Search

OBJECTIVES: To compare contralateral to ipsilateral stimulation with percutaneous and transcutaneous bone conduction implants. BACKGROUND: Bone conduction implants (BCIs) effectively treat conductive and mixed hearing losses. In some cases, such as in single-sided deafness (SSD), the BCI is implanted contralateral to the remaining healthy ear in an attempt to restore some of the benefits provided by binaural hearing. While the benefit of contralateral stimulation have been shown in at least some patients, it is not clear what cues or mechanisms contribute to this function. Previous studies have investigated the motion of the ossicular chain, skull, and round window in response to bone vibration. Here, we extend those reports by reporting simultaneous measurements of cochlear promontory velocity and intracochlear pressures during bone conduction stimulation with two common BCI attachments, and directly compare ipsilateral to contralateral stimulation. METHODS: Fresh-frozen whole human heads were prepared bilaterally with mastoidectomies. Intracochlear pressure (P(IC)) in the scala vestibuli (P(SV)) and tympani (P(ST)) was measured with fiber optic pressure probes concurrently with cochlear promontory velocity (V(Prom)) via laser Doppler vibrometry during stimulation provided with a closed-field loudspeaker or a bone conduction implant (BCI). Stimuli were pure tones between 120 – 10240 Hz, and response magnitudes and phases for P(IC) and V(Prom) were measured for air and bone conducted sound presentation. RESULTS: Contralateral stimulation produced lower response magnitudes and longer delays than ipsilateral in all measures, particularly for high frequency stimulation. Contralateral response magnitudes were lower than ipsilateral response magnitudes by up to 10–15 dB above ~2 kHz for a skin-penetrating abutment, which increased to 25–30 dB and extended to lower frequencies when applied with a transcutaneous (skin drive) attachment. CONCLUSION: Transcranial attenuation and delay suggest that ipsilateral stimulation will be dominant for frequencies over ~1 kHz, and that complex phase interactions will occur during bilateral or bimodal stimulation. These effects indicate a mechanism by which bilateral users could gain some bilateral advantage.

Beginning in the late 20th century, implantable hearing aids were developed and used as an alternative for individuals who were unable to tolerate conventional hearing aids. Since that time, several devices have been developed, with four currently remaining on the international market (Med‐el Vibrant Soundbridge, Envoy Esteem, Ototronix MAXUM, and Cochlear Carina). This review will briefly examine the history of middle ear implant development, describe current available devices, evaluate the benefits and limits of the technology, and consider the future directions of research in the field of implantable hearing aids.

HYPOTHESIS: Insertion of cochlear implant electrodes generates transient pressure spikes within the vestibular labyrinth equivalent to high intensity acoustic stimuli. BACKGROUND: Though cochlear implant (CI) surgery is regarded as having low-risk of impacting the vestibular system, several studies have documented changes in vestibular function after implantation. The mechanism of these changes is not understood. We have previously established that large, potentially-damaging pressure transients can be generated in the cochlea during electrode insertion, but whether pressure transients occur within the vestibular labyrinth has yet to be determined. Here, we quantify the exposure of the vestibular system to potentially-damaging pressure transients during CI surgery. METHODS: Five human cadaveric heads were prepared with an extended facial recess and implanted sequentially with eight different CI electrode styles via a round window approach. Fiber-optic sensors measured intralabyrinthine pressures in scala vestibuli (SV), scala tympani (ST), and the lateral semicircular canal (LSCC) during insertions. RESULTS: Electrode insertion produced a range of high-intensity pressure spikes simultaneously in the cochlea and LSCC with all electrodes tested. Pressure transients recorded were found to be significantly higher in the vestibular labyrinth than the cochlea and occurred at peak levels known to cause acoustic trauma. CONCLUSION: Insertion of CI electrodes can produce transients in intralabyrinthine fluid pressure levels equivalent to high-intensity, impulsive acoustic stimuli. Results from this investigation affirm the importance of atraumatic surgical techniques and suggest that in addition to the cochlea, the vestibular system is potentially exposed to damaging fluid pressure waves during cochlear implantation.

Hypothesis: A cochlear implant electrode within the cochlea contributes to the air-bone gap (ABG) component of postoperative changes in residual hearing after electrode insertion. Background: Preservation of residual hearing after cochlear implantation has gained importance as simultaneous electric-acoustic stimulation allows for improved speech outcomes. Postoperative loss of residual hearing has previously been attributed to sensorineural changes; however, presence of increased postoperative ABG remains unexplained and could result in part from altered cochlear mechanics. Here, we sought to investigate changes to these mechanics via intracochlear pressure measurements before and after electrode implantation to quantify the contribution to postoperative ABG. Methods: Human cadaveric heads were implanted with titanium fixtures for bone conduction transducers. Velocities of stapes capitulum and cochlear promontory between the two windows were measured using single-axis laser Doppler vibrometry and fiber-optic sensors measured intracochlear pressures in scala vestibuli and tympani for air- and bone-conducted stimuli before and after cochlear implant electrode insertion through the round window. Results: Intracochlear pressures revealed only slightly reduced responses to air-conducted stimuli consistent with previous literature. No significant changes were noted to bone-conducted stimuli after implantation. Velocities of the stapes capitulum and the cochlear promontory to both stimuli were stable after electrode placement. Conclusion: Presence of a cochlear implant electrode causes alterations in intracochlear sound pressure levels to air, but not bone, conducted stimuli and helps to explain changes in residual hearing noted clinically. These results suggest the possibility of a cochlear conductive component to postoperative changes in hearing sensitivity.

