Associations between cerebral cortex volume and verbal fluency in community-dwelling adults using magnetic resonance...

With the aging population, identifying the relationship between verbal fluency test (VFT) performance and brain atrophy is crucial for improving the early detection of cognitive decline. This study aimed to investigate the association between cerebral cortical volume and performance on VFTs, specifically category (CFT) and letter (LFT) fluency tests, to identify brain regions associated with verbal fluency. In this cross-sectional observational study, community-dwelling adults underwent brain magnetic resonance imaging (MRI) and completed CFTs and LFTs. Participants with organic brain anomalies on MRI were excluded. Using multiple linear regression, the relationship, adjusted for age, sex, Mini-Mental State Examination score, and total brain volume, between local gray matter volumes in 22 cortical regions in both hemispheres and VFT performance was analyzed. We included 267 community-dwelling adults (70 years and 0.8 months ± 6 years and 2.3 months; 178 men and 89 women). A significant association was found between CFT scores and volume of the left inferior frontal gyrus (R² = 0.1765, corrected-p = 0.0027), specifically the pars orbitalis (R² = 0.1520, corrected-p = 0.011) and pars triangularis (R² = 0.1452, corrected-p = 0.036). No significant associations were observed between LFT scores and cortical volumes. These findings align with previous lesion and functional MRI studies highlighting the left inferior frontal gyrus' role in language production. Lower CFT performance was associated with smaller left inferior frontal gyrus volume. Longitudinal and predictive studies are required before diagnostic or prognostic utility can be inferred.