Showing papers in "Otology & Neurotology in 2004"

Is Perception of Handicap Related to Functional Performance in Persons with Vestibular Dysfunction

Abstract: OBJECTIVE The purpose of this study was to determine if scores between 0 and 30 (mild), 31 and 60 (moderate), and 61 and 100 (severe) on the Dizziness Handicap Inventory (DHI) differentiated a person's functional abilities. STUDY DESIGN Retrospective case series. SETTING Tertiary balance outpatient center. PATIENTS Patients (n = 85; mean age, 61 years) with a variety of vestibular diagnoses participated. INTERVENTIONS Patients completed the DHI, the Dynamic Gait Index (DGI), the 5 times sit to stand test (FTSST), the Activities-specific Balance Confidence (ABC) scale, gait speed, and the Timed "Up & Go" (TUG) during the same session. Reported numbers of falls within the last 4 weeks were recorded. MAIN OUTCOME MEASURES The DGI, FTSST, ABC, gait speed, TUG, and gait speed were compared among DHI groups. RESULTS Significant differences were identified using an analysis of variance between DHI groups on the DGI, the FTSST, ABC, and number of falls (p < 0.05). A significant difference was found between DHI groups (mild vs. severe and moderate vs. severe) on the DGI (p < 0.05) with greater DHI scores exhibiting more impaired walking. The FTSST was different between DHI groups mild and severe and DHI groups moderate and severe (p < 0.05), with slower FTSST scores with higher DHI scores. Reported falls were higher among the severe DHI group and the other 2 DHI groups (p < 0.05). All 3 DHI groupings were different from each other on the ABC (p < 0.001). CONCLUSION Patients who perceive a greater handicap as a result of dizziness demonstrate greater functional impairment than patients who perceive less handicap from dizziness.

Superior semicircular canal dehiscence presenting as conductive hearing loss without vertigo.

Abstract: Objective The objective of this study was to describe superior semicircular canal dehiscence (SSCD) presenting as otherwise unexplained conductive hearing loss without vestibular symptoms. Study design Retrospective. Setting Tertiary referral center. Patients The study comprised 8 patients (10 ears), 5 males and 5 females aged 27 to 59 years. All 10 ears had SSCD on high-resolution computed tomography scan of the temporal bone. DIAGNOSTIC TESTS AND RESULTS: All 10 ears had significant conductive hearing loss. The air-bone gaps were largest in the lower frequencies at 250, 500, and 1000 Hz; the mean gaps for these 3 frequencies for the 10 ears were 49, 37, and 35 dB, respectively. Bone-conduction thresholds below 2000 Hz were negative (-5 dB to -15 dB) at one or more frequencies in 8 of the 10 ears. There were no middle ear abnormalities to explain the air-bone gaps in these 10 ears. Computed tomography scan and laboratory testing indicated lack of middle ear pathology; acoustic reflexes were present, vestibular evoked myogenic potentials (VEMPs) were present with abnormally low thresholds, and umbo velocity measured by laser Doppler vibrometry was above mean normal. Middle ear exploration was negative in six ears; of these six, stapedectomy had been performed in three ears and ossiculoplasty in two ears, but the air-bone gap was unchanged postoperatively. The data are consistent with the hypothesis that the SSCD introduced a third mobile window into the inner ear, which in turn produced the conductive hearing loss by 1) shunting air-conducted sound away from the cochlea, thus elevating air-conduction thresholds; and 2) increasing the difference in impedance between the oval and round windows, thus improving thresholds for bone-conducted sound. Conclusion SSCD can present with a conductive hearing loss that mimics otosclerosis and could explain some cases of persistent conductive hearing loss after uneventful stapedectomy. Audiometric testing with attention to absolute bone-conduction thresholds, acoustic reflex testing, VEMP testing, laser vibrometry of the umbo, and computed tomograph scanning can help to identify patients with SSCD presenting with conductive hearing loss without vertigo.

Expression of Emotion and Quality of Life After Facial Nerve Paralysis

Abstract: Objective:To investigate the facial expression of emotion and quality of life in patients after long-term facial nerve paralysis.Study Design:Cross-sectional.Setting:Facial nerve paralysis clinic.Patients:Twenty-four patients with facial nerve paralysis and 24 significant others (partner, relative,

Clinical, experimental, and theoretical investigations of the effect of superior semicircular canal dehiscence on hearing mechanisms.