This study examined the safety and efficacy of a fully implantable active middle ear (AMEI) system. Outcome measures assessed AMEI performance compared with an optimally fitted conventional hearing aid (CHA). Fifty adults with stable, symmetric moderate-to-severe sensorineural hearing loss were implanted at 9 ambulatory settings. Consonant-Nucleus-Consonant (CNC) words, Bamford-Kowel-Bench Speech in Noise test (BKB-SIN), Abbreviated Profile of Hearing Aid Benefit (APHAB), and unaided hearing thresholds in the implanted ear were compared to baseline measures obtained using a personal CHA. Changes in thresholds were observed from pre- to 12-month postoperative assessments. CNC word scores decreased (within 10%), and the BKB-SIN showed no change from pre- to 12-month postoperative time points. The APHAB revealed improvement. Findings suggest no difference in performance between an appropriately fit CHA and the AMEI at 12 months. This study indicates AMEIs have the potential to help individuals who choose not to use CHAs.

HYPOTHESIS: Simulated otitis media with effusion reduces intracochlear pressures comparable to umbo velocity. BACKGROUND: Otitis media with effusion is a common cause of temporary hearing loss, particularly in children, that can produce conductive deficits of 30–40 dB. Previous studies have measured the effects of simulated effusion on ossicular mechanics; however, no studies have measured cochlear stimulation directly during effusion. Here, we compare pressures in the scala vestibuli and tympani to umbo velocity, before and after induction of simulated effusion in cadaveric human specimens. METHODS: Eight cadaveric, hemi-cephalic human heads were prepared with complete mastoidectomies. Intracochlear pressures were measured with fiber optic pressure probes, and umbo velocity measured via laser Doppler vibrometry (LDV). Stimuli were pure tones (0.1 – 14 kHz) presented in the ear canal via a custom speculum modified to accept speaker and microphone tubing, and sealed with a glass cover slip. Effusion was simulated by filling the mastoid cavity and middle ear space with water. RESULTS: Acoustic stimulation with middle ear effusion resulted in decreased umbo velocity up to ~26 dB, whereas differential pressure at the base of the cochlea, the driving force to the basilar membrane, decreased by only ~16 db. CONCLUSION: Simulating effusion leads to a frequency-dependent reduction in intracochlear sound pressure levels consistent with audiological presentation and prior reports. Results reveal that intracochlear pressure measurements (P(SV) & P(ST)) decrease less than expected, and less than the decrease observed in the differential pressure (P(Diff)). The observed decrease in umbo velocity is greater than in the differential intracochlear pressures, suggesting that umbo velocity overestimates the induced conductive hearing loss. These results suggest that an alternate sound conduction pathway transmits sound to the inner ear during effusion.

Hypothesis Cochlear implants (CIs) designed for hearing preservation will not alter mechanical properties of the middle and inner ears as measured by intracochlear pressure (P(IC)) and stapes velocity (Vstap). Background CIs designed to provide combined electroacoustic stimulation are now available. To maintain functional acoustic hearing, it is important to know if a CI electrode can alter middle or inner ear mechanics because any alteration could contribute to elevated low-frequency thresholds in electroacoustic stimulation patients. Methods Seven human cadaveric temporal bones were prepared, and pure-tone stimuli from 120 Hz to 10 kHz were presented at a range of intensities up to 110 dB sound pressure level. P(IC) in the scala vestibuli (P(SV)) and tympani (PST) were measured with fiber-optic pressure sensors concurrently with VStap using laser Doppler vibrometry. Five CI electrodes from two different manufacturers with varying dimensions were inserted via a round window approach at six different depths (16-25 mm). Results The responses of P(IC) and VStap to acoustic stimulation were assessed as a function of stimulus frequency, normalized to sound pressure level in the external auditory canal, at baseline and electrode-inserted conditions. Responses measured with electrodes inserted were generally within approximately 5 dB of baseline, indicating little effect of CI electrode insertion on P(IC) and VStap. Overall, mean differences across conditions were small for all responses, and no substantial differences were consistently visible across electrode types. Conclusion Results suggest that the influence of a CI electrode on middle and inner ear mechanics is minimal despite variation in electrode lengths and configurations.

HYPOTHESIS Bone-anchored hearing systems (BAHSs) provide sound location-dependent input to the normal ear for reducing the head shadow effect in the case of single-sided deafness (SSD). BACKGROUND Patients with SSD can be fit with a BAHS positioned on the impaired side. Despite successful outcomes and some reports of spatial hearing capabilities, little data are available regarding the physiologic performance of BAHSs in response to free-field sounds. METHODS Cochlear microphonics (CMs) were recorded from five chinchillas before and after destruction of one cochlea. A BAHS (Cochlear Baha) was fitted on the deafened side. CM measurements were made in response to tones, with and without the BAHS, to free-field sounds presented ipsilateral to the SSD, on the side of the normal ear, and along the midline. Stimuli were also presented directly through the BAHS and an earphone to generate sounds with interaural time and level differences approximating free-field sounds. RESULTS With the BAHS, CM thresholds were decreased (re: no BAHS) by approximately 10 dB for sources ipsilateral to the SSD, approximately 14 dB for midline sources, and approximately 5 dB for sources contralateral to the SSD. Changes in CM amplitudes and thresholds were sound location dependent. CM amplitudes were modulated by interaural time and level differences generated by the linear interaction of BAHS and acoustic signals. CONCLUSION This study suggests that BAHS can provide input to the normal ear that is modulated by sound location, which serves to reduce the head shadow effect and may also offer cues to sound location.

Long-term retained foreign bodies in the human body have been reported across many specialties, but relatively few exist in the ENT literature.We present a case report of a patient with a broken dental needle fragment in the posterior oral cavity with subsequent migration to the cochlea over the course of 4 years, eventually leading to hearing loss. CT scan and middle ear exploration demonstrated a 4-cm metallic fragment abutting the base of the cochlea, immediately adjacent to the internal carotid artery.The needle segment was removed through an endaural approach without complication.Postoperatively, the patient had improvements in PTA and speech discrimination, as well as the resolution of chronic otalgia and jaw pain. Imaging, audiologic results, and surgical details and pictures are presented herein.To our knowledge, based on a thorough PubMed and Google Scholar search, there are no reports of such a foreign body migration from the oral cavity to the skull base.

