A comparative study on clinico-radiological profile, treatment responses and outcomes of double seronegative NMOSD
Radhika Sanjay Lotlikar1, Sruthi S Nair1, Arun Prasad2
1Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
Background:
Double seronegative (DSN) central nervous system demyelination is heterogeneous, with limited information on therapeutic options and outcomes. Comparisons with aquaporin-4 antibody-positive (AQP4-IgG+) neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) may provide clarity.
Objective:
To compare the clinico-radiological profiles, treatments, and outcomes of DSN-NMOSD with AQP4-IgG+ NMOSD and MOGAD.
Methodology:
A retrospective review of patients with NMOSD and MOGAD were conducted (2016-2021) to compare disease characteristics, treatments, relapse, and disability at last follow-up between groups.
Results:
The study included 110 patients [AQP4-IgG+ NMOSD (48), MOGAD (38) and DSN-NMOSD (24)] with a mean age of onset of 25.8 ± 14.8 years. In acute events, optic neuritis was common in AQP4-IgG+ NMOSD, while DSN-NMOSD had more frequent brainstem/cerebellar demyelination (p=0.001). Area postrema syndrome (p=0.005) and tonic spasms (p=0.027) were exclusive to AQP4-IgG+ NMOSD. Cervical (p=0.001) and cervico-medullary involvement (p=0.024) in MRI were more frequent in non-MOGAD groups. The majority (82.7%) had a polyphasic course with similar relapse rates across the groups. 107 (97.3%) patients were on maintenance therapy. Rituximab was more effective in preventing relapses in AQP4-IgG+ and DSN-NMOSD compared to MOGAD (p=0.04).
Conclusion:
The three groups had distinct demographic, phenotypic, and radiological characteristics, and varying treatment responses. DSN-NMOSD had more brainstem and cerebellar presentations, with fewer optic neuritis. All shared a tendency for relapse and similar disability outcomes. Therefore, early maintenance therapy in both DSN-NMOSD and MOGAD, similar to the current treatment followed for AQP4-IgG+ NMOSD, may be beneficial.
