Patient profiles and disease characteristics of the IMSRN cohort: a multicentre study (2021-2025).

Abstract

Data of Central Nervous System (CNS) demyelinating disorders from India has been published from limited centres. The Indian Multiple Sclerosis And Allied Demyelinating Disorders Registry and Research Network (IMSRN) is a multicentric database for multiple sclerosis and allied demyelinating disorders in the Indian subcontinent. This study aimed to describe the demographic, clinical, laboratory, treatment, and follow-up details of patients in the IMSRN and summarise the distribution of major disease phenotypes in a real-world cohort. This was a prospective, observational, registry-based analysis of patients with CNS demyelinating disorders enrolled in the IMSRN between 16 August 2021 and 25 October 2025. Data were collected in a predefined case record form at recruitment and periodically every six months on a secure database. We performed descriptive and comparative analyses, including temporal trends, treatment patterns, and longitudinal follow-up. As of 25th October, 2025, 4976 patients have been recruited including radiologically isolated syndrome (RIS), 15 (0.30%); clinically isolated syndrome (CIS), 200 (4.02%); multiple sclerosis (MS), 2479 (49.82%); neuromyelitis optica spectrum disorder (NMOSD), 793 (15.94%); myelin oligodendrocyte antibody associated disease (MOGAD), 698 (14.03%); acute disseminated encephalomyelitis (ADEM), 76 (1.53%); chronic relapsing inflammatory optic neuritis (CRION), 34 (0.68%); chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS), three (0.06%), and others, 562 (11.29%). The mean (SD) age of the entire cohort at enrolment is 34.62 (12.16) years, at disease onset was 29.12 (11.80) years and median (IQR) disease duration at recruitment is 2.79 (0.51-7.22) years; longest for MS. There were 65.33% females and 34.67% males, with a female-to-male ratio of 1.9:1; highest in NMOSD (3.58:1). Most patients are from urban areas and educated. Optic nerve and spinal cord involvement were the dominant areas at first presentation. The median (IQR) number of relapses per patient over follow-up was 2 (1-3) highest in the NMOSD population; dominated by optic nerve and spinal cord symptoms. The median (IQR) EDSS was 2 (1-4.5). Rituximab was the commonest disease modifying therapy (DMT) used. Longitudinal trends reflect improvement in time-to-diagnosis and significant shift in the pattern of DMT use in MS towards oral DMTs and B-cell inhibitors. The paper describes a cohort of patients with MS and allied disorders. The key disease characteristics of the MS population seem similar to those reported in international MS registries. The data adds to the existing literature to ascertain disease patterns, response to treatment, and long-term outcome. The IMSRN registry is funded by the Indian Council of Medical Research (ICMR) vide Grant number 5/4-5/192/NeuroTF/2019-NCD-1.