Review Question - QID 109063

A 28-year-old woman with a history of migraines presents to your office due to sudden loss of vision in her left eye and difficulty speaking. Two weeks ago she experienced muscle aches, fever, and cough. Her muscle aches are improving but she continues to have a cough. She also feels as though she has been more tired than usual. She had a similar episode of vision loss 2 years ago and had an MRI at that time. She has a family history of migraines and takes propranolol daily. On swinging light test there is decreased constriction of the left pupil relative to the right pupil. You repeat the MRI and note enhancing lesions in the left optic nerve. Which of the following is used to prevent progression of this condition?