Temporal Bone Pathology Secondary to Head Trauma-A Human Temporal Bone Study.

HYPOTHESIS/BACKGROUND: We hypothesize that following head trauma there is a difference in temporal bone (TB) pathology in cases with and without skull fracture. Although conductive, sensorineural, mixed hearing loss, and TB pathology following head trauma have been reported, to our knowledge, there are no studies that have compared the pathology of the TB in cases with and without skull fracture. METHODS: We analyzed 34 TBs from donors who had a history of head trauma (20 with skull fracture and 14 without fracture), and 25 age-matched controls without clinical or histological evidence of otologic disorders. We documented the presence and location of TB fracture, ossicular injury, and cochlear hemorrhage and evaluated the loss of spiral ganglion cells and sensory hair cells, damage to the stria vascularis, and the presence of endolymphatic hydrops. RESULTS: We found a significant loss of outer hair cells in the upper basal, lower, and upper middle turns of the cochlea (p = 0.009, =0.019, =0.040, respectively), a significant loss of spiral ganglion cells (p = 0.023), and cochlear hemorrhage predominantly in the basal turns secondary to head trauma. Interestingly, these findings were significantly observed in TBs from donors with a history of head trauma without skull fracture. CONCLUSION: The greatest damage was to the cochlear basal turn. Our findings suggest that head trauma may result in tonotopic high frequency sensorineural hearing loss. TBs from donors with skull fracture have less pathologic changes than those without.

Formations of Host Fibers and Bacteria in Human Temporal Bones With Otitis Media.

HYPOTHESIS: In temporal bones with otitis media, fibrin and neutrophil extracellular traps (NETs) form a fibrous network with bacteria, which is involved in growth of bacterial clusters/biofilms and chronicity of disease. BACKGROUND: NETs and fibrin are important in host defense against pathogens; however, their role in otitis media is not well understood. METHODS: Eight human temporal bones with serous otitis media, 30 with serous-purulent otitis media, 7 with mucoid otitis media, 23 with mucoid-purulent otitis media (OM), 30 with purulent OM, and 30 with chronic otitis media were selected based on histopathologic findings. Fibrous material with bacteria was detected with hematoxylin-eosin, Gram-Weigert, and propidium iodide stains; and its composition was analyzed with immunohistochemistry. RESULTS: Extensive formations of fibrous material with bacteria were observed in 30% of temporal bones with serous-purulent otitis media, 29% with mucoid otitis media, 50% with mucoid-purulent OM, 57% with purulent OM, and 67% of temporal bones with histological evidence of chronic otitis media. Some of these formations showed large bacterial clusters or biofilms. Immunohistochemical analysis showed that fibrous structures were composed of fibrin or NETs. CONCLUSIONS: Formations of fibrous material with bacteria were detected in human temporal bones with different types of otitis media. Inflammatory cells were observed mostly in areas with low presence of fibrous structures. The network of fibrous material seems to prevent clearance of bacteria by phagocytic cells and thus influences growth of bacterial clusters or biofilms. Fibrin and NETs may be important for the recurrences and chronicity of disease, and contribute to clogging of tympanostomy tubes in children.

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.

Cochlear turns measurements in patients with meningitis: A histopathological study.

OBJECTIVE: To demonstrate the cochlear turns area changes among patients with a history of meningitis, through otopatologic study. METHODS: We performed an analysis of the area of the bony cochlear turns and the cochlear lumen of the horizontal sections containing the modiolus and the area of the basal turn at the level of round window, in temporal bones obtained from patients with a history of meningitis and compared to a nondiseased control group. RESULTS: The mean area of the bony walls and the lumen of all cochlear turns are reduced within the meningitis group. Patients who presented a time from the diagnosis of meningitis to death longer than 30 days had a significant reduction in the cochlear turns area, as compared to the control group. CONCLUSION: Future studies may further correlate audiologic outcomes, cochlear volume, and cochlear area among patients with meningitis.

A Structural Analysis of Tympanic Compartments of the Middle Ear in Patients With Down's Syndrome: A Temporal Bone Study.

