A 35-year-old woman comes to the office due to a 2-day history | Obstetrics & Gynecology

A 35-year-old woman comes to the office due to a 2-day history of weakness in her right hand. She has no other symptoms but reports a transient episode of lower extremity numbness that resolved spontaneously. The patient has a history of herpes labialis and she takes valacyclovir as needed. She recently began taking a vitamin D supplement after she was found to have low serum vitamin D levels. Other medications include oral contraceptive pills; she has also received annual influenza vaccines. The patient does not use tobacco, alcohol, or illicit drugs. Family history is significant for type 2 diabetes mellitus in her mother and hypertension in her father. BMI is 28 kg/m2. Examination shows mild spasticity in her right hand. MRI of the brain shows the findings seen below.