[OTONEUROLOGY- A MULTIFACETED FIELD].

INTRODUCTION: Otoneurology is a broad, diverse and multidisciplinary field. On the one hand, it includes everything that relates to hearing: from complex surgery including life-changing implants to effective medical treatments and habilitation. On the other hand, it includes all that has to do with balance, from novel vestibular tests to complex medical treatments and recently, the development of a vestibular implant for patients suffering from bilateral peripheral vestibular loss. This special issue on otoneurology includes 8 original papers and 3 reviews. The first three articles deal with auditory implants. The first describes a series of children who underwent auditory brainstem implantation, including the first implantation in Israel 6 years ago. The second, presents patients with acoustic schwannomas undergoing cochlear implantation and the third relates to patients with Meniere's disease. Cochlear implants are one of the most significant developments in medicine in recent decades that enable most deaf individuals to hear, and develop normal language, heavily influencing all aspects of personal development and social integration.

[AUDITORY BRAINSTEM IMPLANTS (ABI) IN CHILDREN: CASE SERIES IN SHAARE ZEDEK MEDICAL CENTER].

BACKGROUND: Cochlear implants (CI) are the treatment of choice for individuals with severe to profound sensorineural hearing loss. A small group of patients, with pathology central to the cochlea, cannot benefit from CI. Examples in children include absence of the cochlear-nerve or cochlear aplasia. In these cases, implantation of an auditory brainstem implant (ABI), directly stimulating the cochlear nucleus, bypassing the inner-ear and auditory-nerve, may be beneficial. OBJECTIVES: Describe a series of children with ABI's treated in Shaare-Zedek, including the first ABI implantation in Israel (2017). METHODS: Of 9 patients with ABI's treated in Shaare Zedek Medical Center ,7 were children implanted between ages 2-8.6 years. Five boys and two girls. Surgeries were conducted in collaboration between neurosurgeons, neurotologists and audiologists (five implanted in Shaare-Zedek and two in New-York University). Follow-up was between 2-6 years. Hearing evaluation was conducted, mainly, with audiograms, categories of auditory performance (CAP), speech perception testing when possible and estimation of device use per day. RESULTS: Six of the seven children, who initially underwent unsuccessful CI, had deficient auditory-nerves. One child had cochlear-aplasia. In 3 children hearing loss was part of the CHARGE syndrome. CAP scores ranged from 0-7 (0,1,3,5,5,7). One child was able to achieve open-set speech perception. CONCLUSIONS: Although functional auditory outcomes for children with ABI are inferior to CI recipients and are highly variable, some children were able to obtain significant benefit. In these children, who are not candidates for CI, the ABI presents the only chance for auditory awareness and may be recommended. DISCUSSION: John Thomas Roland is a consultant and recipient of research support from Cochlear Americas.

Time from sudden sensory neural hearing loss to treatment as a prognostic factor.

Introduction: The widely accepted treatment for sudden sensorineural hearing loss (SSNHL) is corticosteroid treatment (oral or intratympanic). The main goal of this work is to define the significance of the time between symptom onset and treatment initiation, as well as other prognostic factors, for hearing improvement. Methods: This retrospective study included 666 patients treated for SSNHL. Demographic data, audiometry, treatment method, time since symptom onset, and associated symptoms were recorded for each patient. The patients were divided into five groups according to the treatment initiation time-half a week, one week, 2 weeks, 3 weeks, or 4 weeks and over-after symptom onset. The degree of improvement was assessed by comparing the audiometry at the beginning and the end of the treatment. Results: The average period of hearing loss from symptom onset to treatment initiation was 10.8 days. Significant differences were found between the groups of half a week, one week, and 2 weeks and the groups of 3 weeks and 4 weeks and over (each separately, p < 0.001). No difference was found between the half-week, one-week, and two-week groups, nor was there a difference between the three-week and four-week-and-over groups. A correlation was found between the treatment initiation time in days and the degree of improvement in hearing for both speech recognition threshold (SRT) and discrimination, R = 0.26 p < 0.001 and R = 0.17 p < 0.001, respectively. No correlation was found for gender, age of the patients, comorbidities, or associated symptoms. Conclusion: The threshold for treatment initiation time is up to 2 weeks, after which the amplitude of hearing improvement decreases significantly. The other prognostic factors measured were not found to be statistically significant predictors.

