Logopenic Variant PPA

FTD syndromes characterized predominantly by the gradual loss of the ability to speak, read, write and understand what others are saying fall under the category of primary progressive aphasia, or PPA. PPA is diagnosed when three criteria are met:

  1. There is be a gradual impairment of language (not just speech).
  2. The language problem is initially be the only impairment.
  3. The underlying cause is a neurodegenerative disease.

Experts further subdivide PPA into three clinical subtypes based on the specific language skills that are most affected.

People with logopenic variant PPA (lvPPA, also known as PPA-L) have difficulty finding words when they are speaking. As a result, they may speak slowly and hesitate frequently as they search for the right word. Unlike people with semantic variant PPA, however, they are still able to recall the meanings of words. Unlike people with agrammatic PPA, speech can be perfectly fluent during small talk but then becomes hesitant and halting when the person needs to be specific or use a more unfamiliar word. Speech is usually not effortful or distorted. The lvPPA form is also characterized by a narrow attention span for words that compromise the ability to repeat phrases and sentences. As the disease progresses, affected individuals may develop problems comprehending complex sentences.

Know the Signs… Know the Symptoms

Impaired single-word retrieval

Difficulty finding the right word while speaking

  • Pauses and hesitations due to time needed for word retrieval
  • Extended description (circumlocution) may be substituted for a forgotten word

Impaired repetition

More difficulty with longer phrases and sentences.


Phonological speech errors

Mistakes in speech sounds, including omissions and substitutions. For example, the person affected may substitute sounds made with the tip of the tongue such as “t” or “d” for sounds made near the throat such as “k” or “g”: “tup” instead of “cup” or “dap” instead of “gap.” They may omit final consonants: “slee” instead of “sleep.”


Phonological paraphasias

Substitution of a non-word with some of the same sounds for a legitimate word. For example, the person affected may say “lelephone” for “telephone.”


Poor comprehension of complex sentences

With single-word comprehension spared.


Difficulty swallowing

May develop later in the progression of the disease.

Diagnosis

Doctors will consider a diagnosis of lvPPA based on the following symptoms:

  • Impaired single-word retrieval in spontaneous speech
  • Impaired repetition of phrases and sentences

AND at least three of the following:

  • Phonological speech errors
  • Single-word comprehension and object knowledge unaffected
  • Physical ability to form words (motor speech) unaffected
  • Simple but correct grammar

Treatment, Management, and What to Expect

As with all forms of FTD, there is no cure for PPA, and in most cases its progression cannot be slowed.

Although no studies have shown improvement or slowing of progression when a patient works with a speech and language pathologist (SLP), many centers work with SLPs to hone the diagnosis and to research potential therapeutic interventions.

Patients who do not develop additional behavioral and motor symptoms are able to preserve their independence and active lifestyle for a longer period of time.

Genetics

Logopenic PPA can be sporadic, familial or hereditary. The majority of cases are not hereditary.

Pathology

In contrast to other forms of PPA, the brains of many – but not all – people with lvPPA exhibit pathological features similar to those seen in Alzheimer’s disease, such as neurofibrillary tangles or imaging evidence of amyloid deposits.

 


References

Gorno-Tempini, M.L., Hillis, A.E., Weintraub, S, et.al. Classification of primary progressive aphasia and its variants. Neurology; March, 2011.