Evaluation of the Detection Accuracy of Conventional Magnetic Resonance Imaging in Patients Diagnosed with Optic Neuritis

Abstract

Introduction: Inflammation of the optic nerve is one of the most common causes of unilateral and/or bilateral blindness. The most common cause of this phenomenon is demyelinating processes which involve central nervous system and the diagnosis is suspected via clinical finding and confirmed by Magnetic Resonance Imaging (MRI). In this study we plan to investigate whether isolated conventional MRI is a reliable and sufficient diagnosing tool in approach to patients with clinical finings of optic neuritis. Methods: This retrospective study was performed in patients referred to neurology department of a private hospital in Tehran from 2012 to 2014, and underwent brain MRI after clinical diagnosis has been established. Clinical diagnosis of optic neuritis was confirmed by neuro-ophthalmological examination, visual field assessment and visual evoked potential (VEP). We have utilized SPSS program for statistical analysis, along with Student T-test and Chi-Square test. Result: Demographic analysis and data gathering were performed for all of the patients. Ninety patients were enrolled in the study, which 58 cases (64.4%) showed MRI abnormality in their neuro-imaging. In this group, supratentorial and infratentorial lesions were existed in 34 cases (58.6%) and 24 cases (41.3%) respectively. The most common affected sites of supratentorial region were periventricular region (in 17 cases), followed by juxtacortical (in 6 cases), basal ganglia (in 3 cases), corpus callosum (in 3 cases), centrum semiovale (in 2 cases) and in optic nerve in 3 patients. In patients with lesions in their infratentorial region, the most common sites were cerebellum hemispheres (in 11 cases), followed by mesencephalon (in 6 cases), pons (in 4 cases) and medulla oblongata (in 3 cases). Conclusion: We have found that conventional MRI as a single approach is not reliable in detecting enhancing plaques of white matter tracts in 35.6% of our enrolled cases who their diagnosis of optic neuritis were confirmed by visual field assessment and VEP. This issue raises the importance of addition of other enhancing technique to MRI for better localization of enhancement for multi-disciplinary approach.