Impact of FTD

The involvement of the temporal lobes in frontotemporal lobar degeneration leads to language deterioration, while memory deficits may not be evident at first.

Behavioral variant frontotemporal dementia

Language is generally not primarily affected in the behavioral variant of FTD. Often, people with bvFTD are quiet and talk less, but this change derives more from increased apathy and lack of initiation. Patients may respond when spoken to but tend to otherwise be disinclined to speak. On the other hand, some patients experience euphoria and disinhibition as the disease progresses, and these people may be inclined to talk more.

Semantic dementia

The initial symptoms of semantic dementia often involve problems with finding the right words during conversation.
Bilateral deterioration of the temporal lobes (particularly anterior) leads to:

• fluent speech production,
• grammatically correct language,
• loss of word and object meaning,
• relatively preserved comprehension and
• deficits in comprehending the emotions of others.

Progressive nonfluent aphasia

People with progressive nonfluent aphasia (PNFA) develop difficulties producing speech. They know what they want to say, but they have immense trouble getting the words out of their mouths. The degeneration of cortex in the language-dominant areas of the frontal, parietal and temporal lobes (including Broca’s area) leads to:

• slow, labored non-fluent speech,
• agrammatism (use of high-value content words only without connecting or descriptive words) and
• relatively preserved word comprehension.