The American journal of otology最新文献

Objectives: To evaluate clinical data, extensions, residual and recurrent lesion rates, and functional results in cases of cholesteatoma in pediatric patients.

Design: A retrospective study at a single tertiary care center over a decade.

Patients: In 199 children (mean age 9.6 years), 215 cholesteatomas were treated surgically, and the children were followed up for an average of 70 months (range 25-118 months).

Interventions: Therapeutic and rehabilitative surgical procedures were done, using either a closed technique (CT) or an open technique: tympanoplasty in open technique (TOT), radical mastoidectomy (RM), or Rambo's technique)

Main outcome measures: Surgical findings, residual and recurrent lesions rate, and hearing assessment.

Results: The first surgical procedure was CT in 88% of cases, TOT in 10%, RM and Rambo's technique in 1%. Two operations were done in 61.8% of children; 21% had three operations and 4.5% had four. Residual lesions were observed in 21.5% of all children, 32.8% in those undergoing a planned second look. Recurrence rate was 9.8%. Surprisingly, residual and recurrent lesion rates were higher after TOT (23.8% and 19%) than after CT (20.5%, 8.9%), but TOT-treated children had much more extensive lesions. A speech reception threshold (SRT) <30 dB hearing loss (HL) was achieved in 63.7% of patients, and normal hearing was obtained in 12.1%; SRT was significantly better after CT (mean 26.7 dB) than after TOT (mean 37.4 dB), after type II (mean 27 dB) than after type III (35 dB). A high-frequency pure-tone hearing loss >10 dB was uncommon (7.6%).

Conclusion: These results support the continued use of CT in most cases of cholesteatoma in children in developed countries.

Objective: To determine the effect of topical adrenaline application after myringotomy and before tympanostomy tube placement on the development of myringosclerosis.

Study design: A prospective, randomized, double-blind study, with each patient acting as his or her own control. Ethical approval and full parental consent were obtained.

Setting: Department of Otorhinolaryngology-Head and Neck Surgery in a university teaching hospital.

Patients: Fifty children satisfying inclusion and exclusion criteria for first-time tympanostomy tube insertion. THERAPEUTIC INTERVENTION: Myringotomy followed by adrenaline application to incision before tympanostomy tube insertion. Control contralateral ear received saline application after myringotomy. Follow-up examination was done 14 to 21 days after surgery and again after 1 year by a single blinded surgeon.

Main outcome measure: Comparison of myringosclerosis between adrenaline-treated ears and matched control ears.

Results: No difference was found in early morbidity between the two groups of ears. Myringosclerosis after 1 year was not found to have been significantly affected by adrenaline application (p = 0.2)

Conclusion: The use of adrenaline on the myringotomy site before tympanostomy tube placement was not found to influence early postoperative morbidity or the later development of myringosclerosis.

Objective: To assess the magnetic resonance imaging (MRI) compatibility of stapes prostheses.

Data sources: A comprehensive review of the English literature evaluating MRI compatibility of stapes prostheses. Multiple series of stapes prostheses from different manufactures placed in a 1.5-tesla MRI field to determine ferromagnetic properties.

Results: When MRI was first introduced, reports demonstrated the MRI compatibility of stapes prostheses. The testing was performed on single copies of various prostheses from several manufacturers. Although implant manufacturers have indicated MRI compatibility, several reports of variable ferromagnetic properties of aneurysm clips have been reported. This variability has led to rotation of the clips and hemorrhage in patients with supposed MRI-compatible clips. These findings suggest that testing single stapes prostheses from a manufacturer might not completely assess the safety of MRI on patients with stapes prostheses. We performed MRI compatibility testing on several series of stapes prostheses from Xomed Surgical Products and Smith & Nephew Richards. Two series of Xomed stapes prostheses were found to have ferromagnetic properties.

Conclusion: Manufacturing variability could lead to stapes prostheses being MRI incompatible. Each prosthesis should be tested before implantation for ferromagnetic properties.

Hypothesis: The goals of this investigation were to compare the efficacy of three protective agents against cisplatin-induced elevation of auditory brainstem response (ABR) thresholds and to examine whether these protective agents prevent cisplatin-induced alterations of the antioxidant defense system in the cochlea of the rat.

Background: Cisplatin is an ototoxic antitumor agent. Previous animal studies have shown that cisplatin administration causes an elevation of ABR thresholds. These auditory changes are accompanied by alterations in the concentration of glutathione and the antioxidant enzymes in the cochlea. The authors' previous work has indicated that the protective agent diethyldithiocarbamate (DDTC) prevents decrease in glutathione (GSH), alteration of antioxidant enzyme activity, and disruption of cochlear function with cisplatin administration.