Abstract: HYPOTHESIS A superior semicircular canal dehiscence affects hearing by introducing a third window into the inner ear that 1) lowers cochlear input impedance, 2) shunts air-conducted sound away from the cochlea resulting in conductive hearing loss, and 3) improves bone-conduction thresholds by increasing the difference in impedance between the vestibule and the round window. BACKGROUND Superior semicircular canal dehiscence has been linked to a "conductive" hearing loss characterized by a decrease in the sensitivity to air-conducted sound and hypersensitivity to bone-conducted sound. METHODS Four investigations were performed: 1) laser-Doppler vibrometer measurements of sound-induced umbo velocity in patients with computed tomographic scan-confirmed superior semicircular canal dehiscence; 2) laser-Doppler vibrometry of sound-induced motions of the vestibular lymph (either perilymph or endolymph) exposed in a chinchilla model of superior semicircular canal dehiscence; 3) studies in chinchillas of the effect of superior semicircular canal dehiscence on the cochlea's sensitivity to bone-conducted sounds; and 4) anatomically based theoretical analyses of sound flow through the human cochlea and semicircular canals. RESULTS The low-frequency umbo velocity in superior semicircular canal dehiscence patients without previous middle ear surgery ranged from normal through high normal. This tendency toward hypermobility suggests a decrease in cochlear impedance. Measurements of sound-induced velocity of the lymph within a superior semicircular canal dehiscence in chinchillas demonstrated sound flow through the dehiscence. Measurements of the cochlear potential demonstrated a superior semicircular canal dehiscence-induced increase in response to bone-conducted sound in eight of nine chinchillas. An anatomically based model of the human ear predicts changes in auditory sensitivity similar to audiometric changes in superior semicircular canal dehiscence. CONCLUSION The results suggest that superior semicircular canal dehiscence can affect hearing function by introducing a third window into the inner ear.

Vestibular evoked myogenic potentials show altered tuning in patients with Ménière's disease.

Abstract: Objective:Acoustic stimulation of the saccule gives rise to a vestibulocollic reflex, the output of which can be measured in the neck as inhibition of activity in the ipsilateral sternocleidomastoid muscle. This vestibular evoked myogenic potential has been promoted as a means of assessing integrity

Surgical complications and their management in a series of 300 consecutive pediatric cochlear implantations.

Abstract: Objective:To report the short- and long-term complications encountered in a large number of consecutive children undergoing implantation in a single center. The current study also describes the management and sequelae of each complication.Study Design:Prospective study assessing the surgical finding

Benefits of bilateral electrical stimulation with the nucleus cochlear implant in adults: 6-month postoperative results.

