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A longitudinal investigation of social cognition impairments and their neural correlates in the non-semantic variants of Primary Progressive Aphasia
Poster Session A - Sandbox Series, Thursday, October 24, 10:00 - 11:30 am, Great Hall 3 and 4
This poster is part of the Sandbox Series.
Natacha Cordonier1,2, Ramón Landin-Romero2,3, Olivier Piguet2,4; 1University of Neuchâtel, Neuchâtel, Switzerland, 2Brain and Mind Centre, The University of Sydney, Sydney, Australia, 3School of Health Sciences, The University of Sydney, Sydney, Australia, 4School of Psychology, The University of Sydney, Sydney, Australia
Introduction. Primary progressive aphasia (PPA) encompasses a spectrum of neurodegenerative disorders characterized by progressive language decline. Current diagnostic methods often struggle to accurately diagnose the logopenic variant of PPA (lvPPA) and differentiate it from the non-fluent variant (nfvPPA) due to overlapping language features (Harris et al., 2019). Integrating assessments of nonlinguistic cognitive functions, especially socio-cognitive measures, has emerged as a promising avenue for refining diagnostic accuracy (Piguet et al., 2015; Van Den Stock et al., 2022). Despite this potential, studies focusing on social cognition in lvPPA and nfvPPA remain scarce, with a notable lack of longitudinal studies (De la Sablonnière et al., 2021; Fittipaldi et al., 2019). Understanding the nuances of social cognition deficits, their interplay with language disorders, and their neural correlates in lvPPA and nfvPPA across different disease stages seems essential for improving detection and diagnostic accuracy in these variants of dementia. This Sandbox Series poster, therefore, presents a research project aimed at investigating social cognition in lvPPA and nfvPPA during the early stages of the disease and longitudinally tracking changes by combining behavioral and neuroimaging data. Methods. Retrospective longitudinal data from the FRONTIER database, comprising 80 lvPPA, 80 nfvPPA, and 120 healthy controls (HC), will be analyzed. These datasets include behavioral (language and social cognition test scores - empathy, theory of mind, and emotion recognition) and neuroimaging data collected at multiple appointments one year apart. Statistical analyses will involve univariate ANOVA on baseline behavioral data to compare groups in the disease's early stages, with multiple linear regressions to examine the relationships between language and social cognition. Repeated-measures ANOVA, accounting for social cognition, groups, and time interactions, will assess longitudinal changes. An annual rate of decline will also be calculated. Additionally, vertex-wise (cortical thickness) and fixel-based (fiber bundle integrity) whole-brain general linear models, along with spatiotemporal linear mixed effects whole-brain models, will be fitted to examine grey matter and white matter atrophy and their correlations with social cognition at baseline and throughout disease progression. Expected Results. In the early stages of the disease, lvPPA and nfvPPA participants are expected to exhibit poorer performance in empathy, facial emotion recognition, and theory of mind compared to HC, with potentially better preservation of empathy in lvPPA than in nfvPPA participants (Van Langenhove et al., 2016). These socio-cognitive deficits should be related to language impairment in both PPA variants (Fittipaldi et al., 2019). Over the disease course, socio-cognitive deficits are hypothesized to worsen, particularly in lvPPA, in line with the faster cognitive decline observed in this variant (Foxe et al., 2021). These impairments are likely to be associated with specific brain regions, such as the temporoparietal junction in lvPPA and the prefrontal cortex and insula in nfvPPA. Longitudinally, lvPPA is expected to show different patterns of brain atrophy correlated with more severe social cognition impairments (Tu et al., 2015). Ultimately, these findings should deepen our understanding of socio-cognitive deficits in PPA, their progression over time, their relationship to language, and their neural underpinnings, with implications for diagnosis and intervention strategies.
Topic Areas: Disorders: Acquired,