Methods: Wistar rats were sedated and underwent pretreatment ABR testing using clicks and tone burst stimuli at 8, 16, and 32 kHz. Control rats received saline by intraperitoneal (i.p.) injection. Positive control rats were administered cisplatin 16 mg/kg i.p. Three groups of rats received protective agents in combination with cisplatin. The DDTC-protected rats were given 600 mg/kg of DDTC subcutaneously 1 hour after cisplatin. Animals protected by 4-methylthiobenzoic acid (MTBA) were given 250 mg/kg of this agent i.p. 30 minutes before cisplatin. Animals protected with ebselen were given 16 mg/kg i.p. one hour before cisplatin. The ABR thresholds were recorded 72 hours after cisplatin administration in all groups. Cochleas were removed, and extracts of the tissues were analyzed for GSH, activities of antioxidant enzymes (superoxide dismutase [SOD], catalase, glutathione peroxidase, and glutathione reductase) and malondialdehyde (MDA) (as an index of lipid peroxidation).

Results: Cisplatin-treated rats had significant ABR threshold shifts, ranging from 27 to 40 dB. Rats administered each of the three protective agents in combination with cisplatin had ABR threshold shifts of <10 dB. The cochleae of rats administered cisplatin alone had nearly a 50% depletion of glutathione and about a 50% reduction in the activities of SOD, glutathione peroxidase, and glutathione reductase, while catalase activity was reduced to 70% of control values. These changes were accompanied by a reciprocal elevation of MDA of 165%. These changes, namely, the depletion of GSH and antioxidant enzyme activity and the elevation of MDA in the cochlea, were largely attenuated by the administration of the protective agents tested.

Conclusion: These findings suggest that cisplatin ototoxicity is related to lipid peroxidation and that the use of protective agents prevents hearing loss and lipid peroxidation by sparing the antioxidant system in the cochlea. These results suggest the possibility that the clinical use of

Objective: To determine the prevalence and character of vestibular abnormalities and the changes in vestibular function that occur in unilateral Ménière's disease.

Study design: Retrospective case review.

Setting: Ambulatory patients at a tertiary care facility.

Patients: Entry criteria included a diagnosis of unilateral Ménière's disease and test results from at least two vestibular test sessions at the Johns Hopkins Otologic Vestibular Laboratory. One hundred twenty-two cases were evaluated.

Main outcome measures: Electronystagmographic evaluation, including caloric testing; audiometric tests; and medical records.

Results: Caloric weakness was demonstrated in 58% of patients on the involved side and in 19% on the normal side. Complete paralysis was found in 7%. Directional preponderance was seen in 33% of patients and completely normal scores in 27%. During the course of the disease, responses become weaker in 26% of patients and stronger in 11%. Of 39 patients tested more than twice, 26% showed both increases and decreases in caloric responses. After an acute attack, only one of eight patients showed a depressed response on the diseased side, and three showed an increased response. Spontaneous nystagmus, seen within 24 hours of an attack in 54 cases, was directed away from the diseased ear in only about one half of the cases. Benign paroxysmal positional vertigo was found in 44% of these patients.

Conclusions: Possible pathophysiologic explanations for the various test results in Ménière's disease are discussed. Interpretation of caloric test results should take into account the absolute value of the slow phase eye speed scores, in addition to the right-left difference score. Also, established standards for the normal range of fluctuation in both absolute and comparative scores should be used when more than one test session has been undertaken.

Objective: To investigate the accuracy of magnetic resonance imaging (MRI) as a preoperative imaging technique for cochlear implant candidates.

Study design: Retrospective, blinded.

Setting: Tertiary medical center.

Patients: 31 cochlear implant candidates with various causes of hearing loss.

Intervention: Cochlear implant patients received preoperative high-resolution temporal bone computed tomography (CT), and high-resolution T2-weighted fast spin echo MRI (FSE-MRI). The images were read independently of each other and in a blinded manner by two neuroradiologists. The imaging results were also correlated with intraoperative findings.

Main outcome measures: Lack of agreement between the findings for either imaging technique; also, lack of agreement between imaging findings and intraoperative findings.

Results: FSE-MRI is equal to CT imaging in the detection of abnormalities of cochlear patency. It is better than CT imaging in detecting cochlear dysplasia and large vestibular aqueducts, and in determining the presence of the cochlear nerve.

Conclusion: FSE-MRI is accurate in predicting inner ear anomalies and obstruction of the cochlear lumen. It also adds information not gathered from CT imaging, such as the presence and size of the cochlear nerve.

Objective: It is widely held that an enlarged summating potential (SP) relative to the eighth nerve action potential (AP) is a reflection of endolymphatic hydrops. Aminoglycosides are an accepted treatment for incapacitating Ménière's disease and are known to affect both sensory and secretory cells of the inner ear. The intent of this study was to determine whether this effect on secretory cells could be objectively confirmed by virtue of changes in the electrocochleogram (ECoG) of patients receiving gentamicin therapy for Ménière's disease.

Study design: This was a prospective longitudinal study of repeated ECoG measures in three groups of subjects. Ménière's patients undergoing gentamicin treatment were compared with two control groups: individuals with stable Ménière's disease and normal-hearing control subjects.

