Pars superioris in endolymphatic hydrops.

A volumetric study was made of the endolymphatic compartments of the pars superioris (utricle and semicircular canals). Selected for this comparative study were 15 ears from subjects with unilateral endolymphatic hydrops, 15 contralateral ears, and 15 normal ears. There was an increase in the total volume as well as in the utricular volume. This increase was also correlated with vestibular and auditory symptoms, disclosing a substantial increase in volumes with increasing hearing loss. The magnitude of volume increase correlated inversely with the frequency of vertiginous attacks; no correlation was found with the duration of the disease.