ISSN:0192-9763    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Several types of lasers have been applied to otologic surgery for such procedures as laser stapedotomy and acoustic tumor vaporization. The KTP laser has even broader applications in the field of chronic ear surgery. A three and a half year experience with the KTP laser is described. This laser's performance characteristics makes it well suited for chronic ear surgery. A quartz fiber delivery device enables the surgeon hand control of the laser beam in a microscopic field. Several applications are reviewed. Specifically, the KTP laser has been effective in removing hyperplastic infected mucosa engulfing the stapes, in safely disarticulating a mobile stapes suprastructure for complete cholesteatoma removal, and in atraumatically removing previously inserted ossicles or other middle ear implants. The KTP laser enables the surgeon to avoid mechanical trauma possible with traditional instrumentation and obtain more effective disease removal.

ISSN:0192-9763    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

A columellar ossicular replacement prosthesis has been developed to simplify ossiculoplasties. The hydroxylapatite head has flattened egg-shaped contours set on a teflon shaft. One hundred and twenty-five prostheses have been implanted and the results of eighty-two cases between five and eighteen months' maturity are presented. Sixty-six percent of good risk partial ossicular replacement prosthesis (PORP) cases achieved air-bone closure within ten decibels and eighty-five percent within twenty decibels. Of all total ossicular replacement prosthesis (TORP) and PORP cases, 51.5 percent closed to within ten decibels and 69.5 percent to within twenty decibels. The design has simplified the preparation and implantation techniques and the prosthesis can be used in most ossiculoplasty situations. A malleus handle is not required and interposition of cartilage is unnecessary. The simplicity of the prosthesis should provide particular benefits for the occasional or trainee otologist.

ISSN:0192-9763    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The development of the perisaccular blood vessels is described during embryology and the postnatal period of the mouse. Primitive sinusoidal vessels already appear at the early otocyst stage as the future endolymphatic sac is formed. Before birth the vasculature attains a more mature appearance with tubular, somewhat fully developed blood vessels. At this stage a primitive basement membrane is also formed. Soon after birth the blood vessels appear mature with developed fenestrations and micropores, giving them an appearance comparable to blood vessels in other fluid transporting organs.

ISSN:0192-9763    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Trigeminal neuralgia (tic douloureux) is a condition characterized by intense, unilateral paroxysmal facial pain caused by an abnormality of the root entry zone of the trigeminal nerve. For patients with intractable pain unrelated to a pathologic process who fail to respond to conventional medical management, the microvascular decompression (MVD) is the operation of choice. Conductive or sensorineural hearing loss due either to stretching of the eighth nerve or hemotympanum during the operation is among the possible sequelae of MVD. We report on a perplexing case of delayed sensorineural hearing loss following uneventful microvascular decompression for trigeminal neuralgia that included intraoperative evoked potential monitoring.

ISSN:0192-9763    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Five children between the ages of 6 to 10 years using the Nucleus 22-electrode cochlear implant were tested on a battery of speech-perception tests. None of the five children used any sign language before implantation, and all received extensive training in auditory/verbal rehabilitation postimplantation. Performance ranged from 81 to 97 percent correct on the Matrix Test, from 24 to 80 percent correct on the WIPI test, from 33 to 73 percent correct on a 10-choice vowel recognition test, from 19 to 50 percent correct on a 13-choice consonant recognition test, from 2 to 46 percent words correct on a PB-K word list, from 4 to 71 percent words correct on a recorded BKB sentence test, and from 8 to 71 percent words correct on a live-voice BKB sentence test. In four of the five children, significant lipreading enhancement was observed on consonant recognition and two prelinguistically deafened children demonstrated some open-set word recognition.

ISSN:0192-9763    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Central neurofibromatosis is a genetic disorder of neural crest tissue derivatives that includes bilateral acoustic neuromas and other central nervous system tumors, usually meningiomas or gliomas. This is different from peripheral neurofibromatosis because of the primary central nervous system manifestations and frequent lack of accompanying peripheral neurofibromas and cafe au Iait spots as well as different alterations of nerve growth factor. We present the temporal bone histopathology of a unique case of unsuspected central neurofibromatosis that included bilateral acoustic neuromas invading the cochlea and an asymptomatic glioblastoma multiforme occurring in the absence of a family history and without any accompanying peripheral stigmata of neurofibromatosis. As bilateral tumors frequently invade the cochlea, the modified transotic rather than the translabyrinthine approach is recommended for complete tumor removal. Contralateral tumor removal should be delayed while useful hearing remains.

ISSN:0192-9763    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Cholesteatoma arising in the external ear canal is uncommon. A variety of etiologic factors have been attributed to the development of cholesteatoma in the external ear canal. The various disease processes that cause excessive desquamation and cholesteatoma formation are reviewed and their management is presented.

ISSN:0192-9763    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Hemangiomas of the external auditory canal rarely occur. These lesions have been reported to involve men in their sixth decade. This case report represents the fourth such lesion reported in the literature and the first to be seen in a woman. The clinical presentation, surgical therapy, and pathology are discussed. This tumor represents an unusual cause of hearing loss.

ISSN:0192-9763    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Interest in bone-conducted stimulus auditory brainstem response (BC-ABR) testing has centered around evaluation of cochlear integrity in neonates and in patients who are difficult to evaluate audiometrically. The present study was designed to evaluate the Wave I component of the BC-ABR and to determine the utility of this response in assessment of cochlear reserve. The source of Wave I has been shown to be the distal eighth nerve. It was postulated that the presence or absence of this component would provide ear specific information useful for determination of cochlear integrity. In order to test this hypothesis, patients with a documented unilateral hearing loss were studied. Stimulus presentation was via the Radioear B-70 bone vibrator used in conventional audiometric assessment. Evoked potential responses were recorded at four presentation levels. Subjects had either normal hearing bilaterally or normal hearing in one ear and a mild-to-profound sensorineural hearing loss in the opposite ear. Our data indicate that the Wave I response, when measured in this fashion, is ear specific. Ear specificity was shown to be aided by good waveform morphology, as typically observed in younger subjects, and by a relatively large discrepancy in hearing thresholds between the normal and hearing-impaired ears. This technique may be of value in determination of cochlear reserve in patients with problematic masking dilemmas.

ISSN:0192-9763    

出版商:OVID    

年代:1990

数据来源: OVID