Functional Connectivity Alterations in Neuromyelitis Optica Spectrum Disorder : Correlation with Disease Duration and...

The aim of this study was to investigate resting state functional connectivity alterations within the main brain networks in neuromyelitis optica spectrum disorder (NMOSD) and their associations with disease duration, disability and cognitive dysfunction progression.

Resting state functional magnetic resonance imaging (rs-fMRI), clinical and neuropsychological evaluations were obtained from 41 NMOSD patients and 41 healthy controls. Seed-voxel functional connectivity was analyzed in seven major hubs, including the default mode network, dorsal attention network, visual network, sensorimotor network, cerebellar network, thalamic network and reward-emotion network. Abnormalities of functional connectivity and correlations with disease duration, scores of the expanded disability status scale (EDSS), mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA) were further explored.

Compared with healthy controls, NMOSD patients showed increased functional connectivity in the default mode network, dorsal attention network and thalamic network, while decreased in the visual network and cerebellum networks. At the regional level, increased functional connectivity involved the right superior temporal gyrus, left fusiform gyrus, left inferior parietal lobule, bilateral middle frontal gyrus and right precuneus, whereas functional connectivity was decreased in the right parahippocampal gyrus and left precuneus. Functional connectivity reduction in the right parahippocampal gyrus positively correlated with disease duration (r = 0.488, p = 0.001) and negatively correlated with MoCA scores (r = -0.330, p = 0.035).

The study demonstrated functional alterations in the rs-fMRI of NMOSD, which provide a novel insight into the large-scale selective functional reorganization and could be useful to reveal the characteristics of the physiological mechanism.