: Hypothesis: There may be findings peculiar to the temporal bones of children with Down's syndrome (DS). The purpose of this study is to investigate the temporal bone histopathology of the children with DS. BACKGROUND: Otitis media with effusion is a highly prevalent condition with DS. Knowledge of the volume of the tympanic compartments and the area of the tympanic isthmus might be important to find out the pathogenesis of highly prevalent otitis media with effusion in those patients. METHODS: We compared the volume of the epitympanum, mesotympanum, and the areas of the tympanic isthmus and tympanic orifice of eustachian tube in temporal bones from patients with DS. We also investigated the eustachian tube histopathologically. RESULTS: The mean volume of the epitympanum and the mesotympanum was significantly smaller in the DS group than the control group. We found no significant difference in the mean diameter of the protympanic opening and tympanic orifice between the two groups. The mean narrowest area of the aerated and bony tympanic isthmus also was not significantly different between the two groups. An immature development of eustachian tube and cartilage was seen. We found mesenchyme remaining at the epitympanum and/or mesotympanum in all specimens in the DS group, and in five specimens in the control group. CONCLUSION: In the presence of the small middle ear, poorly developed eustachian tube, and tensor muscle, a vicious circle occurs, making otitis media with effusion difficult to resolve.

Cochleosaccular (Scheibe) dysplasia in dogs: A temporal bone study.

The objective of this study was to evaluate any otopathologic changes in temporal bone specimens from dogs with deafness related to cochleosaccular (Scheibe) dysplasia (CSD). We used the canine temporal bone collections of the Otopathology Laboratory at the University of Minnesota and of the Massachusetts Eye and Ear Infirmary at Harvard University in Boston. Our morphometric analysis included measuring the areas of the stria vascularis and the spiral ligament and counting the number of spiral ganglion cells. In addition, we noted the presence of the organ of Corti and cochlear hair cells, assessed the location of Reissner's membrane and the saccular membrane, and counted the number of both Type I and Type II vestibular hair cells in the macule of the saccule and vestibular ganglion cells. In the group of specimens from dogs with cochleosaccular dysplasia, we observed generalized degeneration in the cochlea and a significantly decreased number of Type I and Type II vestibular hair cells and vestibular ganglion cells. As hereditary deafness is presently untreatable with known therapeutic methods, dogs with cochleosaccular dysplasia should not be considered for breeding. Future therapeutic approaches, such as stem cell therapies, should be designed to target all the elements of the cochlea in addition to the saccule as it was found that both are affected in dogs with CSD.

L'objectif de la présente étude était d'évaluer tous changements otopathologiques dans des spécimens d'os temporal provenant de chiens avec surdité reliée à de la dysplasie cochléosacculaire (Scheibe) (DCS). Nous avons utilisé la collection d'os temporal canin du Otopathology Laboratory à l'Université du Minnesota et du Massachusetts Eye and Ear Infirmary de l'Université Harvard à Boston. Notre analyse morphométrique incluait de mesurer les régions de la stria vascularis et du ligament spiral et de compter le nombre de cellules du ganglion spiral. De plus, nous avons noté la présence de l'organe de Corti et des cellules ciliées cochléaires, évalué la localisation de la membrane de Reissner et de la membrane sacculaire, et compté le nombre de cellules ciliées vestibulaires de Type I et Type II dans la macule du saccule et les cellules vestibulaires ganglionnaire. Dans le groupe de spécimens provenant de chiens avec dysplasie cochléosacculaire, nous avons observé une dégénérescence généralisée de la cochlée et une diminution significative du nombre de cellules ciliées de Type I et Type II et ces cellules du ganglion vestibulaire. Étant donné que la surdité héréditaire est présentement non-traitable par des méthodes thérapeutiques connues, les chiens avec de la dysplasie cochléosacculaire ne devraient pas être utilisés pour la reproduction. Des approches thérapeutiques futures, telles que les thérapies avec des cellules souches, devraient être planifiées afin de cibler tous les éléments de cochlée en plus du saccule étant donné qu'il a été démontré que les deux sont affectés chez les chiens avec DCS.(Traduit par Docteur Serge Messier).

Bilateral glomus tympanicum tumors: Human temporalbone study.

To describe human temporal bones with bilateral glomus tympanicum tumors. Patient is 83-year-old black female who no pulsatile tinnitus. The histopathologic characteristics of human temporal bones after death were setting Department of Otolaryngology of University of Minnesota in USA. Histopathologic observation of temporal bones showed bilateral small glomus tympanicum tumors limited to the promontory. Although there was bilateral tinnitus, there was no pulsatile tinnitus, no conductive hearing loss and both of the tympanic membranes were intact. Histopathologic observation of temporal bones after death showed bilateral glomus tympanicum tumors. To our knowledge, this is the first reported case of bilateral glomus tympanicum tumors.