Abstract: OBJECTIVE: To evaluate the benefits of bilateral electrical stimulation for hearing-impaired adult subjects using the Nucleus 24 cochlear implant in a multicenter study, and to compare and quantify performance on speech perception measures in quiet and in noise and localization ability for unilateral and bilateral cochlear implant use. DESIGN:: Repeated single subject measures were carried out for each subject, with each subject serving as their own control. Assessment of unilateral and bilateral listening conditions for performance on tests of speech comprehension and sound localization were performed. Speech comprehension measures were performed in quiet at 0 degree azimuth and in the presence of background noise simultaneously presented from the same speaker and spatially separated by 90 degrees, at S+45 degrees N45 degrees and at S-45 degrees N+45 degrees . Test materials included Freiburger monosyllabic words, Oldenburger sentences, and the Hochmair-Schulz-Moser sentences. Tests of localization were performed in the horizontal plane with 12 speaker locations 30 degrees apart using a shortened sentence stimulus from the Hochmair-Schulz-Moser sentences at two possible presentation levels of 55 and 70 dB sound pressure level for assessment of directionality. The binaural advantage provided by bilateral stimulation was calculated with respect to each ear separately, classified as either the better or poorer performing ear for each speech material in quiet and in noise test conditions. For localization of sound, the binaural advantage was compared with left and right ears separately. Paired comparisons for performance data in all conditions were carried out by considering measurements for each subject in different conditions as paired observations and applying the Student's t test to determine the statistical difference between the data sets. SETTING: Tertiary referral centers with a cochlear implant program. PATIENTS: Thirty-seven profoundly hearing-impaired adults were enrolled in the study, 22 simultaneously and 15 sequentially bilaterally implanted. All patients received the Nucleus 24 cochlear implant and used the Nucleus SPrint or ESPrit 3G speech processor, with the vast majority using the ACE speech coding strategy. RESULTS: For spatially separated speech in noise conditions, an interaural performance advantage for the ear closest to the speech source (i.e., with a superior signal to noise ratio) compared with that for the ear closest to the noise source (i.e., with an inferior signal to noise ratio) is consistently demonstrated regardless of whether it is the better or poorer performing ear closest to the speech signal. This is referred to as a significant binaural head-shadow benefit, resulting in a mean improvement between -10 dB and -11.4 dB in the critical signal to noise ratio required for 50% speech comprehension for the Olden-burger sentences and a mean improvement in the maximum score of 42% to 55% for the ear closest to the speech signal over the ear farthest away for the Hochmair-Schulz-Moser sentences. Bilateral stimulation is always observed to provide a performance advantage over the unilateral listening condition for either ear when ipsilateral to the noise source. In addition, as demonstrated by approximately half the subjects tested in noise with the Hochmair-Schulz-Moser sentences, a performance advantage of bilateral stimulation may be observed over the better ear alone when positioned ipsilateral to the speech signal, which is referred to as a binaural squelch effect. On average, for the group, this resulted in a statistically significant improvement in speech comprehension scores of 8% in the bilateral listening condition compared with the scores for the better ear alone. Through assessment of comprehension of coincidental speech in noise and speech in quiet, a significant benefit of binaural redundancy was noted for the group for Oldenburger sentence scores in noise and in quiet compared with unilateral scores for either ear and for the Freiburger monosyllabic words in quiet in comparison with the better ear alone scores. Binaural stimulation also led to a significant improvement in localization ability over either monaural condition, with the root mean square degrees of error reduced by 38 degrees compared with that observed for unilateral stimulation. CONCLUSION: Similar to what has been observed for bilateral acoustic stimulation in the past, bilateral electrical stimulation provides the foundation for the potential advantages of the head-shadow effect, providing a binaural head-shadow benefit and binaural auditory processing such as binaural redundancy and binaural squelch effects, all of which combine to lead to improved speech comprehension over unilateral listening conditions. The combination of improved speech comprehension and improved localization ability made available through bilateral electrical stimulation provides the necessary foundation to further assist the hearing-impaired listener to better cope with communication in the everyday listening situation both in noise and in quiet.

Characterizing and treating dizziness after mild head trauma.

Abstract: Objective:The objectives of this study were to characterize patterns of dizziness seen after mild head trauma and to examine the diagnosis and treatment of this disorder.Study Design:Prospective patient registry.Setting:Tertiary referral center.Patients:Fifty-eight cases of active duty and retired m

Intratympanic gentamicin therapy for Ménière's disease: a meta-analysis.

Abstract: Objective:This study compared the effectiveness of five different techniques of intratympanic gentamicin administration for Meniere’s disease.Data Sources:A MEDLINE search of the English language literature from 1978 to 2002 was performed using the key words “intratympanic,” “gentamicin,” “therapy,”

Aging effect on vestibular evoked myogenic potential.

