White Matter Integrity in General Paresis: An Exploratory Tract-Based Spatial Statistical Analysis

The white matter integrity and fine structure changes were rarely reported in General Paresis (GP). We discussed white matter (WM) integrity in GP patients which was analyzed by Diffusion Tensor Imaging (DTI) Tract-Based Spatial Statistical Analysis (TBSS).

This was a prospective cross-sectional study. We recruited 18 GP patients and 24 age-sex-matched healthy controls (HC). DTI for WM of whole-brain was analyzed by TBSS and got of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD), local diffusion homogeneity (Spearman) (LDHs), and local diffusion homogeneity (Kendall) (LDHk). The results of WM tracts with statistical difference between GP and HC groups were analyzed with Mini-Mental State Examination (MMSE) using Pearson correlation. All correlations were statistically tested with a significant p-value <0.05.

GP patients had significantly reduced FA and increased AD, RD, and MD in a wide range of WM. On DTI-TBSS comparison the mean FA decreased in forceps minor (FCP), inferior fronto-occipital fasciculus R (IFOF_R), superior longitudinal fasciculus (temporal part) L (SLFTP_L). MD increased in cingulum (hippocampus) R (Ch_R), FCPm, IFOF_L, IFOF_R, inferior longitudinal fasciculus L (ILF_L), ILF_R, superior longitudinal fasciculus_L (SLF_L), SLF_R, uncinate fasciculus L (UF_L), UF_R and SLFTP_R. AD increased in Ch_R, ILF_L, UF_L. RD increased in FCPm, IFOF_L, IFOF_R, ILF_L, ILF_R, UF_L, UF_R, SLFTP_R. LDHs decreased in anterior thalamic radiation L (ATR_L), cingulum (cingulate gyrus) L (CCG_L). LDHk decreased in ATR_L, CCG_L. The MMSE score correlated with FA (positive correlation) and MD (negative correlation) in FCPm and IFOF_R. The MMSE score correlated with LDHs (positive correlation) and LDHk (positive correlation) in ART_L.

These findings suggest that DTI-TBSS is a sensitive tool for detecting widespread white matter impairment in GP, and that the identified microstructural damage is closely associated with core cognitive deficits in memory and speech, which may inform early diagnosis and monitoring of disease progression.