Quantitative assessment of cochlear and vestibular ganglion neurons in temporal bones with chronic otitis media.

PURPOSE: In this study, we aimed to determine whether or not COM leads to loss of spiral and Scarpa ganglion neurons. METHODS: From the human temporal bone (HTB) collection at the University of Minnesota we selected human temporal bones with COM, defined as the presence of clinically intractable tissue abnormalities in the middle ear (cholesteatoma, perforation of the eardrum, granulation tissue, fibrosis, tympanosclerosis, and cholesterol granuloma). We also selected HTBs from donors with no ear diseases as controls. We quantitatively analyzed the number of spiral and Scarpa ganglion cells and compared the results obtained in the control and study groups. RESULTS: In both COM and control groups we observed a significant negative correlation between age and number of both spiral (R = -0.632; P < 0.001; 95% CI - 0.766 to - 0.434) and Scarpa ganglion (R = - 0.404; P = 0.008; 95% CI - 0.636 to - 0.051) cells. We did not find any significant differences in the number of spiral ganglion cells (in total or per segment) or in the density of Scarpa ganglion cells (in each vestibular nerve or both) in the COM group as compared with controls (P > 0.05). CONCLUSIONS AND RELEVANCE: Our results did not demonstrate significant loss of cochlear or vestibular peripheral ganglion neuron loss in HTBs with COM as compared with controls.

Quantitative assessment of vestibular otopathology in granulomatosis with polyangitis: A temporal bone study.

OBJECTIVE: To investigate the temporal bone histopathology of vasculitis, especially in the vestibular organs, in granulomatosis with polyangitis (GPA). METHODS: Using light and differential interference contrast microscopy, we examined 12 human temporal bones from six deceased GPA patients and 12 histopathologically normal human temporal bones from six deceased age-matched patients. RESULTS: In the GPA group, three patients had undergone tympanostomy tube placement. Two of them had suffered mixed hearing loss; one, sensorineural hearing loss; and one, conductive hearing loss. Of the 12 specimens in the GPA group, the granulation tissue invaded the round window niche in seven; cochlear hair cells were not preserved in five. Hemosiderin was deposited in the stria vascularis in eight specimens, in the ampulla or semicircular duct in 10, and in the vestibule in three. The spiral ligament showed severe loss of cellularity in two specimens. In the GPA group, type I vestibular hair cell density was significantly decreased; however, type II vestibular hair cell density did not significantly differ between the GPA group and the control group. CONCLUSION: Our histopathologic findings in human temporal bone specimens of GPA patients delineated changes in the tympanic membrane, middle ear cavity, round window membrane, organ of Corti, stria vascularis, spiral ligament, ampulla, semicircular duct, and vestibule. Type I vestibular hair cell density significantly decreased in the GPA group, as compared with the control group. LEVEL OF EVIDENCE: N/A.

Quantitative Assessment of Cochlear Histopathologic Findings in Patients With Suppurative Labyrinthitis.

