ISSN:0192-9763    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Intraoperative facial nerve monitoring simultaneously using electromyography and mechanical pressure sensors is being used in retrosigmoid and translabyrinthine approaches for acoustic neuroma resection. Insulated electrified microsurgical instruments and air drills are used to stimulate the facial nerve with a pulsed, constant current through bone and tumor, before the facial nerve is visually encountered. Electrical stimulation is used to help locate the facial nerve, map the course of the facial nerve within tumor, warn the surgeon of unexpected facial nerve locations, and help predict facial nerve function postoperatively. In 57 unmonitored cases a House-Brackmann (H-B) grade I or II result was obtained in 77 percent of small, 81 percent of medium, and 60 percent of large tumors. In 64 monitored cases H-B grade I or II was obtained in 88 percent of small, 79 percent of medium, and 90 percent of large tumors. Overall, facial nerve outcomes were better after monitored procedures (p< 0.02). A modified H-B classification for acute facial nerve injury is introduced to grade facial weakness immediately postoperatively and until function is stable at 1 year. In the unmonitored group there were five (9%) cases with a complete facial paralysis, facial nerve intact (i.e., acute H-B grade VIA) and seven (13%) cases with the facial nerve transected (i.e., acute H-B grade VIB). In the monitored group there were five (8%) acute H-B grade VIAand two (3%) acute H-B grade VIBresults. In the unmonitored group of large tumors, there were statistically more patients with an acute H-B grade VIBresult (p< 0.05). The evolution in techniques and results of intraoperative facial nerve monitoring are presented.

ISSN:0192-9763    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The improvement in surgical techniques and the experience gained in treatment of skull base tumors have stimulated more aggressive management of larger lesions. Patients presenting with limited preoperative deficits have challenged the surgeon to design the surgical approach so as to minimize postoperative morbidity and preserve function. Tumors of the middle fossa and clivus with extension into the posterior fossa are usually approached by a combined subtemporal, transtentorial, transpetrous approach. In patients with preoperative hearing, the surgical exposure is often limited by the labyrinthine portion of the otic capsule. The technique of partial labyrinthectomy, removing the posterior and/or superior semicircular canals, maximizes exposure with preservation of hearing. This report details our experience with the partial labyrinthectomy approach for 14 patients with large skull base lesions. All patients had hearing preserved despite sacrifice of one or two of the semicircular canals. Bone pure-tone averages and speech discrimination scores were maintained near their preoperative levels. The indications, benefits, techniques, and hearing results of this approach are reviewed.

ISSN:0192-9763    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Thrombosis of the cerebral venous sinuses has long been a recognized complication of late stage pregnancy and the puerperium; more recently, this complication has been associated with the use of oral contraceptives. Two cases are presented in which the presenting symptoms of sagittal sinus thrombosis were neurotologic in nature. One case presented with a sudden onset unilateral facial paralysis; another case presented with pressure/fullness sensation in one ear accompanied by nausea and vomiting. Clinical presentation and evaluation of these cases is presented, with a discussion of symptom etiology. Recommended non-invasive medical management methods are discussed. Cases in which the thrombosis involves the sigmoid, transverse, and sagittal sinuses should be suspect for etiologic sources beyond the ear even when the presenting symptoms are neurotologic in nature. Management of these cases is different from that of an otogenic sigmoid sinus thrombosis. A complete medical history taken from women of child bearing age should include the use of oral contraceptives, which may be suspect for inducing intracranial venous thromboses.

ISSN:0192-9763    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Cerebrospinal fluid leakage (otorrhea or otorhinorrhea) from the temporal bone is the end result of rupture of the arachnoid membrane or herniation of the brain through a defect in the protective dura mater and calvarium. The rupture may be small, admitting only a herniation of arachnoid (meningocele), or be large enough to accommodate brain tissue (encephalocele). Flow of cerebrospinal fluid through either type of fistula may be a trickle or profuse, chronic or intermittent, and usually ceases temporarily for a few weeks following an attack of meningitis. The etiology, anatomy, signs and symptoms, and various methods of treatment for cerebrospinal fluid otorrhea and otorhinorrhea are discussed.

