Cochlear changes in serous labyrinthitis associated with silent otitis media: A human temporal bone study.

PURPOSE: To determine histopathological findings in the cochlea of human temporal bones with serous labyrinthitis. MATERIALS AND METHODS: We compared human temporal bones with serous labyrinthitis (20 cases) associated with silent otitis media and without serous labyrinthitis (20 cases) to study location of serous labyrinthitis, the degree of endolymphatic hydrops, number of spiral ganglion cells and hair cells, loss of fibrocytes in the spiral ligament, and areas of the spiral ligament and stria vascularis. RESULTS: The serous labyrinthitis caused significant loss of outer hair cells in the lower basal (P=0.006), upper basal (P=0.005), and lower middle (P=0.011) cochlear turns, and significant increase in the degree of endolymphatic hydrops than the control group (P=0.036). No significant difference was found in the loss of inner hair cells, in the number of spiral ganglion cells and fibrocytes in the spiral ligament, and in areas of the stria vascularis and spiral ligament (P>0.05). CONCLUSIONS: Serous labyrinthitis resulted in significant loss of outer hair cells and significant increase in the degree of endolymphatic hydrops.

Pathologic correlations of otologic symptoms in acute lymphocytic leukemia.

OBJECTIVES: To assess the clinicopathologic correlations of otologic complaints in patients with acute lymphocytic leukemia. DESIGN: Otologic complaints and histologic findings were evaluated in 25 temporal bones of 13 acute lymphocytic leukemia patients. RESULTS: Nine patients had a history of otologic complaints, including hearing loss, otalgia, otorrhea, and vertigo in 5, 3, 3, and 2 patients, respectively. Hemorrhage was most commonly observed in the middle ear (6 patients, 9 temporal bones) and was also observed in cochlea (4 patients, 4 temporal bones), and vestibule (6 patients, 6 temporal bones). Leukemic infiltration was observed in the petrous apex (13 patients, 24 temporal bones), middle ear (7 patients, 14 temporal bones), cochlea (3 patients, 4 temporal bones), vestibule (3 patients, 4 temporal bones), and internal auditory canal (5 patients, 8 temporal bones). Inflammatory changes were observed in the cochlea (5 patients, 8 temporal bones) and vestibule (5 patients, 8 temporal bones). Middle ear effusion containing floating tumor cells was observed in 4 temporal bones of 3 patients. Irreversible histopathologic changes of the middle ear, such as the destruction of the ossicles, perforation of the tympanic membrane, and granulation tissues were observed in 5 temporal bones of 4 patients. CONCLUSIONS: Ear involvement is common in acute lymphocytic leukemia patients. With prolonged survival due to the progress of treatment, the diagnosis and treatment of nonhematopoietic system symptoms, such as ear problems due to acute lymphocytic leukemia, have become more important.

Cochlear changes in presbycusis with tinnitus.

OBJECTIVES: The pathophysiology of tinnitus is obscure and its treatment is therefore elusive. Significant progress in this field can only be achieved by determining the mechanisms of tinnitus generation, and thus, histopathologic findings of the cochlea in presbycusis with tinnitus become crucial. We revealed the histopathologic findings of the cochlea in subjects with presbycusis and tinnitus. MATERIAL AND METHODS: The subjects were divided into 2 groups, presbycusis with tinnitus (tinnitus) group and presbycusis without tinnitus (control) group, with each group comprising 8 temporal bones from 8 subjects. We quantitatively analyzed the number of spiral ganglion cells, loss of cochlear inner and outer hair cells, and areas of the stria vascularis and spiral ligament. RESULTS: There was a significantly greater loss of outer hair cells in the tinnitus group compared with the control group in the basal and upper middle turns. The stria vascularis was more atrophic in the tinnitus group compared with the control group in the basal turn. CONCLUSIONS: Tinnitus is more common in patients with presbycusis who have more severe degeneration of outer hair cells and stria vascularis.

Systemic correction of storage disease in MPS I NOD/SCID mice using the sleeping beauty transposon system.

