Temporal Bone Studies of the Human Peripheral Vestibular System

2000 ◽  
Vol 109 (5_suppl) ◽  
pp. 14-19 ◽  
Author(s):  
Luis Velázquez-Villaseñor ◽  
Kojiro Tsuji ◽  
Conrad Wall ◽  
Saumil N. Merchant ◽  
Robert J. Glynn ◽  
...  

Scarpa's ganglion cell counts were performed in 106 serially sectioned, normal human temporal bones from 75 individuals. Of these 106 bones, 15 were from neonates less than 30 days old, 14 were from infants between the ages of 1 and 12 months, and the remainder were distributed throughout each decade of life, with sample sizes ranging from 4 to 10 per decade. All temporal bones had to meet 2 criteria: no symptoms or signs of inner ear disease except for presbycusis in the medical case history and no abnormality in the inner ear on light microscopy. The total ganglion cell counts declined significantly with age at an average rate of 57 cells per year. The age-related decline was significantly greater in the superior division than in the inferior division. There was also a significant sex effect, independent of age: for any age, the count in men averaged 1,526 cells higher than in women. There was no significant interaural difference. Mathematical models were developed to compute the mean and 95% prediction intervals for Scarpa's ganglion cell counts in terms of age and sex parameters. The counts and models will serve as a normative database against which to compare counts made in temporal bones from subjects with known vestibular disorders.

1981 ◽  
Vol 90 (2) ◽  
pp. 121-125 ◽  
Author(s):  
Ernst Richter

The density of vestibular hair cells and the number of neurons in Scarpa's ganglion were estimated for 11 temporal bones with endolymphatic hydrops. The ten subjects from which these bones were taken all exhibited decreased caloric response (when tested), fluctuating hearing loss, and episodic vertigo. The degeneration of vestibular sense organs was found within the “normal” range for all except one case, which showed total degeneration of the posterior crista ampullaris. Ganglion cell counts in all cases were low. In three of the ten subjects, counts fell below the lowest values seen in a sample of “normal” ears. These three subjects exhibited fluctuating hearing loss and episodic vertigo for more than six years prior to death. In cases of unilateral endolymphatic hydrops there was no significant difference between counts in the affected and unaffected ear. Thus, the apparent ganglion cell degeneration may be due to ear disease other than endolymphatic hydrops.


1989 ◽  
Vol 98 (6) ◽  
pp. 411-416 ◽  
Author(s):  
Joseph B. Nadol ◽  
Yi-Shyang Young ◽  
Robert J. Glynn

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.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Dong-Kee Kim

Nanoparticles are promising therapeutic options for inner ear disease. In this report, we review in vivo animal studies in the otologic field using nanoparticles over the past 5 years. Many studies have used nanoparticles to deliver drugs, genes, and growth factors, and functional and morphological changes have been observed. The constituents of nanoparticles are also diversifying into various biocompatible materials, including poly(lactic-co-glycolic acid) (PLGA). The safe and effective delivery of drugs or genes in the inner ear will be a breakthrough for the treatment of inner ear diseases, including age-related hearing loss.


2001 ◽  
Vol 110 (9) ◽  
pp. 883-891 ◽  
Author(s):  
Joseph B. Nadol ◽  
Barbara J. Burgess ◽  
Bruce J. Gantz ◽  
Newton J. Coker ◽  
Darlene R. Ketten ◽  
...  

The insertion of an intrascalar electrode array during cochlear implantation causes immediate damage to the inner ear and may result in delayed onset of additional damage that may interfere with neuronal stimulation. To date, there have been reports on fewer than 50 temporal bone specimens from patients who had undergone implantation during life. The majority of these were single-channel implants, whereas the majority of implants inserted today are multichannel systems. This report presents the histopathologic findings in temporal bones from 8 individuals who in life had undergone multichannel cochlear implantation, with particular attention to the type and location of trauma and to long-term changes within the cochlea. The effect of these changes on spiral ganglion cell counts and the correlation between speech comprehension and spiral ganglion cell counts were calculated. In 4 of the 8 cases, the opposite, unimplanted ear was available for comparison. In 3 of the 4 cases, there was no significant difference between the spiral ganglion cell counts on the implanted and unimplanted sides. In addition, in this series of 8 cases, there was an apparent negative correlation between residual spiral ganglion cell count and hearing performance during life as measured by single-syllable word recognition. This finding suggests that abnormalities in the central auditory pathways are at least as important as spiral ganglion cell loss in limiting the performance of implant users.


