Apical endolymphatic hydrops.

The incidence of apical endolymphatic hydrops was determined in 495 temporal bones from 300 subjects in whom the otopathologic diagnoses were presbycusis, otosclerosis, otitis media, and nonpathologic cochlea. The overall incidence was 15.8% and was not significantly different in the four diagnostic groups. These findings indicate that apical endolymphatic hydrops is of no pathologic or functional significance.