Poster | Poster Session 06 Program Schedule
02/15/2024
04:00 pm - 05:15 pm
Room: Majestic Complex (Posters 61-120)
Poster Session 06: Aging | MCI | Neurodegenerative Disease - PART 2
Final Abstract #81
Grey and White Matter Correlates of Motor Speech Disturbances in Nonfluent Progressive Aphasia Syndromes
Olivier Piguet, The University of Sydney, Sydney, Australia Ting-Chih Chuang, The University of Sydney, Sydney, Australia Sophie Mattis, The University of Sydney, Sydney, Australia Halle Quang, The University of Sydney, Sydney, Australia Penelope Monroe, The University of Sydney, Sydney, Australia Kirrie Ballard, The University of Sydney, Sydney, Australia Ramon Landin-Romero, The University of Sydney, Sydney, Australia
Category: Neurodegenerative Disorders
Keyword 1: neuroimaging: structural
Keyword 2: language: aphasia
Keyword 3: dementia - other cortical
Objective:
Two nonfluent syndromes of primary progressive aphasia (PPA) are commonly recognised: a non-fluent/agrammatic variant (nfvPPA) and a logopenic variant (lvPPA). Both syndromes are characterised by marked, and overlapping, expressive language deficits and variable disease trajectories. Although apraxia of speech (AOS), a motor speech impairment, has been found to be specific to nfvPPA, it remains difficult to detect, making accurate diagnosis between these two syndromes clinically challenging. Here, we report performance on novel acoustic measures sensitive to AOS in patients diagnosed with these nonfluent PPAs and outline their brain correlates at baseline and with disease progression.
Participants and Methods:
Seventy-nine patients diagnosed with either nfvPPA (n = 39) or lvPPA (n = 40), and 40 healthy controls matched on demographic variables (age, sex, education) were recruited. Participants underwent annual language assessments and high-resolution structural brain MRI (median = 2 years; range 1-4 years). Pairwise variability index (PVI) and word duration (WD) were calculated during a polysyllabic word repetition task comprising weak-strong (W-S; e.g., DInosaur) and strong-weak (S-W; e.g., baNAna) words to determine the presence of AOS. These acoustic speech measures were correlated with measures of grey matter (cortical thickness) and white matter tract (fixel-based analyses) integrity at baseline and with disease progression.
Results:
At baseline, compared with Controls, both PVI and WD were significantly impaired in nfvPPA, regardless of word type. In contrast, only WD for S-W words was impaired in lvPPA. With disease progression, annual change in WD significantly increased in nfvPPA compared with lvPPA, irrespective of word type. For PVI, the annual change was only significantly different for W-S words, but not for S-W words. With disease progression, neuroimaging analyses revealed a significant correlation between PVI for W-S words and cortical grey matter integrity in the frontal region (right inferior and left middle) and with motor association and temporal white matter tracts in nfvPPA only. No significant correlations were observed for the WD metrics. Similarly, no significant correlations emerged for the lvPPA group.
Conclusions:
Our findings highlight the clinical relevance of PVI in W-S words as a sensitive measure of AOS that is specific to nfvPPA, which may help towards the differential diagnosis between nfvPPA and lvPPA. This measure is also associated to grey and white matter changes that are specific to nfvPPA. These findings provide a framework for classifying and staging language impairments in nonfluent PPA syndromes that may be relevant for future pharmacological clinical trials.
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