Review Question - QID 214476

A 52-year-old woman presents to her neurologist for follow-up for her multiple sclerosis. She reports that her last multiple sclerosis flare was approximately 1 year ago. She is currently being treated with natalizumab infusions, which she has been tolerating. Over the course of the last 2 months, she has been experiencing increasing difficulty with ambulation. She feels that her right lower extremity has been more "rigid" and "heavy." She does not endorse any muscle spasms or worsening of her symptoms at night. Neurological examination is notable for spasticity affecting the right lower extremity. Which of the following is the most appropriate next step in managing this patient's symptom?