The Temporal Bone in the Preauricular Pit, Cervical Fistula, Hearing Loss Syndrome

1976 ◽  
Vol 85 (2) ◽  
pp. 268-275 ◽  
Author(s):  
Naomi Fitch ◽  
John R. Lindsay ◽  
Herbert Srolovitz
Keyword(s):  
Hearing Loss ◽  
Middle Ear ◽  
Ganglion Cells ◽  
Stria Vascularis ◽  
Histological Study ◽  
Spiral Ganglion ◽  
Middle Cranial Fossa ◽  
Nerve Fibers ◽  
Horizontal Canal ◽  
Temporal Bones

Histological study of the temporal bones of an infant with the preauricular pit, cervical fistula, hearing loss syndrome revealed abnormalities in the middle ear, the vestibular system, and the cochlea. There is a gross bilateral abnormality in the form and relationship of the middle ear spaces, the middle cranial fossa and the inner ear. The horizontal canal lacks ampulla and crista; the posterior canal terminates a short distance from the ampulla. The cochlear cavity is approximately four fifths of normal size. The modiolus of the cochlea shows minor abnormalities. Spiral ganglion cells and peripheral nerve fibers are present in all coils, but are below normal in population in the basal and apical coils. The stria vascularis is slightly deformed and partly atrophic in the upper apical coil. An occasional concretion is present in the base of the stria vascularis in the middle and apical coils.

Chronic Intracochlear Electrode Implantation: Cochlear Pathology and Acoustic Nerve Survival

1974 ◽  
Vol 83 (2) ◽  
pp. 202-215 ◽  
Author(s):  
Robert A. Schindler ◽  
Michael M. Merzenich
Keyword(s):  
Hair Cells ◽  
Bone Growth ◽  
Ganglion Cells ◽  
Stria Vascularis ◽  
Round Window ◽  
Spiral Ganglion ◽  
Nerve Fibers ◽  
Spiral Ligament ◽  
Scala Tympani ◽  
Temporal Bones

The temporal bones of ten cats implanted with intracochlear electrodes for three to 117 weeks were stained with hematoxylin and eosin and examined with light microscopy. The electrodes were embedded in Silastic® which was molded to fill the most basal 9 mm of the scala tympani. They were inserted directly into the scala through the round window. Among our observations were the following: 1) All or nearly all hair cells were lost in the basal coil during the first several weeks after implantation. Some, but not all, supporting cells were also lost. There was extensive hair cell loss in the middle and apical turns, although some hair cells were seen there in all examined cats. 2) There was evidence of degeneration of spiral ganglion cells in the basal cochlea in several animals, but most primary auditory neurons including (with two exceptions) most of those in the region directly over the electrode, survived implantation in every cat. The radial nerve fibers of the spiral ganglion cells also survived long-term implantation. The functional viability of remaining spiral ganglion cells was confirmed in acute neurophysiological experiments conducted just before the animals were sacrificed. 3) More severe degeneration was seen in two cats in which the electrode perforated the basilar partition. In these animals, there was loss of many spiral ganglion cells, and evidence of new bone growth in the region of the perforation. 4) The appearance of the stria vascularis and spiral ligament in some implanted animals paralleled their descriptions following occlusion of the cochlear vein. 5) Connective tissue formed around the electrode surfaces, apparently displacing perilymph and sealing the electrode into the scala tympani. There was no evidence of perilymph fistula in any animal. 6) There was little evidence of progressive degeneration of the organ of Corti or spiral ganglion from three to 34 weeks after implantation. Some of the implications and limitations of these findings are discussed.

Survival of Spiral Ganglion Cells in Profound Sensorineural Hearing Loss: Implications for Cochlear Implantation

1989 ◽  
Vol 98 (6) ◽  
pp. 411-416 ◽  
Author(s):  
Joseph B. Nadol ◽  
Yi-Shyang Young ◽  
Robert J. Glynn
Keyword(s):  
Hearing Loss ◽  
Ganglion Cell ◽  
Cell Count ◽  
Ganglion Cells ◽  
Spiral Ganglion ◽  
Bivariate Analysis ◽  
Spiral Ganglion Cell ◽  
Cell Counts ◽  
Profound Deafness ◽  
Temporal Bones

Ninety-three temporal bones from 66 patients who were profoundly deaf during life were reconstructed by analysis of serial light microscopic sections. The correlations of total and segmental spiral ganglion cell counts with age, duration of hearing loss and profound deafness, and cause of hearing loss were evaluated. Bivariate analysis demonstrated that total spiral ganglion cell count tended to be lower in older than in younger deaf individuals and lower with longer duration of hearing loss and total deafness. However, multiple regression analysis demonstrated that the cause of hearing loss was the single most significant determinant of total spiral ganglion cell count. Patients with deafness due to aminoglycoside toxicity or sudden idiopathic deafness had the highest residual spiral ganglion cell count and patients with deafness due to presumptive postnatal viral labyrinthitis, bacterial labyrinthitis, and congenital or genetic causes had the lowest numbers of residual spiral ganglion cells.

