Multiple sclerosis with periventricular Dawson fingers on T2

A 29-year-old woman presents with a 2-week history of blurring of vision and pain on eye movement in the right eye, superimposed on a 6-month history of transient lower-limb paresthesias and Lhermitte sign. Examination reveals right afferent pupillary defect and decreased color vision. Brain MRI is shown. The structures marked **A** in the diagram are ovoid periventricular T2/FLAIR hyperintensities radiating perpendicular to the lateral ventricles. Based on the imaging findings and clinical presentation, which of the following best describes the diagnostic significance of these lesions in establishing the diagnosis?