Round Window Stimulation of the Cochlea (original) (raw)
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Electrical Stimulation of the Auditory System
The Human Auditory System - Basic Features and Updates on Audiological Diagnosis and Therapy, 2019
In many healthcare systems electrical stimulation of the human auditory system, using cochlear implants, is a common treatment for severe to profound deafness. This chapter will describe how electrical stimulation manages to compensate for sensory-neural hearing loss by bypassing the damaged cochlea. The challenges involved in the design and application of cochlear implants will be outlined, including the programming of clinical systems to suit the needs of implanted patients. Today's variety of patient will be reviewed: unilaterally and bilaterally implanted, bimodal users of a cochlear implant as well as a contralateral hearing aid, CROS device users having either asymmetrical hearing loss or single-sided deafness. Alternative devices such as auditory brainstem implants will be described, and additionally the more experimental auditory mid-brain implants and intraneural stimulation approaches. Research that is likely to bring medium term benefits to the clinical application of cochlear implants will also be described.
Hearing Research, 2014
Active middle ear implants (AMEIs) have been studied to overcome the limitations of conventional hearing aids such as howling, occlusion, and social discrimination. AMEIs usually drive the oval window (OW) by means of transmitting vibrational force through the ossicles and the vibrational force corresponding to sound is generated from a mechanical actuator. Recently, round window (RW) stimulation using an AMEI such as a floating mass transducer (FMT) to deliver sound to the cochlea has been introduced and hearing improvement in clinical use has been reported. Although previous studies demonstrated that the auditory response to RW stimulation was comparable to a sound-evoked auditory response, few studies have investigated the quantification of the physiologic performance of an AMEI through RW stimulation on the inner ear in vivo. There is no established relationship between the cochlear responses and mechanical stimulation to RW. The aim of this study is to assess the physiologic response in RW stimulation by an AMEI. The transferred energy through the RW to the inner ear could estimate the response corresponding to acoustic stimulation in order to quantify the AMEI output in the ossicular chain or OW stimulation. The parameters of the auditory brainstem responses (ABRs) were measured and compared based on stapes velocities similar enough to be regarded as the same for acoustic stimulation to the external auditory canal (EAC) and mechanical stimulation to the RW in an in vivo system. In conclusion, this study showed that the amplitudes and latencies of the ABRs of acoustic and RW stimulation showed significant differences at comparable stapes velocities in an in vivo system. These differences in the ABR amplitudes and latencies reflect different output functions of the cochlea in response to different stimulation pathways. Therefore, it is necessary to develop a new method for quantifying the output of the cochlea in the case of RW stimulation.
Electrical Stimulation of the Ear: Experimental Studies
Annals of Otology, Rhinology, and Laryngology, 1983
The possibility of stimulating the ear by way of an electrode on the round window in order to relieve tinnitus or to produce auditory sensations has been investigated experimentally in guinea pigs. The deleterious effects of DC currents applied to a normal cochlea clearly demonstrate that this means is unsuitable for use in relieving tinnitus in hearing patients. Although AC currents do not cause further damage in ears with the organ of Corti already destroyed by aminoglycosides, the effects of DC currents in such cases have still to be in vestigated before they can be recommended for the relief of tinnitus in totally deaf patients. Electrical stimulation of the round window combined with masking has made it possible to record responses of auditory neural elements from the eighth nerve to the auditory cortex. This technique could be promising for the basic study of the central auditory nervous system, both experimentally and clinically, and could lead to a more accurate evaluation of candidates for cochlear prostheses. ..uic.v.v^... ..w.., times during the stimulation, bringing about defi-From the Clinique Universitaire d'ORL et Laboratoire d'Audiologie Experimentale. Bordeaux. France. This work was supported hy grants from the Delegation Generate a la Recherche Scientifique et Technique (8I-P-U00) and from the Elablissenient Public Regional (Genie Bio-Medical-Audiologic. 1982).
Round Window Reinforcement-Induced Changes in Intracochlear Sound Pressure
Applied Sciences, 2021
Introduction: The round window membrane (RWM) acts as a pressure-relieving membrane for incompressible cochlear fluid. The reinforcement of the RWM has been used as a surgical intervention for the treatment of superior semicircular canal dehiscence and hyperacusis. The aim of this study was to investigate how RWM reinforcement affects sound pressure variations in the cochlea. Methods: The intracochlear sound pressure (ICSP) was simultaneously measured in the scala tympani (ST) and scala vestibuli (SV) of cadaveric human temporal bones (HTBs) in response to acoustic stimulation for three RWM reinforcement materials (soft tissue, cartilage, and medical-grade silicone). Results: The ICSP in the ST was significantly increased after RWM reinforcement for frequencies below 2 kHz. Between 400 and 600 Hz, all three materials demonstrated the highest median pressure increase. The higher the RWM stiffness, the larger the pressure increase: silicone (7 dB) < soft tissue (10 dB) < cartila...
Recent Developments in Bionic Hearing Restoration from the Round Window to the Inferior Colliculus
Otology Japan, 2009
INTRODUCTION Auditory restoration with implant technology has been a great success story in otology and the ultimate limits of the technology are still not known. Today there are a wide variety of approaches and auditory prostheses for restoration of hearing, each with a precise indication for specific degrees and sites of hearing loss (Figure 1). Modern auditory prostheses range from implants that impart mechanical energy to the cochlea (middle ear implants, MEIs) via the ossicular chain or bypass a damaged ossicular chain and vibrate the round window directly (round window implants, RWI). Cochlear implants (CIs) bypass damaged inner ear cells and electrically stimulate the auditory nerve within the cochlea. The auditory brainstem implant (ABI) bypasses a damaged cochlea and auditory nerve auditory and directly stimulate the brainstem nuclei. The inferior colliculus implant (ICI) or auditory midbrain implant (AMI) bypass damaged brainstem nuclei to stimulate the inferior colliculus...
