The symptoms of a previously healthy 14-year-old female with an initial history of tooth pain and swelling of the left maxillary evolved to a progressive headache and altered neurological findings characterized by auditory hallucinations, sleep disturbances, and aggressiveness. She was brought to the emergency department after 21 days of the initial symptoms. An initial computed tomography (CT) scan showed frontal subdural empyema with bone erosion. The symptoms continued to evolve to brain herniation 24 hours after admission. A second CT scan showed a left internal jugular vein thrombosis. The outcome was unfavorable and the patient died on the second day after admission. The autopsy findings depicted rarefaction of the cranial bone at the left side of the frontal sinus, and overt meningitis. The severe infection was further complicated by thrombophlebitis of the left internal jugular vein up to the superior vena cava with septic embolization to the lungs, pneumonia, and sepsis. This case report highlights the degree of severity that a trivial infection can reach. The unusual presentation of the sinusitis may have wrongly guided the approach of this unfortunate case.