Otopathology in the United States: History, Current Situation, and Future Perspectives.

: Human temporal bone studies have documented the pathophysiologic basis of many pathologic conditions and diseases affecting the ear, contributing to the development of specific clinical knowledge and pathology-oriented treatments. Researchers dedicated to the study of anatomy and histology of the temporal bone emanated from Europe to the United States during the first part of the 20th Century. The first otopathology laboratory was founded in the United States in 1924, at Johns Hopkins University; over time, the otopathology laboratories-considered by some authors as "gold mines" for studying ear diseases-became numerous and very prolific. However, today, only three of the temporal bone laboratories are still running and producing scientific knowledge to the Otology/Neurotology field: the ones at Harvard Medical School, University of Minnesota, and University of California. Molecular biologic assay techniques and new microscopy and computer equipment broadened the possibilities for temporal bone studies; however, the current funding for those laboratories are insufficient to cover the costs for processing and studying human temporal bones. The main objective of this study is to briefly describe the history, current situation, and future perspectives of the otopathology laboratories in the United States.

Current evidence of peripheral vestibular symptoms secondary to otitis media.

BACKGROUND: The association between otitis media and vestibular symptoms has been hypothesized in the past. Thus, in this study, we aimed to critically analyze (based in a systematic review of the literature) whether patients who have otitis media are at greater risk of developing vestibular impairment or not. METHODS: We performed a systematic review of the literature and identified potentially relevant articles reporting vestibular symptoms and results of vestibular function tests in patients with otitis media through searches of the PubMED, Web of Science, Scopus, and Google Scholar databases. The quality of the final set of records was assessed using the "Newcaste-Ottawa Scale". RESULTS: Of the 2334 records searched, 43 met our inclusion and exclusion criteria, and those included 2250 patients. The records comprised 20 longitudinal studies, 21 cross-sectional studies, and 2 case reports. Regarding the type of otitis media studied, 25 examined vestibular impairment in otitis media with effusion, 6 acute otitis media, and 12 chronic otitis media. Results of anamnesis, clinical exams, and several vestibular function tests are reported and critically discussed. CONCLUSION: Most studies evaluating the association between otitis media and vestibular symptoms have potential methodological flaws. Clinical evidence suggests that patients with otitis media have increased chances for having vestibular symptoms, delayed acquisition of developmental milestones, and abnormalities in several vestibular function tests as compared with controls. Future studies with rigorous methodology aiming to assess the clinical significance (and prognostic factors) of the association between otitis media and vestibular impairment are warranted. Key message Several studies demonstrated long-term sequelae secondary to otitis media. However, the evidence supporting those assumptions are based in low-quality evidence. Thus, better structured studies are warranted to better understand the clinical relevance of such association.

Structural Analysis of Tensor Tympani Muscle, Tympanic Diaphragm, Epitympanum, and Protympanum in Menière's Disease: a Human Temporal Bone Study.

HYPOTHESIS: We hypothesized that there would be significant anatomic differences of the tensor tympani muscle (TTM), tympanic diaphragm, epitympanum, and protympanum in patients with versus without Menière's disease. BACKGROUND: The effects of tenotomy on Menière's disease suggested it relieves the pressure on the inner ear of the contraction of the TTM and of negative middle ear pressure. METHODS: Using human temporal bones from patients with Menière's disease, two studies were conducted. We examined the presence of otitis media, cholesteatoma, and endolymphatic hydrops, the length, diameter, configuration, the volume of the TTM and tendon, and the area of the tympanic isthmus (Study 1). We examined the presence of otitis media, cholesteatoma and endolymphatic hydrops, and the area and volume of the protympanum (Study 2). RESULTS: In study 1, we observed no significant differences between the two groups. In study 2, we did not observe a small and narrow protympanum in the Menière's disease group. None of the ears in the Menière's or control groups had otitis media or cholesteatoma in either study. We observed hydrops in all the temporal bones of the Menière's disease group and none in the control groups. CONCLUSION: The position, configuration, and size of the tensor tympani muscle and tendon do not seem to play a role in the pathogenesis of Menière's disease. Because the tympanic isthmus and protympanum in Menière's disease are not smaller than controls and that none of the temporal bones had otitis media or cholesteatoma, it is unlikely that there was dysventilation in the middle ear.

Histopathology of tympanic membranes from patients with ventilation tubes.

