# Fractional Anisotropy Alterations in Key White Matter Pathways Associated with Cognitive Performance Assessed by MoCA

## TL;DR

This study explores how changes in white matter pathways, measured by fractional anisotropy, correlate with cognitive performance levels using the MoCA test.

## Contribution

The study identifies specific white matter tracts where fractional anisotropy differs across cognitive performance groups, suggesting FA's potential as a biomarker for cognitive impairment.

## Key findings

- Moderate cognitive impairment groups showed higher FA in key white matter tracts compared to low performance groups.
- FA values in the superior longitudinal fasciculus and inferior fronto-occipital fasciculus differed significantly across cognitive groups.
- The study highlights the need for larger studies to validate FA as a biomarker for cognitive decline.

## Abstract

Objectives: This study investigated fractional anisotropy (FA) differences within key white matter tracts across patient groups stratified by Montreal Cognitive Assessment (MoCA) scores, aiming to evaluate FA’s potential as a biomarker for cognitive impairment. Methods: Seventy participants (aged 57–96 years) were categorized into high (HP, MoCA ≥ 26), moderate (MP, MoCA 18–25), and low (LP, MoCA < 18) cognitive performance groups. Diffusion Tensor Imaging (DTI) was used to obtain FA values in corticospinal tracts, superior longitudinal fasciculus, inferior fronto-occipital fasciculus, and cingulum. Statistical analyses included ANOVA and post-hoc tests. Results: Significant differences in FA values and normative percentiles were observed across cognitive groups in several tracts. Notably, the MP group exhibited significantly higher FA values in the Left Superior Longitudinal Fasciculus—Arcuate (mean FA 0.329 vs. LP 0.306, p = 0.033) and Right Superior Longitudinal Fasciculus—Arcuate (mean FA 0.329 vs. LP 0.306, p = 0.009), Left Inferior Fronto-Occipital Fasciculus (mean FA 0.308 vs. LP 0.283, p = 0.021), and Right Inferior Fronto-Occipital Fasciculus (mean FA 0.289 vs. LP 0.266, p = 0.017) compared to the LP group. Conclusions: Our findings reveal significant FA alterations across MoCA-defined cognitive groups, with moderate impairment showing higher FA than low performance. This suggests FA may reflect complex microstructural changes in early cognitive decline. While our modest sample size, particularly in the low-performance group, limits definitive conclusions, these results highlight the need for larger, multimodal studies to validate FA’s role as a sensitive, albeit complex, biomarker for cognitive impairment.