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

Li, Peter M. M. C.; Somdas, Mehmet Akıf; Eddington, Donald K.; Nadol, Joseph B.

doi:10.1177/000348940711601004

Cited by 117 publications

(160 citation statements)

References 22 publications

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“…There are known potential problems with cochleostomy, such as perilymph loss and acoustic trauma caused by drilling, especially at the thickest part of the promontory. The bone dust, if present, may lead to the formation of new bone within the cochlea [Li et al, 2007]. There is also a risk of initiating osseous spiral lamina injury, because perilymph is toxic to hair cells.…”

Section: Discussionmentioning

confidence: 99%

Results of Partial Deafness Cochlear Implantation Using Various Electrode Designs

et al. 2009

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Nineteen adults and 9 children who received a unilateral cochlear implant between 2002 and 2007 were included in the study. All subjects were preoperatively diagnosed with significant residual hearing in low frequencies, termed as ‘partial deafness’, and were implanted according to a 6-step round window surgical technique for partial deafness cochlear implantation. Hearing was preserved to a great extent in the partial deafness cochlear implantation (PDCI) group. After a short period following activation of the cochlear implant, highly significant improvement in the recognition of monosyllabic words was observed. With a developed round window surgical procedure and limited electrode insertion, hearing can be preserved in the majority of patients with partial deafness. PDCI is a feasible means of treating individuals who have good low-frequency hearing but severe to profound hearing loss in the mid to high frequencies.

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Section: Discussionmentioning

confidence: 99%

Results of Partial Deafness Cochlear Implantation Using Various Electrode Designs

et al. 2009

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“…Despite the long-term presence of a foreign body (the electrode) in the ampulla, there was no evidence of acute or chronic inflammation in the labyrinth and only minimal new bone formation (Li et al 2007) was observed. The stable back-voltage measurements and single-pulse responses indicate that neither the conductivity of the tissues nor the efficacy of afferent nerve stimulation changed significantly during the course of the experiment.…”

Section: Effects Of Chronic High-frequency Electrical Stimulationmentioning

confidence: 98%

Vestibuloocular Reflex Adaptation Investigated With Chronic Motion-Modulated Electrical Stimulation of Semicircular Canal Afferents

Lewis

Haburcakova

Gong

et al. 2010

Journal of Neurophysiology

141

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Lewis RF, Haburcakova C, Gong W, Makary C, Merfeld DM. Vestibuloocular reflex adaptation investigated with chronic motion-modulated electrical stimulation of semicircular canal afferents. J Neurophysiol 103: 1066 -1079, 2010. First published December 16, 2009 doi:10.1152/jn.00241.2009. To investigate vestibuloocular reflex (VOR) adaptation produced by changes in peripheral vestibular afference, we developed and tested a vestibular "prosthesis" that senses yaw-axis angular head velocity and uses this information to modulate the rate of electrical pulses applied to the lateral canal ampullary nerve. The ability of the brain to adapt the different components of the VOR (gain, phase, axis, and symmetry) during chronic prosthetic electrical stimulation was studied in two squirrel monkeys. After characterizing the normal yaw-axis VOR, electrodes were implanted in both lateral canals and the canals were plugged. The VOR in the canal-plugged/instrumented state was measured and then unilateral stimulation was applied by the prosthesis. The VOR was repeatedly measured over several months while the prosthetic stimulation was cycled between off, low-sensitivity, and high-sensitivity stimulation states. The VOR response initially demonstrated a low gain, abnormal rotational axis, and substantial asymmetry. During chronic stimulation the gain increased, the rotational axis improved, and the VOR became more symmetric. Gain changes were augmented by cycling the stimulation between the off and both low-and high-sensitivity states every few weeks. The VOR time constant remained low throughout the period of chronic stimulation. These results demonstrate that the brain can adaptively modify the gain, axis, and symmetry of the VOR when provided with chronic motion-modulated electrical stimulation by a canal prosthesis.

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“…Damage to the cochlea during surgery, including insertion trauma and effects of drilling, can cause growth of bone and fibrous tissue (Fayad et al, 2009;Li et al, 2007;Somdas et al, 2007). This, in turn, can form regions of high impedance around the implant array, altering the pathway that current must take to activate the auditory nerve (Hanekom, 2005).…”

Section: Misplacement and Obstructed Current Pathsmentioning

confidence: 99%

Probing the Electrode-Neuron Interface With Focused Cochlear Implant Stimulation

Bierer

2010

Trends in Amplification

116

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Cochlear implants are highly successful neural prostheses for persons with severe or profound hearing loss who gain little benefit from hearing aid amplification. Although implants are capable of providing important spectral and temporal cues for speech perception, performance on speech tests is variable across listeners. Psychophysical measures obtained from individual implant subjects can also be highly variable across implant channels. This review discusses evidence that such variability reflects deviations in the electrode-neuron interface, which refers to an implant channel's ability to effectively stimulate the auditory nerve. It is proposed that focused electrical stimulation is ideally suited to assess channel-to-channel irregularities in the electrode-neuron interface. In implant listeners, it is demonstrated that channels with relatively high thresholds, as measured with the tripolar configuration, exhibit broader psychophysical tuning curves and smaller dynamic ranges than channels with relatively low thresholds. Broader tuning implies that frequency-specific information intended for one population of neurons in the cochlea may activate more distant neurons, and a compressed dynamic range could make it more difficult to resolve intensity-based information, particularly in the presence of competing noise. Degradation of both types of cues would negatively affect speech perception.

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

Cited by 117 publications

References 22 publications

Results of Partial Deafness Cochlear Implantation Using Various Electrode Designs

Results of Partial Deafness Cochlear Implantation Using Various Electrode Designs

Vestibuloocular Reflex Adaptation Investigated With Chronic Motion-Modulated Electrical Stimulation of Semicircular Canal Afferents

Probing the Electrode-Neuron Interface With Focused Cochlear Implant Stimulation

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