Review Question - QID 210065

A 23-year-old man is brought into the emergency department by his friends. He has felt ill but refused to come in for the past 24 hours. The patient had a headache and fever that has been worsening steadily. He locked himself in his dark room which is the only place where he felt comfortable. He requests that the lights be shut off in his room. The patient has a medical history of alcohol and marijuana use. His temperature is 103°F (39.4°C), blood pressure is 117/58 mmHg, pulse is 120/min, respirations are 20/min, and oxygen saturation is 98% on room air. The patient is started on IV fluids, magnesium, steroids, and ibuprofen, with a mild improvement in symptoms. Two hours later, the patient is less responsive. His blood pressure is 97/48 mmHg, pulse is 150/min, respirations are 22/min, and oxygen saturation is 98% on room air after 2 liters of fluids are given. Physical exam demonstrates the finding in Figure A. Which of the following is the most likely cause of his worsening symptoms?