A Clinical Profile of Neuromyelitis Optica and Neuromyelitis Optica Spectrum Disorders in a Tertiary Care Hospital in South Tamil Nadu

Background: Neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorders (NMOSD) are severe inflammatory demyelinating disorders predominantly affecting the optic nerves and spinal cord. Data on their clinical profile and outcomes in South Tamil Nadu remain limited. This study aimed to evaluate the clinical characteristics, serostatus, and functional outcomes of NMO/NMOSD patients presenting to a tertiary care center in this region. Materials and Methods: This retrospective observational study included 25 patients diagnosed with NMO/NMOSD between January 2016 and May 2019. Patients fulfilling revised Wingerchuk criteria were analyzed for clinical presentation, laboratory findings, neuroimaging, treatment response, and outcomes. Disability was assessed using the Expanded Disability Status Scale (EDSS) at the last follow-up. Results: Of the 25 patients, 7 (28%) were anti-aquaporin-4 antibody positive and 18 (72%) were seronegative. The female-to-male ratio was 2.57:1, with a median age of onset of 35 years. Combined myelitis and optic neuritis at presentation was significantly more frequent in seronegative patients (28%; p=0.047). Cervico-dorsal spinal cord involvement was observed in 68% of patients with myelitis. All patients received intravenous methylprednisolone; additional therapy included repeat steroids (40%), plasmapheresis (8%), and rituximab (4%). Median EDSS at last follow-up was lower in seronegative patients (3.5) than seropositive patients (5.0), though not statistically significant (p=0.14). Conclusions: Seronegative NMO/NMOSD constituted the majority of cases in this South Tamil Nadu cohort and more commonly presented with combined myelitis and optic neuritis. Functional outcomes were comparable between seropositive and seronegative patients. Larger prospective studies are required to clarify regional disease patterns and optimize management strategies.