Optic Neuritis and the Visual Pathway: Evaluation of Neuromyelitis Optica Spectrum by Resting-State fMRI and Diffusion Tensor MRI

BACKGROUND AND PURPOSE Optic neuritis (ON) is an acute episode of inflammation in the visual pathway (VP). It may occur as part of a demyelinating disease, which can affect white matter (WM) throughout the VP. Compensatory cortical adaptations may occur following WM damage to maintain visual integrity. Our aim was to investigate whether resting-state functional MRI (rsfMRI) can detect cortical adaptations following ON attacks and to correlate rsfMRI with diffusion tensor imaging (DTI) of WM within the VP. MATERIALS AND METHODS Neuromyelitis optica spectrum patients were compared to healthy controls at least 6 months after ON onset. DTI and rsfMRI were performed and post-processed using FSL tools (TBSS for DTI and MELODIC for fMRI). RESULTS Ptients had higher synchronization values than controls in the visual network (3.48 vs. 2.12, P < .05). A weak trend of correlation was revealed between fMRI and structural analysis by DTI using fractional anisotropy (right side: R = −.36, P < .08; left side: R = .075, P < .73). CONCLUSIONS The rsfMRI detected cortical reorganization following ON attack, but WM was considerably preserved in the posterior VP.