Abstract: Objective: Vestibular evoked myogenic potential (VEMP) is applied to explore the integrity of sacculocollic reflex. Although tests to evaluate vestibular-ocular reflex pathway have shown that vestibular function is adversely affected by aging, VEMP, in this study, is used as a novel test to define how aging influences sacculocollic reflex pathway. Study design: Prospective study. Setting: Academic tertiary referral center. Subjects: Eighty normal subjects, equally divided into four groups according to their age, were enrolled to this study. Group I included patients aged <20 years, Group II patient ages ranged from 21 to 40 years, Group III patients were 41 to 60 years, and Group IV included patients older than 60 years. Interventions: Recordings of VEMP responses. Main outcome measures: The response rate and parameters of VEMP, including p13 latency, n23 latency, amplitude, and interaural difference ratio. Results: The VEMP response rates from Groups I to IV was 98%, 98%, 90%, and 60%, respectively, disclosing a significant difference only between Group IV and other groups (p < 0.05). The amplitude was negatively correlated with age in contrast to the n23 latency, correlating positively with age; both reached a significant difference (p < 0.05). Although the p13 latency had a trend to prolong as age increased, no significant correlation existed (p < 0.06). Moreover, the interaural difference ratio was also not significantly correlated with age. Conclusions: As age increased over 60 years, the VEMP response rate decreased dramatically. While age increased, the VEMP amplitude decreased in comparison to n23 latency prolonged. These findings might suggest that aging could deteriorate the saccular and corresponding neural functions. When interpreting the VEMP parameters, it should be kept in mind that aging could affect VEMP responses. Based on this study, we suggest establishing different reference values according to different age groups when evaluating VEMP response in patients with vestibular diseases.

Cochlear implantation between 5 and 20 months of age: the onset of babbling and the audiologic outcome.

Abstract: Results: All children started babbling after a short interval of 1 to 4 months after activation of the device so that the onset of babbling in the youngest subjects occurred at a chronologic age comparable to that of normally hearing infants. The outcomes of the different babbling measures correlated significantly with the age of implantation: the earlier the implantation, the closer the results approached the outcomes of normally hearing infants. The children implanted in their first year of life showed a normal CAP development as early as 3 months after implantation. All CI children were able to discriminate phoneme pairs of the A§E immediately after the fitting of the device. Conclusions: The earlier the implantation took place, the smaller the delay was in comparison with normally hearing children with regard to the onset of prelexical babbling and with regard to auditory performance as measured by CAP. Key Words: Babbling—Children—Outcome—Pediatric cochlear implant. Otol Neurotol 25:263–270, 2004.

Permanent gentamicin vestibulotoxicity.

Abstract: Objective:To determine the natural history of permanent gentamicin vestibulotoxicity.Study Design:Retrospective; comparison of retrospective and prospective studies.Setting:Tertiary neurotology clinic. Clinical research and technology center.Subjects:Thirty-three subjects with permanent gentamicin-i

Intralabyrinthine schwannomas: diagnosis, management, and a new classification system.

Abstract: Objective:To outline the diagnosis and management of intralabyrinthine schwannomas and to propose a new classification system to further define them.Study Design:Retrospective case review.Setting:Tertiary referral center at a university hospital.Patients:Twenty-eight patients seen at the institution

Cochlear implantation in 53 patients with otosclerosis: Demographics, computed tomographic scanning, surgery, and complications

Abstract: OBJECTIVES: To collect data from a large number of cochlear implant recipients with otosclerosis and to make an assessment of these patients' clinical characteristics, computed tomographic scans, surgical findings, and complications, and to quantify the occurrence of postoperative facial nerve stimulation. STUDY DESIGN: Retrospective multicenter study. PATIENTS: Fifty-three patients with otosclerosis from four cochlear implant centers in the United Kingdom and The Netherlands were reviewed. Sixty surgical procedures were performed in these patients: 57 devices were placed in 56 ears. RESULTS: The computed tomographic imaging demonstrated retrofenestral (cochlear) otosclerotic lesions in the majority of patients. Although not statistically significant, the extent of otosclerotic lesions on the computed tomographic scan as categorized in three types tends to be greater in patients with rapidly progressive hearing loss, in patients in whom there is surgically problematic insertion of the electrode array, and in patients with facial nerve stimulation. In four patients, revision surgery had to be performed. Twenty of 53 (38%) patients experienced facial nerve stimulation at various periods postoperatively. CONCLUSION: Cochlear implant surgery in patients with otosclerosis can be challenging, with a relatively high number of partial insertions and misplacements of the electrode array demanding revision surgery. A very high proportion of patients experienced facial nerve stimulation mainly caused by the distal electrodes. This must be discussed with patients preoperatively.

Cochlear implant outcomes in the elderly.

