摘要:

Identification of small acoustic neuromas has become commonplace. Frequently, affected individuals are identified prior to the development of significant hearing loss. Whereas many studies have focused on hearing preservation surgery, few have reported on stability of hearing results after resection of acoustic neuroma. Between 1985 and 1991, 36 patients underwent resection of an acoustic neuroma via a retrosigmoid, internal auditory canal approach with attempted hearing preservation. Hearing was preserved in 24 patients; 17 were available for testing for the present study. Follow-up ranged from 1.5 to 8 years. All patients underwent complete audiologic assessment; most patients also underwent auditory brainstem response testing. There was an average 6 dB increase in pure-tone average between early (1 month) postoperative and long-term postoperative test results. A binomial single subject statistic was used to assess for significant changes in speech recognition scores over time. In two subjects there was a significant decrease; however, speech recognition also improved significantly in two subjects. Five of the 17 subjects demonstrated either a significant (at least 15 dB) increase in pure-tone average or a significant decrease in speech recognition over the time-course of the study. All patients maintained usable hearing. We conclude that long-term hearing preservation is a realistic goal in selected acoustic neuroma operations.

ISSN:0192-9763    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The Xomed Audiant(tm) Bone Conductor(tm) is an implantable hearing device for conductive hearing impairments not adequately relieved by surgical methods or hearing aid amplification. It has now been used long enough for analysis of its present position in our management armamentarium. Data obtained from respondents from the United States and Canada are presented and indicate that this device, properly prescribed and used, almost eliminates the conductive elements of the hearing impairment. During the early years of its use, the device was frequently implanted in patients outside the manufacturer's guidelines for use. Some of the reasons for this discrepancy, as well as evidence that this misapplication is lessening, are presented. When proper guidelines were used, however, the results presented here indicate that socially adequate hearing can be restored to patients with conductive loss by the Audiant(tm). Complications have been few and appear to be diminishing. The results indicate that this device has, in its present state of development, a narrow and restrictive application, but a well-defined and efficient role to play in the management of conductive hearing impairment.

ISSN:0192-9763    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Immune inner ear disease is a relatively new and distinct clinical entity that produces unexplained, rapidly progressive, bilateral sensorineural hearing loss. The diagnosis is based on clinical manifestations, positive immune laboratory testing, and beneficial response to a trial of corticosteroids. Immune laboratory tests are used to confirm a presumptive clinical diagnosis. The two tests most commonly used are the lymphocyte transformation test and Western blot immune assay. The rationale behind these tests is presented, and the role they play in laboratory diagnosis of immune inner ear disease is discussed.

ISSN:0192-9763    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Since my report of 4 years ago at the 8th Shambaugh-Shea Workshop in Otology, equipment and software techniques have continued to evolve with consequent further refinement of imaging studies. Three-dimensional images have greatly improved and have acquired an important role in maxillofacial reconstructive surgery. In otology their value is limited except in congenital atresia. New developments in imaging technique (3-D Fourier transformation) allow sections as thin as 1 mm in any plane. The facial nerve, endolymphatic sac and vestibular aqueduct are well demonstrated but differentiation of the components of the membranous labyrinth is limited. Applications of postcontrast imaging have become more defined for cerebellopontine angle masses, inner ear pathology, and middle ear and facial nerve lesions. Gradient echo techniques and bipolar flow encoding have enabled the development of magnetic resonance angiography. This new, noninvasive procedure is currently useful for the study of aneurysms, vessel stenosis, vascular tumors, and arteriovenous shunts and malformations.

ISSN:0192-9763    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Transiently evoked otoacoustic emissions (TEOAE) are generally present in ears with normal hearing, but absent in ears with cochlear hearing losses greater than 25—30 dB; they have been demonstrated previously in a few ears with retrocochlear hearing losses greater than 30 dB across the frequency range 0.25–8 kHz. To assess the potential of TEOAEs in the diagnosis of retrocochlear hearing losses, measurements were made in 45 patients with retrocochlear disorder attributable to confirmed cerebellopontine angle (CPA) tumors. Transiently evoked OAEs elicited by click stimuli were recordable in 21 (47%) of the ears with tumor. Nine of these had normal hearing at two or more octave frequencies across the range 0.5—4 kHz and so might be expected to have TEOAEs regardless of the type of disorder. The other 12 ears had recordable TEOAEs despite hearing threshold levels greater than 25 dB between 0.5 and 4 kHz. The absence of TEOAEs in the remaining 24 ears (53%) indicated a significant outer hair cell component to the hearing loss. Neither age nor sex were significant factors in the occurrence of TEOAEs. The TEOAE test gives useful differential diagnostic information when emissions are recorded in ears having hearing threshold levels greater than 25 dB at all frequencies. In such ears there is relatively normal cochlear function at the level of the outer hair cells, at least at some frequencies, and hence, by inference, there must be a retrocochlear disorder.