The Effect of Soft Tissue Stimulation on Skull Vibrations and Hearing Thresholds in Humans.

HYPOTHESIS: Hearing via soft tissue stimulation involves an osseous pathway. BACKGROUND: A recent study that measured both hearing thresholds and skull vibrations found that vibratory stimulation of soft tissue led to hearing sensation that correlated with skull vibrations, supporting the hypothesis of an osseous pathway. It is possible, however, that a lower application force of the vibrator on the stimulated soft tissue would not be sufficient to elicit skull vibration suggesting hearing via a nonosseous pathway. The purpose of the present study was to confirm the osseous pathway by measuring skull vibrations and behavioral thresholds using a low application force on a layer of ultrasound gel. Gel was used to mimic soft tissue because of its similar acoustic impedance and to control for variability between participants. METHODS: Hearing thresholds and the skull vibrations of five patients who were implanted with bone-anchored implants were assessed in two conditions when the bone vibrator was applied on the forehead: 1) direct application with 5N force; 2) through a layer of ultrasound gel with minimal application force. Skull vibrations were measured in both conditions by a laser Doppler vibrometer focused on the bone-anchored implant. RESULTS: Skull vibrations were present even when minimal application force was applied on soft tissue. The difference in skull vibrations when the vibrator was directly on the forehead compared with the gel condition was consistent with the variability in hearing thresholds between the two conditions. CONCLUSION: These results reinforce the hypothesis that skull vibrations are involved in hearing when sound is transmitted via either soft tissue or bone.

Vascular Anomaly in the Fallopian Canal Encountered Unexpectedly During Cochlear Implantation.

A 68-year-old male with progressive sensorineural hearing loss underwent left cochlear implant surgery. While developing the posterior tympanotomy and identifying the facial nerve mastoid segment, gentle stimulation by the nerve stimulator resulted in unexpected profuse venous bleeding. After achieving hemostasis with Surgicel and Spongostan, the posterior tympanotomy was extended exposing a large aberrant vein running parallel to the tympanic and mastoid segments of the facial nerve in the fallopian canal. Good exposure and careful palpation of the vein assisted in ruling out facial nerve hemangioma. An intraoperative decision to proceed with implantation, taking into account limited benefit from future magnetic resonance imaging, was taken. The patient had a temporary 3-month post-operative facial nerve weakness, probably from pressure applied during hemostasis. Auditory cochlear implant function was excellent. A larger than normal diameter of the tympanic and mastoid segments of the facial nerve was seen in re-reviews of the preoperative computed tomography. We believe drawing the readers' attention to this anomaly, which to the best of our knowledge has not been previously described, can assist in the choice of preoperative imaging and increase awareness of deviation from the norm of facial nerve diameter. In addition, knowledge of possible venous anomalies may aid surgeons in such intraoperative decisions.

Is it Beneficial to Treat Patients Presenting Three Weeks or Longer after the Onset of Sudden Sensorineural Hearing Loss?

OBJECTIVES: The accepted treatment for idiopathic sudden sensorineural hearing loss (ISSNHL) consists of oral or intratympanic steroids. The time from onset to treatment is considered as an important prognostic factor, although there is no clear cutoff point when treatment is no longer beneficial. This study aimed to assess the efficacy of treatment with oral or intratympanic steroids and carbogen, in patients presenting 21 days or later after the onset of hearing loss. MATERIALS AND METHODS: A total of 895 patients with ISSNHL was seen in our center between 2010 and 2018. The study cohort included 103 patients treated with oral or intratympanic steroids or both with carbogen 21 days or longer after experiencing hearing loss. Retrospective analysis of files and audiometry was conducted, and pre- and post-treatment audiograms were compared. Improvement was defined by SRT (≥15 dB improvement), discrimination (≥15% improvement), or 15 dB improvement at specific frequencies (250-500, 4000-6000 Hz). RESULTS: Hearing improvement, according to the study definition, was seen in 22.3% (23/103) of patients within the time period of the treatment. All the 23 patients had functional hearing after treatment and 16 of them returned to their baseline or normal hearing. While the time from onset of ISSNHL to treatment varied, most patients demonstrating improvement were treated 21-30 days after onset. CONCLUSION: In this patient cohort treated late for sudden sensorineural hearing loss (SSNHL), a small but significant number of patients improved during the time of treatment. Although the lack of a control group makes it difficult to prove that the improvement resulted from the treatment, we recommend not to rule out treatment systematically in patients presenting late after ISSNHL. Additional prospective studies are warranted.

