Histopathology of the Incudomalleolar Joint in Cases of “Indeterminate” Presbycusis

Abstract

Age-related hearing loss (presbycusis) is a prevalent condition attributed primarily to inner ear dysfunction. Little is known about age-related changes in the ossicular joints or their contribution to presbycusis. Herein, we performed a histopathologic analysis of the incudomalleolar joint (IMJ) in specimens from the National Temporal Bone Registry with audiometrically confirmed presbycusis but without histologically observed sensory, neural, strial, or mixed features. Seventeen “indeterminate” presbycusis (IP) ears and 13 young, normal-hearing ears were examined. The age was 73.2 ± 9.5 years for the IP group and 32.1 ± 9.5 for the young group ( P < .05). The joint space between the 2 ossicles was 23% wider in the IP group (139 ± 26.2 µm) compared to young ears (113 ± 49.0 µm) ( P = .02). We report that IP ears have a wider IMJ than young ears. These findings have implications for understanding the etiology of presbycusis in indeterminate cases. Level of Evidence: Retrospective study.

Ossicular joint histopathology in cases of age‐related hearing loss

“…Of note, in a recent study of 153 IMJ specimens, Dobrev et al demonstrated an age‐related increase in the IMJ space with a methodologically similar approach to the one adopted in the current study 29 . This age‐related increase in IMJ width is in keeping with key findings from this study as well as with previous work from our group 30 . However, a key difference between our present work and the analysis performed by Dobrev et al is the lack of comparison of classic histopathologic subtypes of presbycusis.…”

Middle Ear Ossicular Joint Changes in Type 2 Diabetes Mellitus: A Histopathological Study

“…There is a limited number of reports that conducted analyses of the microstructure of the middle ear, particularly focusing on ossicular joints. Roychowdhury (2021) et al reported that in cases of presbycusis, 13 the joint discus distance and the bone‐line distance were significantly longer compared to control cases. In the context of a previous study discussing “age‐related hearing loss” in a broad sense, 13 age‐related changes were characterized by an elongation of both the bone‐line distance and joint discus distance.…”

“…Roychowdhury (2021) et al reported that in cases of presbycusis, 13 the joint discus distance and the bone‐line distance were significantly longer compared to control cases. In the context of a previous study discussing “age‐related hearing loss” in a broad sense, 13 age‐related changes were characterized by an elongation of both the bone‐line distance and joint discus distance. However, within the Control groups of this study, there were no significant differences observed in either the bone‐line distance or joint discus distance between younger and older groups.…”

“…Images of the ligaments and joints were captured using the Ds-Fi2 camera (Nikon Co, Tokyo, Japan) (attached to the light microscope) at Â40 and Â100 magnifications. Using the ImageJ software (U.S. National Institutes of Health, Bethesda, Maryland, USA), we measured and assessed various parameters as per the methods reported by Fausch and Röösli (2015) and Roychowdhury et al (2021) 12,13 (Fig. 1A-C).…”

“…Schematic representations and representative human temporal bone sections showing the measurements conducted in the human temporal bones. (A) Analysis of incudomalleolar joint (IMJ) length, adapted from Fausch and Röösli (2015) and Roychowdhury et al (2021) 12,13 . (B) IMJ section with the central and peripheral positions labeled.…”