摘要:

Objective:To present the technical background of implantable hearing aids and to consider biomechanical problems and selective criteria for candidates.Data Sources:Publications and evidence on biomechanical aspects of middle ear function.Conclusions:Implantable hearing aids represent a technically attractive and clinically promising challenge. Yet, the mechanical mechanical complexity of biotechnical interfaces in the middle ear and technical problems are immense and perhaps not even fully understood. Currently available devices still leave many biomechanical questions unanswered. Therefore candidates should be carefully selected to avoid unsuccessful implantations, in order to prevent a premature discredit of this fascinating technique.

ISSN:0192-9763    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:This study aimed to evaluate the effectiveness of prophylactic ciprofloxacin drops in decreasing the incidence of otorrhea after tympanostomy tube insertion.Study Design:The study design was a single-blind, randomized clinical trial.Setting:The study was conducted at a tertiary care referral center.Patients:One hundred fifty-four patients aged 6 months to 14 years undergoing tympanostomy tube insertion participated.Intervention:For each subject, one ear was randomly assigned to receive topical ciprofloxacin, placed in the middle and external ear after surgery, while the contralateral ear served as a control.Main Outcome Measure:Posttympanostomy otorrhea occurring during the period from 24 hours after surgery until 2 weeks after surgery was measured.Results:Topical ciprofloxacin application after tympanostomy tube insertion was associated with a significantly lower incidence of early posttympanostomy otorrhea. The rates of otorrhea for control and treatment ears were 9.1% and 3.9%, respectively (p=0.029).Conclusions:The topical administration of a single dose of ciprofloxacin solution after surgery is an effective treatment for the prevention of early posttympanostomy otorrhea.

ISSN:0192-9763    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:Delayed facial paralysis after stapes surgery is uncommon and has been reported after traditional, nonlaser techniques for stapedotomy. The purpose of this paper is to inform the reader of the potential risk of delayed facial nerve paralysis associated with the use of the potassium titanyl phosphate (KTP) laser for stapedotomy. Etiologic mechanisms are discussed.Study Design:The study was a descriptive study-case report.Setting:The study was conducted at a university-based otologic practice.Patients:Two patients with otosclerosis and delayed onset facial palsy 5 to 7 days after uncomplicated stapedotomy using the KTP laser were included in the study.Intervention:Potassium titanyl phosphate laser stapedotomy was performed. Patients received treatment of facial palsy with a tapering course of oral steroids.Main Outcome Measure:House-Brackmann facial nerve grade scores were used.Results:Improvement of House-Brackmann facial nerve scores from Grade VI to Grade I—II in one patient, and improvement from Grade IV to Grade I—II in the other was seen.Conclusion:The probable etiology of delayed facial palsy is viral neuritis from reactivation of dormant virus within the facial nerve, initiated by thermal stress of the KTP laser. Presentation and resolution of the facial palsy is similar to other types of delayed facial palsy resulting from nonlaser techniques of stapes surgery and other types of middle ear and neurotologic surgeries previously reported.

ISSN:0192-9763    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:This study aimed to describe far-advanced otosclerosis and to present the authors' results with stapedectomy in 78 ears with far-advanced otosclerosis.Study Design:The study design was a retrospective case review.Setting:The study was conducted at an Otology/Neurotology tertiary referral center.Patients:Stapedectomy was performed on 78 ears of 60 patients with far-advanced otosclerosis, and the results followed from 1 to 21 years with a mean of 5 years.Intervention:Stapedectomy was performed on all ears with faradvanced otosclerosis.Main Outcome Measure:Hearing for air conduction (AC) and bone conduction (BC), speech discrimination, and impedance were tested on all patients before and after operation. The Rinne test was performed on all ears with a 256-cycle magnesium tuning fork. The pure-tone average for AC and BC was computed for 500,1,000, and 2,000 Hz. Hearing improvement was defined as air-bone gap closure to 10 dB or less and/or AC improvement of 20 dB or more, with no decline in speech discrimination score of more than 10%.Results:Hearing improvement was achieved in 52 (66.7%) of 78ears of all operations. In group 1, AC was greater than 90 dB, BC was greater than 60 dB, and hearing improved in 26 (81.2%) of 32 ears of operations. In group 2, AC was greater than 90 dB and no measurable BC and hearing improved in 11 (68.8%) of 16 ears of operations. In group 3, there was no measurable AC and BC greater than 60 dB and hearing improved in two (50%) of four ears of operations. In group 4, there was no measurable AC and BC and hearing improved in 11 (42.3%) of 26 ears of operations. Nonmeasurable BC became measurable in 42.9% of ears, nonmeasurable AC became measurable in 73.3% of ears, and all of these became aidable after operation.Conclusions:A negative Rinne test result with a 256-Hz magnesium tuning fork proved to be the best test to separate far-advanced otosclerosis from sensorineural hearing loss of other causes. Stapedectomy is of benefit in most ears with profound hearing loss of far-advanced otosclerosis, especially in those ears with some measurable hearing by AC.