Revision cochlear implantation using a double array device in the post-meningitis ossified cochlea.

PURPOSE: To describe the surgical technique and outcome in a series of patients who underwent revision cochlear implantation using a double array or split electrode device. All patients developed ossified cochleae due to meningitis and were functioning poorly with the previous implant. METHODS: Four patients between the ages of 4-15 years underwent revision with five double-array cochlear implant devices. One patient underwent bilateral revision surgery. All patients had previous meningitis with CT and MRI imaging studies that demonstrated completely ossified cochleae. The time interval range between the disease and the initial cochlear implantation and was 4 months to 3 years. The patient's data were retrospectively analyzed with emphasis on the surgical technique, the number of electrodes inserted, and the number of active electrodes at follow-up. In addition, pre and post-revision surgery function was compared. RESULTS: The revision surgery was carried out 2-11 years after the initial surgery. Two tunnels, basal and apical, were drilled in the ossified cochlea. In each of the tunnels, 5 to 11 electrodes were inserted. While the number of active electrodes before revision was 0-5, after revision with the double array, it was increased to 8-12, resulting in improved auditory and speech function. CONCLUSION: Revision cochlear implantation with a double array implant using the two tunnel technique can increase the number of active electrodes. This leads to a better outcome in post-meningitis children with completely ossified cochleae and a poor functioning previous device.

Listening in Noise Remains a Significant Challenge for Cochlear Implant Users: Evidence from Early Deafened and Those with Progressive Hearing Loss Compared to Peers with Normal Hearing.

Cochlear implants (CIs) are the state-of-the-art therapy for individuals with severe to profound hearing loss, providing them with good functional hearing. Nevertheless, speech understanding in background noise remains a significant challenge. The purposes of this study were to: (1) conduct a novel within-study comparison of speech-in-noise performance across ages in different populations of CI and normal hearing (NH) listeners using an adaptive sentence-in-noise test, and (2) examine the relative contribution of sensory information and cognitive-linguistic factors to performance. Forty CI users (mean age 20 years) were divided into "early-implanted" <4 years (n = 16) and "late-implanted" >6 years (n = 11), all prelingually deafened, and "progressively deafened" (n = 13). The control group comprised 136 NH subjects (80 children, 56 adults). Testing included the Hebrew Matrix test, word recognition in quiet, and linguistic and cognitive tests. Results show poorer performance in noise for CI users across populations and ages compared to NH peers, and age at implantation and word recognition in quiet were found to be contributing factors. For those recognizing 50% or more of the words in quiet (n = 27), non-verbal intelligence and receptive vocabulary explained 63% of the variance in noise. This information helps delineate the relative contribution of top-down and bottom-up skills for speech recognition in noise and can help set expectations in CI counseling.

Implications from cochlear implant insertion for cochlear mechanics.

It is usually thought that the displacements of the two inner ear windows induced by sound stimuli lead to pressure differences across the basilar membrane and to a passive mechanical traveling wave progressing along the membrane. However, opening a hole in the sealed inner ear wall in experimental animals is surprisingly not accompanied by auditory threshold elevations. It has also been shown that even in patients undergoing cochlear implantation, elevation of threshold to low-frequency acoustic stimulation is often not seen accompanying the making of a hole in the wall of the cochlea for insertion of the implant. Such threshold elevations would be expected to result from opening the cochlea, reducing cochlear impedance, altering hydrodynamics. These considerations can be taken as additional evidence that it may not be the passive basilar membrane traveling wave which elicits hearing at low sound intensities, but rather factors connected with cochlear fluid pressures and fluid mechanics.

Implications for Bone Conduction Mechanisms from Thresholds of Post Radical Mastoidectomy and Subtotal Petrosectomy Patients.

