Review Question - QID 214655

A 22-year-old homeless man presents to the emergency department with acute slurring of his speech. He was brought in by a worker at the homeless shelter where he is staying. He states that he seems lethargic. The patient has a history of seizures but recently stopped taking his seizure medication to lead a “more natural lifestyle.” He is complaining of a severe headache. His temperature is 98.7°F (37.1°C), blood pressure is 121/80 mmHg, pulse is 73/min, respirations are 15/min, and oxygen saturation is 100% on room air. Physical exam reveals a fatigued appearing man who is following commands and answering questions appropriately. Cranial nerves are grossly intact. The patient’s speech is dysarthric but intelligible. He demonstrates 3/5 strength in the right upper and lower extremities. The patient is given acetaminophen and is started on 1L of IV fluids. A CT is performed as seen in Figure A. A neurology consult is placed, and the patient is given prochlorperazine. Upon neurology evaluation, the patient states that his headache has resolved, and he does not demonstrate any neurologic deficits. He is requesting a sandwich and a social work consult to find him a place to stay. Which of the following is the most likely etiology of this patient’s symptoms?