The Sleeping Beauty (SB) transposon system is a nonviral vector that directs transgene integration into vertebrate genomes. We hydrodynamically delivered SB transposon plasmids encoding human alpha-L-iduronidase (hIDUA) at two DNA doses, with and without an SB transposase gene, to NOD.129(B6)-Prkdc(scid) IDUA(tm1Clk)/J mice. In transposon-treated, nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice with mucopolysaccharidosis type I (MPS I), plasma IDUA persisted for 18 weeks at levels up to several hundred-fold wild-type (WT) activity, depending on DNA dose and gender. IDUA activity was present in all examined somatic organs, as well as in the brain, and correlated with both glycosaminoglycan (GAG) reduction in these organs and level of expression in the liver, the target of transposon delivery. IDUA activity was higher in the treated males than in females. In females, omission of transposase source resulted in significantly lower IDUA levels and incomplete GAG reduction in some organs, confirming the positive effect of transposition on long-term IDUA expression and correction of the disease. The SB transposon system proved efficacious in correcting several clinical manifestations of MPS I in mice, including thickening of the zygomatic arch, hepatomegaly, and accumulation of foamy macrophages in bone marrow and synovium, implying potential effectiveness of this approach in treatment of human MPS I.

Polyarteritis nodosa: a human temporal bone study.

PURPOSE: Polyarteritis nodosa is one of the common forms of vasculitis with multiorgan involvement. Hearing loss may be the presenting symptom of this disease. The aim of this histopathologic study was to evaluate temporal bone changes in polyarteritis nodosa and assess the correlation between otologic manifestations and histopathologic findings. MATERIALS AND METHODS: A retrospective human temporal bone analysis was performed at an otopathology laboratory in a tertiary academic medical center. Three cases (5 temporal bones) with pathologically confirmed diagnosis of polyarteritis nodosa were selected for study. The processed temporal bone sections were studied under light microscopy. RESULTS: Two of the 3 cases presented with hearing loss, and one of them had facial palsy. Audiometric data available for one patient demonstrated a bilateral, rapidly progressive, mixed hearing loss. Histopathologically, we found generalized vasculitis involving small- and medium-sized arteries in all cases. Of the 5 temporal bones available for study, 3 had chronic otitis media and 2 had serous otitis media. Arteritis was seen in all middle ears. There was disruption of the organ of Corti and spiral ganglion cells in 4 temporal bones. One temporal bone showed fibrosis and osteogenesis in the scala tympani of the basal turn. Vasculitis of stylomastoid and branches of labyrinthine artery were also found in temporal bones. CONCLUSIONS: Significant temporal bone findings were seen in patients with polyarteritis nodosa, including otitis media, cochlear damage, neo-osteogenesis, and middle and inner ear vasculitis. This temporal bone series also suggests an interesting relationship between sensorineural hearing loss and labyrinthine vasculitis.

Temporal bone study of trisomy 13 syndrome.

The temporal bones of a 23-week-old female who had multiple congenital anomalies and bilateral hearing loss with trisomy 13 syndrome were evaluated under light microscopy. In the left cochlea, spiral ganglion cells and cochlear nerve fibers are absent. In the right ear, an abnormal branch of the singular nerve passes between the utricle and lateral semicircular canals and separates the two portions, one to the flattened crista of the lateral semicircular canal, the other to the utricular macula. This is a rare report describing a patient with abnormalities in three nerves, including the facial, vestibular, and cochlear nerves.

Up-regulation of macrophage migration inhibitory factor induced by endotoxin in experimental otitis media with effusion in mice.

CONCLUSION: Injection of endotoxin into the middle ear causes production of macrophage migration inhibitory factor (MIF) in an experimental mouse model of otitis media with effusion (OME). Down-regulation of MIF may become a new approach for the management of OME. OBJECTIVE: To determine the role of MIF in OME. MATERIALS AND METHODS: Mice were divided into two groups and their middle ears were injected with either endotoxin or phosphate-buffered saline (PBS). Mice were sacrificed at 6 h, 12 h, or 1, 3, 7, or 14 days after injection and concentrations of MIF, interleukin-1 beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) in middle ear effusions were measured by enzyme-linked immunosorbent assay. RESULTS: Concentrations of MIF in the endotoxin group at 1 day and 3 days were significantly higher than in the PBS control group. Concentrations of IL-1beta in the endotoxin group at 6 h, 12 h, 1 day, and 3 days were significantly higher than in controls. Concentrations of TNF-alpha in the endotoxin group at 1 day and 3 days were significantly higher than in controls. Concentration of MIF in the endotoxin group was positively correlated with that of IL-1beta and TNF-alpha.

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.

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.

Contralateral ear in chronic otitis media: a histologic study.

