Spontaneous Temporal Bone Meningocele through Perilabyrinthine Fistula Presented with Post-Traumatic Facial Nerve Paralysis

Perilabyrinthine meningocele is a rare disease entity that occurs through defects close to but not involving the labyrinth. Several different routes for perilabyrinthine meningocele have been proposed. We experienced a case of perilabyrinthine meningocele that developed through abnormal lateral extension of subarachnoid space following the labyrinthine segment of facial nerve to geniculate fossa, producing meningocele in the infratemporal fossa. This patient was asymptomatic before he presented with moderate facial nerve paralysis after in-car traffic accident. MR and CT findings are described. (Korean J OtorhinolaryngolHead Neck Surg 2007;50:1157-60)