Live Imaging of the Dehydration Effect of Isosorbide on the Normal and Hydropic Guinea Pig Cochleae Using Optical Coherence Tomography.

Abstract

OBJECTIVE:

To investigate the isosorbide-induced dehydration effect on the endolymphatic space by intratympanic administration of isosorbide.

BACKGROUND:

Isosorbide, an osmotic diuretic, is used orally as a typical conservative therapy for Menière's disease (MD) in Japan. The dehydration effect occurs 6 hours after isosorbide ingestion. Intratympanic administration of isosorbide resolves endolymphatic hydrops faster than oral ingestion. In addition, the dehydration effect has never been shown directly. Therefore, we investigated the dehydration effect of intratympanic administration of isosorbide on endolymphatic hydrops using optical coherence tomography.

METHODS:

We used eight Hartley guinea pigs, divided into normal and hydrops groups. In the hydrops group, the animals underwent endolymphatic sac obliteration to create endolymphatic hydrops. We obtained midmodiolar section images of the cochleae using optical coherence tomography. Then, 50 to 70% isosorbide was sequentially administered intratympanically for 5 minutes, and the apical turn of the cochlea was observed. The relative midmodiolar cross-sectional area of the scala media was calculated for quantitative assessment of the endolymphatic space.

RESULTS:

In the normal group, 50% isosorbide had a slight but significant dehydration effect on the scala media; at 55 to 70%, Reissner's membrane became flat. In the hydrops group, 50% isosorbide slightly reduced endolymphatic hydrops; 65% flattened Reissner's membrane, and 70% slightly concaved it toward the basilar membrane.

CONCLUSION:

The results suggest that we could select the concentration of isosorbide according to the stage or severity of MD and relief from acute attack. Intratympanic administration of isosorbide may be a promising treatment for patients with MD.

• Authors: Akinobu Kakigi, Naoya Egami, Takeshi Fujita, Natsumi Uehara, Jun Yokoi, Kento Koda, Ken-Ichi Nibu, Shinji Yamashita, Tatsuya Yamasoba
• Journal: Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology (Otol Neurotol) Vol. 44 Issue 8 Pg. 833-837 (09 01 2023) ISSN: 1537-4505 [Electronic] United States
• PMID: 37464452 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2023, Otology & Neurotology, Inc.

Chemical References

• Isosorbide

Topics

• Guinea Pigs
• Animals
• Isosorbide (adverse effects)
• Tomography, Optical Coherence
• Dehydration
• Cochlea (diagnostic imaging)
• Endolymphatic Hydrops (diagnostic imaging, drug therapy, chemically induced)
• Meniere Disease
• Endolymphatic Sac
• Edema