摘要:

Fibrous dysplasia involving the temporal bone is unusual. The most common initial findings are stenosis of the external auditory canal and conductive hearing loss. The frequency of sensorineural hearing loss and facial paresis as complications of fibrous dysplasia have been poorly documented in the past. Forty-three cases of fibrous dysplasia of the temporal bone previously published in the otolaryngologic literature are reviewed, and 10 new cases are reported. In addition to age, sex, and frequency of various presenting complaints, the audiometric, radiographic, and surgical data are evaluated in both groups to better describe the manifestations of disease, degree and type of hearing loss, and success of surgical intervention. In nearly 70% of cases in this study, fibrous dysplasia was monostotic. Although most patients had a conductive hearing loss, 17% of patients demonstrated profound sensorineural hearing loss ascribable to the lesion, and facial nerve sequelae were noted in nearly 10% of cases. Cholesteatoma complicated almost 40% of cases, usually in the form of a canal cholesteatoma. Ten new cases of temporal bone fibrous dysplasia are described not only to further clarify the spectrum of otologic sequelae but also to help illustrate available treatment options. In addition, this report documents, in three new cases, the previously undescribed progression of conductive hearing loss to profound sensorineural deafness secondary to fibrous dysplasia.

ISSN:0192-9763    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Previous investigations into the possible relation between chronic otitis media (COM) and sensorineural hearing loss (SNHL) have resulted in differing results and conclusions. A retrospective study was conducted to examine the relation between COM and SNHL, using strict selection criteria for cases so as to eliminate co-variables. In addition, various COM parameters were studied to determine if a correlation with the severity of the SNHL existed. At the University of Virginia, charts of all patients undergoing chronic ear surgery from September 1983 to March 1993 were reviewed. Sixty-nine patients met the following criteria: unilateral COM and no history of head trauma, meningitis, post-traumatic tympanic membrane perforation, labyrinthine fistula, or coexisting otologic condition of either ear. From these charts, audiograms were then analyzed for evidence of SNHL, defined as the difference in preoperative bone conduction thresholds between diseased and control (normal contralateral) ears. Mean bone conduction differences were small: −0.5 dB at 500 Hz, 0.9 dB at 1000 Hz, 4.4 dB at 2000 Hz, and 3.6 dB at 4000 Hz. There were nonsignificant bone conduction threshold differences that trended toward greater SNHL with diseased mucosa and cholesteatoma at 2000 and 4000 Hz. There was no consistent correlation between severity of SNHL and presence of otorrhea, degree of ossicular erosion, or duration of disease. The authors conclude that COM may cause SNHL, but in the vast majority of patients this loss is not clinically significant.

ISSN:0192-9763    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

This study revealed that some patients with cochlear implants have symptoms of vertigo and imbalance following implant surgery. Although most experience a resolution of these symptoms, some patients have more persistent disturbances of balance. A total of 52 patients were implanted with a Nucleus 22 channel cochlear implant device between September 1988 and February 1994. Preoperatively, all but five of the patients received a vestibular evaluation. Twenty-two of the 52 patients received both pre- and postoperative vestibular evaluation. The cochlear implant was worn and activated during the postoperative vestibular assessment. The vestibular assessment included electronystagmography, computerized dynamic posturography, and harmonic acceleration testing. Five of the 22 patients demonstrated bilateral vestibular weakness preoperatively; that is, no response to caloric stimulation or a total of less than 30 degrees per second for the four irrigations. These patients were not included in the caloric analysis portion of the study. The remaining 17 were divided into groups under 60 years of age (7 patients) and over 60 years of age (10 patients). Analysis of the pre-and postoperative caloric response of the implanted ear showed a significant drop in output for the group over 60 years of age. The difference for the group under 60 years of age was not significant. Forty percent of the patients in the over 60 age group and 43% of those in the under 60 age group developed a peripheral vestibular weakness postoperatively. However, younger individuals in general did not seem to have balance complaints and did not require vestibular rehabilitation as frequently as the older group. Potential cochlear implant candidates should be advised of the possibility of postoperative vestibular effects following cochlear implantation. Most of the symptoms are transient; however, there may be persistent symptoms of imbalance that may be benefited by vestibular rehabilitation.

ISSN:0192-9763    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The outcome of acoustic neuroma (vestibular schwannoma) surgery continues to improve rapidly. Advances can be attributed to several fields, but the most important contributions have arisen from the identification of the genes responsible for the dominant inheritance of neurofibromatosis types 1 (NF1) and 2 (NF2) and the development of magnetic resonance imaging with gadolinium enhancement for the early anatomic confirmation of the pathognomonic, bilateral vestibular schwannomas in NF2. These advances enable early diagnosis and treatment when the tumors are small in virtually all subjects at risk for NF2. The authors suggest that advising young NF2 patients to wait until complications develop, especially hearing loss, before diagnosing and operating for bilateral eighth nerve schwannomas may not always be in the best interest of the patient. To the authors' knowledge, this is the first reported case of preservation of both auditory and vestibular function in a patient after bilateral vestibular schwannoma excision.

