Journal Club: Analysis of endolymph volume in Ménière’s disease inner ear

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Today's journal article

Kanaris AA, Xiao AY, Biswas E, Lekovic GP, Go JL, Cai SS, Ishii M, House JW, Lopez IA, Ishiyama GP, Ishiyama A. Temporal Bone 3D Reconstruction and Analysis of Endolymph Volume in Meniere Disease. 

Why I picked this article

Today's journal article Endolymph volumes within the cochlea and vestibule differ between Ménière’s disease (MD) and similar‑age controls. Researchers have used archival human temporal bone, 3D reconstruction and volume analysis study. 

Ménière’s disease (MD) is a chronic disorder with a triad of spontaneous vertigo, fluctuating hearing loss, and tinnitus. Endolymphatic hydrops, or the distension of the endolymph space, was described as the histologic feature of MD. Endolymphatic hydrops alone does not equal MD, but modern MD almost always shows EH on histopathology. MRI has emerged to visualise endolymphatic hydrops in vivo: first with intratympanic gadolinium, then intravenous protocols, and more recently, even non‑contrast methods. This research provides human‑tissue-based volumetric reference values—the vestibular and cochlear endolymphatic ratios (vELR, cELR) that complement existing efforts by other researchers using MRI. 

Some of the research findings

Analysis sample:
  • Human temporal bones: 19 total selected from the National Institute of Health-funded National Temporal Bone Laboratory at the University of California. 
    • 12 with MD from 10 donors (7 males and 3 females)
    • 7 age‑similar controls (not MD) from 5 donors (4 females, 1 male)
    • Average age: MD cohort = 78.3 ± 11.5 years, Matched control = 74.3 ± 12.6 years
Methodology: 
  • Samples were fixed in 10% neutral buffered formalin and processed for celloidin sectioning. 
  • Histology images were taken, and aligned using TrakEM2 plug in on ImageJ
  • Segmentation and 3D reconstruction with Amira 3D Application (Thermofisher) 
  • 3D segmentation of vestibule and cochlea to quantify endolymph volume and total bony volume.
  • vestibular endolymphatic ratio (vELR) = endolymph volume divided by total cochlear volume.
  • cochlear endolymphatic ratio (cELR) = endolymph volume divided by total cochlear volume. Higher ratios indicate more hydrops.
Findings: 
  • Endolymph volumes were significantly higher in MD ears in both the vestibule and the cochlea.
  • Bony vestibule and bony cochlea volumes did not differ between MD and controls. 
  • vELR and cELR were significantly larger in MD.
  • Upper bound of normal from controls: vELR 33.2%; cELR 8.84%.
  • These ELR thresholds are anatomical reference values that align with MRI‑based hydrops readouts. 
Figure 2D. Ménière’s disease inner ear reconstruction. Kanaris et al 2025.

Haruna's takeaway

Anatomical analysis to shine some light on Ménière’s disease & hydrops. 33% sounds like a huge change. Reference data like this is valuable as a landmark. I wonder how long it takes to develop these hydrops - don't we wish we had more resolution with MRI to be able to collect more data, so that we can really understand how Ménière’s disease develops. The inner ear is a really hard place to understand! 

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This is Haruna's 88/100 of the 100-day challenge to post a science blog article every day! I love inner ear biology & cochlear physiology.