Pressure relationship between perilymph and endolymph associated with endolymphatic infusion.

The pressure difference between the perilymph and the endolymph following infusion of artificial endolymph into the endolymphatic space was studied in guinea pigs. Both the perilymphatic and the endolymphatic pressures were measured simultaneously with use of two sets of a servo-nulling system. Endolymphatic infusion caused pressure increases in both the endolymphatic and the perilymphatic spaces, but no measurable pressure difference between them. Soon after the endolymphatic infusion, both pressures returned nearly to the initial levels. We conclude that 1) the endolymphatic and the perilymphatic pressures are very closely related, and 2) if a physiologically significant pressure difference exists between endolymph and perilymph in endolymphatic hydrops, it is below the resolving power of the methods used in this study (+/- 0.1 mm Hg).