Exploring Abstract Semantic Associations in the Frontotemporal Dementia Spectrum in a Dutch Population

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Frontotemporal dementia (FTD) encompasses several neurodegenerative disorders affecting behavior and language.
• Abstract semantic knowledge is crucial for higher cognitive functions and can be impaired in FTD.
• Current diagnostic tools may not fully capture the nuances of semantic deficits across FTD subtypes.

Purpose of the Study:

• To evaluate the diagnostic utility of the "Test Relaties Abstracte Concepten" (TRACE), a Dutch test of abstract semantic knowledge, in various FTD subtypes.
• To compare the TRACE's performance against a test of concrete semantic knowledge and other neuropsychological assessments.
• To determine the TRACE's ability to discriminate between FTD subtypes and healthy controls.

Main Methods:

• The TRACE was administered to patients diagnosed with behavioral variant FTD (bvFTD), nonfluent variant (nfvPPA), logopenic variant (lvPPA), semantic variant PPA (svPPA), and a control group.
• Group differences, correlational analyses with other neuropsychological tests, and discriminative ability were examined.
• The TRACE was compared with a semantic association test for concrete stimuli (SAT).

Main Results:

• Patients with bvFTD, lvPPA, and svPPA showed significantly worse performance on the TRACE compared to controls.
• svPPA patients exhibited the most severe impairment on the TRACE, performing worse than other FTD subtypes.
• The TRACE demonstrated high sensitivity and specificity in discriminating between svPPA and other FTD groups, and between patient groups and controls (excluding nfvPPA).

Conclusions:

• Impaired abstract semantic knowledge is evident in bvFTD, lvPPA, and svPPA, with svPPA being the most affected.
• The TRACE serves as a valuable tool for differentiating FTD subtypes from controls and distinguishing svPPA from other FTD variants.
• Integrating abstract semantic tests like the TRACE into neuropsychological assessments can enhance the early differential diagnosis of FTD subtypes.