Conversion from Radiologically Isolated Syndrome to Multiple Sclerosis: Single Center Retrospective Study

Objective: The study aimed to investigate the conversion duration from Radiologically Isolated Syndrome (RIS) to multiple sclerosis (MS) and identify factors associated with an increased risk of progression. Materials and Methods: The study involved a meticulous review of the medical records of 18 patients diagnosed with RIS, who presented without demyelinating clinic in the first applying. Data on patient demographics, laboratory findings, and clinical outcomes were collected. Those who converted from RIS to MS and their conversion duration were recorded. Patients were categorized into two groups; group 1 who progressed to clinically definite MS, and group 2  who remained asymptomatic without clinical progression. The duration of conversion from RIS to MS was also recorded. Results: The study population had a mean age of 39.8 ± 11.5 years, with 15 females and 3 males. All male patients belonged to Group 1. Although the ages between the two groups did not significantly differ, it was noteworthy that all RIS patients were female. No significant difference between the two groups was observed in the presence of oligoclonal bands or the IgG index. Additionally, the evaluation of spinal lesions did not reveal a statistically significant disparity. The median conversion duration for patients progressing from RIS to MS was 19.5 (interquartile range: 29.25) months. Conclusion: The study provides valuable insights into the conversion from RIS to MS. The study did not identify spinal lesions, oligoclonal bands, or age as prominent indicators for predicting RIS conversion to MS. Early identification of RIS patients at higher risk of progression may enable timely intervention and improve long-term outcomes.