Setting: The study was conducted at a tertiary referral center.

Patients: The sample included 21 normal-hearing subjects, 15 patients with stable unilateral Ménière's disease, and 12 with disabling unilateral Ménière's disease.

Interventions: For patients with disabling Ménière's disease, gentamicin was administered transtympanically. Audiograms, impedance tests, and ECoG were performed twice for all subjects.

Main outcome measures: The SP and AP amplitudes, AP latency, and SP/AP ratio of the EcoG were measured.

Results: A statistically significant reduction in the SP/AP ratio was observed after gentamicin administration (analysis of variance interaction effect: F2 = 5.64; p = 0.0065).

Conclusions: The significant reduction in the SP/AP ratio in the gentamicin-treated Ménière's group supports the hypothesis that gentamicin improves the electrophysiologic function of the cochlea, possibly by reducing the severity of the associated endolymphatic hydrops.

Hypothesis: Round window membrane application of immunosuppressives reduces cochlear inflammation and hearing loss in a guinea pig model of sterile labyrinthitis.

Background: Systemic immunosuppressives are used to treat sensorineural hearing loss due to inflammation (autoimmune, bacterial, viral), which in animal models causes hearing loss. Transtympanic application of drugs is an attractive and possibly efficacious method of treatment that avoids systemic toxicities.

Methods: Sterile labyrinthitis was created using keyhole limpet hemocyanin (KLH). Dexamethasone (0.048 mg/day and 0.288 mg/day), cyclosporine (0.5%), prednisolone acetate (1%), fluorouracil, (5%), and FK506 (0.01%) were delivered to the round window membrane with one injection (filling middle ear space) or osmotic minipumps. Efficacy was evaluated by auditory brainstem response and histology.

Results: No drug was effective at reducing hearing loss or inflammation.

Conclusion: Local application of immunosuppressives did not suppress inner ear inflammatory infiltrates and hearing loss in KLH-induced labyrinthitis in a guinea pig model.

Objective: To define the indications for surgery in lesions of the internal auditory canal (IAC) and cerebellopontine angle (CPA) in an only hearing ear.

Study design: Retrospective case series.

Setting: Tertiary referral center.

Patients: Seven patients with lesions of the IAC and CPA who were deaf on the side opposite the lesion. Five patients had vestibular schwannoma (VS), and one each had meningioma and progressive osseous stenosis of the IAC, respectively. The opposite ear was deaf from three different causes: VS (neurofibromatosis type 2 [NF2]), sudden sensorineural hearing loss, idiopathic IAC stenosis.

Intervention(s): Middle fossa removal of VS in five, retrosigmoid resection of meningioma in one, and middle fossa IAC osseous decompression in one.

Main outcome measure: Hearing as measured on pure-tone and speech audiometry.

Results: Preoperative hearing was class A in four patients, class B in two, and class C in one. Postoperative hearing was class A in three patients, class B in one, class C in two, and class D in one.

Conclusions: Although the vast majority of neurotologic lesions in an only hearing ear are best managed nonoperatively, in highly selected cases surgical intervention is warranted. Surgical intervention should be considered when one or more of the following circumstances is present: (1) predicted natural history of the disease is relatively rapid loss of the remaining hearing, (2) substantial brainstem compression has evolved (e.g., large acoustic neuroma), and/or (3) operative intervention may result in improvement of hearing or carries relatively low risk of hearing loss (e.g., CPA meningioma).

Objective: The role of transient evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) as early indicators of cisplatin-induced ototoxicity in three different rodent species--the guinea pig. the albino rat, and the fat sand rat (Psammomys obesus)--was investigated. In addition, an attempt was made to determine which of the three rodent species is most susceptible to cisplatin-induced ototoxicity as measured by auditory brainstem responses (ABR), BACKGROUND: There have been numerous clinical and experimental reports on cisplatin-induced ototoxicity, but to the authors' best knowledge, there has been no comparative report on the short-term effects of cisplatin on OAE measured with commercially available equipment between different rodent species.

Methods: Cisplatin was systemically administered as a single high dose (12 mg/kg intraperitoneally) to all three species, and the ototoxic effects were measured before and 3 days after the injection of cisplatin in the same animals, using ABR, TEOAE, and DPOAE.

Results: The ABR thresholds were significantly elevated in the guinea pigs and the albino rats but not in the sand rats. Significant depression of TEOAE energy and DPOAE amplitude occurred only in the guinea pigs. The depression of the DPOAE was greater than that of the TEOAE. The guinea pigs showed the greatest degree of ototoxicity (depression of ABR and OAE).

Conclusions: Among the three rodent species, the guinea pig has the potential to be used as a sensitive animal model in studies of cisplatin ototoxicity. The study also showed that the recordings of TEOAE and DPOAE, in addition to ABR, are sensitive techniques for the assessment of cisplatin-induced ototoxicity.