Transient hearing loss with metrizamide.

Two case studies are reported in which transient low frequency sensorineural hearing loss was experienced following myelography and CT scanning with metrizamide. Low frequency sensorineural hearing loss is considered to be the result of increased stiffness of one or both of the inner ear membranes. A review of the literature regarding an osmotic relationship between blood, cerebrospinal fluid, and the inner ear fluids attempts to explain how this phenomenon may have occurred with metrizamide. The transient sensorineural loss observed in the case studies presented is compared to the pathophysiology attributed to the formation of endolymphatic hydrops.