IMPORTANCE: Better understanding of the effects of suppurative labyrinthitis (SL) on cochlear elements will aid the development of new approaches to treat its sequelae and complications in the ear. OBJECTIVE: To quantitatively evaluate the effects of SL on cochlear elements in humans. DESIGN, SETTING, AND PARTICIPANTS: A comparative study was conducted at a tertiary academic medical center from October 20, 2014, to January 3, 2015, of the histopathologic characteristics of 28 archived human temporal bone samples from 19 deceased patients with SL and 20 temporal bone samples from 14 deceased, age-matched controls. EXPOSURES: Evaluation of archived human temporal bone samples. MAIN OUTCOMES AND MEASURES: The locations of SL in the inner ear and the degree of endolymphatic hydrops were noted; the area of the stria vascularis and the spiral ligament in all turns of the cochlea at the midmodiolar level and in the adjacent 2 sections were measured; and the number of remaining outer and inner hair cells of the cochlea were counted to calculate the loss of both types of cells. To evaluate the loss of fibrocytes in the spiral ligament, a rating scale in each cochlear turn was used. For each segment of the cochlea, the number of spiral ganglion cells was determined. Outcomes between the group with SL and the control group were compared. RESULTS: Of the 28 temporal bone samples from the 19 deceased patients (16 men and 3 women; mean [SD] age, 23.1 [24.6] years) with SL, all showed SL in the scala tympani of the basal turn. In the group with SL vs the control group, the mean (SD) loss of outer hair cells was significantly higher in the lower (28.6% [11.4%] vs 12.4% [6.2%]; P = .02) and upper (22.3% [9.7%] vs 8.8% [3.2%]; P = .01) basal cochlear turn, the mean (SD) loss of inner hair cells was significantly higher in the lower (15.4% [6.7%] vs 2.6% [1.1%]; P = .02) and upper (10.6% [4.6%] vs 2.2% [0.7%]; P = .03) basal cochlear turn, the mean (SD) total number of spiral ganglion cells (28,132 [2068] vs 30,358 [2036]; P = .001) and the mean (SD) number of spiral ganglion cells in segment I (3554 [847] vs 4223 [649]; P = .003) was significantly decreased, the mean (SD) degree of atrophy of the stria vascularis in the lower (8455 [924] vs 9368 [1049] µm2; P = .003) and upper (7911 [837] vs 8474 [813] µm2; P = .02) basal cochlear turn was significantly greater, and the degree of endolymphatic hydrops was significantly greater (10 bone samples [36%] vs 1 [5%]; P = .006). No significant differences were found between the 2 groups in the number of fibrocytes and in the presence of atrophy of the spiral ligament in any cochlear turn. CONCLUSIONS AND RELEVANCE: This study demonstrates that SL can lead to cochlear damage, especially in the basal turn of the cochlea. These pathological observations have formed the basis for clinical findings of hearing loss and tinnitus detected in those patients with SL.

Quantitative assessment of vestibular otopathology in otosclerosis: A temporal bone study.

OBJECTIVES/HYPOTHESIS: To determine if peripheral vestibular otopathology is present in human temporal bones with otosclerosis. STUDY DESIGN: Comparative human temporal bone study. METHODS: Seventy-four human temporal bones from 46 subjects with otosclerosis (mean age of 61 ± 18 years) and 20 within histologically normal limits from 17 subjects (mean age of 59 ± 14 years) were included in this study. Temporal bones with otosclerosis were divided into those with and without endosteal involvement. Using differential interference contrast microscopy at 1008× magnification, type I and type II vestibular hair cell counts were performed on each vestibular sense organ in which the neuroepithelia was oriented perpendicular to the plane of section. The organ-specific cell densities (cells/0.01 mm(2) surface area) were compared between the groups with and without endosteal involvement, and also compared to counts in the nonotosclerosis control group using Student's t-test. RESULTS: Mean type I and type II hair cell densities of all vestibular structures in the group with endosteal involvement were significantly lower compared to the group without endosteal involvement. Mean type I and type II hair cell densities of all vestibular structures in the group with endosteal involvement were also significantly lower compared to the control group, but they were not in the group without endosteal involvement compared to the control group. CONCLUSION: Endosteal involvement of otosclerotic foci is associated with vestibular hair cell loss that may contribute to the vestibular symptoms in otosclerosis. LEVEL OF EVIDENCE: N/A. Laryngoscope, 126:E118-E122, 2016.

Peripheral vestibular system in Down syndrome: quantitative assessment of vestibular histopathology.

OBJECTIVE: To evaluate the maturity of the peripheral vestibular system in Down syndrome by examining the number of Scarpa's ganglion cells and the density of vestibular hair cells. STUDY DESIGN: Case-control study using human temporal bones. SETTING: Tertiary academic center, otopathology laboratory. SUBJECTS AND METHODS: Sixteen temporal bones from 8 patients with Down syndrome and 15 control temporal bones from 8 individuals with no history of otologic disease were selected. Hypoplasia of the lateral semicircular canal (LSC) and vestibule was investigated by measuring the dimensions of the structures. Scarpa's ganglion cells were counted under light microscopy. The vestibular hair cells were counted in the LSC crista and the utricular and saccular maculae under differential interference contrast (Nomarski) microscopy and expressed as density. RESULTS: The patients with Down syndrome were divided into 2 groups: with and without LSC hypoplasia. The number of Scarpa's ganglion cells and the density of vestibular hair cells were significantly smaller in both groups of patients with Down syndrome than in the control group. There was no significant difference in the number of Scarpa's ganglion cells or the density of vestibular hair cells between the groups with and without LSC hypoplasia. CONCLUSION: The peripheral vestibular system, including Scarpa's ganglion cells and vestibular hair cells, is hypoplastic irrespective of the vestibular malformation in Down syndrome.