scholarly journals Within-Subject Comparison of Word Recognition and Spiral Ganglion Cell Count in Bilateral Cochlear Implant Recipients

2014 ◽  
pp. 1 ◽  
Author(s):  
Mohammad Seyyedi ◽  
Lucas M. Viana ◽  
Joseph B. Nadol
Keyword(s):  
Word Recognition ◽  
Cochlear Implant ◽  
Ganglion Cell ◽  
Cell Count ◽  
Spiral Ganglion ◽  
Spiral Ganglion Cell ◽  
Bilateral Cochlear Implant ◽  
Subject Comparison

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.

Diameter of the Cochlear Nerve in Deaf Humans: Implications for Cochlear Implantation

1992 ◽  
Vol 101 (12) ◽  
pp. 988-993 ◽  
Author(s):  
Joseph B. Nadol ◽  
Wen-Zhuang Xu
Keyword(s):  
Ganglion Cell ◽  
Cell Count ◽  
Cochlear Implantation ◽  
Ganglion Cells ◽  
Cranial Nerves ◽  
Spiral Ganglion ◽  
Normal Hearing ◽  
Maximum Diameter ◽  
Eighth Nerve ◽  
Spiral Ganglion Cell

Although the parameters that are most important for postoperative speech perception in cochlear implantation have not been identified, it is assumed that the numbers of remaining cochlear neurons and spiral ganglion cells in the implanted deaf ears are critical. In this study, we evaluated the correlation of the maximum diameter of the cochlear and vestibular nerve trunks with the number of spiral ganglion cells in horizontal sections of the temporal bone of 42 patients who were profoundly deaf during life, and in 5 patients with normal hearing. The maximum diameters of the cochlear, vestibular, and eighth cranial nerves were significantly smaller in the deaf population as compared to normal-hearing controls. In addition, the counts of the remaining spiral ganglion cells were significantly correlated with the maximum diameter of the cochlear (p = .0006), vestibular (p = .001), and eighth cranial nerves (p = .0003). The regression equation estimated that 25% of the variance of the spiral ganglion cell count was predicted by the maximum diameter of the eighth nerve. Although the results of this study suggest that preoperative radiographic imaging of the diameter of the eighth nerve may be helpful in predicting the residual spiral ganglion cell count, the wide variability of diameters of the eighth nerve in hearing and deaf subjects militates against this theoretic usefulness.

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.

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.

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.

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