Review Question - QID 212480

A 34-year-old woman comes to the clinic complaining of numbness and tingling of her right arm for 2 days. She reports that she was washing dishes when she felt a burning sensation along her right forearm. The patient has been relatively healthy except for an episode of right eye pain and vision loss 4 years ago. She does not recall specific details but claims that “it just went away on its own after a couple of days.” The patient denies any recent travel, trauma, loss of consciousness, speech changes, weakness, or vision change but does endorse gastroenteritis about 1 week ago. She is sexually active with multiple partners and rarely uses contraception. Her last HIV testing 2 weeks ago was negative. A magnetic resonance image (MRI) of her brain is shown in Figure A. What is the most likely explanation for this patient’s symptoms?