Mechanical stimulation through a cochlear third window into the scala tympani in a chinchilla model with normal and fixed stapes can generate cochlear responses equivalent to acoustic stimuli.Cochlear stimulation via the round window (RW) using active middle ear implants (AMEIs) can produce physiologic responses similar to acoustic stimulation including in a model of stapes fixation. However, pathologic conditions, such as advanced otosclerosis, can preclude delivery of sound energy to the cochlea through the oval window and/or the RW.Cochlear microphonic (CM) and laser Doppler vibrometer measurements of stapes and RW velocities were performed in 6 ears of 4 chinchillas. Baseline measurements to acoustic sinusoidal stimuli (0.25-8 kHz) were made. Measurements were repeated with an AMEI driving the RW or a third window to the scala tympani before and after stapes fixation.AMEI stimulation of the third window produced CM waveforms with morphologies similar to acoustic stimuli. CM thresholds with RW and third-window stimulation were frequency dependent but ranged from 0.25 to 10 and 0.5 to 40 mV, respectively. Stapes fixation, confirmed by laser Doppler vibrometer measurements, resulted in a significant frequency dependent impairment in CM thresholds up to 13 dB (at3 kHz) for RW stimulation and a nonsignificant frequency-dependent improvement of up to 10 dB (at3 kHz) via third-window stimulation.AMEI mechanical stimulation through a third window into the scala tympani produces physiologic responses nearly identical to acoustic stimulation including in a model of stapes fixation with decreased efficiency.

Objective To compare the speech understanding abilities of cochlear implant listeners using 2 microphone technologies, the Otologics fully implantable Carina and the Cochlear Freedom microphones. Study design Feasibility study using direct comparison of the 2 microphones, nonrandomized and nonblinded within case studies. Setting Tertiary referral center hospital outpatient clinic. Patients Four subjects with greater than 1 year of unilateral listening experience with the Freedom Cochlear Implant and a CNC word score higher than 40%. Intervention A Carina microphone coupled to a percutaneous plug was implanted on the ipsilateral side of the cochlear implant. Two months were allowed for healing before connecting to the Carina microphone. The percutaneous plug was connected to a body worn external processor with output leads inserted into the auxiliary port of the Freedom processor. Subjects were instructed to use each of the 2 microphones for half of their daily implant use. Main outcome measures Aided pure tone thresholds, consonant-nucleus-consonant (CNC), Bamford-Kowel-Bench Speech in Noise test (BKN-SIN), and Abbreviated Profile of Hearing Aid Benefit. Results All subjects had sound perceptions using both microphones. The loudness and quality of the sound was judged to be poorer with the Carina in the first 2 subjects. The latter 2 demonstrated essential equivalence in the second two listeners, with the exception of the Abbreviated Profile of Hearing Aid Benefit reporting greater percentage of problems for the Carina in the background noise situation for subject 0011-003PP. CNC word scores were better with the Freedom than the Carina in all 4 subjects. The latter 2 showed improved speech perception abilities with the Carina, compared with the first 2. The BKB-SIN showed consistently better results with the Freedom in noise. Conclusion Early observations indicate that it is potentially feasible to use the fully implanted Carina microphone with the Freedom Cochlear Implant. The authors would anticipate that outcomes would improve as more knowledge is gained in signal processing and with the fabrication of an integrated device.

Purpose: This paper presents longitudinal case studies of children who received (cochlear implants) CIs and a controlled sample of children with normal hearing (NH). Phoneme discrimination (i.e., /sa-ma/, /a-i/, /a-u/, /u-i/, /ta-da/, /pa-ka/) was assessed prior to receiving CIs and monthly for 3 mo following CI activation. Research Design: Case studies. Study Sample: Three cochlear implant recipients and seven NH control participants were recruited through the University of Colorado Hospital and the University of Colorado, Boulder. Data Collection and Analysis: The study utilized the visual reinforcement audiometry and interactive play assessment of speech pattern contrasts (VRASPAC) algorithm. A comparison of scoring was conducted using Cohen's kappa to determine interrater reliability. Results: Findings from this study revealed that CI recipients could discriminate at least three out of five phoneme contrasts at mastery level (≥90%) by 2 mo of device use. None of the CI recipients reached mastery prior to implantation. Following 3 mo of CI use there was no difference in contrast discrimination performance between the CI users and their NH age-matched peers (with the exception of /pa-ka/ for one CI user). Conclusions: The CI users in this case study, who were implanted between 12 and 16 mo of age, were able to master the phoneme contrasts regardless of bilateral or unilateral CI, socioeconomic status, or language spoken at home.

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 (0.25-20 kHz) presented at differing intensities (-20 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 without fixation by a frequency-dependent 4- to 13-dB mV (mean, 7.9 +/- 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 +/- 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.

Pruritus, the subjective sensation of itch, can be a difficult symptom to assess and treat. Evaluating levels of patient discomfort across populations has proven to be challenging because of a lack of a standardized measurement tool to quantify levels of itch. The most widely used tool is the 4-point verbal rating scale (VRS-4), but others use an 11-point verbal numeric rating scale (VNRS-11). Therefore, the purpose of our study was to correlate a VNRS-11 to a VRS-4 for the assessment of pruritus. Fifty parturients were enrolled in this correlational study. Each subject's level of pruritus was measured at five specific intervals after administration of intrathecal opioids. The scales were administered one minute apart in random order. Data analysis demonstrated a strong correlation between these two scales, (r=.910 to .853) indicating that each verbal descriptor on the VRS-4 could readily be substituted with a quantifiable range on the VNRS-11.

