Neuromyelitis Optica Spectrum Disease (NMOSD) is an autoimmune neurodegenerative process which affects not only the optic nerve and spinal cord, but also other structures in central nervous system (CNS). The increased use of different techniques of magnetic resonance imaging (MRI) analysis, such the voxel-based morphometry (VBM), has improved our knowledge about the real CNS damage in NMOSD patients.

To investigate cerebellar atrophy in NMOSD and subsyndromes.

 Thirty-two NMOSD AQP4-IgG positive patients from UNICAMP’s Neurology Service were selected (15 with neuromyelitis optica (NMO), 9 with longitudinally extensive transverse myelitis (LETM) and eight with optic neuritis (ON)). For group comparisons, forty-three healthy controls (balanced for age (p=0.5) and sex (p=0.7)). 3D-T1 images (3T) were segmented according to standard SUIT protocol () and CERES (). After extracting individual maps of the cerebellum with SUIT, we investigated areas of atrophy with T-test on SPM12 (). We used a more detailed parcellation (12 portions) from CERES to complement our subsyndrome analysis, applying multivariate analysis with SPSS20. 

While SUIT/SPM analysis revealed areas with cerebellar cortical atrophy in NMOSD patients (p<0.05, T-statistic >3.9), multivariate analyses showed that NMO group presented more atrophic areas than other groups, compared to controls. After correcting for multiple comparisons (Sidak), confirmed severe atrophy on lobule VIIIB on NMO, p<0.001.

Cerebellar cortical atrophy was observed in NMOSD patients, especially in the ones who present NMO. The severe injury observed in lobule VIIIB in NMO group suggests some degree of impairment for motor tasks, while other affected areas (lobule VI and crus I) are related with working memory, language and emotional processing, as observed in a series of studies involving fMRI and PET analysis. Further studies of clinical symptoms in these patients or using other MRI techniques may reveal the complete clinical meaning of these findings.