ISSN:0192-9763    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTThis report examines the effect of the endolymphatic shunt on hearing. The study group was drawn from 101 shunt operations for intractable vertigo between 1983 and 1987. Thirty ears met criteria for diagnosis, level of preoperative hearing impairment, and length of follow-up. The control group consisted of 30 ears with symptoms severe enough to prompt recommendations for shunt surgery, but the patients either opted against surgery or improved. The results were analyzed using the 1985 AAO-HNS reporting criteria. When looking at worst postoperative (or worst scores after 2 years of follow-up in controls) compared to worst preoperative (or worst scores in the first 6 months of presentation in controls), we found no significant difference between the study group (average loss of 9 dB pure-tone average [PTA] and 16% speech discrimination [SD]) as compared to the control group (average loss of 3 dB PTA and 10% SD). However, when using the first and last audiograms for the control group, there was a statistically significant difference as compared to the worst preoperative and postoperative scores in the shunt group. Using the first and last scores, the control group had a better outcome (PTA improved 2 dB, SD score dropped 5%). There was no significant difference between groups for percentage of patients whose hearing improved, remained the same, or worsened. In conclusion, the endolymphatic shunt operation did not significantly effect the long-term hearing results.

ISSN:0192-9763    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTStudies of aural and other body tissues suggest that otosclerosis represents the local manifestation of a general disorder of connective tissue. In particular, collagen abnormalities have been described. We have undertaken a pilot study of the in vivo messenger RNA (mRNA) transcription for procollagenase (precursor of collagenase), as well as for stromelysin and tissue inhibitor of metalloprotease (TIMP), an activator and a specific inhibitor of tissue collagenase activity, respectively. Human skin from individuals with surgically confirmed otosclerosis was compared to skin from their family members (clinically positive and clinically negative) and from unrelated normal controls. Preliminary data indicate that on average there are significantly lower levels of mRNA production for stromelysin among individuals with otosclerosis as compared to all others tested. Similar trends were demonstrated for TIMP and procollagenase, although these did not achieve statistical significance. In addition to suggesting a pathogenetic mechanism for the development of the disease, these data could serve as the basis of possible confirmatory tests for early diagnosis of otosclerosis and as a method for evaluating the genotype of offspring of affected individuals prior to their age of clinical manifestation. This could translate into the application of prophylactic treatment regimens in the future. The proposed abnormalities also suggest candidate genes for otosclerosis.

ISSN:0192-9763    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTMeningiomas of the cerebellopontine angle (CPA) most often arise from the posterior surface of the petrous pyramid and may extend along the dura to involve the tentorium. Petroclival meningiomas often involve Meckel's cavity and the tentorium. It is impossible to completely remove these large lesions with extension to the supratentorial region by conventional surgical approaches to the CPA such as the suboccipital, middle fossa, or translabyrinthine routes. If total tumor resection is not accomplished, recurrence inevitably follows. A transcochlear approach and actual excision of a large portion of the tentorium allows wide exposure to these large CPA and petroclival meningiomas with supratentorial extension. Thirty-three CPA meningiomas were reviewed from 1976 to 1991. Fourteen patients had tumor extension not only into Meckel's cavity but to the supratentorial region. Ten patients had complete tumor removal, whereas subtotal removal was associated with cavernous sinus invasion. The surgical technique is described in detail with accompanying illustrations. Preoperative symptoms, medical imaging scans, results, and complications are discussed.

ISSN:0192-9763    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTEarly results for hearing and vertigo are reported for 47 labyrinthotomies with streptomycin infusion (LSI) by 13 coinvestigator-surgeons. Sixty-eight percent of patients had worse hearing after surgery (10 dB or 15% word recognition). Patients with a preoperative pure-tone average better than or equal to 40 dB appeared to suffer less postoperative hearing loss than those with a greater preoperative deficit. Severe to profound postoperative hearing loss was experienced by 27 patients (57%), all of whom had preoperative pure-tone averages worse than 40 dB. Opening the endolymphatic space was associated with a deleterious effect on hearing. Because of persistent vertigo, 17 percent of patients required a secondary procedure during the period of observation. These early results indicate that LSI is associated with a significant risk of postoperative hearing loss. Of the 13 coinvestigator-surgeons, four have stopped using LSI, while one considers his results satisfactory. The remaining surgeons have taken an intermediate position and feel it is useful in selected cases. Longer follow-up is required to judge the efficacy of LSI for controlling vertigo. We are currently studying these long-term results.

ISSN:0192-9763    

出版商:OVID    

年代:1992

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTVarious surgical approaches to the cerebellopontine angle have been used for removal of acoustic neuromas. A retrolabyrinthine transtentorial approach has been developed that allows (1) access to the anterior cerebellopontine angle and all portions of the basilar artery, (2) extra dural retraction of the lateral sinus and cerebellum while avoiding the vein of Labbé, and (3) preservation of hearing. This approach allows good exposure of tumor and accurate visualization of cranial nerves. To avoid complications, control of spinal fluid is mandatory and great care must be taken to avoid injury of the cranial nerves. The retrolabyrinthine or translabyrinthine transtentorial approach enables skilled neurosurgeons and neurotologists to gain access to lesions that are located in areas difficult to approach.

ISSN:0192-9763    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTThe entire endolymphatic duct and sac as well as the vestibular epithelia were obtained from four patients with Menierés disease during translabyrinthine (TL) eighth nerve section and from 12 patients undergoing TL resection of acoustic schwannomas. After these specimens were processed for routine transmission electron microscopy (TEM), they were studied for morphologic evidence of viral infection. Although no virus particles were identified, numerous regularly occurring cell components and artifacts were found to morphologically mimic viruses. An atlas of these structures is presented.

ISSN:0192-9763    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTAspartame is a low-calorie food sweetener recently approved by the FDA for general human consumption. One of us (AJG) treated a patient whose symptoms of episodic vertigo and continuous unsteadiness resolved upon ceasing aspartame intake. A literature review revealed that although dizziness has been associated with aspartame intake, no systematic study of the problem exists. As an initial attempt to ascertain the prevalence of aspartame-related dizziness in an otolaryngologic clinic, we elected to study prospectively all patients entering with the complaint of vertigo by means of a standardized questionnaire. Those patients determined to consume aspartame were further studied in a nonblinded manner to see if aspartame intake could be correlated to symptomatology. A cross-over limb was also attempted, but no patient would participate. This presentation details the case history of the propositus patient and the preliminary results of the currently ongoing prospective study.

ISSN:0192-9763    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTAn acute animal model has been developed in the chinchilla for the study of perilymphatic fistulas. Micropunctures were made in three sites to simulate bony, round window, and oval window fistulas. The eye movements in response to pressure applied to the external auditory canal were recorded after micropuncture induction and in preoperative controls. The main pressure stimulus was a pseudorandom binary sequence (PRBS) that rapidly changed between plus and minus 200 mm of water. The PRBS stimulus, with its wide frequency bandwidth, produced responses clearly above the preoperative baseline in 78 percent of the runs. The response was better between 0.5 and 3.3 Hz than it was below 0.5 Hz. The direction of horizontal eye movement was toward the side of the fistula with positive pressure applied in 92 percent of the runs. Vertical eye movements were also observed. The ratio of vertical eye displacement to horizontal eye displacement depended upon the site of the micropuncture induction. Thus, such a ratio measurement may be clinically useful in the noninvasive localization of perilymphatic fistulas in humans.

ISSN:0192-9763    

出版商:OVID    

年代:1992

数据来源: OVID