AUTHOR=Liang Xiao , Wang Lei , Zhu Yanyan , Wang Yao , He Ting , Wu Lin , Huang Muhua , Zhou Fuqing 

TITLE=Altered neural intrinsic oscillations in patients with multiple sclerosis: effects of cortical thickness

JOURNAL=Frontiers in Neurology

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1143646

DOI=10.3389/fneur.2023.1143646

ISSN=1664-2295

ABSTRACT=Objective: To investigate the effects of cortical thickness on the identification accuracy of fractional amplitude of low-frequency fluctuation (fALFF) in patients with Multiple sclerosis (MS). Methods: Resting-state functional magnetic resonance imaging data was collected from 31 remitting MS, 20 acute MS, and 42 healthy controls (HCs). After preprocessing, we first calculated two-dimensional fALFF (2d-fALFF) maps using the DPABISurf toolkit. 2d-fALFF per unit thickness was obtained by dividing 2d-fALFF by cortical thickness. Then, betweengroup comparison, clinical correlation, and classification analyses were performed in 2d-fALFF and 2d-fALFF per unit thickness maps. Finally, we also examined whether the effect of cortical thickness on 2d-fALFF maps was affected by the subfrequency band. Results: In contrast with 2d-fALFF, more changed regions in 2d-fALFF per unit thickness maps were detected in MS patients, such as increased region of the right-inferior frontal cortex and faded regions of the right-paracentral lobule and middle cingulate cortex and rightmedial temporal cortex. There was a significant positive correlation between the disease duration and the 2d-fALFF values in the left-early visual cortex in remitting MS patients (r = 0.517, Bonferroni-corrected, P=0.008×4 < 0.05). In contrast with 2d-fALFF, we detected a positive correlation between the 2d-fALFF per unit thickness of the right-ventral stream visual cortex and the modified Fatigue Impact Scale (MFIS) scores (r=0.555, Bonferronicorrected, P=0.017×4 > 0.05). 2d-fALFF and 2d-fALFF per unit thickness both performed remarkably well in support vector machine (SVM) analysis for detecting MS patients, especially in the remitting phase (AUC=86%, 83%). Compared with 2d-fALFF, the SVM model of 2d-fALFF per unit thickness had significantly higher classification performance in distinguishing between remitting and acute MS. More changed regions and more clinically relevant 2d-fALFF per unit thickness maps in the subfrequency band were also detected in MS patients. Conclusion: By dividing the functional value by the cortical thickness, the identification accuracy of fALFF in MS patients was detected to be potentially influenced by cortical thickness. Additionally, 2d-fALFF per unit thickness is a potential diagnostic marker that can be utilized to distinguish between the acute and remitting MS patients. Excitingly, we observed similar variations in the subfrequency band.