OBJECTIVE: The objective of this study is to determine the prevalence of the contralateral ear changes in human temporal bones of donors with chronic otitis media. STUDY DESIGN: Transversal. MATERIAL AND METHODS: The temporal bones were examined under light microscopy and then described. Chronic otitis media was defined by the presence of irreversible inflammatory alterations in the middle ear cleft. The contralateral ear was defined as the normal or the less affected ear. To compare the qualitative variables, the chi test was used. Spearman's nonparametric test was used for correlations. P values less than or equal to .05 were considered significant. RESULTS: We studied 85 pairs of temporal bones. Cholesteatoma was observed in 22.4% of the more damaged ears. The prevalence of contralateral ears with alterations was 91.8%. The main alterations were granulation tissue (81%), effusion (58%), and tympanic membrane retractions (35%). There was a direct and moderately strong correlation between the extent of granulation tissue in the more damaged ear and the contralateral ear (r(s) = 0.345, P = .004). A strong correlation was observed between the extent of cholesteatoma in the more damaged ear and in the contralateral ear (rs = 0.617, P < .001). CONCLUSION: We observed a high prevalence of changes in the contralateral ear. There was a direct correlation between the extent of both granulation tissue and cholesteatoma between the two ears, demonstrating that the more extensive the manifestation of these pathologies in the more damaged ear, the greater they will be in the contralateral ear.

Comparison of the quantity of cochlear melanin in young and old C57BL/6 mice.

OBJECTIVE: To elucidate the functional relationship between cochlear melanin and aging. DESIGN: Melanin has been described in the cochlear labyrinth and has been suggested to protect the cochlea from various types of trauma. The quantity of melanin has been shown to change with aging in several organs; however, to our knowledge, aging changes in the cochlea have not been documented. Therefore, we chemically quantified cochlear eumelanin and pheomelanin contents and compared these in young and old C57BL/6 mice using high-performance liquid chromatography. Because melanin deposits in the cochlea present most extensively in the stria vascularis, we morphologically examined the stria using transmission electron microscopy. SUBJECTS: Cochleae from an inbred strain of C57BL/6 male and female mice; 6 at the age of 10 weeks and 5 at the age of 100 weeks were studied. RESULTS: The quantities of cochlear eumelanin and pheomelanin were 421 and 480 ng per cochlea in young mice, and 2060 and 765 ng per cochlea in old mice, respectively. Under transmission electron microscopy, the number of pigmented granules seemed to be greater in older mice compared with younger mice, especially in marginal cells. CONCLUSION: To our knowledge, our findings are the first quantitative evidence to show an age-related overexpression of cochlear melanin and an alteration in the proportion of eumelanin and pheomelanin with aging, suggesting a possible otoprotective function of eumelanin against age-related cochlear deterioration.

Histopathologic changes of contralateral human temporal bone in unilateral Ménière's disease.

HYPOTHESIS: To disclose the histopathologic findings in the contralateral temporal bone in unilateral Ménière's disease. BACKGROUND: Several functional studies reported abnormal findings in the contralateral ears in patients with unilateral Ménière's disease. METHODS: This study involved quantitative analysis, including the number of spiral ganglion cells, the loss of cochlear hair cells, the area of stria vascularis, and the density of fibrocytes in the spiral ligament. It included 14 temporal bones from 7 subjects with bilateral Ménière's disease, 30 temporal bones from 15 subjects with unilateral Ménière's disease, and 17 age-matched normal control temporal bones from 12 subjects. RESULTS: The mean number of spiral ganglion cells in the contralateral temporal bones in patients with unilateral Ménière's disease was 17,376.0 and was significantly lower than that in normal controls. The mean loss of inner and outer hair cells in the contralateral temporal bones in patients with unilateral Ménière's disease was significantly greater than that in normal controls in all turns. The stria vascularis was severely atrophic and degenerated in patients with Ménière's disease. The mean area of stria vascularis in contralateral temporal bones in patients with unilateral Ménière's disease was significantly smaller than normal controls. There was no significant difference in the density of fibrocytes in the spiral ligament between the diseased side and the contralateral side in patients with unilateral Ménière's disease and between normal control and contralateral side. CONCLUSION: The contralateral inner ear in patients with unilateral Ménière's disease has significantly more damage compared with inner ears of normal controls.

Age-related functional and histopathological changes of the ear in the MPS I mouse.