Objectives The safety of the Otologics Fully-Implantable MET Ossicular Stimulator was assessed in adult patients with bilateral moderate to severe sensorineural hearing loss. Methods Surgical implantation of the ossicular stimulator was performed. A repeated-measure, within-subjects design assessed safety and aided sound field thresholds and speech performances with the subject’s own, appropriately fitted, walk-in hearing aid(s) and the Otologics Fully-Implantable MET Ossicular Stimulator. Results Twenty patients were implanted and activated as part of the Phase I clinical trial. Results demonstrated 10-20 dB of functional gain across audiometric frequencies. Pure tone averages and monaural word recognition scores were slightly better for the walk-in−aided condition, while patient benefit scales favored the postoperative implant-aided conditions. Conclusion/Significance Although monaural word scores and aided thresholds favored the walk-in−aided condition, preliminary results indicate that the Otologics MET Fully-Implantable Ossicular Stimulator is an alternative to currently available hearing aids in patients with sensorineural hearing loss.

HYPOTHESIS The goal of this study was to measure the tissue vibration amplitude that would be associated with an implantable microphone. BACKGROUND Totally implantable hearing devices have been desired by the hard-of-hearing community for some time. However, an implanted microphone must pick up desired acoustic signals in the presence of undesired signals, including vibration. To design an effective microphone, the level of tissue vibrations originating from anatomical sources and the implanted transducer must be understood. METHODS Using a laser Doppler vibrometer and an accelerometer, tissue vibrations were measured under the following conditions: (1) Normal control subjects during vocalization (n=4); (2) Vocalization and biological sounds measured on cranium and in soft tissue on normal subjects (n=6); (3) Transducer vibration measured on Otologics semi-implantable hearing device wearer (n=1) and human cadavers (n=4 ears). RESULTS Anatomical noise vibrations are 20 to 25 dB greater in soft tissue for frequencies less than 1,000 Hz than on the cranium, whereas vibrations due to implanted transducers are 20 to 25 dB greater on the cranium than in soft tissue inferior to the mastoid. Chewing vibrations are 10 to 15 dB greater than vocalization on the mastoid. Mastoid vibration levels measured in patients are equivalent to those in cadavers. Vibration levels do not vary significantly with respect to location on the cranium next to the pinna. CONCLUSION The greatest anatomical vibrations that an implanted microphone must overcome are because of vocalization in the soft tissue inferior to the mastoid and chewing vibrations on the mastoid. A human cadaver is an appropriate model for transducer cranial vibration studies. If the implantable microphone is placed on the cranium near the pinna, it makes little difference with regard to actual location.

HYPOTHESIS Intracochlear sound pressures (PIC) and velocity measurements of the stapes, round window, and promontory (VStap/RW/Prom) will show frequency-dependent attenuation using magnet-based transcutaneous bone conduction implants (TCBCIs) in comparison with direct-connect skin-penetrating implants (DCBCIs). BACKGROUND TCBCIs have recently been introduced as alternatives to DCBCIs. Clinical studies have demonstrated elevated high-frequency thresholds for TCBCIs as compared with DCBCIs; however, little data exist examining the direct effect of skin thickness on the cochlear input signal using TCBCIs. METHODS Using seven cadaveric heads, PIC was measured in the scala vestibuli and tympani with fiber-optic pressure sensors concurrently with VStap/RW/Prom via laser Doppler vibrometry. Ipsilateral titanium implant fixtures were placed and connected to either a DCBCI or a TCBCI. Soft tissue flaps with varying thicknesses (no flap and 3, 6, and 9 mm) were placed successively between the magnetic plate and sound processor magnet. A bone conduction transducer coupled to custom software provided pure-tone stimuli between 120 and 10,240 Hz. RESULTS Stimulation via the DCBCI produced the largest response magnitudes. The TCBCI showed similar PSV/ST and VStap/RW/Prom with no intervening flap and a frequency-dependent nonlinear reduction of magnitude with increasing flap thickness. Phase shows a comparable dependence on transmission delay as the acoustic baseline, and the slope steepens at higher frequencies as flap thickness increases, suggesting a longer group delay. CONCLUSION Proper soft tissue management is critical to optimize the cochlear input signal. The skin thickness-related effects on cochlear response magnitudes should be taken into account when selecting patients for a TCBCI.

Chronic otitis media was previously a contraindication to cochlear implantation. In recent years, potential benefits of implantation in deaf children with chronic suppurative otitis media has fueled new approaches to this treatment dilemma. We review the current and historical literature, analyze the risk and benefits, and perioperative treatments and operative techniques to improve outcomes and minimize complications of cochlear implantation in children with chronic suppurative otitis media. We conclude that cochlear implantation in children with chronic suppurative otitis media is a viable therapy if adequate and meticulous preoperative and perioperative management is undertaken.

Cavernous hemangiomas are rare lesions that may be difficult to distinguish from acoustic neuromas, schwannomas, or other lesions of the cerebellopontine angle on imaging studies. The clinical history, workup including radiologic evaluation, histologic assessment, and a brief review of the literature are presented.

This study was conducted to demonstrate the safety and efficacy of the Otologics Middle Ear Transducer (MET) Ossicular Stimulator and, in particular, to compare the audiologic benefits of this novel form of electromechanical stimulation with those of conventional acoustical amplification.A total of 282 patients were implanted with the device in Europe and the USA. Pure-tone audiometry, speech recognition and subjective assessment of benefit were tested before the surgery and 2, 3, 6 and 12 months afterwards. The US patients were fitted with a digital hearing aid for a minimum of 4 weeks prior to surgery, and the same benefit measures were performed with the digital hearing aid and their "walk-in" hearing aid.Group mean postoperative bone and air conduction thresholds did not change significantly from preoperative levels. Postoperative air conduction thresholds decreased slightly in some individual patients, due to the mass loading effect exerted by the transducer on the ossicles. Sufficient gain was available to reach target prescription levels for moderate to severely impaired hearing individuals. Speech and subjective assessment of patient preference indicated that patients did as well or better with the MET Ossicular Stimulator than with their "walk-in" aid or the standardized digital aid.The capability of the MET Ossicular Stimulator to provide appropriate gain as a function of degree of hearing loss indicates that the device is a viable treatment for moderate to severe sensorineural hearing loss in adults.

