Apr 1, 2026 · 1 hr 30 min · 14 segments
This episode is a conversation about primary progressive aphasia (PPA). We discuss the definition of PPA, the three widely used subtypes, common clinical symptoms, neuroanatomy and proteinopathies…
Emily RogalskiGuestRyan Van PattenHostJohn BelloneHostSo our topic today, this time, is the clinical syndrome of primary progressive aphasia, or PPA, which refers to a prominent impairment in language with relative initial sparing in other cognitive domains.
Compared to Alzheimer's disease, the onset of PPA is typically a bit younger, more often in the 50s and 60s, although it can occur in older ages as well.
Semantic variant PPA is characterized by impaired single-word retrieval with a loss of crystallized semantic knowledge and vocabulary.
Neuroanatomically, classically, it's associated with left anterior temporal atrophy.
Then we have non-fluent agrammatic PPA with effortful halting speech production, potentially apraxia of speech, poor articulation, grammatical errors, speech sound mistakes.
In the brain, we tend to see atrophy in the left anterior perisylvian regions.
And last but not least, logopenic variant is defined by impaired single word retrieval, inability to name objects or anomia, poor repetition, and deficits in verbal or phonological working memory.
For this one, there's a notable pathological focus in the left temporal parietal junction.
So if we step back for a minute, whenever reading about PPA, I come across a lot on the three canonical categories, and that's helpful, but there's also a lot of heterogeneity within the subtypes and overlap across them.
I've come across data suggesting maybe about a third of cases are best classified as mixed subtypes.
But for now, what else should we know about the definition and the core clinical characteristics of PPA?
When we think about PPA in general, the one favor that the name did for us is it actually builds in the definition into the syndrome title.
And that's often not the case in neurodegenerative diseases or other diseases.
They are sometimes named after someone else, and you don't have those semantic clues to really define it.
So You did a really elegant job of saying, yeah, there's these three features.
So our topic today, this time, is the clinical syndrome of primary progressive aphasia, or PPA, which refers to a prominent impairment in language with relative initial sparing in other cognitive domains.
Compared to Alzheimer's disease, the onset of PPA is typically a bit younger, more often in the 50s and 60s, although it can occur in older ages as well.
Semantic variant PPA is characterized by impaired single-word retrieval with a loss of crystallized semantic knowledge and vocabulary.
Neuroanatomically, classically, it's associated with left anterior temporal atrophy.
Then we have non-fluent agrammatic PPA with effortful halting speech production, potentially apraxia of speech, poor articulation, grammatical errors, speech sound mistakes.
In the brain, we tend to see atrophy in the left anterior perisylvian regions.
And last but not least, logopenic variant is defined by impaired single word retrieval, inability to name objects or anomia, poor repetition, and deficits in verbal or phonological working memory.
For this one, there's a notable pathological focus in the left temporal parietal junction.
So if we step back for a minute, whenever reading about PPA, I come across a lot on the three canonical categories, and that's helpful, but there's also a lot of heterogeneity within the subtypes and overlap across them.
I've come across data suggesting maybe about a third of cases are best classified as mixed subtypes.
But for now, what else should we know about the definition and the core clinical characteristics of PPA?
When we think about PPA in general, the one favor that the name did for us is it actually builds in the definition into the syndrome title.
And that's often not the case in neurodegenerative diseases or other diseases.
They are sometimes named after someone else, and you don't have those semantic clues to really define it.
So You did a really elegant job of saying, yeah, there's these three features.
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