OBJECTIVE: Mucopolysaccharidosis type I (MPS I) is an autosomal recessive disorder caused by a mutation in the gene encoding the enzyme alpha-L-iduronidase. This enzyme is responsible for degradation of dermatan and heparan sulfates. Enzyme deficiency results in their accumulation in lysosomes of virtually all organs, resulting in severe somatic and neurological changes. Clinical findings of otitis media with mixed hearing loss are common. Cellular and molecular mechanisms of ear pathology and hearing loss are not understood. The purpose of this study is to describe the age-related audiologic and histopathologic changes of the ear in the mouse model of MPS I. METHODS: Auditory brainstem responses (ABR) were obtained to clicks and tone bursts at 1-32kHz, and pathological changes to middle and inner ears were studied with light and electron microscopy in 53 mice that included: (1) wild type (+/+)-five at 2 months, five at 4-6 months, and five at 13-19 months; (2) heterozygotes (+/-)-four at 2 months, five at 4-6 months, and eight at 13-19 months; and (3) homozygotes (-/-)-five at 2 months, six at 4-6 months, and five at 13-19 months. Histopathology was also done on five newborn -/- mice. RESULTS: In newborns, no lysosomal storage was observed and the ear appeared age appropriately normal. In all other -/- mice, cells with lysosomal storage vacuoles were observed in spiral ligament, spiral prominence, spiral limbus, basilar membrane, epithelial and mesothelial cells of Reissner's membrane, endothelial cells of vessels, and some ganglion cells; their number increased with aging. Hair cell loss was not observed at 2 or 6 months, but there was total loss of the organ of Corti in year-old mice. Hearing of -/- mice was significantly decreased at all ages compared to +/+ and +/-. Hearing loss progressed from mild to moderate loss at 2 months to profound at 6 months and total deafness by 1 year of age. CONCLUSIONS: Progressive age-related changes suggest early therapeutic intervention to prevent sensory cell damage and hearing loss.

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.

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.

A three-dimensional analysis of the endolymph drainage system in Ménière disease.

OBJECTIVES/HYPOTHESIS: To measure the volume of the endolymph drainage system in temporal bone specimens with Ménière disease, as compared with specimens with endolymphatic hydrops without vestibular symptoms and with nondiseased specimens STUDY DESIGN: Comparative human temporal bone analysis. METHODS: We generated three-dimensional models of the vestibular aqueduct, endolymphatic sinus and duct, and intratemporal portion of the endolymphatic sac and calculated the volume of those structures. We also measured the internal and external aperture of the vestibular aqueduct, as well as the opening (if present) of the utriculoendolymphatic (Bast's) valve and compared the measurements in our three study groups. RESULTS: The volume of the vestibular aqueduct and of the endolymphatic sinus, duct, and intratemporal endolymphatic sac was significantly lower in the Ménière disease group than in the endolymphatic hydrops group (P <.05). The external aperture of the vestibular aqueduct was also smaller in the Ménière disease group. Bast's valve was open only in some specimens in the Ménière disease group. CONCLUSIONS: In temporal bones with Ménière disease, the volume of the vestibular aqueduct, endolymphatic duct, and intratemporal endolymphatic sac was lower, and the external aperture of the vestibular aqueduct was smaller as compared with bones from donors who had endolymphatic hydrops without vestibular symptoms and with nondiseased bones. The open status of the Bast's valve in the Ménière disease group could be secondary to higher retrograde endolymph pressures caused by smaller drainage systems. These anatomic findings could correlate with the reason that some patients with hydrops develop clinical symptoms, whereas others do not. LEVEL OF EVIDENCE: N/A Laryngoscope, 127:E170-E175, 2017.

Large vestibular aqueduct syndrome: a human temporal bone study.

OBJECTIVES/HYPOTHESIS: Large vestibular aqueduct syndrome (LVAS) is one of the common causes of hearing loss (HL). All prior studies have reported some anomalies associated with LVAS by imaging techniques. This study was undertaken to determine prevalence of LVAS in our temporal bone (TB) collection and its relationship to other systemic or otologic anomalies. STUDY DESIGN: Retrospective, TB histopathologic study. METHODS: Anteroposterior diameters of internal (IA) and external (EA) apertures were measured in 40 normal TBs (40 cases). TBs were considered as large vestibular aqueduct (LVA) if width of apertures was 95% greater than "normals." Systemic and otologic anomalies and histopathology of ears with LVAS were noted. RESULT: Of 1,608 non-"normal" TBs, 63 had LVA. There was negative correlation between IA and EA in 48 TBs with only enlarged IA. Fifteen TBs with enlarged EA always had enlarged IA and were therefore considered as LVAS. The most common pathologic condition was congenital heart anomaly. The most common syndrome or dysplasia was Mondini's. The most common anomalies of external and middle ears were dehiscent facial nerves, low set auricles, and ossicular deformities. Inner ear anomalies included modiolar deficiencies, hair cell loss, interscalar septum defects, and strial atrophy. There was no record of family history of HL, head injury, or craniofacial, branchial, or thyroidal abnormalities. CONCLUSION: Because HL associated with LVAS may be attributed to other ear anomalies, it is important to investigate other inner ear problems and system diagnoses that may indicate a syndrome in patients with radiologically diagnosed LVAS.

Association between cupular deposits and otosclerosis.

