Intracranial Epidural Abscess: Radiologic Features and Therapy

Abstract

Two cases of epidural abscess are described. One patient was a 15-year-old male admitted because of left forehead swelling accompanied by paranasal sinusitis. A left frontal ring-like enhanced mass was demonstrated by computed tomography (CT). External carotid angiography revealed a diffuse homogeneous stain fed by the middle and accessory meningeal arteries. The abscess cavity disappeared after burr-hole aspiration and postoperative drainage. The second patient, a 56-yearold female, was unconscious and had right hemiparesis on admission. A large left temporal epidural abscess was diagnosed by means of CT. Following aspiration, the patient appeared to do well. However, a follow-up CT scan showed re-expansion of the abscess cavity and an external carotid angiogram disclosed a thin layer of staining at the periphery of the abscess capsule. The abscess was totally excised via craniotomy. Since this abscess had entered the chronic stage, its capsule was thick and hard; this may have been important in the induction of the recurrence. Although burr-hole aspiration is usually adequate for the therapy of epidural abscess, some chronic cases recur after aspiration. Angiography is helpful in determining the clinical stage and selecting the best treatment.