, encompassing a wider array of cognitive deficits.

Overall, both conditions involve the progressive loss of semantic memory — difficulties with word meanings, concepts, and relationships. However, semantic dementia is seen as a broader syndrome encompassing cognitive and behavioral changes, while svPPA is categorized within the spectrum of primary progressive aphasia.

As semantic dementia progresses, it may be reclassified as svPPA, depending on other symptoms that develop.

Some of the key symptoms of svPPA include:

  • Difficulty finding words: People with svPPA may have trouble finding the right words to express themselves, leading to frequent pauses, hesitations, and substitutions while speaking.
  • Preservation of grammar and syntax: Unlike other language conditions, grammar and sentence structure are often preserved in the early stages of svPPA.
  • Object recognition problems: Difficulty recognizing familiar objects, faces, and their associated meanings can occur, often leading to trouble naming or describing them.
  • Difficulty with single-word reading and writing: Reading and writing individual words may become increasingly difficult due to the loss of word meanings and associations.
  • Obsessive focus: Some people with svPPA may have obsession-driven behaviors. This is a sign of heightened focus on specific thoughts or fears.
  • Depressive symptoms: Research suggests that people with svPPA may experience more depressive symptoms compared to other types of frontotemporal dementia (FTD).
  • Repetitive behaviors: People with svPPA may engage in repetitive actions driven by obsessive thoughts.
  • Behavioral changes: In the later stages, people may experience changes in personality, social conduct, and emotional expression. This may manifest as decreased awareness of social norms, impulsivity, and changes in interests.
  • Mutism: In the late stages of svPPA, speech may become very limited, potentially leading to mutism.

The exact cause of svPPA isn’t fully understood. However, one key contributing factor is the accumulation of abnormal proteins in the brain, particularly in areas responsible for language and semantic memory.

In most svPPA cases — around 75–100% — there is an association with abnormal protein aggregates, such as TDP-43-C (transactive response DNA-binding protein 43).

The rest are linked to the FTD tau protein, and a few have both Alzheimer’s disease changes and svPPA symptoms.

In a 2017 study involving 69 people with different types of PPA, the researchers found that svPPA was associated with a distinct pattern of brain atrophy (shrinkage), primarily affecting gray and white matter in specific brain regions.

Risk factors of svPPA

While specific svPPA risk factors aren’t fully established, certain factors might increase the likelihood of developing this condition:

  • Age: SvPPA often happens in people over age 60, with a higher incidence in older adults.
  • Genetics: A family history of neurodegenerative disorders, including svPPA, could indicate a genetic predisposition. However, research suggests that svPPA is usually not inherited and is less likely to run in families compared to other frontotemporal lobar degeneration (FTLD) types.
  • Genetic mutations: Specific genetic mutations could increase the likelihood of svPPA development, potentially involving gene variations linked to different forms of FTD. For instance, a study in 2023 revealed that within a family carrying a genetic mutation (MAPT P301L), multiple members were affected by svPPA.
  • Neuroinflammation: Ongoing inflammation in the brain might contribute to the neurodegenerative process. A 2021 study found that inflammation was stronger in brain areas where the disease was spreading, suggesting a link between inflammation and disease progression. Targeting inflammation might potentially slow down the disease’s progression.

Currently, there’s no cure or treatment for svPPA, but ongoing research suggests that certain non-drug interventions can help.

Research has shown that people with svPPA might relearn lost words and benefit from behavioral therapies. These interventions, like naming therapy, can improve word recall in the short term. Some improvements might last over time.

Therapies focusing on conversations, daily activities, psychoeducation, and peer support groups have also shown promise.

When it comes to drug interventions, research from 2018 suggests antidepressants like selective serotonin reuptake inhibitors (SSRIs) may treat comorbid psychiatric conditions, such as depression and anxiety, or behavioral symptoms. Antipsychotics may also be considered.

The life expectancy of someone with svPPA

People with semantic variant primary progressive aphasia (svPPA) have a mean life expectancy of 12 years after the start of symptoms.

svPPA is a subtype of primary progressive aphasia that primarily affects language comprehension and word recognition.

While there is currently no cure, ongoing research into non-drug interventions offers hope for improving communication and quality of life for people with svPPA.

If you or a loved one is showing signs of svPPA, you can reach out to a medical professional. You can schedule an appointment with a neurologist or cognitive disorder specialist for a comprehensive assessment, including tests and imaging, to identify the cause of the symptoms.