OBJECTIVES: To assess bone conduction (BC) thresholds following radical mastoidectomy and subtotal petrosectomy, in which the tympanic membrane and the ossicular chain, responsible for osseous BC mechanisms, are surgically removed. The removal of the tympanic membrane and the ossicular chain would reduce the contributions to BC threshold of the following four osseous BC mechanisms: the occlusion effect of the external ear, middle ear ossicular chain inertia, inner ear fluid inertia, and distortion (compression-expansion) of the walls of the inner ear. MATERIALS AND METHODS: BC thresholds were determined in 64 patients who underwent radical mastoidectomy and in 248 patients who underwent subtotal petrosectomy. RESULTS: BC thresholds were normal (≤15 dB HL, i.e., better) in 19 (30%) radical mastoidectomy patients and in 19 (8%) subtotal petrosectomy patients at each of the frequencies assessed (0.5, 1.0, 2.0, and 4.0 kHz). CONCLUSION: Normal BC thresholds seen in many patients following mastoidectomy and petrosectomy may be induced by a non-osseous mechanism, and the onset ("threshold") of the classical osseous BC mechanisms may be somewhat higher.

Does hearing in response to soft-tissue stimulation involve skull vibrations? A within-subject comparison between skull vibration magnitudes and hearing thresholds.

Hearing can be elicited in response to bone as well as soft-tissue stimulation. However, the underlying mechanism of soft-tissue stimulation is under debate. It has been hypothesized that if skull vibrations were the underlying mechanism of hearing in response to soft-tissue stimulation, then skull vibrations would be associated with hearing thresholds. However, if skull vibrations were not associated with hearing thresholds, an alternative mechanism is involved. In the present study, both skull vibrations and hearing thresholds were assessed in the same participants in response to bone (mastoid) and soft-tissue (neck) stimulation. The experimental group included five hearing-impaired adults in whom a bone-anchored hearing aid was implanted due to conductive or mixed hearing loss. Because the implant is exposed above the skin and has become an integral part of the temporal bone, vibration of the implant represented skull vibrations. To ensure that middle-ear pathologies of the experimental group did not affect overall results, hearing thresholds were also obtained in 10 participants with normal hearing in response to stimulation at the same sites. We found that the magnitude of the bone vibrations initiated by the stimulation at the two sites (neck and mastoid) detected by the laser Doppler vibrometer on the bone-anchored implant were linearly related to stimulus intensity. It was therefore possible to extrapolate the vibration magnitudes at low-intensity stimulation, where poor signal-to-noise ratio limited actual recordings. It was found that the vibration magnitude differences (between soft-tissue and bone stimulation) were not different than the hearing threshold differences at the tested frequencies. Results of the present study suggest that bone vibration magnitude differences can adequately explain hearing threshold differences and are likely to be responsible for the hearing sensation. Thus, the present results support the idea that bone and soft-tissue conduction could share the same underlying mechanism, namely the induction of bone vibrations. Studies with the present methodology should be continued in future work in order to obtain further insight into the underlying mechanism of activation of the hearing system.

Inner Ear Excitation in Normal and Postmastoidectomy Participants by Fluid Stimulation in the Absence of Air- and Bone-Conduction Mechanisms.

