A 37-year-old female presents to the clinic with concerns she has multiple sclerosis. She states she has had what she describes as fatigue and fluctuating muscle weakness for the past month. She has noticed this is worse after exercise and better after resting. She also reports she has had intermittent double vision.
She has been reading on the internet that these could be symptoms of multiple sclerosis. On physical examination, she exhibits upgaze fatigue. The remainder of the neurologic examination including reflexes is within normal limits.
What testing is indicated for this patient?