ISSN:0192-9763    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

We describe a laser Doppler system (LDS) that can be used clinically for the measurement of tympanic membrane (TM), malleus and prosthesis head displacement in response to sound inputs of 80− to 100-dB sound-pressure level (SPL). It also has the potential for use in the operating room to perform measurements of prosthesis and stapes displacement. The information provided by such testing gives the otologist knowledge of TM and ossicular function that is unique in evaluating middle ear function; it should help select the best type of reconstruction in a given case and direct us toward new and better methods of TM and ossicular reconstruction. The results of umbo displacement measurements in 95 human ears are reported. Examples are provided of LDS measurements in representative ears and how they can be of help to the clinician. The potential of multisite TM-displacement testing is demonstrated in two temporal bones, including before and after partial ossicular replacement prosthesis (PORP) insertion.

ISSN:0192-9763    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Posteromedial retraction of the tympanic membrane, between the oval window superiorly and the round window niche inferiorly, results in the formation of an epitheliumlined pocket within the sinus tympanic recess. Failure to recognize posterior invagination of the tympanic membrane intraoperatively leads to inadvertent tearing of the tympanomeatal flap at the level of the annulus with epithelial seeding of the middle ear and probably cholesteatoma recurrence. This article focuses on the clinical manifestations and radiographic findings suggestive of sinus tympanic epithelial retraction of the pars tensa and provides direct correlation between human cross-sectional temporal bone anatomy and otomicroscopy. The surgical management of these challenging lesions includes initial endaural access, external meatal bone removal posteromedial to the tympanic annulus and anterior to the vertical portion of the facial nerve, and middle ear ventilation after marsupialization of the epithelial retraction. Although early tympanic membrane retraction can be treated with a ventilation tube, deep epithelial pockets may require additional surgical treatment. A method for the management of sinus tympanic cholesteatomas is demonstrated.

ISSN:0192-9763    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Investigation of a possible viral etiology for otosclerosis was initiated because of the clinical and histopathologic similarities between otosclerosis and Paget's disease of bone and the mounting evidence of a viral etiology in Paget's disease. Thus far, ultrastructural and immunohistochemical studies have revealed measles-like structures and antigens in active otosclerotic lesions. A method for isolation and identification of both DNA and RNA sequences in archival human temporal bone specimens using the polymerase chain reaction technique has been developed. With use of this technique, a 115-base pair sequence of the measles nucleocapsid gene has been identified in 8 of 11 different temporal bone specimens with histologic evidence of otosclerosis. Zero of nine control specimens without histologic evidence of otosclerosis were positive. The association between the presence of the measles nucleocapsid gene sequence and histologic otosclerosis was significant (p<0.01). This study provides further evidence for a possible measles virus etiology in otosclerosis.

ISSN:0192-9763    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Clinical records were reviewed to examine the effectiveness of stapedectomy in patients 70 years and older. A total of 154 patients was studied, including 11 with profound hearing loss with long-standing otosclerosis. Ages at the time of surgery ranged from 70 to 92 years (mean, 76.3 years). The mean pure-tone average (500, 1,000, 2,000, and 4,000 Hz) improved 30.6 dB after surgery for the 143 patients in the main otosclerotic group and 26.8 dB for the patients in the profound-hearing-loss group. The rate of successful stapedectomies for the 70+-year-old patients (90.9%) and the younger comparison group (90.0%) were similar. These findings extend the documented range of stapedectomy as a safe and effective procedure through the eighth decade of life.

ISSN:0192-9763    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo identify a consensus on the postoperative barore-strictions after stapes surgery and to examine the clinical barotrauma experience within this patient population encountered by the surveyed physicians.Data SourceA 34-item survey was developed, allowing for detailed analysis of physician demographic data, practice characteristics, surgical experience, and clinical experience with barotrauma after stapes surgery. The postoperative restrictions addressed by the survey included those for air travel, snorkeling, and scuba diving. Recommendations for the use of ventilation tubes and hyperbaric oxygen therapy were investigated as well.Study SelectionSurveys were mailed to 419 active members of the American Otological Society and the American Neurotology Society as listed in the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) 1994–1995 Conjoint Directory. A total of 284 (67.8%) surveys were returned, of which 53 were not sufficiently completed and were excluded in the statistical analysis.Data ExtractionThe demographic data and clinical experience were analyzed to determine statistical association with the postoperative recommendations using χ2or Fisher's exact tests. The kappa statistic was used as a measure of consistency between physicians' recommended restriction for a specific activity after a stapedectomy or stapedotomy.ConclusionNo consensus was demonstrated as to restrictions from activities such as air travel, snorkeling, or scuba diving. Despite this lack of consensus, no significant difference was demonstrated in the prevalence of barotrauma reported within the responding physicians' practices based on their individual recommendations for these activities.