OBJECTIVE: To evaluate the histopathologic changes in tympanic membranes (TMs) with ventilation tubes (VTs). METHODS: In this retrospective human temporal bone study our overall study group included 4 subgroups of TMs from deceased donors as follows: 24 with a history of VT insertion for chronic otitis media with effusion (COME-VT); 5 with a history of VT insertion for Meniere's disease (MD-VT); 33 without a history of VT insertion for chronic otitis media with effusion (COME); and 14 without a history of VT insertion for Meniere's disease (MD). We classified the extent of migration of the outer keratinized squamous epithelium onto the inner surface of TM perforations and noted the presence and location of tympanosclerosis, of atrophy, of perforation, and/or of cholesteatoma formation. RESULTS: Tympanosclerosis occurred in 14/24 TMs in the COME-VT subgroup; 2/5, MD-VT; 7/33, COME; and 0/14, MD. The VT insertion site was mostly in the anteroinferior (63%) quadrant of the TM; tympanosclerosis occurred more frequently in the posteroinferior (42%) and posterosuperior (33%) quadrants. We found no significant correlation between the location of tympanosclerosis and the VT insertion site (P>0.05). Atrophy occurred in 7/24 TMs in the COME-VT subgroup; 3/5, MD-VT; 8/33, COME; and 2/14, MD. We found no significant correlation between the location of atrophy and the VT insertion site; however, atrophy was located mostly in the anteroinferior quadrant (one of the most common VT insertion sites) of the TM. Regarding the ingrowth of keratinized epithelium, the mucocutanous junction was detected at any point at the inner surface of the TM in 50% of the specimens. We observed intratympanic cholesteatoma formation in 2/24 TMs in the COME-VT subgroup. CONCLUSION: TM changes due to VT insertion are more common than previously realized. Meticulous otomicroscopic evaluation of the TM is necessary during tympanomastoidectomies in order to prevent the intratympanic inclusion pearls and squamous epithelial ingrowth to prevent any further cholesteatoma formation.

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.

Evidence against the mucosal traction theory in cholesteatoma.

OBJECTIVES: To investigate the distribution of ciliated epithelium in the human middle ear and its potential role in the formation of cholesteatoma. STUDY DESIGN: Comparative human temporal bone study. METHODS: We selected temporal bones from 14 donors with a diagnosis of cholesteatoma, 15 with chronic otitis media without retraction pockets, 14 with chronic otitis media with retraction pockets, 14 with cystic fibrosis (CF), and 16 controls. We mapped the distribution of the ciliated cells in the mucosal lining of the middle ear and tympanic membrane using three-dimensional reconstruction analysis, and counted the number of ciliated cells in the middle ear mucosa. RESULTS: Ciliated cells are extremely sparse in the epithelial lining of the lateral surface of the ossicles in the epitympanum and the medial surface of the tympanic membrane. Furthermore, there is a significant decrease in the number of ciliated cells in these areas in temporal bones with cholesteatoma, chronic otitis media, chronic otitis media with retraction pockets, and CF compared to controls. Ciliated cells most commonly are located at the hypotympanum and the Eustachian tube opening but not the tympanic membrane or epitympanum. CONCLUSION: The paucity of ciliated epithelial cells on the medial side of the tympanic membrane and the lateral surface of the ossicles in the epitympanum in cases with cholesteatoma and/or chronic otitis media do not support the mucosal migration theory of cholesteatoma formation. LEVEL OF EVIDENCE: NA. Laryngoscope, 128:1663-1667, 2018.

Neutrophil Extracellular Traps and Fibrin in Otitis Media: Analysis of Human and Chinchilla Temporal Bones.

