Painless vision blurring

A 9-year-old child with no substantial medical history and had been experiencing painless vision blurring for two days reported to the emergency room. His vision changes started at school and got worse the following day to the point where he could only make out the forms and outlines of objects. Headache at the front of the head and light dizziness were accompanying symptoms. Initial testing showed an erythrocyte sedimentation rate of 29 mm/h [ref,<15) and C-reactive protein of 10.9 mg/L (ref<10) to be just slightly increased. Brain MRI showed aberrant thickness and amplification of the optic nerves along with bilateral papilledema. (Figure) Bilateral optic neuritis was verified by a follow-up orbital MRI.