Qualitative Assessment of Verbal Fluency Performance in Frontotemporal Dementia

Abstract

Background/Aims: Verbal fluency is impaired in patients with frontotemporal dementia (FTD) and primary progressive aphasia (PPA). This study explored qualitative differences in verbal fluency (clustering of words, switching between strategies) between FTD and PPA variants. Methods: Twenty-nine patients with behavioral variant FTD (bvFTD) and 50 with PPA (13 nonfluent/agrammatic, 14 semantic, and 23 logopenic) performed a semantic and letter fluency task. Clustering (number of multiword strings) and switching (number of transitions between clustered and nonclustered words) were recorded by two independent raters. Between-group differences, associations with memory, language, and executive functioning, and longitudinal change (subsample) in clustering and switching were examined. Results: Interrater reliability was high (median 0.98). PPA patients generated (a) smaller (number of) clusters on semantic and letter fluency than bvFTD patients (p < 0.05). Semantic variant patients used more switches than nonfluent/agrammatic or logopenic variant patients (p < 0.05). Clustering in semantic fluency was significantly associated with memory and language (range standardized regression coefficients 0.24-0.38). Switching in letter fluency was associated with executive functioning (0.32-0.35). Conclusion: Clustering and switching in verbal fluency differed between patients with subtypes of FTD and PPA. Qualitative aspects of verbal fluency provide additional information on verbal ability and executive control which can be used for clinically diagnostic purposes.

Cognitive profiles discriminate between genetic variants of behavioral frontotemporal dementia

“…Another explanation might be that the nature of naming errors differed in each genetic variant. MAPT mutation carriers were relatively more impaired on BNT and semantic fluency compared to letter fluency, whereas GRN performed equally impaired on all language tests, suggesting different underlying mechanisms (e.g., semantic problems versus dysexecutive control) (e.g., [36]. We included all fluency tasks in the language domain, but it has been previously demonstrated that fluency also involves other cognitive functions such as executive functioning and semantic memory.…”

Longitudinal cognitive biomarkers predicting symptom onset in presymptomatic frontotemporal dementia

“…Reliable phenotypic prediction furthermore optimizes the diagnostic process by shortening the current diagnostic delay [47], and is helpful for the patient, caregiver and clinician in knowing what disease presentation and course to expect. Verbal fluency tests are widely used in dementia diagnosis setting [48], and are affected in both presymptomatic [8, 11] and symptomatic FTD [49, 50]. Future research could additionally investigate the use of qualitative assessment of verbal fluency (e.g.…”

Fully Automatic Speech-Based Analysis of the Semantic Verbal Fluency Task

“…In addition to the assessment of cognitive decline, these qualitative measures extracted from the SVF performances may be of great interest as well for other neurocognitive disorders affecting verbal ability and executive control such as frontotemporal dementia or primary progressive aphasia [55]. …”