MR imaging differences between Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders: A single institutional study in a tertiary referral centre in Sri Lanka.

Abstract

Background and objectives- Multiple Sclerosis (MS) and Neuromyelitis Optica Spectrum Disorders (NMOSD) are the commonest demyelinating diseases of the central nervous system with overlapping clinical and radiological features, leading to frequent misinterpretation. This study aimed to describe neuroimaging features for differentiating MS and NMOSD and also comparing NMOSD subcategories.Methods- A cross sectional study was conducted at a single tertiary referral center in Sri Lanka. The magnetic resonance imaging (MRI) characteristics of 82 MS and 36 NMOSD patients were prospectively evaluated by a fourth-year resident under the supervision of consultant radiologists and were analyzed using standard descriptive statistical tests. Results- Statistical analyses indicated significance (p<0.05) in distinguishing both entities (MS and 36 NMOSD) across lesions in periventricular, subcortical, intracortical, inferior temporal, corpus callosum, and infratentorial locations by MRI. Dawson finger lesions, U fibers, calloso-septal interface involvement and T1 black holes indicated MS, whereas linear ependymal lesions suggested NMOSD. In the spinal cord, peripherally located short-segment lesions were significant for MS (p=0.000) and longitudinally extensive lesions involving central grey matter (p=0.000) pointed towards NMOSD. There was only a slight variation in lesion distribution between cervical and thoracic cord. MS showed more brain parenchymal volume loss while spinal cord atrophy was higher in NMOSD. Symmetry and location of the optic pathway lesions reinforced the differentiation.Conclusion- Comprehensive analyses support the use of neuroimaging in distinguishing between NMOSD and MS. However, further multicentric longitudinal studies are required to differentiate NMOSD phenotypes.