Objectives/Hypothesis: Delayed-onset facial paralysis (beginning more than 3 d after the procedure) has been described as a complication of many different types of otological procedures. The incidence of this problem in vestibular neurectomy and the relationship to surgical approach are detailed in the study. Study Design: Retrospective case review. Methods: In the setting of a tertiary referral center, vestibular neurectomy was performed in 70 individuals with disabling vertigo unresponsive to medical therapy who elected vestibular neurectomy. The main outcome measure was incidence of delayed onset facial paralysis. Results: Delayed-onset facial paralysis was significantly more common after the middle fossa (18%) and translabyrinthine (11%) approaches compared with the retrosigmoid approach (0%) Conclusions: Surgical approach influences the incidence of delayed-onset facial paralysis. Measures to prevent this complication such as prophylactic antiviral medication or labyrinthine segment decompression may be considered in middle fossa and translabyrinthine operations.

In order to determine which variables influence recovery from acoustic neuroma resection, acutely postoperative patients were divided into two groups and treated twice daily at bedside as inpatients at a tertiary care center. Treatment times were increased gradually from 5 to 30 min. Exercise subjects underwent passive and active head movements and walking with augmented head movements. Control subjects received attention without exercise. Pre- and post-tests included vertigo intensity and frequency, low-frequency vestibulo-ocular reflex (VOR), posturography and path integration. Post-tests were given at discharge and at approximately 4-week intervals for 3 months. Multilevel statistical analyses showed that neither group assignment nor age affected the outcome. All measures were abnormal at discharge but improved towards normal within 3 weeks. VOR on the unoperated side returned to normal values but on the lesioned side did not. Therefore, compensation is influenced by tumor size but not by age or early postoperative vestibular rehabilitation. Most compensation occurs within 3 weeks, probably due to central mechanisms, although some measures may not recover completely.

This article describes outcomes for the Otologics active middle ear implant for the semi-implantable and fully implantable (Carina, Otologics LLC, Boulder, CO) devices. Inclusion and exclusion criteria are reported in detail for surgical and audiologic management. Results from the clinical trial demonstrated no change for unaided air and bone conduction thresholds and no significant change in monosyllabic word scores or sentences in noise. Experiments are reported for conductive and mixed types of hearing losses in animal and human cadaveric models. These devices are in their infancy, and further study is needed to better identify candidates and develop appropriate expectations.

Long-term changes in the parameters of the vestibulo-ocular reflex (VOR) were evaluated using recently developed multilevel statistical modelling techniques in a group of patients who had undergone ablative inner ear procedures. Data from 84 patients were available for study. The most dramatic recovery in the VOR occurred during the first 60 postoperative days, however, slow changes continued, levelling off at about 120 days. While frequency was a highly significant predictor of outcomes in all parameters, age showed significant predictive value only to phase measures (p = 0.006) and gender had no effect. Sum gain at the lowest frequency tested remained below the 5th percentile and at the higher frequencies remained below the 50th percentile for normal subjects. Phase decreased exponentially, but remained above the 95th percentile for normal subjects, except at the highest frequency where it remained above the 50th percentile. DC bias decreased exponentially, dropping to the 50th percentile by day 146. Asymmetry stayed between the 50th and 95th percentile, except at the highest frequency, where it was at the 50th percentile by day 125.

Physiology and Biophysics Departments, University of Colorado School of Medicine,Aurora, Colorado, U.S.A.Hypothesis: Active middle ear implant (AMEI) generatedvibromechanical stimulation of the ossicular chain (ossicularchain vibroplasty [OCV]) or the round window (round windowvibroplasty [RWV]) is not significantly affected by simulatedmiddle ear effusion in a human temporal bone model.Background: OCV and RWV may be employed for sensori-neural, mixed, and conductive hearing losses. Although middleeareffusionsmaybeencounteredacrosspatientpopulations,littleisknownabouthoweffusionsmayaffectAMEIvibromechanicalefficiency.Methods: Laser Doppler vibrometry of stapes velocities (SVs)were performed in a human temporal bone model of simulatedeffusion (N = 5). Baseline measurements to acoustic sinusoidalstimuli, OCV, and RWV (0.25Y8 kHz) were made without ef-fusion. The measurements were repeated with simulated middleear effusion and compared with baseline measurements. Datawere analyzed across 3 frequency bands: low (0.25Y1 kHz),medium (1Y3 kHz), and high (3Y8 kHz).Results: Acousticstimulation withsimulated middle ear effusionresulted in a significant (p G0.001) frequency-dependent atten-uation of SVs of 4, 10, and 7 dB (low, medium, and high ranges,respectively). OCV in simulated effusion resulted in attenuatedSVs of 1, 5, and 14 dB (low, medium, and high) compared towithout effusion; however, this attenuation was not significant(p = 0.07). Interestingly, in the setting of RWV, simulated effu-sion resultedinsignificantly(p =0.001)increased SVsof16,11,and 8 dB (low, medium, and high). A 3-dB variance in AMEIefficiency was observed in repeated measurements in a singletemporal bone.Conclusion: The efficiency of OCV was not significantly af-fected by the presence of a middle ear effusion. Improved effi-ciency, however, was observed with RWV. Key Words: Activemiddle ear implantVLaser Doppler vibrometryVMiddle eareffusionVTemporal bone.Otol Neurotol 35:470Y475, 2014.

