Fernanda Cristina Rueda Lopes MD, Presenter: Nothing to Disclose

Fernanda Miraldi MD, Abstract Co-Author: Nothing to Disclose

Soniza Alves-Leon PhD, Abstract Co-Author: Nothing to Disclose

Roberto Cortes Domingues MD, Abstract Co-Author: Nothing to Disclose

Vanessa Granado Alves Itagiba MD, Abstract Co-Author: Nothing to Disclose

Emerson L. Gasparetto MD, Abstract Co-Author: Nothing to Disclose

Our objective was to investigate NMO patients using the resting-state functional magnetic resonance imaging (RS fMRI) compared to the controls, regarding the default-mode network and the visual network, in order to evaluate the cortical adaptations in NMO.

We studied 28 patients with NMO spectrum [mean age 38 years (SD +/- 3,2, 18 female), and also 19 sex and age matched controls. All participants signed informed consent. A magnetic resonance imaging (MRI) was performed in a 1.5 Tesla scanner with protocol that included 3D T1 GRE weighted-images and resting-state functional MRI. fMRI data was post-processed using MELODIC (FMRIB’s Software Library, fsl). The fMRI data set was decomposed using independent component analysis (ICA) to identify large-scale patterns of functional connectivity and a ‘dual-regression’ approach was carried out allowing voxel-wise comparisons of resting functional connectivity between both groups. Threshold-Free Cluster Enhancement (tfce) maps of comparison between both groups were analysed, and the corrected p-corrected maps were also considered. A p-value of 0.05 was considered statistically significant.

Fourteen components were computed in the entire subject group by ICA, including default-mode (DMN) and visual networks. In the DMN, the evaluation of tfce maps showed areas of significantly higher synchronization in NMO patients compared to healthy controls in the parietal lobes, precuneus region and also in the right hippocampus (p<0.01), that remained after p-correction. Also for DMN, controls had areas of higher synchronization in the frontal areas in relation to the patients in the tfce maps. In the visual network, there were increased synchronization values in the whole occipital cortex in NMO patients compared to controls (p<0.01) in both maps.

NMO patients have an increased synchronization during rest in the parietal and precuneus areas of the default-mode network as a form of compensation for the decreased synchronization in the frontal area. Also, the higher synchronization values found in the occipital cortex in patients may be a form of compensation for the optical neuritis.

Neuromyelitis optica (NMO) spectrum is an auto-imune demyelinating disease usually related to optical neuritis and extensive myelitis. Diffusion Tensor Imaging (DTI) has shown diffuse white matter damage, but the cortex was poorly studied in such disease.

Lopes, F, Miraldi, F, Alves-Leon, S, Domingues, R, Itagiba, V, Gasparetto, E, Resting-state Functional Magnetic Resonance Imaging in the Assessment of Patients with Neuromyelitis Optica.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045610.html