Bilateral Meningoencephalocele Repair Complicated by Superior Semicircular Canal Dehiscence: Case Report

To describe an unusual case of bilateral meningoencephaloceles with concurrent bilateral superior semicircular canal dehiscene (SSCD) and to discuss the clinical presentation, diagnosis, and treatment of SSCD. A 34-year-old man presented with unsteadiness and bilateral conductive hearing loss. He was diagnosed with bilateral meningoencephaloceles and underwent staged middle fossa approaches for repair. Following the second (right-sided) surgery, he developed sensorineural hearing loss and severe dizziness, indicating labyrinthine insult in the operated ear. He was then referred to our institution for further management. On our evaluation, the patient was continuing to experience disequilibrium and sensitivity to loud sounds. Examination revealed a positive Hennebert's sign and nystagmus consistent with symptomatic SSCD in the left ear. Computed tomography scanning with reformatting into Poeschel and Stenvers views identified bilateral SSCD. Plugging of the left SSCD was performed via a middle cranial fossa approach and resulted in improvement of the conductive hearing loss and after a period of compensation, resolution of the vestibular symptoms. This case illustrates that tegmental defects may result in simultaneous meningoencepaholcele and SSCD that may complicate their repair. The importance of having a high index of suspicion and evaluation with high resolution CT scanning with appropriate reformatting is emphasized. When present and symptomatic, SSCD can be successfully managed by plugging the canal.