Hypothesis: Coupling and placement of actuators onto the ossicular chain have a significant influence on active middle ear implant (AMEI) performance. Background: AMEIs have proved to be effective in treating moderate-to-severe sensorineural hearing loss as well as mixed and conductive loss. Here, we assess the effect on performance of an AMEI prosthesis using 5 different methods of coupling to the ossicular chain in 6 temporal bones. Methods: The AMEI provided direct vibratory stimuli to the incus using the following methods: 1) tip of the transducer in contact with incus body (baseline condition), 2) tip of the transducer placed in a laser-drilled hole in the incus body, 3) the aWengen clips (straight and articulated) crimped to the transducer and attached to the incus long process, 4) a 0.5-mm diameter cylinder placed in contact with the incus long process, and 5) a bell-shaped prosthesis in contact with the head of the stapes. Performance in each condition was assessed by measuring the resultant stapes velocities (HEV) from which the maximum equivalent ear canal sound pressure levels (LEmax) were computed. Results: Relative to the baseline condition, which produced LEmax of 112 to 126 dB SPL for frequencies of 0.25 to 8 kHz, the other coupling methods produced similar or substantially improved (increased LEmax) performance. Best performance was achieved by providing vibratory stimulation to the head of the stapes directly with the bell-shaped tip where performance improved significantly by 16 to 22 dB. Conclusion: Stapes velocities produced by AMEI transducers may be increased depending on the tip used to couple the transducer to the ossicular chain and the placement of the stimulating tip along the incus. Improvement in coupling the transducer to the incus and stapes produced significant improvements in the transfer of vibratory stimuli to the ossicular chain.

The sinus tympani (ST) is a critical anatomic region of the temporal bone. It lies medial to the facial nerve, between the ponticulus and the subiculum, and therefore is not easily visualized by routine surgical approaches to the middle ear and mastoid. This limited access makes the ST a site that is notorious for residual cholesteatoma. An extensive evaluation of the anatomic dimensions of the ST was made from human temporal bones. Three hundred twenty-seven bones were examined at four standardized levels to describe the dimensions and anatomic relationships of the ST with other structures of the temporal bone. The region of the stapedial tendon was found to be the most limited anatomic substructure in the vicinity of the ST. This study demonstrates the feasibility of a retrofacial approach to the ST as an aid in eradication of otherwise hidden disease.

Objective: The purpose of this study was to determine the level of disability among patients with Meniere's disease, information needed by clinicians when evaluating patients for coverage under the Americans With Disabilities Act. We hypothesized that the unpredictability of vertiginous episodes or "Meniere's attacks" would be the most disabling problem, combined with the lack of a safe place to sit down during Meniere's attacks. Design: All patients seen in the otolaryngology faculty practice at Baylor College of Medicine, Houston, Tex, and diagnosed as having Meniere's disease over a 3-year period were sent a self-administered questionnaire. Setting: This practice is located at a tertiary care center. Subjects: One hundred forty-nine potential subjects constituted the pool, from which data from 50 subjects provided complete data sets. Results: The data from 50 adults suggested that the most problematic symptom was vertigo, followed by hearing loss. The unpredictability of Meniere's attacks and the lack of a safe place to rest during attacks was a significant problem for few subjects. (Arch Otolaryngol Head Neck Surg. 1995;121:29-33)

Biochemical and pharmacologic studies suggest a role for the ornithine decarboxylase-polyamine system as a modulator of behavioral changes during vestibular compensation. alpha-Difluoromethylornithine specifically blocks the rate-limiting step of polyamine biosynthesis. To assess the effects of alpha-difluoromethylornithine on the acute phase of postural compensation, guinea pigs were divided into groups subjected to either unilateral labyrinthectomy only (n = 7), alpha-difluoromethylornithine (500 mg/kg/day) for 4 days before labyrinthectomy (n = 10), equivalent volumes of saline for 4 days before labyrinthectomy (n = 8), and sham operations (n = 5). Yaw head tilt and roll head tilt, trunk curvature, and air-righting reflex were measured at baseline and at regular intervals up to 4 weeks. alpha-Difluoromethylornithine significantly delayed recovery of normal air-righting but had no effect on yaw head tilt, roll head tilt, and trunk curvature. We also evaluated effects of alpha-difluoromethylornithine in compensated guinea pigs. Fully compensated animals from phase 1 were randomly assigned to receive alpha-difluoromethylornithine (500 mg/kg/day) or saline once daily for 4 days. Only 33% of alpha-difluoromethylornithine animals maintained air-righting, compared with 100% of saline-treated animals (p = 0.003). Maximum trunk curvature was greater in the alpha-difluoromethylornithine group (p = 0.02). Thus alpha-difluoromethylornithine not only delayed the time course for postural recovery after unilateral labyrinthectomy, it also transiently disrupted the maintenance of the compensated state.

To study the effects of various active middle ear implant loading parameters on round window stimulation in an animal model.Physiological measurements of the cochlear microphonic and stapes velocity were made from active middle ear implant-generated sinusoidal stimuli with controlled changes in loading parameters.Prospective study at an academic research institution.Cochlear microphonic and stapes velocities (H(EV)) were measured in 6 study subjects (Chinchilla lanigera) in response to active middle ear implant (Otologics MET, Boulder, Colorado) round window stimulation with assessment of effects of varying parameters of loading pressure, interposed connective tissue, and angle of stimulation with respect to the round window membrane.The measured performance variabilities in repeated applications of the active middle ear implant to the round window were 2.5 dB and 5.0 dB for H(EV) and cochlear microphonic thresholds, respectively. Loading pressure applied to the round window (51-574 dynes) and angle of approach (±30° with respect to coronal plane) did not have a significant effect on cochlear microphonic thresholds or H(EV). Significant improvements in cochlear microphonic thresholds and H(EV) were observed for interposed connective tissue regardless of tissue type.Variability in performance due to repeated couplings of the active middle ear implant to the round window is small and reproducible. Interposition of connective tissue significantly improves vibration energy transfer to the cochlea. Neither changes in loading pressure nor angle of stimulation of the round window affected active middle ear implant performance.

