Effects of hypobaric pressure on the labyrinth. Cochlear aqueduct patent.

Published

Journal Article

Cats with the cochlear aqueduct patent were placed in a pressure chamber and exposed for 10 min to hypobaric pressures of 5.1 and 6.8 kPa relative to atmospheric pressure. The experiments were designed according to a program used for treatment of Meniere's disease. The perilymph, middle ear, cerebrospinal fluid (CSF), venous, arterial and chamber pressures were recorded. The results demonstrated that hypobaric effects on the labyrinth were mediated via pressure changes in the middle ear and not via a systemic vascular or CSF influence. A reduction in chamber pressure induced a relative increase in middle ear pressure. It was the rate of the hypobaric change as well as the patency of the cochlear aqueduct and the Eustachian tube function that determined the magnitude of the initial perilymph peak pressure and the duration of this pressure increase. A rapid versus a slow rate induced an initial perilymph increase of 3.4 and 2.2 kPa, respectively. This relative pressure increase was eliminated within 1 min via the patent aqueduct. Thus, neither did a longstanding perilymph pressure increase occur during the hypobaric exposure, nor did a prolonged significant reduction in perilymph pressure occur after atmospheric pressure was restored.

Full Text

Cited Authors

  • Carlborg, B; Farmer, J; Carlborg, A

Published Date

  • November 1990

Published In

Volume / Issue

  • 110 / 5-6

Start / End Page

  • 386 - 393

PubMed ID

  • 2284913

Pubmed Central ID

  • 2284913

International Standard Serial Number (ISSN)

  • 0001-6489

Digital Object Identifier (DOI)

  • 10.3109/00016489009107459

Language

  • eng

Conference Location

  • England