ISSN:0192-9763    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:To assess the efficacy of intraoperative brainstem auditory evoked responses (BAER) in predicting postoperative hearing improvement in surgery for conductive hearing loss.Study Design:A prospective study of consecutive patients undergoing surgery for conductive hearing loss under general anesthesia by a single surgeon.Setting:A tertiary care university affiliated medical center.Patients:All patients undergoing surgery for conductive hearing loss by the senior author between June 25,1993 and March 20,1995.Interventions:Pre- and postreconstruction intraoperative BAERs; pre- and postoperative pure tone and speech audiometry.Main Outcome Measures:Changes in audiometric pure tone air-conduction thresholds, bone-air gaps (BAG), and speech reception thresholds (SRT), compared with changes in BAER wave five (V) latencies.Results:A decrease in the wave V latency on the intraoperative BAER correlates significantly with improvement in postoperative puretone air-conduction, BAG, and SRT using X2and linear regression analyses.Conclusions:Improvement in intraoperative BAER correlates with postoperative hearing improvement in surgery for conductive hearing loss done under general anesthesia in our population.

ISSN:0192-9763    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Summary:Successful canal wall reconstruction after open cavity surgery may be compromised by both immediate (graft dehiscence and infection) or delayed (graft retraction, absorption, and extrusion) complications. Many of the healing problems following canal wall reconstruction are related to incomplete soft tissue coverage of the graft and limited blood supply. Under these conditions, we sought to increase graft viability with a broad-based perichondrial flap developed from the posterior surface of the auricle. The flap was used over a period of 3 years at a tertiary referral center in 36 cases of canal wall reconstruction in conjunction with composite grafts of cartilage and perichondrium. The patients ranged in age from 12 to 63 years and in all cases had undergone a canal down tympanomastoidectomy that was reconstructed either primarily or secondarily. The canal wall was successfully reconstructed in 35 of 36 ears. These results demonstrate a reduction in our dehiscence rate from 10 to 3% since the introduction of the perichondrial flap. With the perichondrial flap, we were consistently able to achieve better soft tissue coverage of the composite cartilage graft, eliminate lateral graft dehiscence, and encourage reepithelization of the canal. By implication, we believe this flap provides a source of nutritional support for the free cartilage graft as well as the overlying skin.

ISSN:0192-9763    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Summary:The objective of this study was to describe the light microscopic pathology of labyrinthine fistulae in chronic otitis media (COM) in seven temporal bones and to discuss clinical and surgical implications. In COM, labyrinthine fistulae are usually caused by cholesteatoma, with the lateral semicircular canal being the most commonly affected site. Some fistulae are asymptomatic, whereas others affect the auditory and vestibular systems to varying degrees. Surgical removal of cholesteatoma matrix over a fistula carries a risk of sensorineural hearing loss. Knowledge of the pathology of fistulae may provide a better understanding of their clinical manifestations and may allow a more rational approach to surgical management. The Massachusetts Eye and Ear Infirmary temporal bone collection contains 115 specimens with COM, of which seven specimens show pathologic fistulization of the bony labyrinth. Histologic sections from these seven bones were evaluated with respect to type of COM, location and size of fistula, changes in the inner ear adjacent to the fistula, middle ear and mastoid disease, and pathology in the vestibular and cochlear sense organs. The following conclusions are presented (a) Labyrinthine fistulae can be caused not only by cholesteatoma, but also by granulomatous COM without cholesteatoma and even by localized infection within a canal-down mastoid cavity. (b) Cholesteatoma matrix or inflammatory tissue usually becomes apposed to the endosteum or membranous labyrinth within the fistula. In most cases, reactive inner ear changes do not occur at the fistula site. Occasionally, there is thickening of the endosteum or chronic localized labyrinthitis. (c) Most bones do not show any alterations of the vestibular and cochlear sense organs. Occasionally, there is serous labyrinthitis, which might lead to partial sensorineural hearing loss. (d) A protective “walling-off” phenomenon in the labyrinth is not common. Therefore, if overwhelming infection or surgical trauma breaches the natural barriers of the endosteum/ membranous labyrinth, then the fistula may allow rapid dissemination of infection throughout the inner ear.

