Year 3common
A 34-year-old woman presents to the clinic with sudden onset right eye pain and blurred vision that worsens with eye movement for the past 4 days. She denies fever, trauma, or recent illness. Her medical history includes an episode of numbness and tingling in her left arm and leg 2 months ago that resolved spontaneously. On examination, there is decreased visual acuity in the right eye with an afferent pupillary defect. Flexion of the neck induces an electric shock-like sensation along the spinal cord. MRI of the brain shows multiple periventricular white matter lesions. Laboratory tests show no abnormalities.
What is the most likely diagnosis?