The American journal of otology最新文献

Objective: The aim of the current study was to provide support for a combination of the retraction and proliferation theories of acquired cholesteatoma.

Background: There is clinical evidence for formation of a retraction, but there is a lack of explanation for the transition from a retraction pocket to an active and expanding attic cholesteatoma.

Methods: Epidemiologic studies on the incidence of attic retractions and follow-up studies on patients with attic retractions were performed. Additionally, expression of proliferation marker and analysis of basement membrane were studied in samples of attic cholesteatoma.

Results: The prevalence of attic retractions was between 14% and 25% of investigated ears. In children with manifest secretory otitis, there were some attic cholesteatomas and 5% to 6% severe retractions. Some of them became precholesteatomas, requiring treatment and controls. Immunohistochemistry of attic cholesteatomas showed that proliferating keratinocytes were very often seen within epithelial cones growing toward the underlying stroma. These growth cones exhibited focal discontinuities of the basement membrane, especially in areas of intense subepithelial inflammation.

Conclusions: As a possible explanation based on clinical and immunohistochemical findings, the authors propose a four-step concept for the pathogenesis of cholesteatoma that combines the retraction and proliferation theories: (a) the retraction pocket stage; (b) the proliferation stage of the retraction pocket, subdivided into cone formation and cone fusion; (c) the expansion stage of attic cholesteatoma; and (d) bone resorption.

Objective: The purpose of this study was to clarify whether higher doses of steroids improve the prognosis of idiopathic sensorineural hearing loss (ISHL) and the suitable dose of steroid hormone.

Study design: The study was a retrospective statistical analysis.

Setting: This study was performed at the Department of Otolaryngology, Head Neck Surgery, Kumamoto University School of Medicine.

Patients: Two hundred fifty patients with ISHL were analyzed in this study. They were divided into two groups: those receiving less than a specified daily dose of steroid and those receiving a daily dose greater than or equal to the specified dose.

Interventions: The patients received systemic steroid therapy combined with adenosine triphosphate, vitamins, diuretics, vasodilators, hyperbaric oxygen therapy, stellate ganglion block, or volume expander.

Main outcome measures: The correlation between the initial dose of steroid hormone and the improvement rate was analyzed.

Result: Spearman's correlation coefficients and partial correlation coefficients between the initial dose and the prognosis were all significantly negative. On the other hand, the correlations between the initial dose and the prognosis were positive in the group receiving <30 mg/day, whereas they were negative in the group receiving > or =30 mg/day, although these correlations were not significant.

Conclusion: The general use of steroid hormone to treat ISHL is not recommended. Furthermore, if steroid hormone is used for treatment, the use of <30 mg/day of prednisolone is preferable.

Objective: To describe an atypical waveform, termed an abnormal positive potential (APP), on round window electrocochleograms (RW ECochG) of children and to relate its occurrence to clinical history.

Study design: APPs were identified prospectively, and a retrospective analysis was made of these patients' clinical histories, audiograms, and auditory outcomes (hearing aid, cochlear implant, or nonauditory communication)

Setting: Tertiary referral teaching hospital, day surgery and clinics.

Patients: All 431 children <110 months of age suspected of a severe to profound hearing loss who underwent RW ECochG from January 1993 to August 1997.

Intervention: Diagnostic RW ECochG for auditory threshold estimation.

Main outcome measure: The presence on the RW ECochG of the APP: an early positive potential in the absence of a compound action potential (CAP).

Results: An APP was observed in 34 children. The APP was most marked in response to clicks and 8-kHz tones. The APP click threshold averaged 70 dB hearing loss. The brainstem evoked potential of these children showed an absence of waves, or a broad positive wave with no subsequent waves. Twenty-nine of 30 behavioral audiograms obtained were indicative of severe to profound hearing loss. Auditory outcomes were available from 26 children; 45% of them derived no help from a hearing aid, and 8 children received a cochlear implant. Clinical factors frequently associated with APP were prematurity in combination with kemicterus or hypoxia.

