Bilateral middle cranial fossa encephaloceles presenting as conductive hearing loss

Abstract

We report a case involving a patient with bilateral middle cranial fossa encephaloceles extending into the middle ear and causing conductive hearing loss. An obese, 47-year-old woman with a history of a seizure disorder presented with a slow-onset subjective hearing loss. Examination revealed opaque tympanic membranes, and audiometry showed a mixed hearing loss bilaterally. Myringotomy demonstrated soft tissue behind each tympanic membrane. Biopsy, computed tomography, magnetic resonance imaging, and mastoidectomy confirmed the diagnosis of bilateral middle cranial fossa encephaloceles. Bilateral encephaloceles are uncommon, and the resulting bilateral conductive hearing loss secondary to mechanical obstruction of ossicular vibration is even more rare. This patient's obesity and seizures perhaps contributed to her disease process.