ISSN:0192-9763    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Electrocochleography (ECoG) has become a mainstay in the diagnostic armamentarium used by otolaryngologists and audiologists in the evaluation of patients suffering auditory and vestibular symptoms. Controversy exists, however, regarding the relative accuracy of ECoG when recorded with a non-invasive external auditory canal (EAC) electrode as compared to that recorded using a transtympanic electrode. In an effort to resolve this controversy, 19 healthy volunteers (37 ears) with no history of otologic disease or symptoms and a normal screening pure-tone audiogram were studied. For each volunteer, a transtympanic electrode was placed on the cochlear promontory bilaterally under iontophoretic anesthesia followed by the immediate placement of an EAC TIPtrode (Etymotic Research Laboratory, Elk Grove Village, Illinois). Signals from both the transtympanic electrode and the TIPtrode were recorded simultaneously following click stimulus using the Nicolet CA 1000. Preliminary analysis of these recordings identify no significant difference in summating potential/action potential ratios between EAC and transtympanic electrodes in this normal subject population.

ISSN:0192-9763    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Hypoglossal schwannomas are rare cranial base neoplasms that originate in the posterior cranial fossa and extend through the hypoglossal canal in a dumbell fashion. Recent experience with this unusual neoplasm prompted a search for an operative approach to remove the lesion with a minimization of postoperative morbidity from bleeding and iatrogenic cranial nerve deficits. This report describes the use of the transcondylar approach with monitoring of the lower basal cranial nerves to totally remove a transcranial hypoglossal schwannoma with no new-onset cranial nerve palsies. The regional anatomy of the hypoglossal nerve and canal is reviewed in relation to the operative approach.

ISSN:0192-9763    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Delayed facial palsy occurs after approximately 15% of acoustic neuroma resections. Whereas in most cases facial nerve function recovers satisfactorily, in about 12% of cases delayed facial palsy may have a poor functional recovery. The fate of facial nerve function was studied in 55 consecutive translabyrinthine acoustic neuroma resections, 23 of whom underwent meatal facial nerve decompression (MFND) at the time of tumor resection. The facial nerve results also were reviewed in 19 middle cranial fossa resections, of whom 14 underwent MFND. There was a bimodal distribution of the delayed palsies, with one group having the onset of palsy within hours to 2 days after surgery and the second group having onset of palsy up to 17 days after surgery. The poorest recoveries were seen in the first group. Although the effect was not statistically significant due to the small sample size, the chance of facial weakness in patients who underwent MFND after translabyrinthine surgery was about 40% less than in those who did not undergo decompression. The apparent protective effect of MFND was increased when the confounding factors of tumor size and degree of resection were taken into account, although the effect was not statistically significant. The duration of palsy was shorter and ultimate recovery better among the patients who underwent facial nerve decompression than in those who did not. Of the translabyrinthine patients who underwent MFND, 100% had House-Brackmann grade I-II function at 2 years, whereas 87% of patients who did not have MFND had grade I-II function and 13% had grade III-IV function. Without MFND, 57% of translabyrinthine patients whose onset of facial palsy was within 2 days of surgery had grade III-IV facial nerve function.

ISSN:0192-9763    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Preliminary data on the use of hydroxyapatite cement to restore cranial bone integrity has shown excellent results. Cranial base reconstruction has been accomplished for translabyrinthine, middle cranial fossa, and suboccipital craniectomy defects, as well as extensive temporal bone fractures. Fifteen patients have been followed for up to 2 years with no evidence of complication from use of the hydroxyapatite cement. Exposure to cerebrospinal fluid does not appear to alter its stability, and pre-existing infection appears to be the only contraindication to its use. Stability of the cement has been confirmed by serial radiographic analyses. This paper reviews the chemical structure and bioactivity of hydroxyapatite cement and employs case studies to illustrate the applications of this new biomaterial in lateral skull base surgery.

ISSN:0192-9763    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Postural instability and falls in the elderly patient constitute a major health care problem. The etiology is often multifactorial, involving abnormal sensory input (visual, vestibular, and somatosensory), poor central processing, and suboptimal musculoskeletal biomechanics. Estrogen replacement therapy has been shown to prevent Alzheimer's disease and to improve cognitive performance in women with dementia. It was, therefore, postulated that estrogen replacement may improve central processing speed, which would result in improved postural stability. In this prospective, randomized, double-blinded study, 87 elderly female subjects (age > 69) were examined by repeated dynamic platform posturography, to measure the effect of estrogen therapy versus placebo upon postural stability. Results indicate that those receiving estrogen had no significant improvement in postural stability at 2 and 8 months of treatment relative to those receiving placebo. Trail Making B test was used as the psychometric test of central processing speed. There was no significant effect of estrogen on this measure over the 8 months of observations. It is concluded that 8 months of estrogen replacement therapy has no significant effect on central processing speed or postural stability in a healthy older female population.

ISSN:0192-9763    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Conventional stereotactic surgery has been utilized primarily for intracranial neurosurgical procedures. Despite their utility, head-frame systems are restrictive and often inconvenient, thus they have not proved applicable for neurotologic surgery. Recently frameless stereotactic navigational systems have been developed that employ threedimensional digitizers to transform the coordinates in surgical space to the corresponding image space, without the employment of head frames. This allows the determination of position of a surgical instrument in real time during surgery, and its display on video-projected computed tomography or magnetic resonance imaging scanned images. This preliminary report focuses upon an optoelectric referenced frameless stereotactic system, the NeuroStation, as it relates to minimally invasive neurotologic surgery. Clinical applications, limitations, and future directions are discussed, and three representative surgical cases are presented. This device has potential as an adjunctive navigational tool for certain neurotologic procedures.

ISSN:0192-9763    

出版商:OVID    

年代:1995

数据来源: OVID