Abstract: Objective:This study aimed to review cochlear implantation with respect to surgical and auditory outcomes in subjects aged 70 years and older.Study Design:Retrospective chart review.Setting:Tertiary referral centers.Patients:Sixty-five patients aged 70 years or older at the time of implantation were

Perioperative Complications in Acoustic Neuroma (Vestibular Schwannoma) Surgery

Abstract: Objective:Retrospective study and review of the complications other than those related to the facial nerve and hearing, encountered in acoustic neuroma surgery Also, an evaluation of hospital stay and its relation with various factorsStudy Design:Retrospective case reviewSetting:Tertiary neurotol

The incidence of cerebrospinal fluid leak after vestibular schwannoma surgery.

Abstract: Objective:To review the incidence of cerebrospinal fluid leak after vestibular schwannoma removal reported in the literature.Data Sources:MEDLINE and PubMed literature search using the terms “acoustic neuroma” or “vestibular schwannoma,” and “cerebrospinal fluid leak” or “cerebrospinal fluid fistula

Caspases, the enemy within, and their role in oxidative stress-induced apoptosis of inner ear sensory cells.

Abstract: This review covers the general roles of members of the cysteine protease family of caspases in the process of apoptosis (programmed cell death) looking at their participation in both the "extrinsic" cell death receptor and the "intrinsic" mitochondrial cell death pathways. It defines the difference between initiator and effector caspases and shows the progression of caspase activations that ends up in the apoptotic cell death and elimination of a damaged cell. The review then presents what is currently know about the participation of caspases in the programmed cell death of inner ear sensory cells during the process of normal development and maturation of the inner ear and their importance in this process as illustrated by the results of caspase-3 gene knockout experiments. The participation of specific caspases and the sequence of their activation in the elimination (apoptosis) of damaged sensory cells from adult inner ears after an injury that generates oxidative stress are reviewed. Both the possibility and the potential efficacy of caspase inhibition with a broad-spectrum pancaspase inhibitor as an interventional therapy to treat and rescue oxidative stress-damaged inner ear sensory cells from apoptosis are presented and discussed.

Pediatric cochlear implant patient performance as a function of age at implantation.

Abstract: Objective The objective of this study was to examine the effect that age at implantation has on performance of children who received multichannel cochlear implants. Study design This is a retrospective study of 295 children who were broken down into 5 age groups based on age at implantation: 1-3 years, 3-5 years, 5-7 years, 7-9 years, and 9-11 years. Speech perception test scores obtained 12, 24, and 36 months postactivation were compared for the 5 groups using repeated-measures analysis of variance. Setting This study was carried out at a tertiary academic medical center. Patients Subjects consisted of 295 children who ranged in age from 12 months to 10 years 11 months at the time they obtained their cochlear implant. Intervention All patients received their cochlear implant at a single implant facility. Main outcome measures Performance on several speech perception tests was compared 12, 24, and 36 months postactivation. Performance was evaluated as a function of age at implantation. Results Patients in all 5 groups demonstrated improved scores when compared with scores obtained preoperatively with hearing aids. Repeated-measures analysis of variance (ANOVA) revealed a significant group by time interaction for 3 of the 5 measures. For all three of these measures, children implanted at younger ages demonstrated greater gains in speech perception over time than children implanted at older ages. Conclusions These results are in agreement with those of previous studies indicating that early implantation facilitates improved development of speech perception skills in profoundly deaf children.

Prevention of cisplatin ototoxicity using transtympanic N-acetylcysteine and lactate.

Abstract: Hypothesis:Transtympanic administration of the antioxidant N-acetylcysteine or lactated Ringer’s solution onto the round window membrane will prevent cisplatin ototoxicity in the guinea pig model.Background:Cochlear ototoxicity is a well-known side effect of cisplatin administration, with the mechan

Management of jugular paragangliomas: the Gruppo Otologico experience.

Abstract: Objective The objective of this study was to review the outcome of surgical management in patients of jugular paragangliomas Study design We conducted a retrospective case review Setting Tertiary care otology and skull base center Materials and methods Fifty-five patients with the diagnosis of a jugular paraganglioma (Fisch Class C and D Glomus Jugulare) were managed over a period of 15 years All patients with adequate follow up and complete records (53 cases) were reviewed with emphasis on the results of surgical management and the factors influencing them Intervention All 53 patients were managed with a view to surgically extirpate the tumor The primary approach was the infratemporal fossa approach-Type A used in the majority of the patients In eight cases, the procedure was staged owing to the presence of large intracranial extension Three patients required additional procedures to ameliorate the after-effects of lower cranial nerve resection Results Gross total tumor removal was achieved in 49 patients There were five cases of recurrence Coupled with the residual tumors in five patients, the surgical control achieved was 83% There was no perioperative mortality There were two cases of postoperative cerebrospinal fluid leak, both of which required surgical exploration and closure The facial nerve was resected in seven patients The overall preservation rate of clinically uninvolved lower cranial nerves was 75% Conclusions The low level of complications along with a high surgical control achieved makes surgery the primary mode of treatment in the vast majority of these tumors, regardless of the size and location