2017 ◽  
Vol 22 (3) ◽  
pp. 135-145 ◽  
Author(s):  
Kuwon Sekine ◽  
Tomohiro Matsumura ◽  
Toshihiro Takizawa ◽  
Yurika Kimura ◽  
Shiho Saito ◽  
...  

The molecular mechanisms underlying age-related hearing loss are unknown, and currently, there is no treatment for this condition. Recent studies have shown that microRNAs (miRNAs) and age-related diseases are intimately linked, suggesting that some miRNAs may present attractive therapeutic targets. In this study, we obtained 8 human temporal bones from 8 elderly subjects at brain autopsy in order to investigate the expression profile of miRNAs in the inner ear with miRNA arrays. A mean of 478 different miRNAs were expressed in the samples, of which 348 were commonly expressed in all 8 samples. Of these, levels of 16 miRNAs significantly differed between young elderly and old elderly subjects. miRNAs, which play important roles in inner ear development, were detected in all samples, i.e., in both young and old elderly subjects, whether with or without hearing loss. Our results suggest that these miRNAs play important roles not only in development, but also in the maintenance of inner ear homeostasis.


2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P155-P155
Author(s):  
Helen Xu ◽  
Natasha Pollak ◽  
Sebahattin Cureoglu ◽  
Michael M Paparella

Objectives 1) To exam the histopathology of multichannel cochlear implant temporal bones. 2) To evaluate the relationship of residual spiral ganglion cell counts to clinical hearing performance. Methods 8 temporal bones from 4 cochlear implant patients were examined histologically. Paired comparisons were made between implanted and nonimplanted temporal bones. Clinical performance data was obtained from patient charts. Results There were varying amounts of inflammation (fibrosis and ossification) in the basal turn of the cochlear in all implanted temporal bones. Trauma to the facial nerve at facial recess site was noticed in 1 case. Compared with nonimplanted ears, 2 implanted bones with less than 10-year duration of implantation had no significant changes of spiral ganglion cell population. One case with prolong implant duration (15 years) showed about 36% decrease of spiral ganglion cells at the implanted site. The case with best speech recognition (89% with CID sentence) had the highest residual spiral ganglion cells (30% of normal spiral ganglion cell population). 2 cases with poor clinical performance (< 10% with CID sentence) had the residual spiral ganglion cells at 11% and 22%. The case with moderate clinical performance (30% with CID sentence) had 14% of normal spiral ganglion cell population. Surviving dendrites varied from 5% to 30% among 4 cases with no relationship to clinical performance. Conclusions Our findings suggest prolonged implantation may affect spiral ganglion cell population. There is no reverse relationship between residual spiral ganglion cells in implanted temporal bones to clinical speech performance observed from our limited cases.


1993 ◽  
Vol 102 (6) ◽  
pp. 425-428 ◽  
Author(s):  
Charlotte M. Chiong ◽  
Robert J. Glynn ◽  
Wen-Zhuang Xu ◽  
Joseph B. Nadol

The electrically evoked auditory brain stem response in some cochlear implant patients may be confounded by evoked potentials generated by vestibular neurons. The magnitude of this contribution to the response from the vestibular system is unknown, in part because the survival of cells within Scarpa's ganglion in profoundly deaf humans is unknown. Therefore, we undertook a quantitative study of Scarpa's ganglion in 48 deaf subjects who in life would have been candidates for cochlear implantation and in 5 subjects with normal hearing. The numbers of residual cells in both Scarpa's ganglion and the spiral ganglion in deaf subjects were significantly less than in individuals with normal hearing. Bivariate analysis demonstrated a highly significant positive correlation between cell counts of Scarpa's ganglion and the spiral ganglion. The durations of hearing loss and of profound deafness were negatively correlated with Scarpa's ganglion cell counts. However, in contrast to spiral ganglion cell survival, the cause of profound deafness did not predict the number of Scarpa's ganglion cells. Multiple linear regression analysis using a variety of clinical parameters demonstrated that the best predictor of the number of Scarpa's ganglion cells in profoundly deaf humans was the number of remaining spiral ganglion cells.