ISSN:0192-9763    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Hypothesis:The hypothesis that metronidazole can augment the ototoxicity of gentamicin was tested.Background:Metronidazole and gentamicin are antibiotics that are used in combination to provide broad-spectrum antimicrobial coverage. It has been observed clinically that an increased ototoxic effect occurs when these agents are used in combination.Methods:Groups of guinea pigs were given various doses of gentamicin alone, various doses of gentamicin in combination with metronidazole, or metronidazole alone. Auditory damage was determined electrophysiologically by measurement of the compound action potential. Hair cell damage was quantified by immunofluorescent microscopy.Results:Electrophysiologic data revealed an augmented ototoxic effect when metronidazole was given with both a moderate and a high dose of gentamicin. Thresholds (dB SPLp) for the compound action potential (Nl) for animals receiving a medium dose of gentamicin alone (50 mg/kg) were approximately 20-dB SPLp. This threshold increased to approximately 50-dB SPLp when metronidazole (35 mg/kg) was administered along with the medium-dose gentamicin. Additionally, animals receiving high-dose gentamicin (75 mg/kg) alone demonstrated increased NI thresholds from 85 to 95 when metronidazole (35 mg/kg) was added to the gentamicin regimen. This effect was evident histopathologically by increased cochlear hair cell damage. Outer hair cell loss for animals receiving medium-dose gentamicin alone did not differ from that of controls. When metronidazole (35 mg/kg) was combined, however, outer hair cell loss increased to approximately 50%.Conclusions:These data support the clinical observation of augmented ototoxicity in patients receiving combined gentamicin and metronidazole. Caution should be used when administering these two agents together. Clinicians should consider other antibiotic strategies whenever possible.

ISSN:0192-9763    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:To compare the short-term development of openset speech perception between implementations of the spectral peak (SPEAK) strategy in adults using the Nucleus 22 (N22) Spectra processor and the Nucleus 24 (N24) system with the SPrint processor.Study Design:Two sets of patients with a follow-up period of 3 months were compared.Setting:This study was conducted at the New York University (NYU) Medical Center.Patients:Thirty-six profoundly hearing-impaired adults were included in this study.Intervention:Sixteen adults received the N22 cochlear implant with the Spectra speech processor and twenty adults received the N24 cochlear implant with the SPrint speech processor.Main Outcome Measures:Open-set speech perception for the patients with N22 implants was evaluated preoperatively and postoperatively using the following measures: NU-6 monosyllabic words, Iowa sentences, and CID sentences. CNC words, CUNY sentences, and HINT sentences were used to assess the patients with N24 implants.Results:Results revealed that the N22 and N24 cochlear implant recipients had significant open-set speech recognition 3 and 6 months after implantation. The apparent favorable absolute scores for the patients with N24 implants were equalized when a multivariate analysis was performed to account for their younger age at time of implantation and shorter length of deafness.Conclusions:The growth of open-set word and sentence recognition in similar between the N22 and N24 cochlear implants. Longitudinal studies are needed to determine if higher ceiling scores are present in the N24. Further exploration of monopolar versus bipolar stimulation is warranted.