BACKGROUND: Hearing can be induced not only by airborne sounds (air conduction [AC]) and by the induction of skull vibrations by a bone vibrator (osseous bone conduction [BC]), but also by inducing vibrations of the soft tissues of the head, neck, and thorax. This hearing mode is called soft tissue conduction (STC) or nonosseous BC. PURPOSE: This study was designed to gain insight into the mechanism of STC auditory stimulation. RESEARCH DESIGN: Fluid was applied to the external auditory canal in normal participants and to the mastoidectomy common cavity in post-radical mastoidectomy patients. A rod coupled to a clinical bone vibrator, immersed in the fluid, delivered auditory frequency vibratory stimuli to the fluid. The stimulating rod was in contact with the fluid only. Thresholds were assessed in response to the fluid stimulation. STUDY SAMPLE: Eight ears in eight normal participants and eight ears in seven post-radical mastoidectomy patients were studied. DATA COLLECTION AND ANALYSIS: Thresholds to AC, BC, and fluid stimulation were assessed. The postmastoidectomy patients were older than the normal participants, with underlying sensorineural hearing loss (SNHL). Therefore, the thresholds to the fluid stimulation in each participant were corrected by subtracting his BC threshold, which expresses any underlying SNHL. RESULTS: Hearing thresholds were obtained in each participant, in both groups in response to the fluid stimulation at 1.0 and 2.0 kHz. The fluid thresholds, corrected by subtracting the BC thresholds, did not differ between the groups at 1.0 kHz. However, at 2.0 kHz the corrected fluid thresholds in the mastoidectomy patients were 10 dB lower (better) than in the normal participants. CONCLUSIONS: Since the corrected fluid thresholds at 1.0 kHz did not differ between the groups, the response to fluid stimulation in the normal participants at least at 1.0 kHz was probably not due to vibrations of the tympanic membrane and of the ossicular chain induced by the fluid stimulation, since these structures were absent in the mastoidectomy patients. In addition, the fluid in the external canal (normal participants) and the absence of the tympanic membrane and the ossicular chain (mastoidectomy patients) induced a conductive hearing loss (threshold elevation to air-conducted sounds coming from the bone vibrator), so that AC mechanisms were probably not involved in the thresholds to the fluid stimulation. In addition, as a result of the acoustic impedance mismatch between the fluid and skull bone, the audio-frequency vibrations induced in the fluid at threshold would probably not lead to vibrations of the bony wall of the meatus, so that hearing by osseous BC is not likely. Therefore, it seems that the thresholds to the fluid stimulation, in the absence of AC and of osseous BC, represent an example of STC, which is an additional mode of auditory stimulation in which the cochlea is activated by fluid pressures transmitted along a series of soft tissues, reaching and exciting the inner ear directly. STC can explain the mechanism of several auditory phenomena.

Fluid stimulation elicits hearing in the absence of air and bone conduction--An animal study.

Conclusion Cochlea can be directly excited by fluid (soft-tissue) stimulation. Objective To determine whether there is no difference in auditory-nerve-brainstem evoked response (ABR) thresholds to fluid stimulation between normal and animal models of post radical-mastoidectomy, as seen in a previous human study. Background It has been shown in humans that hearing can be elicited with stimulation to fluid in the external auditory meatus (EAM), and radical-mastoidectomy cavity. These groups differed in age, initial hearing, and drilling exposure. To overcome this difference, experiments were conducted in sand-rats, first intact, and after inducing a radical-mastoidectomy. Methods The EAM of five sand-rats was filled with 0.3 ml saline. ABR thresholds were determined in response to vibratory stimulation by a clinical bone-vibrator with a plastic rod, applied to the saline in the EAM. Then the tympanic membrane was removed, and malleus dislocated (radical-mastoidectomy model). The cavity was filled with 0.45 ml saline and the ABR threshold was determined in response to vibratory stimulation to the cavity fluid. Results There was no difference in ABR fluid thresholds to EAM and mastoidectomy cavity stimulation. Air-conduction stimulation from the bone-vibrator was not involved (conductive loss due to fluid). Bone-conduction stimulation was not involved (large difference in acoustic impedance between fluid and bone).

Surgical techniques and outcomes of cochlear implantation in patients with radiographic findings consistent with X-linked deafness.

OBJECTIVES: X-linked deafness is a potential etiology of sensorineural hearing loss characterized by bulbous dilatation of the fundus of the internal auditory canal (IAC) and the absence of the bony plates separating the basal turn of the cochlea and IAC. These malformations predispose patients to IAC insertion during cochlear implantation (CI). Our objective is to describe the surgical technique, audiometric and speech performance outcomes in a group of patients with this unique cochlear malformation. METHODS: A retrospective chart review was performed of all patients at a tertiary care facility who underwent CI between January 2006 and July 2011. RESULTS: A total of five patients were identified with radiographic findings characteristic of X-linked deafness, specifically a deficient modiolous, absent lamina cribrosa and bulbous IAC. A modified cochleostomy was utilized to ensure electrode insertion within the scala tympani avoiding the IAC. In each case, fluoroscopy was utilized to visual electrode progression during insertion and complete insertion was accomplished. All patients demonstrated improved speech performance following implantation. CONCLUSIONS: Utilizing the techniques described, patients with these unique radiographic findings consistent with X-linked deafness may successfully undergo CI with excellent potential for auditory rehabilitation.

Air, bone and soft tissue excitation of the cochlea in the presence of severe impediments to ossicle and window mobility.

