Review Question - QID 213797

A 17-year-old girl is brought to the emergency department following a seizure. She is accompanied by her father. He states that they were at a barbeque when the patient fell out of her chair and started “shaking uncontrollably.” The father denies that this has ever happened before. The patient is otherwise healthy. She takes an oral contraceptive pill and a daily multivitamin. On physical examination, the patient is awake and oriented, but slow to respond. She has bruising on her extremities and a cut over her right eyebrow. A brain MRI is obtained, as shown in Figure A. A brain biopsy shows glial proliferation and some eosinophilic corkscrew-shaped fibers. Which of the following is the most appropriate prognostic indicator for the patient’s diagnosis?