Inner Ear Degeneration in Acoustic Neurinoma

1976 ◽  
Vol 85 (3) ◽  
pp. 343-358 ◽  
Author(s):  
Fumiro Suga ◽  
John R. Lindsay
Keyword(s):  
Inner Ear ◽  
Blood Circulation ◽  
Ganglion Cells ◽  
Stria Vascularis ◽  
Nerve Fibers ◽  
Sensory Cells ◽  
Tectorial Membrane ◽  
Acoustic Neurinoma ◽  
Pathological Findings ◽  
Temporal Bones

The temporal bones of three cases of acoustic neurinoma are described to illustrate histopathological features of inner ear lesions due to chronic partial obstruction of blood circulation by the tumor in the internal auditory meatus. Degenerative changes in the inner ear due to acoustic neurinoma were evaluated and compared with changes in the opposite ear. The main pathological findings in the inner ear which were attributed to the tumor were degeneration of nerve fibers and of ganglion cells, degeneration of the stria vascularis, degeneration of the tectorial membrane, fibrosis and ossification of a semicircular canal. Fairly good preservation of sensory cells was observed in the presence of total degeneration of nerve fibers and ganglion cells and subtotal degeneration of the stria vascularis.

Cochlear Changes in Patients with Type 1 Diabetes Mellitus

2005 ◽  
Vol 133 (1) ◽  
pp. 100-106 ◽  
Author(s):  
Hisaki Fukushima ◽  
Sebahattin Cureoglu ◽  
Patricia A. Schachern ◽  
Takeshi Kusunoki ◽  
Mehmet F. Oktay ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 1 Diabetes ◽  
Type 1 Diabetes Mellitus ◽  
Hair Cells ◽  
Ganglion Cells ◽  
Stria Vascularis ◽  
Spiral Ganglion ◽  
Temporal Bones ◽  
Lateral Walls

OBJECTIVE: To evaluate the effects of diabetes on cochlear elements in human beings. STUDY DESIGN AND SETTING: Twenty-six temporal bones (mean age, 37.5 years) with type 1 diabetes and 30 age-matched controls were examined by light microscopy. We compared the findings of cochlear vessels, hair cells, spiral ganglion cells, and cochlear lateral walls. RESULTS: In diabetics, the walls of vessels of the basilar membrane ( P < 0.001) and vessels of the stria vascularis were ( P < 0.01) significantly thicker in all turns and loss of outer hair cells (OHCs) was significantly greater in the lower basal turn ( P < 0.01). Atrophy of the stria vascularis in all turns ( P < 0.0001) and loss of spiral ligament cells in upper turns ( P < 0.01) were significantly higher than controls. No significant difference was obtained in the number of spiral ganglion cells between groups. CONCLUSION: This study suggests that type 1 diabetes mellitus can cause cochlear microangiopathy and subsequently degeneration of cochlear lateral walls and OHCs.

Ear Anomalies Associated with Renal Dysplasia and Immunodeficiency Disease

1978 ◽  
Vol 87 (1) ◽  
pp. 10-17 ◽  
Author(s):  
John R. Lindsay ◽  
Raúl hinojosa
Keyword(s):  
Ganglion Cells ◽  
Normal Population ◽  
Stria Vascularis ◽  
Renal Dysplasia ◽  
Middle Cranial Fossa ◽  
Bilateral Absence ◽  
Cranial Fossa ◽  
Immunodeficiency Disease ◽  
Ear Anomalies ◽  
Temporal Bones

The histopathologic study of the temporal bones of a case with low-set rudimentary auricles, without preauricular pits or cervical fistula is presented. Abnormalities of the middle and inner ear, fusion of the kidneys, hydrocephalus, short-limbed dwarfism and immunodeficiency are described. An abnormally low position of the middle cranial fossa in relation to the petrous pyramid was observed. The cochlea was of normal length. The modiolus was poorly developed with apparently normal population of ganglion cells and moderate diffuse hydrops of the cochlear duct and saccule. The stria vascularis was partially degenerated in the upper apical coil. Vestibular abnormalities included bilateral absence of common crus of the vertical canals and unusually high origin of endolymphatic aqueduct with no medial dilation present, the convoluted portion of the sac located beneath the dura.