ISSN:0192-9763    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:To compare results of post-meningitic children who had cochlear implantation with partial or complete drill-out to those who had no drill-out.Study Design:This study is a retrospective case review.Setting:The Atlanta Cochlear Implant Group is a private, tertiary, outpatient clinic.Patients:Eligibility included all our post-meningitic patients, 2-17 years, having a cochlear implant between June 1990 and July 1997.Interventions:All subjects had a Nucleus 22 cochlear implant surgically implanted, speech processor programming and follow-up testing in our center, and aural rehabilitation in a variety of therapy settings.Main Outcome Measure:Open and closed set speech discrimination tests.Results:Test performance for speech understanding was highest in the non-ossified group and lowest, but above chance, in the ossified group with complete drill-out.Conclusions:While children with non-ossified cochleas performed best, even children with extensive ossification requiring complete drill-out benefited from cochlear implantation.

ISSN:0192-9763    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:This study aimed to determine the effects of preoperative speech reception on postoperative speech recognition with a cochlear implant and to develop a statistical index allowing prediction of postoperative speech recognition before implantation.Study Design:The study design was a retrospective case review with statistical modeling.Setting:The study was conducted at a tertiary referral center with an associated Veteran's Administration hospital.Patients:Postlingually deafened adults with and without residual speech reception participated.Intervention:Cochlear implantation with Cochlear Corporation CI-22 and CI-24 devices was performed.Main Outcome Measures:Monosyllabic word recognition was measured.Results:Duration of deafness and preoperative sentence recognition are both significant predictors of word recognition with a cochlear implant and can account for 80% of the variance in word recognition.Conclusions:Cochlear implant outcomes are variable but predictable within specific ranges.

ISSN:0192-9763    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:Insertion of complex, multichannel cochlear implant (CI) electrode arrays into ossified cochleas is now performed routinely. This study describes the hearing results obtained in a consecutive series of 21 patients with obstructed cochleas and compares these results to those in patients with open cochleas. The purpose of this study was to determine whether patients with ossification have speech perception results that are inferior to those of patients with no evidence of cochlear bone formation.Study Design:Retrospective analysis of consecutive clinical series.Methods:CI database review of 191 CI procedures at the University of Miami Ear Institute between 1990 and 1997 showed that 24 (13%) procedures were performed on patients with ossified cochleas. Open-set speech recognition scores obtained on the 11 pediatric and 7 adult English-speaking patients are compared to scores of 51 adult and 61 pediatric English-speaking CI patients with open scala.Results:Results of open-set speech recognition measures in adults and children with ossified cochleas were not significantly different from those of the reference groups.Conclusion:Speech recognition results of patients with ossified cochleas are essentially equal to those of patients with open cochleas. Degree of obstruction appears to have less effect on outcome than other factors such as duration of profound deafness or communication methodology in children among this group.

ISSN:0192-9763    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Hypothesis:The relative dose-related cochlear and vestibular ototoxicity produced by transtympanically injected streptomycin (SM) compared to that of gentamicin (GM) was assessed.Background:Although SM, the first aminoglycoside used transtympanically, is thought to be selectively vestibulotoxic, it has been replaced by GM in current clinical use. Little experimental data exist that directly demonstrate the relative cochlear and vestibular ototoxicity resulting from transtympanic administration of SM compared to GM.Methods:Histologic evaluation was performed on inner ears from Mongolian gerbils to study vestibular and cochlear damage. Comparisons were made between animals receiving single (1 X SM) and five daily (5 X SM) injections of SM/Gelfoamslurry and similarly injected and noninjected controls. These data were compared to results obtained using GM (1 X GM and 5 X GM) reported previously.Results:Two weeks after injection, parallel qualitative and quantitative changes were seen in posterior cristae and cochlear sensory epithelia in the 1 X and 5 X SM injected groups, similar those resulting from GM injections. Statistically significant decreases in number of hair cells were seen when 5 X SM injected ears were compared to 1 X SM injected ears and control ears. Increased damage was seen with increased dosage of each drug. Whenever damage was observed to the posterior crista sensory cells, damage was also seen in cochlear hair cells.Conclusions:In this model, SM and GM produced significant cochlear damage when vestibular damage occurred. These results suggest that, in the gerbil, SM and GM are ototoxic but not selectively vestibulotoxic. Increasing the number of transtympanic injections generally increases the damage to sensory hair cells in the posterior crista and the cochlea. A variation in interanimal susceptibility to ototoxic effects exists, but the amount of damage is consistent in cochlear and vestibular hair cells from the same animal. No evidence for selective vestibular ototoxicity from transtympanic SM was found.

ISSN:0192-9763    

出版商:OVID    

年代:1999

数据来源: OVID