Conclusions: APP thresholds were lower than neural thresholds or behavioral thresholds. Children with APP need close follow-up, because half of those studied needed nonauditory strategies to develop effective communication.

Objective: The purpose of this study was to assess whether pretreatment tumor patterns of nasopharyngeal carcinoma (NPC) can predict the status of the middle ear after radiation treatment.

Materials and methods: Pretreatment and follow-up magnetic resonance imaging (MRI) was performed in 32 patients (64 ears) who had radiation therapy for NPC. For the purpose of analysis, the ears were placed into their pre-radiation therapy tumor pattern groups and the presence of middle ear effusion (MEE) with regard to eustachian tube (ET) invasion or displacement was identified.

Results: MEEs were present in 31 (48.4%) ears after radiation therapy. All of the MEEs that resolved were in the preradiation therapy groups where tumor invasion of the eustachian tube was present irrespective of the amount of ET displacement. There was, however, no significant difference for resolved MEEs between ears with ET invasion or displacement (p = 0.32 and p = 0.71, respectively, Fisher's exact test). The MEEs occurred with significantly greater frequency in ears with minor ET displacement than in those with major ET displacement (p = 0.013, Fisher's exact test) as well as in previously normal ears compared with other groups (p = 0.008, Mann-Whitney U test).

Conclusion: A pre-radiation therapy NPC tumor pattern was not found that clearly predicted the outcome of MEE after radiation treatment. The findings, however, suggest that approximately one third of MEEs in patients with invasion of ET or paratubal structures, irrespective of the amount of ET displacement, resolve after therapy. The MEEs that were present in ears with ET displacement and no invasion did not resolve despite reversal of the displacement after treatment, which suggests that ET position plays a less important role than invasion in the resolution of MEE. It is, however, difficult to be certain, because ears with invasion were invariably associated with ET displacement, and the contribution of radiation therapy to the development of MEE further complicates the issue.

Objective: To describe our experience with the retrosigmoid-transmeatal (RS-TM) approach in auditory brainstem implantation (ABI) as well as the anatomosurgical guidelines for this route.

Study design: Retrospective case review.

Setting: Ear, Nose, and Throat Department of the University of Verona.

Patients: Five patients with neurofibromatosis type 2 (NF2) were operated on for vestibular schwannoma removal with ABI implantation from April 1997 to June 1999. The patients were four men and one woman, whose ages ranged from 22 to 37 years. The tumor sizes ranged from 12 to 30 mm. The records of a total of 179 patients operated on for vestibular schwannoma (VS) removal via the RS-TM approach from January 1990 to June 1999 were also evaluated. Their ages ranged from 18 to 88 years (average 54 years). The tumor sizes ranged from 4 to 50 mm. Five patients had a solitary VS in the only hearing ear.

Intervention: The classic RS-TM approach was used in all patients. After tumor excision, for ABI implantation, the landmarks (seventh, eighth, and ninth cranial nerves, choroid plexus) for the foramen of Luschka were carefully identified. The choroid plexus was then partially removed, and the tela choroidea was divided and bent back. The floor of the lateral recess of the fourth ventricle and the convolution of the dorsal cochlear nucleus became visible. The electrode array was then inserted into the lateral recess and correctly positioned with the aid of electrically evoked auditory brainstem responses (EABRs).

Main outcome measures: Intraoperative EABR and postoperative speech perception evaluation.

Results: Auditory sensations were induced in all patients with various numbers of electrodes. Different pitch sensations could be identified with different electrode stimulation.

Conclusions: In the authors' experience, the RS-TM approach is the route of choice for patients who are candidates for ABI when there is a chance of hearing preservation during surgery. If auditory function is lost during surgery, anatomical preservation of the cochlear nerve may allow hearing restoration with a cochlear implant. Direct intraoperative recording of cochlear nerve action potentials (CNAPs) and round window electrical stimulation are mandatory for these purposes. In addition, decompression of the intrameatal portion of the vestibular schwannoma and planned partial tumor resection with hearing preservation are also possible with the RS-TM approach.

