Comparison of Initial MRI Characteristics of the Optic Nerve and Brain in Patients with Optic Neuritis with Different Diagnoses in One-Year Follow-Up

Abstract

Background: This study investigates and compares the initial MRI characteristics of the optic nerve and brain in patients with optic neuritis across different diagnoses during a one-year follow-up. Methods: In this cross-sectional study, 30 patients with acute optic neuritis referred to Kashani and Feiz hospitals from 2022 to 2024 were examined. Visual acuity was assessed using a Snellen chart, and relative afferent pupillary defect and color vision testing were conducted within 48 hours. The DWI sequence was analyzed for the apparent diffusion coefficient (ADC) of optic nerve lesions. Patients were monitored for one-year post-attack, with clinical examinations, paraclinical tests (AQP4 and MOG antibody evaluation), and follow-up MRI performed. Findings: Right optic nerve involvement was observed in 63 of cases, with less than half length of the nerve affected in 63 of those cases. The frequency distribution of gender, side of involvement, increased contrast uptake and segment of involvement, and extent of ON involvement were not significantly different between patients with MS and CIS (P value>0.05). MRI findings of the brain revealed that 18.5 were normal, 7.4 were unclear, 59.3 had spatial dissemination lesions, and 14.8 had lesions disseminated in both space and time. Oneyear follow-up imaging showed that 63 of patients were diagnosed with multiple sclerosis (MS), 33.3 with clinically isolated syndrome (CIS), and 3.7 with neuromyelitis optica (NMO). Conclusion: While the correlation between the initial MRI pattern and visual recovery remains unclear, the presence and number of brain lesions during the initial manifestations of optic neuritis may help predict the development of MS. © 2026, Isfahan University of Medical Sciences(IUMS). All rights reserved.