Because of the diminishing number of patients diagnosed with otosclerosis, the adequacy of residency training in stapedectomy techniques remains controversial. A prospective study, conducted from 1986 to 1991, assessed whether or not surgical outcome obtained by residents, under close supervision by otologic faculty, could be improved using a single stapedectomy technique. Comparison of pre- and postoperative hearing results (pure-tone averages of 500, 1000, and 2000 Hz) from 49 cases revealed closure of the air-bone gap to within 10 dB in 68 percent of procedures. Complications included failure to improve the conductive hearing loss, tympanic membrane perforations, transient facial nerve weakness, subluxation of the incus, and adhesions. The failure to improve the success rate in resident-performed procedures relates to the individual learning curve and the limited number of training cases.

HYPOTHESIS Driving the oval window directly with an active middle ear implant (AMEI) can produce high levels of input to the inner ear. BACKGROUND Treatment of otosclerosis bypasses the stapes with a piston that penetrates the vestibule. Although this treats the conductive component of hearing loss, it does not treat the sensorineural part, which can be improved using an additional conventional hearing aid. Active middle ear implants have been proposed to be an alternative in treating otosclerosis in cases of mixed hearing losses. METHODS Seven temporal bones were prepared to expose the stapes and round window (RW). Stapes and RW velocities were measured while driving with an AMEI the stapes head with a bell-shaped tip. The stapes footplate was then fixed with acrylic cement; fixation was confirmed through attenuated RW velocities. A cylinder tip (0.5 mm) was then used to drive the inner ear through a stapedotomy with and without interposition of fascia. RESULTS Driving the stapes with an AMEI produced mean maximum equivalent ear canal sound pressure levels (SPL) of 138 dB (0.25-8 kHz at 1 V [RMS]). Stapes fixation caused a approximately 25-dB attenuation. Driving with a cylinder tip through the stapedotomy produced 114 dB SPL (24 dB less than normal) and 110 dB SPL (28 dB less than normal) performance with and without fascia, respectively. Performance with fascia was greater than without. CONCLUSION Driving the oval window with an AMEI in a scenario of stapes fixation was demonstrated to be feasible, with performance comparable to traditional AMEI coupling to the incus or stapes. These possibilities offer new perspectives to treat mixed hearing loss in case of fixed footplate.

• The temporal bone histopathologic findings of a patient having received a Nucleus 22-channel cochlear implant (Cochlear Corp, Englewood, Colo) following bilateral transverse otic capsule fractures is presented. The case was complicated by perilymph fistulas, labyrinthitis, meningitis, and death due to drowning. The left cochlea revealed complete labyrinthitis ossificans; the implanted right cochlea demonstrated new bone formation in the basal turn of the scala tympani, degeneration of the organ of Corti, but normal ganglion cell counts. Results of psychophysical and speech perception 4 months after implantation are presented. ( Arch Otolaryngol Head Neck Surg. 1992;118:1257-1265)

The basic electonystagmography battery (saccade, gaze, position, caloric tests, and spontaneous nystagmus) are described along with rotational testing and dynamic posturography. Emphasis is« placed on interpretation, relative benefits, and limitations as an aid in diagnosis.

ObjectiveThe efficacy of the Otologics Fully Implantable Hearing Device (MET) was assessed in adult patients with bilateral moderate to severe sensorineural hearing loss.MethodsSurgical insertion of this totally implanted system was identical to the Phase I study. A repeated-measures within-subjects design assessed aided sound field thresholds and speech performances with the subject's own, appropriately fit, walk-in hearing aid(s) and the Otologics Fully Implantable Hearing Device.ResultsSix- and 12-month Phase II data will be presented. Ten patients were implanted and activated as part Phase II clinical trial. Three patients were lost to long term follow-up due to two coil failures and one ossicular abnormality preventing proper device placement. No significant differences between preoperative (AC = 59 dB, BC = 55 dB) and postoperative (AC = 61 dB, BC = 54 dB) unaided pure tone averages were noted (p < 0.05). Pure tone average implant aided thresholds (41 dB) were equivalent to that of walk-in-aided (37...

Objective To analyze test-retest reliability of vestibular evoked myogenic potential (VEMP) responses with and without the use of electromyography (EMG) monitoring in people with normal audiovestibular function. Patients Twenty adult volunteers with no history of ear disease, normal otoscopic examination, normal pure-tone audiometry thresholds, and normal tympanograms. Interventions Prospective evaluation of VEMP responses with and without the use of EMG monitoring in 2 separate sessions 1 to 4 weeks apart. Main outcome measures Threshold repeatability, p13 and n23 latency, p13-n23 interlatency, and interamplitude and interaural amplitude difference from the first and the second sessions were assessed via the intraclass correlation coefficient. Results Test-retest reliability of p13-n23 interamplitude was found to be excellent, and the reliability of threshold and latency was found to be fair to good (with the exception of poor reliability for p13 latency in the EMG monitoring condition). Conclusion Overall, VEMP response parameters were found to have fair to good test-retest reliability. The intraclass correlation coefficient value for amplitude was found to be more reliable than latency, with the latency of n23 more reliable than the latency of p13. Clinicians should consider these findings when interpreting VEMP responses. Maintenance of symmetric head rotation with and without EMG monitoring produced reliably reproducible results, the VEMP amplitude being the best criteria.