Objective: To determine to what extent patients with vestibular hypofunction experience falls.

Study design: Prospective clinical study.

Setting: Outpatient tertiary care facility in a university.

Patients: Patients with unilateral (n = 70) and bilateral (n = 45) vestibular hypofunction, confirmed on vestibular function testing, aged 24 to 89 years.

Intervention: None.

Main outcome measure: Incidence of falls.

Results: There was a significant difference in the incidence of falls reported since the onset of the vestibular deficit by patients with unilateral (UVL) and bilateral (BVL) vestibular hypofunction. The incidence of falls for BVL was significantly greater than that for UVL. The incidence of falls for UVL was not different from that expected in a community-based population when age was considered. The incidence of falls for BVL was significantly greater than that reported for the general population aged 65 through 74 years (51.1% for BVL, 25% for community-dwelling individuals) but was significantly less than expected for persons aged > or =75 years (18.2% for BVL, 49% for community-dwelling individuals). The lower incidence of falls in patients with BVL aged > or =75 years may be related to the use of assistive devices and to a decrease in risky behavior. All patients with serious injury were from the UVL group, and all were >65 years old. The incidence of fall-related injuries requiring medical attention among patients with UVL was similar to that in community-dwelling individuals.

Conclusions: Falls are an important consequence of bilateral vestibular hypofunction, and patients should be counseled about the increased risk of falling. Assistive devices should be considered, especially for persons aged >65 years with BVL.

Purpose of study: To study the historical development of the binocular microscope used in ear surgery.

Method: Compilation of the texts of the era and books dealing with ear surgery, and a review of the international literature on the subject.

Results: The first descriptions of the microscope date to the 17th century; however, it was not until 1921 that the microscope was used for the first time in ear surgery by a Swedish otologist, Carl Olof Nylen. This monocular microscope was rapidly replaced by a binocular microscope developed in 1922 by Gunnar Holmgren. Because of its limited field of vision, very short focal distance, poor light quality, and instability, this microscope was seldom used initially. Despite the development of many different models, it was not until 1951 that a new model appeared, perfected by Littmann and the Zeiss Company. This model replaced all other models progressively, thanks to its ease of use and the possibility of changing the magnification without modifying its focal distance. It allowed for the development of tympanoplasties and stapes surgery. The latest developments include the three-dimensional imaging and navigation systems.

Conclusion: The microscope followed an evolutionary process that led to the actual binocular microscope, which is found in every institution where otology and ear surgery are performed.

Objectives: To determine the optimal medical or surgical treatment of osteomas of the internal auditory canal (IAC) as well as their growth characteristics.

Study design: Information was obtained from case histories, images from computed tomography and magnetic resonance imaging, surgical and pathologic findings, and long-term clinical results.

Methods: Two patients, along with 10 additional patients reported in the literature, with osteomas of the IAC with varying symptoms were studied. Clinical history, audiometric and vestibular test results, and radiographic studies were reviewed on all patients. Histopathologic examination of the surgical specimens confirmed the presence of osteomas. The clinical outcomes were studied to determine if the preoperative symptoms had resolved.

Results: Eight of 12 patients underwent surgical removal of their IAC osteomas. Three of eight patients had total resolution of all symptoms. Three patients had improvement of their sensorineural hearing loss. Five patients had resolution of their dizziness. Four patients noted resolution of their tinnitus. In the absence of auditory symptoms, vestibular symptoms may be controlled with medical therapy. Long term follow-up of the two patients discussed showed little or no growth over a 4- to 5-year period.

Conclusions: Surgical intervention may be warranted to remove an osteoma of the IAC if symptoms are present. Patients should be made aware that symptoms may or may not improve. Continuation of symptoms may be a result of chronic compression of the auditory and vestibular nerves.