Factors Related to the Progression of Clinically Isolated Syndrome to Multiple Sclerosis: A Retrospective Study in Lithuania.

Background and Objectives: Multiple sclerosis (MS) is a demyelinating disease which usually manifests as clinically isolated syndrome (CIS). Approximately 70% of patients with CIS progress to MS. Therefore, there is a pressing need to identify the most accurate predictive factors of CIS developing into MS, some of which could be a clear clinical phenotype of early MS as well as lesions in magnetic resonance imaging (MRI), pathological findings in cerebrospinal fluid (CSF) and evoked potentials (EP) tests.