From Headache to Hydrocephalus: The Hidden Pulmonary Arteriovenous Malformation Behind Multiple Brain Abscesses.

A 24-year-old man experienced high-grade fever, chills, and headaches for 2 months. From August 18 to 28, 2021, he received intraperitoneal treatment, then remained at home. One month passed before he underwent external ventricular drainage for hydrocephalus. Two days later, he presented with vomiting, altered sensorium, and a foreign body sensation. Upon examination, the patient's vitals were stable. Clubbing was noted on all digits. He was afebrile but had an abnormal central nervous system exam with a Glasgow Coma Scale score of E4V3M5. He was disoriented and nonresponsive to commands. The patient had no relevant past medical history and was generally healthy, but a previous blood culture identified Pseudomonas. He had no prior respiratory issues or admissions. His diagnosis included multiple cerebral abscesses, ventriculitis, and hydrocephalus. The underlying reason? A pulmonary arteriovenous malformation in the left lung.