A Case of Encephalocele in the Temporal Bone Repeating Intracranial Infection

Abstract

Temporal bone encephalocele is an abnormal condition in which the meninges protrude into the pneumatized cranial base. It can result in intracranial complications, including meningitis, intracranial abscess, and epilepsy, so that surgical repair is recommended to decrease the risk of these complications. Herein, we report a case of temporal bone encephalocele in which the transmastoid approach was used for surgical repair. A 64-year-old female patient admitted to our hospital had a history of diagnosed as having meningitis and intracranial abscess in the right lateral lobe. Otoscopic examination revealed a normal tympanic membrane with an inserted ventilation tube. Pure-tone audiometry showed slight conductive hearing loss in the right ear. High-resolution computed tomography of the temporal bone revealed a bone defect behind the tegmen tympani and the mastoid filled with soft tissue. We performed mastoidectomy to perform biopsy. Frozen section diagnosis of the specimen revealed that the soft tissue was brain tissue. On the basis of these findings, we diagnosed the patient as having temporal bone encephalocele. The herniating tissue was resected, and the defect in the bone was covered with fascia, and then with the cartilage of the pinna and temporal bone plate. A year after the surgery, the patient remains free of any complications of encephalocele. Otolaryngologists should bear in mind the possibility of encephalocele in subjects with defects of the temporal bone, since patients with temporal bone encephalocele usually present with otologic symptoms, including hearing loss and otorrhea.