Quantitative assessment of grammar in amyloid-negative logopenic aphasia

• Published in: Brain and language Vol. 186; pp. 26 - 31
• Main Authors: Tetzloff, Katerina A., Whitwell, Jennifer L., Utianski, Rene L., Duffy, Joseph R., Clark, Heather M., Machulda, Mary M., Strand, Edythe A., Josephs, Keith A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.11.2018; Academic Press
• Subjects: Agrammatism; Alzheimer's disease; Amyloid; Aphasia; Function words; Grammar; Logopenic; Logopenic aphasia; Mean length of utterance; PET; Primary progressive aphasia; Quantitative analysis; Sentence structure; Speech disorders; Syntax; Logopenic aphasia; Logopenic; Agrammatism; Aphasia; Amyloid; Primary progressive aphasia; Syntax; PET
• ISSN: 0093-934X; 1090-2155; 1090-2155
• DOI: 10.1016/j.bandl.2018.09.003

•Amyloid-negative lvPPA subjects have a unique linguistic profile.•Amyloid-negative lvPPA has some language features similar to amyloid-positive.•Amyloid-negative lvPPA also shares language features with agrammatic PPA.•The speech of lvPPA can help distinguish amyloid-negative versus-positive subjects. Logopenic primary progressive aphasia (lvPPA) typically results from underlying Alzheimer's disease, but subjects have been reported that do not show beta-amyloid (Aβ) deposition. These subjects do not differ on neurological and speech-language testing from Aβ-positive lvPPA, but they impressionistically show increased grammatical deficits. We performed a quantitative linguistic analysis of grammatical characteristics in Aβ-negative lvPPA compared to Aβ-positive lvPPA and agrammatic PPA, which is characterized by increased grammatical difficulties. Aβ-negative lvPPA used fewer function words and correct verbs but more syntactic and semantic errors compared to Aβ-positive lvPPA. These measures did not differ between Aβ-negative lvPPA and agPPA. Both lvPPA cohorts showed a higher mean length of utterance, more complex sentences, and fewer nouns than agPPA. Aβ-negative lvPPA subjects appear unique and share linguistic features with both agPPA and Aβ-positive lvPPA. Quantitative language analysis in lvPPA may be able to distinguish those with and without Aβ deposition.