Temporal Bone Histopathology in Deafness Due to Cryptococcal Meningitis

1979 ◽  
Vol 88 (5) ◽  
pp. 630-636 ◽  
Author(s):  
Takehiko Harada ◽  
Isamu Sando ◽  
Eugene N. Myers
Keyword(s):  
Temporal Bone ◽  
Cryptococcal Meningitis ◽  
Ganglion Cells ◽  
Spiral Ganglion ◽  
Organ Of Corti ◽  
Nerve Fibers ◽  
Vestibular Nerve ◽  
Cochlear Nerve ◽  
Internal Auditory Meatus ◽  
Temporal Bones

This paper reports on a patient who survived an attack of cryptococcal meningitis eight years prior to his death. A bilateral sensorineural hearing loss had been noted a short time before the patient was admitted to the hospital, and was the only complication after he recovered from the disease. Histopathologic study of the temporal bones showed a similar pattern of pathology in both ears, the most striking finding being a severe loss of spiral ganglion cells in Rosenthal's canal, and of cochlear nerve fibers in the osseous spiral lamina and internal auditory meatus. The vestibular nerve was mostly free from pathology. The organ of Corti was atrophic but the hair cell population appeared to be almost normal. A slight number of cryp-tococci were observed in limited areas of the cochlear and the saccular nerves in the internal auditory meatus. The severe pathology of the cochlear nerve was compatible with audiologic evaluations, which pointed to a retrocochlear lesion. Thus, this case demonstrates some characteristic aspects of cryptococcal infection of the temporal bone: The primary site of invasion was the cochlear nerve in the internal auditory meatus and the modiolus, leading to the loss of ganglion cells and nerve fibers, while the vestibular nerve appears to have been resistant to infection.

Histopathological Observations of Presbycusis

1976 ◽  
Vol 85 (2) ◽  
pp. 169-184 ◽  
Author(s):  
Fumiro Suga ◽  
John R. Lindsay
Keyword(s):  
Hearing Loss ◽  
Ganglion Cells ◽  
Stria Vascularis ◽  
Spiral Ganglion ◽  
Organ Of Corti ◽  
Histopathological Change ◽  
High Tone ◽  
Present Material ◽  
Aged Patients ◽  
Vascular Elements

Temporal bone histopathology of 17 aged patients who had spontaneous and gradually progressive bilateral sensorineural hearing losses associated with aging was studied. Six cases in the present material showed the gradually sloping audiometric curve; nine cases, abrupt high tone hearing loss; and two cases, the flat audiometric curve. The most prominent histopathological change in the inner ear was a decrease in the population of the spiral ganglion cells. However, diffuse senile atrophy was also often seen in the organ of Corti and the stria vascularis. A positive correlation between the degree of arteriosclerosis and the degree of sensorineural degeneration in the cochlea was not obtained in the present cases. Also, the correlation was not found to be consistent between the type of the audiometric curve and the localization of lesions in the sensory, the neural or the vascular elements in the cochlea. Our observations show that a certain type of audiometric curve does not necessarily indicate a lesion in a specific cochlear element.

R450 – Manganese Superoxide Dismutase in Spiral Ganglion Cells

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P195-P196
Author(s):  
Yu-Lan M. Ying ◽  
Carey D Balaban
Keyword(s):  
Superoxide Dismutase ◽  
Hearing Loss ◽  
Temporal Bone ◽  
Manganese Superoxide Dismutase ◽  
Ganglion Cells ◽  
Spiral Ganglion ◽  
Manganese Superoxide ◽  
Human Temporal Bone ◽  
Temporal Bones

Problem Manganese superoxide dismutase (Mn SOD2) is a key metabolic anti-oxidant enzyme of the superoxide dismutase family for detoxifying the free radical cascade inside the mitochondria of the cochlea via activation of downstream uncoupling proteins. Copper/zinc superoxide dismutase (Cu/Zn SOD1) is localized in the cytoplasm. This study examined whether the pattern of expression of these SODs in the cochlea is correlated with the differential cellular vulnerability found in basal versus apical turn of the cochlea. Methods Immunohistochemical methods were used to identify the distribution of Mn SOD2 and Cu/Zn SOD1 in paraffin embedded sections of paraformaldehyde fixed formic acid decalcified temporal bones from mice, rats, and macaques; and special archival celloidin-embedded human temporal bone sections. Results In mice, rats and macaques, both the proportion of Mn SOD2 immunopositive type 1 spiral ganglion cells and the intensity of immunoreactivity were elevated near the cochlear apex. Strongly stained Mn SOD2 type 1 spiral ganglion cells were also observed in archival human temporal bone sections. In contrast, the Cu/Zn SOD1 immunopositive type 1 spiral ganglion cells were distributed identically across cochlear turns in rats and macaques. Conclusion These findings suggest that spiral ganglion cellular responses to ROS exposure may vary along the cochlear spiral, with a lower response capacity in the basal turn. Significance Hair cells and spiral ganglion cells appear to be more vulnerable to ototoxins at the base of the cochlea than at the apex. Our data raises the general hypothesis that a lower Mn SOD2 anti-oxidative capacity at the cochlear base could contribute to the high frequency hearing loss seen in presbycusis and ototoxin-induced hearing loss. The conservative pattern of Mn SOD2 immunostaining across species further suggests that it may be a fundamental mechanism in ROS metabolism and signaling. Support PA Lions Hearing Research Foundation, American Otologic Society Research Fellowship.

