Effect of transverse temporal bone fracture on the fluid compartment of the inner ear.

Five temporal bones exhibiting transverse fractures were studied with a view to determining whether such fractures could lead to symptomatic endolymphatic hydrops. Four out of the five temporal bones showed the fracture line traversing the vestibular aqueduct. Two of these four showed complete obstruction of the endolymphatic duct. One of these had an intact membranous labyrinth and severe endolymphatic hydrops. The other had ruptures of the membranous labyrinth and no hydrops. Three ears exhibited partial preservation of auditory and vestibular hair cells and neurons. These findings are consistent with the concept that a transverse fracture may produce endolymphatic hydrops by obstructing the vestibular aqueduct while preserving enough audiovestibular epithelium and neurons to present as symptomatic Menière's disease.