Detection of postoperative relapsing/residual cholesteatomas with diffusion-weighted echo-planar magnetic resonance imaging.

Abstract: PURPOSE To assess the capability of echo-planar diffusion-weighted magnetic resonance imaging (MRI) (EPI-DWI) in diagnosing relapsing/residual cholesteatomas after canal wall-up mastoidectomy. MATERIALS AND METHODS In a blinded study design, we investigated with MRI, including standard spin-echo sequences, 18 patients evaluated with clinical examination and computed tomography (CT) suspected for relapsing/residual cholesteatoma 7 to 19 months after a canal wall-up mastoidectomy. Images were evaluated by two radiologists blinded to patients' identities, CT findings, and clinical data set, who decided in a consensus agreement whether there was a pathologic signal increase in the petrous bone in a single-shot EPI-DWI sequence. All the patients underwent a second tympanoplasty or revision surgery of the mastoidectomy cavity within 15 days after magnetic resonance investigation.Sensitivity, specificity, and predictive values were evaluated separately for standard sequences and EPI-DWI. RESULTS In EPI-DWI, five of six patients with cholesteatoma showed a bright signal, whereas those patients with a noncholesteatomatous tissue showed no anomalies. The only misdiagnosed cholesteatoma was a pearl 2 mm in diameter. Sensitivity, specificity, and positive predictive values, and negative predictive values of EPI-DWI in diagnosing relapsing/residual cholesteatomas were 86, 100, 100, and 92%, respectively. CONCLUSION EPI-DWI may be a useful tool in differentiating between cholesteatomatous and noncholesteatomatous tissues after closed cavity mastoidectomy. Further investigations are, however, required to establish the practical utility of EPI-DWI on larger series as a screening modality in the follow-up after closed cavity mastoidectomies.

Prediction of fall risk reduction as measured by dynamic gait index in individuals with unilateral vestibular hypofunction.

Abstract: Objective: To determine the effect of vestibular rehabilitation on reduction of fall risk in individuals with unilateral vestibular hypofunction and to identify those factors that predict fall risk reduction. Study Design: Retrospective chart review. Setting: Tertiary referral center. Patients: Forty-seven patients with unilateral vestibular hypofunction, aged 28 to 86 years, who were at risk for falls on initial assessment. Intervention: All patients underwent vestibular rehabilitation including adaptation exercises, designed to improve gaze stability, and gait and balance exercises. Main Outcome Measures: Fall risk (Dynamic Gait Index), visual acuity during head movements (Dynamic Visual Acuity), and subjective complaints were measured initially, at 2-week intervals, and at completion of physical therapy. Results: As a group, the patients had significantly reduced risk for falls (p < 0.001) after rehabilitation. Time from onset of symptoms did not affect the efficacy of vestibular rehabilitation. Both older ( 65 yr) and younger (< 65 yr) adults showed significant reductions in fall risk with vestibular rehabilitation (p < 0.001). However, a significantly greater proportion ( 2 0.016) of older adults remained at risk for falls at discharge compared with young adults (45% versus 11%). Initial Dynamic Gait Index and Dynamic Visual Acuity scores predicted fall risk reduction in patients with unilateral vestibular hypofunction. A model was developed using initial Dynamic Gait Index and Dynamic Visual Acuity scores to predict fall risk reduction. Conclusions: Vestibular rehabilitation is effective in significantly reducing fall risk in individuals with unilateral vestibular deficit. The model predicts fall risk reduction with good sensitivity (77%) and specificity (90%). Key Words: Dynamic visual acuity—Falls—Vestibular adaptation—Vestibular hypofunction. Otol Neurotol 25:746–751, 2004.

