An 18-year-old male was admitted to the department of neurosurgery on March 14, 2016, with headache, nausea, and vomiting for 2 days. The patient denied a history of head trauma, operation, or any other infectious or systemic diseases, and he was not taking any medication.
On examination, the patient's consciousness level according to the Glasgow Coma Scale was E4V4M6, and the patient exhibited confusion, lethargy, and disorientation. There were no meningeal signs or any other neurological deficits. The temperature on admission was 36.8 C, and the blood pressure and laboratory tests were within the normal range. A noncontrast computed tomography (CT) scan of the head showed a mixed density lenticular mass with some air collection in the left frontal region [Figure 1a], which is associated with compression of the left lateral ventricle, and a 10 mm midline shift to the right and effacement of the left ambient cistern were observed [Figure 1b]. The bone window revealed thickening of the left frontal bone [Figure 1c]. The axial sinus CT image demonstrated opacification of the left frontal, ethmoid, and maxillary sinuses [Figure 2a], and the corresponding image in the bone window revealed diffuse thickening and sclerosis of the right maxillary sinus wall [Figure 2b], suggesting paranasal sinusitis and osteomyelitis of the maxillary wall.
After obtaining informed consent for surgery, an emergency operation was performed. Under general anesthesia, the patient was placed in a supine position, and a left frontotemporal craniotomy was performed. When the first burr hole was made, approximately 50 mL of odorous, thick, yellow pus was removed from the epidural space and bone edge. After elevation of the bone flap, bone was further removed until the normal bone edge was encountered. The infected bone was hypertrophic and soft, and its surface was irregular with some small pores. A fresh EDH beneath the abscess was also found after removal of the EDA, which was carefully evacuated. After abundant irrigation, subdural exploration was deemed unnecessary. The bone flap was discarded. Before closure, the wound was thoroughly washed with povidone-iodine and hydrogen peroxide, and an epidural drainage tube was placed.
On the 1st day after the operation, a CT scan revealed that the left frontal EDA was removed, with return of the midline and enlargement of the ambient cistern [Figure 3]. The epidural drainage tube was removed 48 h after surgery. The pus was examined for fungi, Mycobacterium tuberculosis, and aerobic and anaerobic bacteria, but no organisms were identified. Histopathological examination of the bone flap revealed findings consistent with chronic osteomyelitis, including inflammatory granuloma, massive bone necrosis, and pus formation, but no neoplastic process was identified. The blood culture was also negative. Echocardiography did not show any signs suggestive of endocarditis.
Empiric antibiotic therapy (vancomycin 1 g bid combined with metronidazole 500 mg bid) was initiated intravenously for 4 weeks. Postoperatively, the patient's condition improved with the resolution of symptoms, and he was discharged home 4 weeks later with an indication for 4 more weeks of oral antibiotic therapy (cefixime capsule 100 mg bid). A subsequent CT scan 3 months after surgery showed no signs of infection [Figure 4a-c]. Cranioplasty with titanium mesh was performed nine months after surgery [Figure 4d], and the patient recovered uneventfully. At the 3-year follow-up after cranioplasty, the patient was doing well.