Journal Club: Characterisation of the human round window membrane and the false membrane.

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Today's journal article

Li H, Staxäng K, Agrawal S, Ladak HM, Rask-Andersen H. The Multifaceted Human Round Window Anatomical Aspects and Clinical Relevance. 

Why I picked this article

The hearing organ, the cochlea, is buried deep inside the skull. There are two openings on the cochlea: the oval window and the round window. The round window is covered by the round window membrane. When the stapes footplate on the oval window moves, the round window membrane moves to provide compliance. 

The round window is considered the entry point for therapies administered through the ear canal (i.e. intratympanic injection). This research uses the synchrotron phase-contrast imaging to visualise the round window and the round window membrane of the human temporal bone.

Some of the research findings

Samples:

  • 66 cadaveric human temporal bones - gender and age were unknown. -> 3D imaging. 
  • Five archival human round window membranes were collected from patients with petroclival
  • meningioma -> analysed by histology. 

Methodology:

  • synchrotron phase-contrast imaging (Canadian light source inc.) 
  • Image analysis by 3D slicer 

Findings:

  • False membrane or mucosal plug was observed in 80% of the temporal bone (53 out of 66 bones)
  • Many were "incomplete" or web-like structures. 
  • Location: "The PMs were often located at the entrance of the RWN but also near the RWM or both."
  • The false membrane generally bulged towards the round window membrane. 

From Figure 1A: PM = false membrane and RWM = round window membrane. Li et al. 2025.

Haruna's takeaway

This is a very important observation about the false membrane. We have also observed the false membrane in the past, and believe this could be the barrier to drug delivery. We need to understand more about the variability in this false membrane to see if it really impacts the drug delivery or not. 

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This is Haruna's 73/100 of the 100-day challenge to post a science blog article every day! I love inner ear biology & cochlear physiology.