ISSN:0192-9763    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The incidence and outcome of bony wall defects in the mastoid bowl were studied in 175 ears of 167 patients who underwent staged tympanoplasty by the intact canal-wall technique. In the first stage, the middle fossa dura was exposed iatrogenically in 38 ears and pathologically in eight ears through a defect at the tegmen. In the second stage, the bone defect was cured in 27 ears of the former group and in 3 ears of the latter group. The overall cure rate of the defect in the tegmen during these stages was 65.2 percent (30/46). Exposure of the sigmoid sinus or posterior fossa dura, which had occurred iatrogenically in 12 ears in the first stage, was cured in 11 ears (91.7%) in the second stage. Defects of the anterior wall of the mastoid bowl, i.e., the posterior wall of the external auditory canal, were recognized in 105 ears in the first stage, 91 of which involved pathologic defects of the tympanic scutum caused by cholesteatoma. In the second stage, these defects remained unhealed with cures occurring in only two ears (1.9%), in which a small hole had been created iatrogenically in the middle of the canal wall. Defects in the canal wall due to bone resorption following the first stage operation were noted in the second stage in 26 of 175 ears (14.9%).

ISSN:0192-9763    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

In order to study the mechanical properties of the tympanic membrane in diseased ears, we have designed and evaluated an experimental tympanometric model.Isolated temporal bones of healthy Mongolian gerbils were studied with a Grason-Stadler 1723 typanometer in two-component admittance measurements with probe tones of 220 and 660 Hz. The normal tympanometric curve is described, and the validity and reproducibility of the model are assessed. The morphology of the gerbil tympanic membrane is described and compared with those of other species.Various alterations were produced in the middle ear, and it was found that tympanometry showed high sensitivity for tympanic membrane stiffness but not for mass changes. The condition of the pars flaccida did not significantly influence admittance, which was also resistant to osmotic challenge to the membrane. Ossicular chain disruption caused an increased admittance, whereas malleus fixation, without affecting the tympanic membrane itself, caused a pronounced reduction. The tympanometric patterns during tympanic membrane mass increase, and with hypertrophic myringeal scars and perforations were also determined.We conclude that tympanometry in the invitromiddle ear of gerbils offers possibilities for studying changes of the tympanic membrane physiology in disease.

ISSN:0192-9763    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

We have attempted to increase the sensitivity of dynamic posturography testing by adding head extension and sway energy measurement to the standard Equitest protocol. Both procedures were applied to 121 patients and to 89 normal subjects. A portion of the standard protocol was repeated with the patient's head extended 55 degrees. Head extension significantly increases the number of “falls” or losses of balance experienced by normal subjects 50 years or older.Using the formula, Energy = Force × Distance, and appropriate corrections for platform tilt and body weight, any previously recorded test can be analyzed with computer programming to give energy values in joules per kilogram. Adding the two criteria of head extension and sway energy to the standard protocol increased the percentage of patients classified as abnormal from 48 to 68 percent. The two added criteria are useful in separating symptomatic from asymptomatic subjects and patients.

ISSN:0192-9763    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Mastoidectomy reconstruction is a complex procedure in which the use of porous hydroxylapatite ceramic wall implant is optimal. Fitting the implant to the operation site requires considerable reshaping of the prosthesis with resultant delays and occasional breakages. The reshaping can be expedited considerably if a metal template is used to obtain the pattern required for the implantation site. A technique using aluminum foil templates to obtain a precise fit is outlined and discussed. The method has been utilized successfully in a series of 42 cases and is recommended to improve the speed and precision of the reconstruction considerably.

ISSN:0192-9763    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Bestron,®a new otic preparation containing cefmenoxime, was applied to the round window membrane of the chinchilla and the long-term cochleotoxicity was evaluated by means of electrocochleography. The thresholds of the compound action potential (CAP) in all frequency areas tested ranged within normal values. The input-output and -latency relationships of the CAP resulted in no significant deterioration of hearing. However, identical treatment with Cortisporin®resulted in elevated CAP threshold in the high frequency area and deterioration of the input-output and -latency of the CAP. These findings indicate that Bestron is noncochleotoxic as compared with Cortisporin and therefore may be used safely in the treatment of infected ears.

ISSN:0192-9763    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The present study was designed to evaluate transiently evoked otoacoustic emissions in an otologically normal adult population. Using the ILO 88 Otodynamic Analyzer, the recorded otoacoustic emission responses were analyzed for five parameters. Considering the variability of instrumentation and technique in otoacoustic emission testing, we have defined a normative data pool using standard commercially available testing equipment. These data should facilitate comparison with data acquired in various pathologic states. The test-retest validity of this procedure also was evaluated and was found to be high. Use of click evoked otoacoustic emissions, with some caveats, appears to be a promising technique for further research into the assessment of normal/abnormal cochlear function.

ISSN:0192-9763    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Certain failures of the stapes operation are caused by loosening of the crimped metal loop on the long process of the incus, atrophy or necrosis of the lenticular process, erosion of the long process with the prosthesis causing injury to the labyrinth, erosion of the incudostapedial joint with upward rotation of the long process, and dislocation of the prosthesis. To reduce the occurrences of these failures following stapes removal, we close the oval window by gluing a fascia graft into place with fibrin tissue adhesive. A ceramic strut with a cup on its upper end that fits the lenticular process is glued between the fascia graft and the lenticular process. This method does not cause bone necrosis or blood circulation disturbances. The hearing results are the same or better than those reported for other stapes procedures.

ISSN:0192-9763    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Facial nerve monitoring during otologic and neurotologic procedures has been previously described, and its use is becoming routine. Although these procedures are done under general anesthesia, lidocaine is often used as a vehicle for epinephrine to aid hemostasis during the procedure. The routine use of lidocaine in these preparations presents the theoretical and sometimes real problem of anesthetizing the facial nerve at the start of the procedure, thereby invalidating subsequent attempts at monitoring and stimulation. We present the data from our experience with 74 patients using an epinephrine solution 1:100,000 for infiltration without any local anesthetic. We have found this procedure to be effective in maintaining hemostasis, quite safe and well tolerated, and without adverse effects on the desired monitoring of the facial nerve.

ISSN:0192-9763    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Facial paralysis, although a rare complication of AIDS related complex (ARC) or AIDS, may well be the presenting symptom of HIV positivity. A case report of facial paralysis followed closely by discovery of HIV positivity is described, along with a pertinent and extensive literature review. Seroconversion to HIV-positive status should be suspected in any high-risk patient presenting with idiopathic facial paralysis. HIV testing should be included in the evaluation of Bell's palsy and other idiopathic forms of facial paralysis in the at-risk patient.

ISSN:0192-9763    

出版商:OVID    

年代:1991

数据来源: OVID