2005 ◽  
Vol 114 (5) ◽  
pp. 381-385 ◽  
Author(s):  
Aayesha M. Khan ◽  
Ophir Handzel ◽  
Donald K. Eddington ◽  
Doris Damian ◽  
Joseph B. Nadol

It is generally assumed that at least a minimal number of spiral ganglion cells is essential for successful speech perception with a cochlear implant. Although the insertion of a multichannel cochlear implant frequently results in loss of residual hearing in the implanted ear, this outcome does not imply that significant damage to residual populations of spiral ganglion cells has occurred. The purpose of the current study was to compare spiral ganglion cell counts in implanted and nonimplanted cochleas in 11 patients for whom both temporal bones were available and in whom a multichannel cochlear implant had been placed unilaterally. The temporal bones were processed for light microscopy by standard techniques. The cochleas were reconstructed by 2-dimensional methods. Spiral ganglion cell counts of the implanted and nonimplanted sides were compared by a paired t-test (2-tailed). The mean spiral ganglion cell counts for implanted and nonimplanted ears were not statistically different in the most basal three segments of the cochlea. However, the mean spiral ganglion cell count in segment 4 (apical segment) and the mean total spiral ganglion cell count were lower in the implanted cochleas than in the nonimplanted cochleas (p < .01). The results of this study suggest a modest decrease in the total spiral ganglion cell count in the implanted ears as compared to the nonimplanted ears, principally in the apical segment. Possible interpretations of this finding are discussed.


1989 ◽  
Vol 101 (4) ◽  
pp. 459-465 ◽  
Author(s):  
Stephen P. Cass ◽  
Paul Davidson ◽  
Harry Goshgarian

Temporal bone studies in cat, monkey, and man demonstrate that the cell bodies of the primary vestibular neurons located in Scarpa's ganglion persist after labyrlnthectomy. However, it is not known whether the centrally directed axon process of deafferented vestibular neurons survive or degenerate after labyrinthectomy. If the central axon were to persist, then the primary vestibular neuron could influence vestibular compensation or produce symptoms of vestibular dysfunction. In the present study the temporal bones and brain stem of four cats were prepared for light microscopic examination with hematoxylin-eosin, silver, and trichrome connective tissue stains. Cell counts within Scarpa's ganglion were performed. After labyrinthectomy, many intact axons were demonstrated in the brain stem, a finding that correlated with survival of neurons in Scarpa's ganglion. This study provides anatomic evidence that primary vestibular neurons that survive labyrinthectomy may retain their central axon processes. The persistence of this neural pathway and data from behavioral studies in the cat suggest that vestibular neurons may affect vestibular compensation after labyrinthectomy. Deafferented vestibular neurons may play a role in human vestibular compensation and dysfunction.


1988 ◽  
Vol 97 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Naohiro Sudo ◽  
T. J. Yoo

Animals that had collagen-induced autoimmune inner ear disease were treated with anti-inflammatory drugs: Solu-Medrol (steroid), sulindac (nonsteroid), or a combination of both. Temporal bones from drug-treated animals were examined for histopathologic and immunohistochemical changes, and sera were examined for levels of circulating antibody to type II collagen. Therapy was beneficial to the animals whether the drugs were administered alone or in combination; however, fewer lesions were observed in animals given either drug alone. Further, animals treated with steroid alone showed the least amount of inner ear damage. Immunohistochemical changes and serum levels of antibodies against type II collagen correlated with the pathologic changes. These findings suggest that both steroidal and nonsteroidal anti-inflammatory drugs may have potential therapeutic value in the treatment of autoimmune ear disease.


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