A 28-year-old woman presents with a 3-month history of progressive visual blurring in the right eye and mild lower limb weakness. MRI brain shows multiple T2 hyperintense lesions. The structure marked **A** in the diagram demonstrates ovoid lesions perpendicular to the lateral ventricles with perivenular distribution. Which of the following clinical features would BEST support a diagnosis of multiple sclerosis in this patient based on the imaging pattern shown?