Recovery of sensorineural hearing loss following operative management of a posterior fossa arachnoid cyst

Arachnoid cysts are benign, intraarachnoid cysts filled with cerebrospinal fluid that are usually encountered in the middle cranial fossa. If present in the posterior fossa, they usually produce nonspecific signs and symptoms such as headaches, dizziness and vertigo. We report the rare presentation of a young girl with right-sided sensorineural hearing loss and tinnitus secondary to a right cerebellopontomedullary arachnoid cyst. The patient underwent a suboccipital retrosigmoid (retromastoid) craniectomy with fenestration of the arachnoid cyst. Subsequently, the patient experienced improvement in hearing with near-complete resolution of sensorineural hearing loss. To the authors' knowledge, postoperative near-complete resolution of hearing loss secondary to posterior fossa arachnoid cysts in a pediatric patient has not been previously reported. The authors also review the literature with respect to posterior fossa arachnoid cysts and discuss their clinical features, diagnosis, and management. (DOI: 10.3171/2009.3.PEDS08416)