Development of Multiple Sclerosis in Patients with Optic Neuritis:  Analysis of Predictive Factors

Hacer Durmuş; Murat Kürtüncü; Erdem Tüzün; Bora Akalın; Melike Mutlu; Gülşen Akman Demir; Mefküre Eraksoy

Hacer Durmuş¹, Murat Kürtüncü¹, Erdem Tüzün¹, Bora Akalın², Melike Mutlu¹, Gülşen Akman Demir¹, Mefküre Eraksoy¹

¹Istanbul Faculty of Medicine, University of Istanbul, Department of Neurology, Istanbul, Turkey
²Istanbul Faculty of Medicine, University of Istanbul, Istanbul, Turkey

Keywords: Optic neuritis, multiple sclerosis, demyelinating diseases.

Abstract

OBJECTIVE: Optic neuritis (ON) is inflammation of the optic nerve that generally leads to transient loss of vision. Unilateral optic neuritis is quite common upon first presentation in multiple sclerosis (MS) patients, but it may also remain as a clinically isolated syndrome. In this study we aimed to determine what factors are associated with the development of MS in isolated ON patients.

METHODS: Medical charts of patients followed-up at Istanbul University, Faculty of Medicine, Department of Neurology between 1987 and 2003 were screened for patients with isolated ON at first presentation. A cohort of 90 patients was thusly obtained. Clinical and demographic features, visual evoked potential, cerebrospinal fluid (CSF), and magnetic resonance imaging findings, and time to definitive MS according to McDonald’s criteria were recorded.

RESULTS: In all, 50% of the patients developed definitive MS after 13 months (95% CI: 4.4-19.6). Two of the patients developed neuromyelitis optica during the course of their follow-up. The development of MS was significantly associated with the presence of a T2 lesion (p= 0.001), oligoclonal bands (OCBs) in the CSF (p= 0.002), absence of papilledema (p= 0.027), absence of severe visual impairment (p= 0.016), and subacute (> 1 day) visual impairment (p= 0.005), as per log rank testing. According to the Cox proportional hazard regression model, the presence of a T2 lesion (hazard ratio: 4.8; 95% CI: 1.5-15.4) and OCBs (hazard ratio: 3.6; 95% CI: 1.1-11.5) are strongly predictive of the progression to MS.

CONCLUSION: As some previous studies have noted, the risk of developing MS after ON is significantly higher in the presence of a T2 lesion and OCBs in the CSF. We think that this should be taken into account before starting early treatment for MS. Recent studies on the pathogenesis of MS have suggested that early treatment of MS reduces neurological disability in the long term. Our results might aid patient selection for early treatment and the determination of prognosis.