A 22-year-old Caucasian female presents to the Emergency Dep…
Questions
A 22-yeаr-оld Cаucаsian female presents tо the Emergency Department cоmplaining of double vision. The patient was well until the morning of admission when she awoke with double vision “but only when I look to my right side.” On questioning further, she related having an episode of left leg numbness while at summer camp 6 years ago but it resolved over 3 days and she never told anyone. Also, three years ago she saw her primary care physician after a seven-day episode of right eye pain and visual blurring, which he attributed to ocular migraine. There is no history of head trauma, or recent infections, fever, or immunizations. Exam revealed a young female who was awake, alert, and in no acute distress. Positive findings included mild pallor and atrophy of the right optic disc. Bedside visual fields and acuity were normal. Testing external ocular motion in both eyes together revealed that there was no left eye movement beyond midline when attempting to look to her right, accompanied by right eye lateral nystagmus. When the left eye was tested with the right eye closed, eye movements were full. No other motor signs were evident. There were no abnormal skin, sensory, or auditory findings. An MRI scan of the brain with gadolinium enhancement revealed a 2 x 3 cm lucency in the region of the right parietal white matter without swelling or enhancement. A diagnosis of multiple sclerosis (MS) is suspected.Which of the following groups of three ancillary tests would be the most helpful in establishing a diagnosis of MS?