OBJECTIVE: To evaluate whether otosclerosis is an underlying mechanism for the production of cupular deposits and to study the association between cupular deposits and dysequilibrium in otosclerosis. DESIGN: Retrospective human temporal bone (TB) study. The incidence of cupular deposits in these 70 TBs was analyzed. Correlations between cupular deposits and vestibular symptoms, endosteal involvement of the otosclerotic focus, stapedial fixation, and clinical history of stapes surgery were evaluated. SETTING: Otolaryngology laboratory in a tertiary academic medical center. PATIENTS: The study material consisted of 35 human TBs with otosclerosis and 35 age-matched controls. MAIN OUTCOME MEASURES: Morphometric evaluations of the incidence of cupular deposits, endosteal involvement of the otosclerotic focus, and stapedial fixation were made by light microscopy. Clinical records were reviewed retrospectively for clinical history of stapes surgery and prevalence of vestibular symptoms. The incidence of cupular deposits was compared between the otosclerotic and control groups. Correlations between cupular deposits and vestibular symptoms, endosteal involvement of the otosclerotic focus, stapedial fixation, and clinical history of stapes surgery were evaluated in the subjects with otosclerosis. RESULTS: The incidence of cupular deposits in TBs with otosclerosis was significantly higher than in those without whereas there was no correlation between the incidence of the deposits and dysequilibrium in cases of otosclerosis. An increase in deposits did not correlate with stapedial fixation, stapes surgery, or endosteal involvement. CONCLUSIONS: Our results suggest otosclerosis as an underlying mechanism for the production of cupular deposits; however, we did not find an association between these deposits and vestibular symptoms.

Effects of type 2 diabetes mellitus on cochlear structure in humans.

OBJECTIVE: To evaluate the effects of type 2 diabetes mellitus on cochlear elements in humans. DESIGN: Comparative study of the histopathologic characteristics of human temporal bones. SETTING: Otopathology laboratory in a tertiary academic medical center. PATIENTS: Temporal bones from 18 patients with type 2 diabetes mellitus were divided into 2 groups according to the method of management of diabetes: insulin in 11 patients (mean age, 51.9 years; age range, 44-65 years) and oral hypoglycemic agents in 7 patients (mean age, 54.4 years; age range, 45-64 years). The diabetic groups and 26 age-matched controls (mean age, 52.9 years) were examined using light microscopy, and the cochlear changes were compared between groups. MAIN OUTCOME MEASURES: Morphometric measurements of vessel wall thickness in the basilar membrane and stria vascularis were made in all turns of the cochlea at the midmodiolar level. Area measurements of the stria vascularis were made in all turns of the cochlea at the midmodiolar level. Cochlear reconstructions and standard cytocochleograms were prepared using an oil immersion objective. The number of spiral ganglion cells was determined for each segment of the cochlea. Comparisons were made in each segment between diabetic and control groups. RESULTS: In the insulin group, walls of the vessels of the basilar membrane and stria vascularis in all turns were significantly thicker than those of controls. Walls of the vessels of the stria vascularis in the basal turn were also significantly thicker in the oral hypoglycemic group than in controls. Atrophy of the stria vascularis in most turns of the insulin group and the lower middle turn of the oral hypoglycemic group was significantly greater than in the controls. Loss of cochlear outer hair cells was significantly greater in the lower and upper basal turns in both diabetic groups. No significant difference was found in the number of spiral ganglion cells or inner hair cells between groups. CONCLUSION: This study demonstrates that cochlear microangiopathy and degeneration of the stria vascularis and cochlear outer hair cells are found in patients with type 2 diabetes mellitus.

Histologic changes in the anterior mallear ligament and the head of the malleus in otosclerosis.

OBJECTIVE: To determine ossicular and anterior mallear ligament (AML) changes in otosclerosis. STUDY DESIGN AND SETTING: Hyalinization of AML was graded as follows: none, patchy, or diffuse in 95 temporal bones (TBs) with otosclerosis: 52 with stapedial fixation (SF); 43 without fixation (NSF); and 52 age-matched controls. Fixation of the head of the malleus was noted. RESULTS: Hyalinization with SF was 17 none, 23 patchy, and 12 diffuse; with NSF it was 16 none, 20 patchy, and 7 diffuse; and in controls, 23 none, 24 patchy, and 5 diffuse. There was no significant difference in hyalinization among groups and no correlation between degree of hyalinization and age. The malleus head was fixed in 4 TBs with SF. CONCLUSION: Based on our findings, we do not believe that there is a relationship between hyalinization of the AML and otosclerosis; however, otosclerosis with SF seems to be a predisposing factor for fixation of the head of the malleus.