scholarly journals Meta-Analysis—Correlation between Spiral Ganglion Cell Counts and Speech Perception with a Cochlear Implant

2021 ◽  
Vol 11 (2) ◽  
pp. 220-226
Author(s):  
Yew-Song Cheng ◽  
Mario A. Svirsky
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Ganglion Cells ◽  
Meta Analysis ◽  
Spiral Ganglion ◽  
Spiral Ganglion Cell ◽  
Cell Counts ◽  
Temporal Bones ◽  
The Relationship ◽  
Existing Data

The presence of spiral ganglion cells (SGCs) is widely accepted to be a prerequisite for successful speech perception with a cochlear implant (CI), because SGCs provide the only known conduit between the implant electrode and the central auditory system. By extension, it has been hypothesized that the number of SGCs might be an important factor in CI outcomes. An impressive body of work has been published on findings from the laborious process of collecting temporal bones from CI users and counting the number of SGCs to correlate those numbers with speech perception scores, but the findings thus far have been conflicting. We performed a meta-analysis of all published studies with the hope that combining existing data may help us reach a more definitive conclusion about the relationship between SGC count and speech perception scores in adults.

S240 – Human Cochlear Implant Histopathology

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P155-P155
Author(s):  
Helen Xu ◽  
Natasha Pollak ◽  
Sebahattin Cureoglu ◽  
Michael M Paparella
Keyword(s):  
Cochlear Implant ◽  
Ganglion Cell ◽  
Cell Population ◽  
Ganglion Cells ◽  
Clinical Performance ◽  
Spiral Ganglion ◽  
Spiral Ganglion Cell ◽  
Cell Counts ◽  
Temporal Bones ◽  
Normal Spiral

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.

Effect of Cochlear Implantation on Residual Spiral Ganglion Cell Count as Determined by Comparison with the Contralateral Nonimplanted Inner Ear in Humans

2005 ◽  
Vol 114 (5) ◽  
pp. 381-385 ◽  
Author(s):  
Aayesha M. Khan ◽  
Ophir Handzel ◽  
Donald K. Eddington ◽  
Doris Damian ◽  
Joseph B. Nadol
Keyword(s):  
Cochlear Implant ◽  
Ganglion Cell ◽  
Cell Count ◽  
Ganglion Cells ◽  
Spiral Ganglion ◽  
Apical Segment ◽  
Spiral Ganglion Cell ◽  
Cell Counts ◽  
The Mean ◽  
Temporal Bones

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.

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.

Analysis of Intracochlear New Bone and Fibrous Tissue Formation in Human Subjects with Cochlear Implants

2007 ◽  
Vol 116 (10) ◽  
pp. 731-738 ◽  
Author(s):  
Peter M. M. C. Li ◽  
Mehmet A. Somdas ◽  
Donald K. Eddington ◽  
Joseph B. Nadol
Keyword(s):  
Word Recognition ◽  
Cochlear Implantation ◽  
Ganglion Cells ◽  
Human Subjects ◽  
Fibrous Tissue ◽  
Spiral Ganglion ◽  
Tissue Formation ◽  
Spiral Ganglion Cell ◽  
Cell Counts ◽  
Temporal Bones

Objectives: In this study we aimed to evaluate new bone and new fibrous tissue formation in the inner ear following cochlear implantation. Methods: Twelve temporal bones from patients who underwent cochlear implantation during life were prepared for histologic study. The specimens were reconstructed by both 2-dimensional and 3-dimensional methods. These reconstructions were used to calculate the total volume and distribution of new bone and new fibrous tissue in the cochlea, the number of spiral ganglion cells, and other histopathologic parameters. Clinical data, including the last-recorded word recognition scores, were obtained from the patients' medical records. Results: New bone and new fibrous tissue were found in all 12 specimens, particularly at the site of cochleostomy. There was a significant correlation between overall damage to the lateral cochlear wall and the total volume of intracochlear new tissue (Spearman rho = .853; p = .0004). The total volume of new tissue did not correlate with word recognition scores or spiral ganglion cell counts. Conclusions: These preliminary results suggest that the degree of damage to the lateral cochlear wall may play an important role in influencing the amount of new tissue formation following cochlear implantation. Intracochlear new tissue does not appear to be an important determinant of performance as measured by word recognition scores or the total number of remaining spiral ganglion cells.

Histopathology of Cochlear Implants in Humans

2001 ◽  
Vol 110 (9) ◽  
pp. 883-891 ◽  
Author(s):  
Joseph B. Nadol ◽  
Barbara J. Burgess ◽  
Bruce J. Gantz ◽  
Newton J. Coker ◽  
Darlene R. Ketten ◽  
...  
Keyword(s):  
Ganglion Cell ◽  
Cochlear Implantation ◽  
Single Channel ◽  
Spiral Ganglion ◽  
Electrode Array ◽  
Speech Comprehension ◽  
Spiral Ganglion Cell ◽  
Cell Counts ◽  
Significant Difference ◽  
Temporal Bones

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.

Survival of Scarpa's Ganglion in the Profoundly Deaf Human

1993 ◽  
Vol 102 (6) ◽  
pp. 425-428 ◽  
Author(s):  
Charlotte M. Chiong ◽  
Robert J. Glynn ◽  
Wen-Zhuang Xu ◽  
Joseph B. Nadol
Keyword(s):  
Ganglion Cell ◽  
Ganglion Cells ◽  
Linear Regression Analysis ◽  
Spiral Ganglion ◽  
Normal Hearing ◽  
Auditory Brain Stem Response ◽  
Spiral Ganglion Cell ◽  
Cell Counts ◽  
Profound Deafness ◽  
Scarpa's Ganglion

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.