ISSN:0192-9763    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Between 1977 and 1995, nine stapedectomies using the Robinson-vein graft technique were performed in six high-performance airplane pilots diagnosed with otosclerosis. All of them returned to full active duty after stapedectomy without any vestibular symptoms. These cases illustrate that it can be safe for fighter or test pilots to return to full flight status after stapedectomy. These cases also suggest that full flight status can be reinstated as soon as 3 months after stapedectomy without endangering flight safety.

ISSN:0192-9763    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Mitochondrial ribosomal RNA mutation has been shown to predispose affected individuals to aminoglycoside-induced hearing loss (AIHL). An A-to-G nucleotide substitution at the 1555 position within the 12S ribosomal RNA gene has been identified with a maternally inherited pattern in affected Asian pedigrees. The aim of this study was to identify the frequency of this DNA polymorphism in subjects who appear to show hypersensitivity to topical (middle ear) application of aminoglycoside. In this pilot study, 10 subjects with AIHL were recruited. Eight underwent vestibular ablative therapy with middle ear instillation of gentamicin for disabling vertigo, and two were treated with topical antibiotic drops for otitis media in the presence of a tympanic perforation. DNA samples were extracted, and polymerase chain reaction (PCR) technique was used for gene amplification and purification, searching for 1555 A-to-G substitution in the 12S ribosomal RNA gene. None of the subjects demonstrated this specific mutation.

ISSN:0192-9763    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Some studies in the past have shown that carriers of genes for recessive deafness cannot be identified by standard audiometry. However, remarkable results with regard to the identification of heterozygotes have been reported using Békésy audiometry and Audioscan audiometry. In the present study, nine obligate carriers from five families with the Usher syndrome type IB were examined. Methods that reflect the function of the cochlea, including pure-tone audiometry, Audioscan audiometry, and otoacoustic emission measurements were used to detect (subtle) audiometric manifestations of heterozygosity. Abnormalities in hearing sensitivity were found in some obligate carriers but to the same extent in some of the controls. No statistically significant differences were found in the presence of audiometric abnormalities between carriers and controls. Additional audiologic measurements indicated that if hearing loss was present in Usher type IB carriers, it was presumably of cochlear origin. It is concluded that carriers of the Usher syndrome type IB cannot be identified properly via standard audiometric methods.

ISSN:0192-9763    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo develop techniques for measuring the positions of the individual electrodes of a multiple channel cochlear implant and for estimating associated characteristic frequencies.BackgroundInformation concerning the positions of the individual electrodes of a cochlear implant array is important for analyzing speech perception or psychophysical data and for optimizing speech-processing strategies. This study presents two techniques for obtaining such information from postoperative plain film radiographs.MethodsA template spiral shape, derived from analysis of the radiographs of 30 cochlear implant patients, is used to obtain measurements of the angular positions of the electrode bands within scala tympani. A research technique measures angular positions and estimates characteristic frequencies for all electrode bands but requires that the positions of two cochlear landmarks and all electrode bands be digitized. A clinical technique provides similar angle and frequency estimates but requires a minimum of information to be extracted visually from the radiograph. The lateral positions of the bands are estimated, in the research technique, using mean outer and inner wall functions obtained from 11 Silastic molds of scala tympani.Results:The mean position of the implanted array relative to the mean scala tympani outer wall function was consistent with published histologic observations of implanted temporal bones. Measured angles did not vary greatly with experimenter or with rotation of the cochlea relative to the radiographic beam by up to 20°.ConclusionsThe techniques described allow, principally, measurement of the longitudinal positions of the bands of a cochlear implant in scala tympani and estimation of corresponding characteristic frequencies.

ISSN:0192-9763    

出版商:OVID    

年代:1996

数据来源: OVID