ISSN:0192-9763    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:To describe clinical and radiographic characteristics of vascular loops occupying the internal auditory canal.Study Design and Setting:A retrospective review of patients with lesions initially suggestive of neoplasm, such as acoustic neuroma, who were subsequently found to have vascular compression of the facial and/or cochleovestibular nerves. The symptoms suggestive of this retrocochlear pathology, including vertigo, tinnitus, hearing loss, hemifacial spasm, and facial paralysis, were assessed. Subsequent evaluation with MRI revealed findings suggestive of intracannalicular neoplasm in three patients.Main Outcome Measures:Vascular loops within the cerebellopontine angle have been reported to approach the facial and cochleovestibular nerves at the level of the porus acousticus or within the internal auditory canal in ˜65% of postmortem specimens. Although presumably the majority of individuals are asymptomatic, several cases are presented where vascular loop compression created symptoms and radiographic findings suggestive of neoplasm.Results:Within this study, two patients underwent surgical exploration for expected neoplasm and were subsequently found to have pathology secondary to vascular loop compression. A third patient avoided surgical exploration due to radiographic confirmation with angiography.Conclusions:Although skepticism exists regarding true pathology occurring secondary to vascular loop compression, histologic confirmation of neural compression injury secondary to a vascular loop is presented. Further, diagnostic parameters and treatment are presented as well.

ISSN:0192-9763    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:Our goal was to describe three cases of acute sensorineural hearing loss (ASNHL) that might be caused by arterial dissection of the vertebrobasilar system.Design:Retrospective case review. Setting: Yamagata University Hospital, Yamagata, Japan.Patients:Thirty-seven patients with ASNHL underwent magnetic resonance (MR) imaging between September 1993 and March 1995.Interventions:Proton density and T2-weighted axial images and three-dimensional spoiled gradient-recalled acquisition in steady state (3-D SPGR) imaging with gadopentetate dimeglumine were obtained with a 1.5 T MR system in all patients. T1-weighted images were obtained in 23 patients. Vertebral angiography (VAG) was performed in 4 of the 37 patients.Results:In 3 of the 37 patients, the presence of vertebrobasilar dissection was confirmed: contrast-enhanced 3-D SPGR images disclosed double lumen of the proximal basilar artery and/or the ipsilateral vertebral artery in all of the 3 patients. In two of them, the vertebrobasilar dissection was also confirmed by VAG. The hearing loss of all three patients improved after the onset. Audiograms revealed no characteristic pattern of the initial hearing loss among them.Conclusions:Vertebrobasilar dissection may cause an intramural hematoma involving the orifice of the anterior inferior cerebellar artery or a distal thromboembolism reducing the blood flow of the labyrinthine artery; these conditions can lead to onset of hearing loss. Arterial dissection of the vertebrobasilar system might be one of the causes of ASNHL.

ISSN:0192-9763    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Summary:Transtympanic electrical stimulation, either in the form of round window or promontory placement of electrode prior to cochlear implantation is an accepted and commonly used psychophysical tool. Certain response parameters have been identified as predictors of outcome. This study compared the subjective auditory responses generated by promontory electrical stimulation (PES) with those from two noninvasive modalities, namely peritympanic electrical stimulation (PTES) and transcranial magnetic stimulation (TMS). Ten postlingually deafened adult cochlear implant candidates were studied. Standard psychophysical parameters were obtained from patients undergoing PES and PTES. A more subjective form of evaluation was conducted for TMS. Subsequently, nine patients received the multichannel Nucleus (Cochlear Corp., Denver, CO, U.S.A.) implant and one patient a Clarion (Advanced Bionics, Sylmar, CA, U.S.A.) implant. Compared with PES, PTES elicited increased threshold responses with similar dynamic ranges between 50 and 400 Hz of stimulation. The differences were, by and large, insignificant. PTES appeared to be a useful alternative in selected individuals owing to its noninvasiveness. TMS, on the other hand, was incapable of clearly inducing auditory percepts. It also produced concomitant facial and trigeminal stimulation, limiting its potential use as a prognostic tool.

