Overlapping and Distinguishing Features Among MS, NMOSD, MOGAD and Other Atypical Demyelinating Syndromes of the Central Nervous System (P11-3.016)

Abstract

<h3>Objective:</h3> To describe and identify the clinical-demographic, imaging and serological overlapping and distinguishing features among MS, NMOSD, MOGAD, and atypical demyelinating syndromes (ADS) in an attempt to define whether ADS-suggestive diagnostic indicator(s) emerge. <h3>Background:</h3> The era of the enlarging spectrum of MS, NMOSD, MOGAD, and a subgroup of patients with ADS overlapping features has resulted in diagnostic and therapeutic challenges. Since there is a significant diagnostic gap in some patients due to these overlapping features, further research is warranted to describe better diagnostic markers. <h3>Design/Methods:</h3> A total of 204 MS patients fulfilling the McDonald 2017 criteria, 36 AQP4-IgG+ NMOSD patients, 21 double-seronegative NMOSD patients fulfilling the 2015 diagnostic criteria for NMOSD, 15 MOG-IgG+ patients, and 80 ADS patients not fulfilling any of the aforementioned diagnostic criteria were included. Clinical, serological, and neuroimaging findings of the patients were retrospectively evaluated. <h3>Results:</h3> Positive oligoclonal bands (OCBs) in the CSF were found to be significantly higher in the MS and ADS groups than in both seropositive and seronegative NMOSD groups (all p&lt;0.001). The MS group had the highest average number of periventricular (PV) lesions(≥3 lesions) compared with the AQP4+NMOSD and MOGAD groups(no lesions, P&lt;0.001) and the ADS and seronegative NMOSD groups(1–2 lesions, P&lt;0.001). Temporal PV lesions and ovoid PV lesions were significantly higher in MS patients than in ADS patients(both p&lt;0.001). Juxtacortical/cortical (JC/C) lesions were significantly higher in the MS group than in the ADS group(p&lt;0.001). <h3>Conclusions:</h3> Differential features of overlapping demyelinating disorders revealed imaging features such as the presence of temporal PV, ovoid PV, and JC/C lesions, which are highly suggestive of MS, whereas the absence of these imaging features, absence of all diagnostic criteria as well as negative antibody serology but positive OCBs are more common in ADS. Further research and molecular diagnostic markers are required to elaborate on these results and fill this diagnostic gap. <b>Disclosure:</b> Bade Gulec has nothing to disclose. Samet Cam has nothing to disclose. Dr. Bilge has nothing to disclose. Melih Tutuncu has nothing to disclose. Sabahattin Saip, 6729 has nothing to disclose. Ugur Uygunoglu has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche Turkey . The institution of Ugur Uygunoglu has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Novartis. The institution of Ugur Uygunoglu has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen Idec/Gen Pharma of Turkey. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Roche. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sanofi-Genzyme. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen - TR. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Abdi Ibrahim Ilac - TR. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen - TR. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Merck Serono . The institution of Dr. Siva has received research support from Turkish MS Society. The institution of Dr. Siva has received research support from The Scientific and Technological Research Council Of Turkey - Health Sciences Research Grants.