scholarly journals Physiopathological Relevance of D-Serine in the Mammalian Cochlea

2021 ◽  
Vol 15 ◽  
Author(s):  
Jing Wang ◽  
Nicolas Serratrice ◽  
Cindy J. Lee ◽  
Florence François ◽  
Jonathan V. Sweedler ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Nmda Receptors ◽  
Guinea Pigs ◽  
Stria Vascularis ◽  
Spiral Ganglion ◽  
Nerve Fibers ◽  
Inner Hair Cell ◽  
Ganglion Neurons

NMDA receptors (NMDARs) populate the complex between inner hair cell (IHC) and spiral ganglion neurons (SGNs) in the developing and mature cochlea. However, in the mature cochlea, activation of NMDARs is thought to mainly occur under pathological conditions such as excitotoxicity. Ototoxic drugs such as aspirin enable cochlear arachidonic-acid-sensitive NMDAR responses, and induced chronic tinnitus was blocked by local application of NMDAR antagonists into the cochlear fluids. We largely ignore if other modulators are also engaged. In the brain, D-serine is the primary physiological co-agonist of synaptic NMDARs. Whether D-serine plays a role in the cochlea had remained unexplored. We now reveal the presence of D-serine and its metabolic enzymes prior to, and at hearing onset, in the sensory and non-neuronal cells of the cochlea of several vertebrate species. In vivo intracochlear perfusion of D-serine in guinea pigs reduces sound-evoked activity of auditory nerve fibers without affecting the receptor potentials, suggesting that D-serine acts specifically on the postsynaptic auditory neurons without altering the functional state of IHC or of the stria vascularis. Indeed, we demonstrate in vitro that agonist-induced activation of NMDARs produces robust calcium responses in rat SGN somata only in the presence of D-serine, but not of glycine. Surprisingly, genetic deletion in mice of serine racemase (SR), the enzyme that catalyzes D-serine, does not affect hearing function, but offers protection against noise-induced permanent hearing loss as measured 3 months after exposure. However, the mechanisms of activation of NMDA receptors in newborn rats may be different from those in adult guinea pigs. Taken together, these results demonstrate for the first time that the neuro-messenger D-serine has a pivotal role in the cochlea by promoting the activation of silent cochlear NMDAR in pathological situations. Thus, D-serine and its signaling pathway may represent a new druggable target for treating sensorineural hearing disorders (i.e., hearing loss, tinnitus).

Otopathologic Abnormalities in CHARGE Syndrome

2021 ◽  
pp. 019459982110089
Author(s):  
Rafael da Costa Monsanto ◽  
Renata Malimpensa Knoll ◽  
Norma de Oliveira Penido ◽  
Grace Song ◽  
Felipe Santos ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Middle Ear ◽  
Spiral Ganglion ◽  
Internal Auditory Canal ◽  
Semicircular Canals ◽  
Charge Syndrome ◽  
University Of Minnesota ◽  
Bony Canal ◽  
Ganglion Neurons ◽  
Temporal Bones

Objective To perform an otopathologic analysis of temporal bones (TBs) with CHARGE syndrome. Study Design Otopathologic study of human TB specimens. Setting Otopathology laboratories. Methods From the otopathology laboratories at the University of Minnesota and Massachusetts Eye and Ear Infirmary, we selected TBs from donors with CHARGE syndrome. These TBs were serially sectioned at a thickness of 20 µm, and every 10th section was stained with hematoxylin and eosin. We performed otopathologic analyses of the external ear, middle ear (middle ear cleft, mucosal lining, ossicles, mastoid, and facial nerve), and inner ear (cochlea, vestibule, internal auditory canal, and cochlear and vestibular nerves). The gathered data were statistically analyzed. Results Our study included 12 TBs from 6 donors. We found a high prevalence of abnormalities affecting the ears. The most frequent findings were stapes malformation (100%), aberrant course of the facial nerve (100%) with narrow facial recess (50%), sclerotic and hypodeveloped mastoids (50%), cochlear (100%) and vestibular (83.3%) hypoplasia with aplasia of the semicircular canals, hypoplasia and aplasia of the cochlear (66.6%) and vestibular (91.6%) nerves, and narrowing of the bony canal of the cochlear nerve (66.6%). The number of spiral ganglion and Scarpa’s ganglion neurons were decreased in all specimens (versus normative data). Conclusions In our study, CHARGE syndrome was associated with multiple TB abnormalities that may severely affect audiovestibular function and rehabilitation.

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