Central nervous system infections Quiz: Ace Your Exams

A 6-year-old boy is brought to the emergency department by his parents due to acute onset of seizure 1 hour ago. His parents state that several days ago, he started complaining of headaches and fever. Last week, he experienced an episode of sinus congestion and purulent mucus production which was treated symptomatically with nasal saline irrigation. Past medical history is unremarkable other than a few episodes of otitis media. He was born via normal vaginal birth and delivery and has reached all milestones appropriately. The family owns a cat and a dog. The parents deny any trauma. Temperature is 38.5°C (101.3°F), pulse is 100/min, and blood pressure is 104/68 mmHg. On physical examination, the patient is lethargic but arousable. There is no nuchal rigidity or photophobia. Fundoscopic examination reveals bilateral papilledema. Strength is 5/5 on the left side of the body and 3/5 on the right. The patient responds to questions, but his speech is incomprehensible. Which of the following is the most likely diagnosis?