Background: Bacterial resistance in acute otitis can result in bacterial persistence and biofilm formation, triggering chronic and recurrent infections. Objective: To investigate the middle ear inflammatory response to bacterial infection in human and chinchilla temporal bones. Design, Setting, and Participants: Six chinchillas underwent intrabullar inoculations with 0.5 mL of 106 colony-forming units (CFUs) of Streptococcus pneumoniae, serotype 2. Two days later, we counted bacteria in middle ear effusions postmortem. One ear from each chinchilla was processed in paraffin and sectioned at 5 µm. The opposite ear was embedded in epoxy resin, sectioned at a thickness of 1 µm, and stained with toluidine blue. In addition, we examined human temporal bones from 2 deceased donors with clinical histories of otitis media (1 with acute onset otitis media, 1 with recurrent infection). Temporal bones had been previously removed at autopsy, processed, embedded in celloidin, and cut at a thickness of 20 µm. Sections of temporal bones from both chinchillas and humans were stained with hematoxylin-eosin and immunolabeled with antifibrin and antihistone H4 antibodies. Main Outcome Measures: Histopatological and imminohistochemical changes owing to otitis media. Results: Bacterial counts in chinchilla middle ear effusions 2 days after inoculation were approximately 2 logs above initial inoculum counts. Both human and chinchilla middle ear effusions contained bacteria embedded in a fibrous matrix. Some fibers in the matrix showed positive staining with antifibrin antibody, others with antihistone H4 antibody. Conclusions and Relevance: In acute and recurrent otitis media, fibrin and neutrophil extracellular traps (NETs) are part of the host inflammatory response to bacterial infection. In the early stages of otitis media the host defense system uses fibrin to entrap bacteria, and NETs function to eliminate bacteria. In chronic otitis media, fibrin and NETs appear to persist.

Progression of changes in the sensorial elements of the cochlear and peripheral vestibular systems: The otitis media continuum.

Our study aimed to evaluate pathologic changes in the cochlear (inner and outer hair cells and stria vascularis) and vestibular (vestibular hair cells, dark, and transitional cells) sensorial elements in temporal bones from donors who had otitis media. We studied 40 temporal bones from such donors, which were categorized in serous otitis media (SOM), serous-purulent otitis media (SPOM), mucoid/mucoid-purulent otitis media (MOM/MPOM), and chronic otitis media (COM); control group comprised 10 nondiseased temporal bones. We found significant loss of inner and outer cochlear hair cells in the basal turn of the SPOM, MOM/MPOM and COM groups; significant loss of vestibular hair cells was observed in the MOM/MPOM and COM groups. All otitis media groups had smaller mean area of the stria vascularis in the basal turn of the cochlea when compared to controls. In conclusion, our study demonstrated more severe pathologic changes in the later stages of the continuum of otitis media (MOM/MPOM and COM). Those changes seem to progress from the basal turn of the cochlea (stria vascularis, then inner and outer hair cells) to the middle turn of the cochlea and to the saccule and utricle in the MOM/MPOM and COM stages.

Histopathologic Changes of Human Vestibular Epithelia in Intralabyrinthine Hemorrhage.

OBJECTIVE: To determine whether intralabyrinthine hemorrhage affects vestibular hair cells, dark cells, and transitional cells in human temporal bones. METHODS: We examined 9 temporal bone specimens from 9 deceased donors with unilateral intralabyrinthine hemorrhage (the hemorrhage group) along with their 9 contralateral temporal bone specimens without hemorrhage (the control group). We estimated the density of type I and type II hair cells in all peripheral sensorial organs (including the cristae of the superior, lateral, and posterior semicircular canals, as well as the maculae of the saccule and utricle). We also estimated the density of dark and transitional cells in the lateral and posterior semicircular canals. RESULTS: The loss of type I hair cells in the cristae of the superior, lateral, and posterior semicircular canals and in the maculae of the saccule and utricle was significantly higher in the hemorrhage group, as compared with the control group ( P < .05). The density of type II hair cells in the cristae of the superior and posterior canals and in the macula of the saccule significantly differed between the hemorrhage group and the control group ( P < .05). CONCLUSION: The loss of vestibular hair cells might be the cause of vestibular symptoms in patients with intralabyrinthine hemorrhage.

Secondary Endolymphatic Hydrops.

HYPOTHESIS: A review of the most recent literature will provide clinicians with an update of secondary endolymphatic hydrops, aiding in diagnosis and treatment of affected patients. BACKGROUND: Secondary endolymphatic hydrops is a pathologic finding of the inner ear resulting in episodic vertigo and intermittent hearing loss. It is a finding for which extensive research is being performed. METHODS: A review of the most recent literature on secondary endolymphatic hydrops was performed using PubMed literature search. RESULTS: Recent investigation of secondary endolymphatic hydrops has brought attention to traumatic and inflammatory insults as causes for secondary endolymphatic hydrops. Such etiologies, including postsurgical effects of cochlear implantation and endolymphatic sac ablation; otosclerosis and its operative intervention(s); acoustic and mechanical trauma; medications; and systemic inflammatory processes, have been determined as causes of secondary lymphatic hydrops. Histopathological slides for many of the etiologies of secondary endolymphatic hydrops are presented. CONCLUSION: Through an understanding of the pathophysiology and etiologies of secondary endolymphatic hydrops, clinicians will gain a better understanding of this complex disease process, which will aid in treatment of patients with this disease process.