The objective of this study was to present 5 years of surgical experience, and the extended results of hearing preservation (based on 3-year follow-up), with the Med-El Vibrant Soundbridge (VSB) in which the floating mass transducer (FMT) is placed directly against the round window membrane, and the fascia is used only as covering tissue to keep it in position. A retrospective survey of surgical and audiological data was conducted to evaluate the performance and stability of patient hearing, with audiometric measurements performed over fixed time intervals up to 36 months. 21 patients, aged 19–62 years (mean 48.4), with mixed or conductive, bilateral or unilateral hearing loss were included in this study. Surgical intervention involved monaural implantation of the Med-El VSB between 2006 and 2009. The results were assessed using pure tone audiometry. In 5 years of experience with the technique, no significant complications or device extrusion were observed except for two revision surgeries requiring FMT repositioning. In the 3-year follow-up, we observed stable hearing in the implanted ear. It is concluded that direct round window stimulation without interposed fascia is an alternative for patients with hearing impairment caused by chronic otitis media and/or lack of ossicles, especially after modified radical mastoid-ectomy. It allows good results in a selected group of patients, although further observation on a larger population is needed to confirm long-term validity and effectiveness. Keywords Hearing loss Á Middle ear implant Á Vibrant Soundbridge Á Round window implants Á Partial deafness treatment Á Radical cavity Á Cochlea
Otolaryngology Case Reports, 2020
Background: Previous studies in the field of cochlear implantation have proven that the use of electro-acoustic stimulation systems in patients with low frequency residual hearing results in improved speech perception scores compared to electric only stimulation. Unfortunately, many patients cannot use these systems because of inflammatory responses to the external ear piece of the system. In these cases, the substitution of low frequency acoustic stimulation through an external ear piece by mechanical stimulation with a middle ear implant could be a way to take advantage of the remaining residual hearing. Case: We report on a patient who was bilaterally implanted with a MED-EL Vibrant Soundbridge. After 12 years, her hearing loss had progressed such that she was acoustically indicated for electro-acoustic stimulation. Since she could not wear an external ear piece due to medical reasons, she was then implanted with a cochlear implant in addition to her middle ear implant on the right-hand side, hence benefitting from electro-mechanical stimulation in the right ear. For the follow-up period of 12 month her hearing loss was found stable, and speech perception results were satisfying. Conclusion: The ipsilateral use of a Vibrant Soundbridge in addition to a cochlear implant was found to be a feasible and save option for providing electro-mechanical auditory stimulation. Speech performance results comparable to electro-acoustic stimulation patients can be expected for patients with substantial low frequency residual hearing.
Electroacoustic cochlear stimulation advantages in severe-profound hearing loss
Hearing, Balance and Communication, 2019
Objectives: Electroacoustic stimulation allow very interesting performances mainly in noisy condition for bisyllabic words recognition. In this paper, we studied some very difficult timbric tasks in noise conditions. Methods: We studied 10 adult patients with Hybrid implants (group A-Hybrid implants) and 70 adult patients with traditional ones (group B-Traditional implants). We made the following tests in noise: (1) Bisyllabic words recognition; (2) Voice kinds recognition; and (3) Musical instruments recognition. Results: Mean results in quiet: test 1: 63% for group A, 42% for group B; test 2: 75% group A, 33% group B; test 3: 55% group A, 20% group B. We obtained a p < .05 for tests 2 and 3. Conclusions: Hybrid patients seem to have better results mainly in noisy timbric tasks. This should be explained by the better quality of low frequency stimulation. The presence of good residual hearing on low frequencies should orientate surgeons and audiologists to consider electroacoustic stimulation procedures.
Otology & Neurotology, 2009
Hypothesis: Mechanical stimulation of the round window (RW) with an active middle ear implant (AMEI) with and without experimentally induced stapes fixation (SF) results in equivalent electrophysiologic measures of cochlear microphonic (CM), compound action potential (CAP), and auditory brainstem response (ABR). Background: Where normal oval window functionality is mitigated, the RW provides a pathway to mechanically stimulate the inner ear. Methods: Measurements of the CM, CAP, and ABR were made in 5 ears of 4 chinchillas with acoustic stimulation and with application of the AMEI to the RW with and without experimentally induced SF using pure-tone stimuli (0.25Y20 kHz) presented at differing intensities (j20 to 80 dB SPL vs. 0.01 mV to 3.16 V). Results: Morphologies of the CM, CAP, and ABR were similar between acoustic and RW stimulation with and without SF. Stapes fixation increased CM thresholds relative to RW stimulation with-out fixation by a frequency-dependent 4-to 13-dB mV (mean, 7.9 T 3.2 dB mV). Although the thresholds changed with SF, CM sensitivities and amplitude dynamic range were identical to normal. The CAP in all conditions demonstrated equivalent decreasing amplitudes and increasing latency with decreasing intensity (decibel sound pressure level versus decibel millivolt). Stapes fixation increased the CAP thresholds at all frequencies, ranging from 9 to 24 dB mV (mean, 17.7 T 4.9 dB mV). Auditory brainstem response waveforms were preserved across experimental conditions. Conclusion: Mechanical stimulation of the RW in an animal model of SF generates functionally similar inputs to the cochlea as normal acoustic and RW mechanical inputs but with increased thresholds. With further study, AMEIs may provide a surgical option for correction of otosclerosis and ossicular chain disruption.