Clinical conditions have been described in which one of the two cochlear windows is immobile (otosclerosis) or absent (round window atresia), but nevertheless bone conduction (BC) thresholds are relatively unaffected. To clarify this apparent paradox, experimental manipulations which would severely impede several of the classical osseous mechanisms of BC were induced in fat sand rats, including discontinuity or immobilization of the ossicular chain, coupled with window fixation. Effects of these manipulations were assessed by recording auditory nerve brainstem evoked response (ABR) thresholds to stimulation by air conduction (AC), by osseous BC and by non-osseous BC (also called soft tissue conduction-STC) in which the BC bone vibrator is applied to skin sites. Following the immobilization, discontinuity and window fixation, auditory stimulation was also delivered to cerebro-spinal fluid (CSF) and to saline applied to the middle ear cavity. While the manipulations (immobilization, discontinuity, window fixation) led to an elevation of AC thresholds, nevertheless, there was no change in osseous and non-osseous BC thresholds. On the other hand, ABR could be elicited in response to fluid pressure stimulation to CSF and middle ear saline, even in the presence of the severe restriction of ossicular chain and window mobility. The results of these experiments in which osseous and non-osseous BC thresholds remained unchanged in the presence of severe restriction of the classical middle ear mechanisms and in the absence of an efficient release window, while ABR could be recorded in response to fluid pressure auditory stimulation to fluid sites, indicate that it is possible that the inner ear may be activated at low sound intensities by fast fluid pressure stimulation. At higher sound intensities, a slower passive basilar membrane traveling wave may serve to excite the inner ear.

Multiple electrostimulation treatments to the promontory for tinnitus.

OBJECTIVES: To assess the safety and efficacy of multiple sessions of electrostimulation by a transtympanic needle electrode on the promontory for tinnitus relief. STUDY DESIGN: Prospective open, unblinded, uncontrolled clinical trial. SETTING: Tertiary academic referral center. PATIENTS: Ten patients (8 male and 2 female subjects), mean age 50.1 ± 12 years (range, 34-67) with severe unilateral tinnitus completed all stages of the study. Patients with tinnitus duration between 6 months to 3 years were included. INTERVENTION: The patients underwent 3 consecutive 30-minute sessions, every other day, of biphasic, charge balanced electrostimulation pulses to the promontory delivered by a transtympanic needle electrode. MAIN OUTCOME MEASURES: 1) Tinnitus loudness reported by visual analog scale (VAS) between 1 and 10, at baseline, before and after each treatment, and 1, 2, 3, and 4 weeks after the last treatment. 2) Tinnitus Handicap Inventory (THI) questionnaire at baseline and 4 weeks after treatment. 3) Basic audiometry and tinnitus specific tests such as minimum masking level, tinnitus loudness, and pitch. RESULTS: No long-term adverse safety outcomes were noted in physical examination or audiologic evaluation. VAS levels decreased by ≥2 levels in 5 patients (50%) and returned to baseline 4 weeks after treatment. The VAS decrease was found significant (p = 0.048) in those patients. A statistically significant decrease in THI score was noted 4 weeks after treatment. Tinnitus specific tests at that time were unchanged from baseline. CONCLUSION: Multiple sessions of electrostimulation to the promontory seem to be safe and may be beneficial for some tinnitus patients. Further clinical trials are warranted.

Investigation of the mechanism of soft tissue conduction explains several perplexing auditory phenomena.

Soft tissue conduction (STC) is a recently expounded mode of auditory stimulation in which the clinical bone vibrator delivers auditory frequency vibratory stimuli to skin sites on the head, neck, and thorax. Investigation of the mechanism of STC stimulation has served as a platform for the elucidation of the mechanics of cochlear activation, in general, and to a better understanding of several perplexing auditory phenomena. This review demonstrates that it is likely that the cochlear hair cells can be directly activated at low sound intensities by the fluid pressures initiated in the cochlea; that the fetus in utero, completely enveloped in amniotic fluid, hears by STC; that a speaker hears his/her own voice by air conduction and by STC; and that pulsatile tinnitus is likely due to pulsatile turbulent blood flow producing fluid pressures that reach the cochlea through the soft tissues.

The mechanism of direct stimulation of the cochlea by vibrating the round window.