OBJECTIVE To assess the safety of the Otologics fully implantable hearing system after 1 year of use in a Phase I clinical trial. STUDY DESIGN Repeated-measures within-subjects design. SETTING Procedures were performed in a variety of facilities, including a university, military, and private hospital's ambulatory surgical center and outpatient clinical audiologic test facilities. PATIENTS Adult patients with bilateral moderate to severe sensorineural hearing loss. INTERVENTION(S) Surgical insertion of this prosthesis included an atticotomy to expose the incus, securing the transducer to the mastoid bone, attaching the transducer tip to the incus via insertion into a laser-drilled hole, and postauricular implantation of the microphone/battery/electronics capsule. MAIN OUTCOME MEASURE(S) Subjective patient benefit, aided sound field thresholds, and speech discrimination with the subject's own, appropriately fit, walk-in hearing aid(s) and the prosthesis were assessed. RESULTS There were no pre-post-implant differences noted for bone conduction: slight differences were noted in the pre-post-implant air conduction results (p < 0.05). These differences were attributed to the healing process and reversed to almost preimplant assessment levels by the third-month evaluation. Pure-tone averages and monaural word recognition scores were slightly better for the walk-in-aided condition (p < 0.05), whereas the patient benefit scales favored the postoperative implant-aided conditions.Adverse effects of the implant were encountered on 14 occasions after the implantation of the 20 subjects. With the exception of partial device extrusions (that occurred later), all were rectified by the time of initial activation. At the 12-month data collection point, problems that had been encountered by subjects included 1) partial device extrusion (3 subjects), necessitating explantation in 2; 2) loss of external communication (2 subjects), resulting in 1 explantation; and 3) increased charging times beyond 1.5 hours (7), resulting in 3 explantations and 2 patients not using their device while awaiting explantation. CONCLUSION Phase I trial results provide evidence that this fully implantable device can provide sound amplification to sensorineural hearing loss patients, with performance results similar to the patients' walk-in hearing aids.

Objective: The goal was to measure quality of life (QOL) and hearing-specific functional status before and after treatment of conductive hearing loss (CHL). Study Design and Setting: A prospective, longitudinal, outcomes-based study was performed at an academic medical center. Results: Mean baseline QOL scores in CHL patients were comparable with those of the general population. Audiometric studies indicated significant improvements in hearing threshold in all treated patients. There was no significant improvement in mean global QOL scores after treatment of CHL, although there was little room for improvement over baseline. The hearing-specific instrument did demonstrate significant improvements in emotional and social/situational hearing status after treatment. Patients treated with hearing aids had poorer baseline QOL and hearing status than patients treated with surgery and tended to show declines in QOL and only partial improvement in hearing-specific functional status after treatment. Conclusions: Treatment of CHL resulted in improvements in hearing-specific functional status, although changes were difficult to detect with a global QOL instrument. (Otolaryngol Head Neck Surg 2000;123:527-3.)

Balance disorders in elderly patients are associated with an increased risk of falls but are often difficult to diagnose because of comorbid chronic medical problems. We performed a cross-sectional study to determine the prevalence of unrecognized benign paroxysmal positional vertigo (BPPV) and associated lifestyle sequelae in a public, inner-city geriatric population. Dizziness was found in 61% of patients, whereas balance disorders were found in 77% of patients. Nine percent were found to have unrecognized BPPV. Multivariate analysis demonstrated that the presence of a spinning sensation and the absence of a lightheadedness sensation predicted the presence of unrecognized BPPV. Patients with unrecognized BPPV were more likely to have reduced activities of daily living scores, to have sustained a fall in the previous 3 months, and to have depression. These data indicate that unrecognized BPPV is common within the elderly population and has associated morbidity. Further prospective studies are warranted.

The sensory hair cells of the inner ear are responsible for converting balance and hearing stimuli into electrical signals. Until recently, all previous studies of hair cell physiology had been performed on tissue obtained from non-mammals and rodents. In primates, hair cells are difficult to access, because they rest within the densest structure of the body, the otic capsule of the temporal bone. In this report, we describe a technique that we have used in physiological studies to harvest living human hair cells. We collected vestibular and cochlear tissue specimens from adult humans undergoing translabyrinthine and transotic surgical approaches for resection of lateral skull base tumors. Viable hair cells were identified and visualized with light microscopy. The ability to study normal hair cells from humans may further the study of normal and pathological human sensation, hair cell regeneration, and genetic causes of balance and hearing disorders.

Objective: To evaluate the cost-effectiveness of several diagnostic tests used in the evaluation of vertigo. Study Design: Cost-effectiveness analysis, using data from retrospective case review. Methods: Charts and test results were reviewed from 192 outpatients seen in an academic tertiary referral center for evaluation of vertigo. Cost-effectiveness analysis was performed using decision analysis software, data from office and hospital charges, and expert-based estimations of the utility of different test outcomes. Sensitivity analysis was performed using standard algorithms and wide variable ranges. Results: We found that audiologic testing, posturography, and electronystagmography were the most cost-effective tests, and that magnetic resonance imaging and blood tests had the lowest cost-effectiveness. The analysis was sensitive to the effects of financial costs of tests but, with a few exceptions, was typically not sensitive to the utility of test outcomes or the distribution of test results. Conclusions: The use of cost-effectiveness analysis, the estimation of utility of test outcomes, and techniques of sensitivity analysis should help guide the clinician's decision making on appropriate testing for patients with vertigo.

Electrocochleography, H. Kumagami et al auditory brainstem response - recent developments in recording and analysis, J.W. Hall and K.A. Rupp hearing as reflected by middle and long latency event-related potentials, G.P. Jacobson et al objective measurements and the audiological management of cochlear implant patients, J.K. Shallop electroneuronography, J.M. Dennis and N.J. Coker testing the vestibulo-ocular reflex, G.M. Halmagyi et al vestibular evoked potentials, K.F. Trinus otoacoustic emissions, R. Probst and F.P. Harris.

Iron deficiency anemia is a frequently occurring clinical disorder. Despite the suggested association with hearing loss in the literature, cochlear sequelae of iron deficiency have yielded conflicting results in experimental studies. Auditory function was tested in iron-deficient and normal male Wistar albino rats using distortion product otoacoustic emissions and auditory brainstem response audiometry for the clarification of the opposing results in the literature. Hemoglobin, hematocrit, serum iron and albumin levels were monitored to verify iron deficiency. Although dramatic differences in weight gain and blood test parameters were noted, no significant change in auditory function due to iron deficiency was detected.