Cochlear Nerve Stimulation With Optical Radiation

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P99-P99 ◽  
Author(s):  
Claus-Peter Richter ◽  
Andrew J Fishman ◽  
Agnella D Izzo
Keyword(s):  
Cochlear Implant ◽  
Ganglion Cells ◽  
Spiral Ganglion ◽  
Neural Prostheses ◽  
Cell Populations ◽  
Small Populations ◽  
Spiral Ganglion Cell ◽  
Implant Prosthesis ◽  
Stimulation Of

Problem Neural prosthetic devices are artificial extensions to the body that restore or supplement nervous system function that was lost during disease or injury. The devices stimulate remaining neural tissue with electric current, providing some input to the nervous system. Hereby, the challenge for neural prostheses is to stimulate remaining neurons selectively. However, electrical current spread does not easily allow stimulation of small neuron populations. In neural prostheses developments, particular success has been realized in the cochlear prostheses development. The devices bypass damaged hair cells in the auditory system by direct electrical stimulation of the auditory nerve. Stimulating discrete spiral ganglion cell populations in cochlear implant users’ ears is similar to the encoding of small acoustic frequency bands in a normal-hearing person's ear. In contemporary cochlear implants, however, the injected electric current is spread widely along the scala tympani and across turns. Consequently, stimulation of spatially discrete spiral ganglion cell populations is difficult. Methods Spiral ganglion cells in guinea pigs were stimulated with laser pulses from an Aculight Capella infrared laser. Results With our experiments we demonstrate that extreme spatially selective stimulation is possible using light. Conclusion Our long-term goal is to develop and build an optical cochlear implant prosthesis to stimulate small populations of spiral ganglion cells. Significance Our long-term goal is to develop and build an optical cochlear implant prosthesis to stimulate small populations of spiral ganglion cells. Support This project has been funded with federal funds from the National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Department of Health and Human Services, under Contract No. HHSN260-2006-00006-C / NIH No. N01-DC-6-0.

Otologic Histopathology of Fabry's Disease

1989 ◽  
Vol 98 (5) ◽  
pp. 359-363 ◽  
Author(s):  
Patricia A. Schachern ◽  
Michael M. Paparella ◽  
Donald A. Shea ◽  
Tae H. Yoon
Keyword(s):  
Temporal Bone ◽  
Ganglion Cells ◽  
Spiral Ganglion ◽  
Cell Loss ◽  
The Body ◽  
Spiral Ligament ◽  
Fabry’S Disease ◽  
Fabry's Disease ◽  
Temporal Bones ◽  
Spiral Ganglia

Fabry's disease is a rare progressive X-linked recessive disorder of glycosphingolipid metabolism. The accumulation of glycosphingolipids occurs in virtually all areas of the body, including the endothelial, perithelial, and smooth-muscle cells of blood vessels, the ganglion cells of the autonomic nervous system, and the glomeruli and tubules of the kidney. Although otologic symptoms have been described in these patients, to our knowledge there have been no temporal bone histopathologic reports. We describe the clinical histories, audiometric results, and temporal bone findings of two patients with this rare disorder. Both patients demonstrated a bilateral sloping sensorineural hearing loss audiometrically. Middle ear findings of seropurulent effusions and hyperplastic mucosa were seen in all four temporal bones. Strial and spiral ligament atrophy in all turns, and hair cell loss mainly in the basal turns, were also common findings. The number of spiral ganglion cells was reduced in all temporal bones; however, evidence of glycosphingolipid accumulation was not observed in the spiral ganglia.

scholarly journals The relationship between speech intelligibility and speech perception in cochlear implant patients

2018 ◽  
Author(s):  
N Freimann ◽  
D Polterauer ◽  
S Gollwitzer ◽  
J Müller ◽  
ME Schuster
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Speech Intelligibility ◽  
The Relationship

scholarly journals Neural Tissue Degeneration in Rosenthal’s Canal and Its Impact on Electrical Stimulation of the Auditory Nerve by Cochlear Implants: An Image-Based Modeling Study

2020 ◽  
Vol 21 (22) ◽  
pp. 8511
Author(s):  
Kiran Kumar Sriperumbudur ◽  
Revathi Appali ◽  
Anthony W. Gummer ◽  
Ursula van Rienen
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implants ◽  
Auditory Nerve ◽  
Ganglion Cells ◽  
Spiral Ganglion ◽  
Sensorineural Deafness ◽  
Neural Tissue ◽  
Neural Degeneration ◽  
Tissue Degeneration ◽  
Ganglion Neurons

Sensorineural deafness is caused by the loss of peripheral neural input to the auditory nerve, which may result from peripheral neural degeneration and/or a loss of inner hair cells. Provided spiral ganglion cells and their central processes are patent, cochlear implants can be used to electrically stimulate the auditory nerve to facilitate hearing in the deaf or severely hard-of-hearing. Neural degeneration is a crucial impediment to the functional success of a cochlear implant. The present, first-of-its-kind two-dimensional finite-element model investigates how the depletion of neural tissues might alter the electrically induced transmembrane potential of spiral ganglion neurons. The study suggests that even as little as 10% of neural tissue degeneration could lead to a disproportionate change in the stimulation profile of the auditory nerve. This result implies that apart from encapsulation layer formation around the cochlear implant electrode, tissue degeneration could also be an essential reason for the apparent inconsistencies in the functionality of cochlear implants.

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