BACKGROUND: Active middle ear implants such as the vibrant sound bridge (VSB) have been placed on the round window (RW) in patients with conductive or mixed hearing loss, with satisfactory hearing results. Several observations show that the mechanism of RW stimulation is not completely understood. The purpose of the present study was to compare different coupling procedures between the transducer and the RW in order to contribute to an understanding of the mechanism of RW stimulation. METHODS: Five fat sand rats underwent ablation of the left ear and opening of the right bulla, followed by baseline measurements of thresholds of auditory nerve brainstem evoked responses (ABR) to air and bone conduction click stimuli. Subsequently the malleus and incus were removed from the right middle ear, modeling a conductive hearing loss in which the VSB on the RW is indicated. In the next stage of the experiment, a rod attached to the bone vibrator was placed gently on the RW membrane and then on saline fluid applied to the RW niche. ABR thresholds were recorded following both placements. RESULTS: Mean baseline ABR threshold in response to air conduction stimuli was 48 ± 4 dB; mean ABR threshold when the rod was placed on the dry RW membrane was 99 ± 12 dB; mean ABR threshold when the rod was in the saline on RW niche was 79 ± 7 dB. CONCLUSIONS: ABR thresholds were better (lower) with stimulation of fluid on the RW membrane compared to direct stimulation of the RW, providing further evidence of a direct fluid pathway.

Harmonic scalpel assisted superficial parotidectomy.

OBJECTIVE: The Harmonic Scalpel (HS) has been recently widely used to perform a variety of surgical procedures. We reviewed our experience with the use of HS in superficial parotidectomy to determine the safety and efficacy of this procedure, with regard to operative time, postoperative facial nerve function, and drainage output. STUDY DESIGN: Nonrandomized retrospective review. MATERIALS AND METHODS: The medical records of all patients who underwent superficial parotidectomy for benign pathology at Shaare Zedek Medical Center from January 2006 to July 2009 were retrospectively reviewed. Patients with prior facial nerve weakness or prior parotid surgery or who had undergone concurrent neck dissection or total parotidectomy were excluded. RESULTS: Fifty-eight patients were reviewed; 26 patients underwent HS parotidectomy and 32 patients underwent conventional (cold knife) parotidectomy (control group). Harmonic Scalpel assisted parotidectomy was associated with significantly decreased length of surgery from 163.12 ± 21.8 minutes for controls to 137.3 ± 18.6 minutes in the HS assisted group (P < .05). The incidence of temporary postoperative facial nerve paresis was significantly reduced from 43% in the controls to 23% in the HS group (P < .05). No permanent facial nerve paralysis was reported. There were differences in the overall postoperative drain output between the HS and control groups, 68 ± 22.3 mL and 73.5 ± 38.2 mL, respectively, but these differences did not achieve significance. CONCLUSION: This study shows that HS assisted superficial parotidectomy for benign pathology is a safe technique and associated with reduced surgical time and incidence of temporary postoperative facial nerve paresis compared with conventional techniques.

[Fluoroscopic assisted cochlear implantation in children with inner ear malformations].

BACKGROUND: Cochlear implants are the treatment of choice for individuals with severe to profound sensorineural hearing loss. In most cases, the anatomy is normal and the insertion of the electrode-array is straightforward, complete and in the correct position. In the presence of inner-ear malformations, the risk of an intra or extra-cochlear malpositioned electrode-array increases. OBJECTIVES: To describe the technique of fluoroscopic assisted cochlear implantation in children with severe inner-ear malformations and present the results with respect to the number of active electrodes and function. METHODS: Fifteen fluoroscopy assisted implantations in 9 children were conducted at the Shaare Zedek Cochlear Implant Center between 2009-1014. All implanted ears had severe anatomic malformations. Mean implantation age was 3.5 years (range 1-11). Six children underwent sequential bilateral implantation. Two children underwent revision surgery due to a malpositioned electrode initially implanted without fluoroscopy at other centers. RESULTS: There was no radiologic or electro-physiologic evidence of kinking, bending or electrode damage in all 15 implantations. Complete insertion was achieved in all ears except one with partial insertion. There were no extra-cochlear or intrameatal placements. In 9 ears, all electrodes were active at switch-on and in the remaining, 15-20 were active. In all ears the Ling-6 sounds were detected and in 13 they were also identified. CONCLUSION: Fluoroscopy is an effective tool in complex cochlear implant surgeries and its use is simple and safe. As demonstrated in this study, with fluoroscopy assistance, good results are achieved in children with inner-ear malformations.