ISSN:0192-9763    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:To evaluate the efficacy and toxicity of intratympanic gentamicin therapy for the treatment of Meniere's disease.Study Design:We compared retrospective case series with historical controls.Setting:A tertiary referral center—the ambulatory clinic at The University of Pittsburgh Medical Center.Patients:The study consisted of 28 patients with Meniere's disease who failed conventional medical therapy and were offered gentamicin treatment or surgical intervention. Patients had to be followed for at least 2 years to be eligible for review.Intervention:Intratympanic gentamicin solution injections were given by serial titration to the involved ear on a weekly or biweekly schedule.Main Outcome Measures:Adhering to the American Academy of Otolaryngology—Head and Neck Surgery 1985 criteria for reporting treatment results in Meniere's disease, the hearing status, control of vertigo, and disability scores using intratympanic gentamicin therapy were reported and compared with historical controls.Results:Complete or substantial control of vertigo was achieved in 91% of patients. Hearing loss occurred in approximately one third of patients. Historically, similar hearing loss occurs in patients who were treated successfully, either medically or surgically. Ototoxicity (high frequency hearing loss) was more likely to be seen in patients with pretreatment 8,000 Hz hearing thresholds better than 65dB.Conclusions:Intratympanic gentamicin therapy given by serial titration injections provides significant control of vertigo without the significant cost and potential morbidity of a more invasive surgical procedure.

ISSN:0192-9763    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Summary:To define better the benefits and risks of intratympanic gentamicin injection treatment of intractable vertigo or drop attacks due to Ménière's disease, we reviewed the charts of 18 patients whom we have now observed for >1 year after having completed this mode of therapy. There were nine women and nine men aged 29-81 years; all had poor hearing in the affected ear. Of the 18 patients, 14 have had no further vertigo or drop attacks (11 patients after a single set of three to five injections, another three after a further set of one to five injections). The treatment could be effective even if it did not abolish caloric responses from the treated ear, even if it did not produce an acute vestibular deafferentation syndrome afterwards, and even after a failed vestibular nerve section. After treatment, five of the 18 patients developed oscillopsia and ataxia—symptoms and signs of (presumably permanent) chronic vestibular insufficiency; this proportion is not obviously lower than that after vestibular neurectomy or surgical labyrinthectomy. Of the 18 patients, 12 showed no change in the 1-kHz threshold and 13 showed no change in the 4-kHz threshold. When hearing did deteriorate, the threshold rose by more than 30 dB at 1 kHz in four patients and at 4 kHz in six patients. We conclude and confirm that intratympanic gentamicin injections are a convenient and, in most cases, effective and safe treatment for intractable vertigo or drop attacks due to Ménière's disease.

ISSN:0192-9763    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Summary:The pathophysiology of hearing deterioration in Meniere's disease (MD) is unclear. Hair cell loss has been proposed to be the cause of severe hearing loss in Meniere's disease. The cochlear microphonic (CM) is known to be the receptor potential of the outer hair cells in the cochlea. This study measured the CM in Meniere's disease and investigated its relationship with the degree of hearing impairment and endolymphatic hydrops. Transtympanic electrocochleography (ECoG) using rarefaction (RAR) and condensation (CON) tonebursts at 1 kHz was performed on 130 ears of 119 patients. Ninety six ears were diagnosed to have MD and 34 were diagnosed non-Meniere's disease (NMD). The mean amplitude of the CM was 33.10 ± 46.04 µV in the MD group and 13.15 ± 12.77 µV in the NMD group (p <0.001). Enlarged negative summating potential and action potential ratios (SP:AP >40%) were found in 81.3% of the MD group and 17.6% of the NMD group. In the MD group, the CM in the group with an enlarged negative SP was 36.98 ± 49.78 µV, and 16.31 ± 15.88 µV in the group without (p <0.01). The CM was 34.33 ± 49.28 µV in the pure-tone average (PTA) ≤ 25 dB group, 46.97 ± 58.31 µV in the 26-40 dB group, 29.12 ± 42.62 µV in the 41-70 dB group, and 26.20 ± 22.41 µV in the >70 dB group (p >0.05). The CMs in 11 pairs of MD ears and sensorineural hearing loss (SNHL) ears with matching hearing (MD 44 dB, SNHL 45 dB) were measured. They were 71.42 ± 75.94 µV and 7.90 ± 5.89 µV, respectively (p <0.01). Our study shows that the CM is higher in ears with endolymphatic hydrops, evidenced by an enlarged SP:AP ratio, than ears without and the CM shows no statistical difference in groups with different levels of hearing loss. These findings suggest that hearing loss with a large CM in Meniere's disease patients may be the result of an alteration of cochlear mechanics and only severe hearing loss with a small CM is caused by hair cell loss. The CM measurement, to evaluate the hair cell status, may be helpful in identifying patients whose hearing may be recoverable if the underlying hydrops can be corrected. Our data do not permit the conclusion that an enlarged CM can be used in the diagnosis of MD.

ISSN:0192-9763    

出版商:OVID    

年代:1997

数据来源: OVID