Changes in the inner ear structures in cystic fibrosis patients.

OBJECTIVE: Although prolonged use of antibiotics is very common in cystic fibrosis (CF) patients, no studies have assessed the changes in both cochlear and peripheral vestibular systems in this population. METHODS: We used human temporal bones to analyze the density of vestibular dark, transitional, and hair cells in specimens from CF patients who were exposed to several types of antibiotics, as compared with specimens from an age-matched control group with no history of ear disease or antibiotic use. Additionally, we analyzed the changes in the elements of the cochlea (hair cells, spiral ganglion neurons, and the area of the stria vascularis). Data was gathered using differential interference contrast microscopy and light microscopy. RESULTS: In the CF group, 83% of patients were exposed to some ototoxic drugs, such as aminoglycosides. As compared with the control group, the density of both type I and type II vestibular hair cells was significantly lower in all structures analyzed; the number of dark cells was significantly lower in the lateral and posterior semicircular canals. We noted a trend toward a lower number of both inner and outer cochlear hair cells at all turns of the cochlea. The number of spiral ganglion neurons in Rosenthal's canal at the apical turn of the cochlea was significantly lower; furthermore, the area of the stria vascularis at the apical turn of the cochlea was significantly smaller. CONCLUSIONS: Deterioration of cochlear and vestibular structures in CF patients might be related to their exposure to ototoxic antibiotics. Well-designed case-control studies are necessary to rule out the effect of CF itself.

Does Otosclerosis Affect Dark and Transitional Cells in the Human Vestibular Labyrinth?

HYPOTHESIS: The density of vestibular dark cells (DCs) and vestibular transitional cells (TCs) can be quantitatively decreased in human temporal bones with otosclerosis. BACKGROUND: Previous reports have shown that otosclerosis can lead to vestibular symptoms. METHODS: We examined 61 human temporal bone specimens from 52 deceased donors with otosclerosis group-with and without endosteal involvement (EI), and with and without endolymphatic hydrops (EH)-versus 25 specimens from 18 age-matched controls. Using light microscopy, we evaluated the nonsensory epithelium of the lateral semicircular canal (LSC) and posterior semicircular canal (PSC) of the human vestibular labyrinth, focusing on the density of DCs and TCs. RESULTS: In both the LSC and the PSC, as compared with the control group, the mean density of DCs significantly decreased in the EI (+) group, in the EI (+) and EH (+) subgroup, and in the EI (+) and EH (-) subgroup (p < 0.05). In addition, we found a significant difference in the mean density of DCs between the EI (+) group and the EI (-) group in the LSC and in the PSC (p < 0.05). But we found no significant difference in the mean density of TCs in any of the otosclerosis groups or subgroups as compared with the control group (p > 0.05). CONCLUSION: We found a decrease in the density of DCs associated with EI in human temporal bone specimens with otosclerosis, regardless of the presence of EH. This decrease might cause damage in ion and water transportation, leading to vestibular symptoms.

Deterioration of Vestibular Cells in Labyrinthitis.

OBJECTIVE: To quantitatively assess the effect of serous labyrinthitis, suppurative labyrinthitis, and labyrinthitis ossificans on vestibular hair cells, dark cells, and transitional cells. METHODS: We examined human temporal bone specimens with serous labyrinthitis, suppurative labyrinthitis, and labyrinthitis ossificans, then compared them with age-matched control groups without labyrinthitis. We evaluated the density of type I and II vestibular hair cells, dark cells, and transitional cells in the peripheral sensorial organs. RESULTS: The mean density of type I vestibular hair cells in the maculae of the saccule significantly differed between the serous labyrinthitis group and its control group. The loss of type I and II vestibular hair cells in all of the peripheral sensorial organs was significantly higher in the suppurative labyrinthitis group than in its control group. The mean density of dark cells in the lateral and posterior semicircular canals was significantly lower in the suppurative labyrinthitis group than in its control group. The mean density of type I and II vestibular hair cells, dark cells, and transitional cells was significantly lower in the labyrinthitis ossificans group than in its control group. CONCLUSION: The loss of vestibular hair cells and degenerative changes in dark cells and transitional cells could affect vestibular function in patients with labyrinthitis.