Intratympanic steroid treatment: a review.

Abstract: Objective:To review published literature regarding the use of intratympanic steroids in the treatment of Meniere’s disease and sudden sensorineural hearing loss and to make recommendations regarding their use based on the literature review.Data Sources:Literature review from 1996 to 2003, PubMed, Me

Histologic evaluation of the tissue seal and biologic response around cochlear implant electrodes in the human.

Abstract: Hypothesis:Histopathologic study of the tissue seal and biologic response around cochlear implant electrodes in patients who had received a cochlear implant during life could provide clues concerning the pathogenesis of meningitis after cochlear implantation.Background:Bacterial meningitis has been

Human middle ear transfer function measured by double laser interferometry system.

Abstract: Hypothesis:Simultaneous measurements of vibrations on the stapes footplate, incudostapedial (IS) joint, and tympanic membrane (TM) can be made in both normal and drained cochleae, and the stapes displacement transfer function (S-DTF) and TM displacement transfer function (TM-DTF) are derived.Backgro

Agreement between the Sunnybrook, House-Brackmann, and Yanagihara facial nerve grading systems in Bell's palsy

Abstract: Objective:To assess the agreement between the Sunnybrook facial nerve grading system and the House-Brackmann and Yanagihara systems.Study Design:Prospective clinical facial nerve grading.Setting:Tertiary referral center.Patients:One-hundred assessments, 94 in patients with Bell’s palsy and 6 with he

Acoustic responses of vestibular afferents in a model of superior canal dehiscence.

Abstract: HYPOTHESIS Afferents innervating the superior semicircular canal are rendered especially sensitive to acoustic stimulation when there is a dehiscence of the superior canal. Other vestibular end organs are also more sensitive to acoustic stimulation. BACKGROUND Dehiscence of the superior semicircular canal is associated with vertigo and nystagmus caused by loud sounds (Tullio phenomenon) or changes in middle ear or intracranial pressures. The mechanisms by which acoustic stimuli act on the vestibular end organs are unclear. The nystagmus caused by acoustic stimuli generally aligns with the affected superior canal. METHODS Responses to acoustic stimuli in the superior vestibular nerves of anesthetized chinchillas were recorded before and after fenestration of the superior canal. RESULTS Two acoustic response patterns were seen: rapid phase locking and slow tonic changes in firing rate. Phasic responses principally occurred in irregular afferents and tonic responses in regular afferents. Afferents from all of the vestibular end organs encountered could respond to acoustic stimuli, even before fenestration. However, fenestration lowered the thresholds for acoustic stimulation in superior canal afferents with phasic responses and increased the magnitude of tonic responses. CONCLUSIONS Superior canal dehiscence may render the irregular afferents innervating the superior canal particularly sensitive to loud sounds. Rapid phase-locking responses may explain the short latency of nystagmus seen in patients with superior canal dehiscence syndrome. The mechanisms by which acoustic stimuli activate the vestibular end organs may differ from the damped endolymph motion associated with head acceleration.

Differential grading of endolymphatic sac tumor extension by virtue of von Hippel-Lindau disease status.

Abstract: Objective:Endolymphatic sac tumors are aggressive papillary tumors of the temporal bone frequently associated with von Hippel-Lindau disease The goal of this study was to use a newly devised classification system as a means to analyze differences between endolymphatic sac tumor extension in von Hip

Bacterial biofilms may contribute to persistent cochlear implant infection.

Abstract: Objectives To determine if bacterial biofilms are present on the surface of extruding or persistently infected cochlear implants. Methods Scanning electron microscopy was performed on cochlear implants removed from two patients because of recalcitrant infection, two implants removed secondary to device failure, and two devices that had never been implanted. Preparations were examined by experienced microbiologists for the presence of bacterial biofilms. Results Microorganisms and amorphous extracellular debris were found on the surface of the infected cochlear implants and the implants removed because of device failure. Biofilm formation was deemed definite in one infected device and possible in the other explanted devices. The never-implanted controls demonstrated microbial contamination without exopolymeric matrix, inconsistent with biofilms. Conclusion Bacterial biofilm formation may play a role in recalcitrant cochlear implant infections. This may have profound implications for the treatment of cochlear implant infections.