ISSN:0192-9763    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The retrosigmoid approach to acoustic neuroma removal has recently been criticized for causing frequent and severe headache postoperatively. We review 331 patients who had acoustic neuroma removal by the retrosigmoid approach at one institution. The incidence of postoperative headache was 23 percent at 3 months, 16 percent at 1 year, and 9 percent at 2 years. Management was primarily with analgesics, physiotherapy, and reassurance. No patient had additional surgical treatment. Information available indicates that the incidence of postoperative headache associated with the translabyrinthine approach is similar to that of the retrosigmoid approach. Perhaps filling the craniectomy defect will decrease further the incidence of headache postoperatively.

ISSN:0192-9763    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

A possible complication of postmeningitic deafness is cochlear ossification. Reports of immediate response to electrical stimulation despite this ossification have been encouraging. This report discusses three children who initially failed to perceive stimulation from their Nucleus multichannel cochlear implants. These patients showed no behavioral responses to any of 10 to 20 electrodes inserted into their ossified cochleae, even at maximum stimulus levels (1750 μA). Stimulus-response behavior had been well documented prior to implantation and was not considered a factor in their failure to respond. These patients continued to wear the speech processors programmed at maximum stimulus/current levels. Eventually, all three patients began responding following 5 to 12 months of device use. These results suggest that continued use of electrical stimulation may result in eventual perception.

ISSN:0192-9763    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Patients with neurofibromatosis type 2 (NF2) develop bilateral acoustic neuromas, but preservation of hearing while achieving tumor removal may present several unique problems. Our philosophy regarding hearing preservation attempts in these cases has evolved over several decades. The outcome of hearing preservation surgery using the middle cranial fossa approach for 13 procedures in 10 patients with NF2 is presented. There were 12 total tumor removals and one partial tumor removal. Two ears retained good postoperative hearing, three had serviceable hearing, four had measurable hearing, and four had no measurable hearing. Both cases with tumors 2 cm or larger retained no hearing. For the 12 total tumor removals, the rate of hearing preservation was 67 percent. Of four total removals with long-term follow-up, two retained good or serviceable hearing. The rate of hearing preservation is similar to that found in our series of unilateral acoustic neuroma surgeries. Based on these findings, hearing preservation surgery is recommended for patients with NF2 who have acoustic neuromas 1.5 cm or smaller.

ISSN:0192-9763    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

It is important to evaluate both vestibulo-oculomotor and vestibulospinal pathways in patients with balance disorders. While moving-platform posturography can assess vestibulospinal function, the cost and time required to perform this test may limit its clinical use. A clinical office vestibulospinal evaluation that could be done quickly and inexpensively would be of benefit. In this study we used foam posturography to prospectively evaluate 50 patients with vestibular complaints to determine its predictive value in comparison with moving-platform posturography results. Our results demonstrate a significant correlation (p< 0.005) with a sensitivity and specificity of 95 percent and 90 percent, respectively, between the clinical office assessment using foam posturography and the results of moving-platform posturography. The ability of patients to utilize vestibular cues to maintain posture may be accurately assessed in a clinical office examination and should be useful to otolaryngologists to evaluate the vestibulospinal system.

ISSN:0192-9763    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Streptomycin perfusion of the labyrinth is the logical choice of treatment for the third stage of Meniere's disease with intractable vertigo. The results of streptomycin perfusion of the labyrinth are comparable to those of other treatments, including endolymphatic shunt and vestibular nerve section. Refinements must be made in the process of selecting candidates for the operation. To study the factors influencing the results of streptomycin perfusion of the labyrinth, 144 patients who had streptomycin perfusion of the labyrinth and were followed for 1 year were studied using the 1972 AAOO classification of results. The findings of this study indicate that only a low dosage of streptomycin and a small volume of perfusate are required to obtain good results. Patients who have long lasting severe endolymphatic hydrops with poor hearing preoperatively are less likely to achieve good results.

ISSN:0192-9763    

出版商:OVID    

年代:1993

数据来源: OVID