ISSN:0192-9763    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Cholesteatoma epithelium is characterized by a keratinocyte dysregulation with an aggressive growth that leads to the destruction of normal middle ear mucosa. The abnormal behavior of cholesteatoma epithelium seems to be induced by the presence of a heavy immune cell infiltrate releasing different cytokines and growth factors in high amounts. Middle ear mucosa rests are often observed within the cholesteatoma stroma or adjacent to the advancing front of cholesteatoma epithelium. This study investigated the presence of interleukin-1 (IL-1), transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF), and epidermal growth factor-receptor (EGF-R) in the mucosa rests as well as the expression of an activation marker, 4F2. The findings were correlated with the features of a surrounding stroma with an enhanced immune cell infiltrate. Cholesteatoma epithelium showed a high staining intensity of IL-1, TGF-alpha, and EGF-R. In contrast to this, middle ear mucosa did not show any positive reactions for the mentioned factors. Epidermal growth factor immunoreactivity was found in neither cholesteatoma epithelium nor in middle ear mucosa residues. The authors found a high concentration of lymphocytes and macrophages in the surrounding stroma. Most of these cells expressed TGF-alpha, IL-1, and 4F2, suggesting an activated form. Results indicate that keratinocytes present in the middle ear mucosa do not appear to react to the stimuli released by the inflamed stroma, reflecting important differences in the cell biological features of the keratinocytes that form parts of both types of epithelium.

ISSN:0192-9763    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The presence of antibodies to collagens type I, II, III, VI, IX, and XI was studied in patients with otosclerosis, using enzyme-linked immunosorbent assays. Levels of antibodies to collagens type II and IX were significantly higher in these patients as compared to sex- and age-matched control subjects, whereas no differences were found between the levels of antibodies to collagens type I, III, VI, and XI. These observations for the first time document the presence of autoantibodies against a minor collagen type IX in patients with otosclerosis and support a possible role for collagen autoimmunity in the etiology of otosclerosis.

ISSN:0192-9763    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Far-advanced otosclerosis (FAO) is an uncommon diagnosis. Hearing levels in patients with FAO may range from profound loss, by air conduction and fragmentary bone conduction thresholds, to no measurable air or bone conduction thresholds. Thus, FAO may be difficult to distinguish from a sensorineural hearing loss. This report presents the results of surgery in 73 ears with FAO, 77 percent of which had improvement in air conduction thresholds of greater than 20 dB. Discrimination was improved by more than 15 percent in 54 percent of cases, and 75 percent realized improvement in use of a hearing aid. There was no evidence that success was related to preoperative hearing. The surgical results of a subgroup of 14 patients having bilateral FAO were also analyzed. For all 14, similar surgical outcomes were achieved in both the initial and the contralateral ear, with six successes bilaterally and eight failures bilaterally. Although far advanced otosclerosis is uncommon and difficult to diagnose, surgery is worthwhile.

ISSN:0192-9763    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Surgical findings and long-term results of 112 revision operations performed for failures after cholesteatoma surgery were studied. The indication for revision was recurrence of cholesteatoma in 43 percent, persistent otorrhea in 27 percent, dry reperforation in 10 percent, and unsatisfactory hearing result in 18 percent. Of the recurrences, 71 percent were regarded as residual cholesteatomas (i.e., arising from a cholesteatoma remnant left at the primary operation). Infected unexenterated mastoid air cells were found in 63 percent of ears reoperated on for persistent discharge. Thus, it is reasonable to conclude that at least 48 percent of our revisions could have been avoided if the surgeon had used more skillful and more radical surgical technique when performing the primary operation. On the other hand, the persistence of cholesteatoma and the difficulty of eradicating the disease is highlighted by the finding that cholesteatoma again recurred in three patients (3%) after the first revision.

ISSN:0192-9763    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Auditory brainstem response (ABR) is a good screening test for cerebellopontine angle (CPA) tumors and other retrocochlear diseases. The pathologic correlates of many cases with positive ABR remain unknown. A two-staged clinical study was performed to help us understand the significance of a false-positive ABR. In the first stage, data from 66 patients with abnormal ABR were reviewed. Nineteen patients had identifiable causes for the ABR abnormality, whereas 47 patients had no lesions identified. In the second phase of the study 21 of the 47 patients were re-evaluated with a minimum follow-up period of 1 year. A detailed interval history was obtained, and the work-up, including imaging studies, was repeated in an attempt to reach a diagnosis. One patient was found to have a CPA tumor, but for nine patients a definite final diagnosis could not be determined. The implications of abnormal ABR and normal initial imaging study are discussed, and a plan for the work-up of these patients is suggested.

ISSN:0192-9763    

出版商:OVID    

年代:1994

数据来源: OVID