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Biomedical subjects

D B Kamerer

Publications and source records attributed to D B Kamerer.

At least 55 records · Page 3Linked to original sources
PubMed1987

Perilymph fistula resulting from microfissures.

Perilymphatic fistulas are well documented in the otolaryngologic literature as a cause for both auditory and vestibular symptoms. The anatomic location of fistulas has been clinically confirmed in both the oval and round windows. Furthermore, membranous tears within the cochlea have been described post mortem and may be the cause of the remaining fistulas which are suspected but not confirmed surgically. A fourth source of perilymph fistula has previously been suggested by Okano and Harada. During the past several years, surgical confirmation of perilymph leakage from two microfissure areas has been observed. These cases will be briefly discussed along with their clinical implications. Speculation as to the type of hearing loss caused by fistulas will be offered. Hypotheses concerning the various symptoms encountered in patients and the location of the defect will also be addressed.

Adult↗
PubMed1978

Electromyographic correlation of tensor tympani and tensor veli palatini muscles in man.

It is the purpose of this study to attempt a correlation of function, by electromyographic means, of the tensor tympani and tensor veli palatini muscles in humans. Despite the small number of patients tested, it is believed that the similarities and characteristics of the two are unmistakably equivalent. A separate theory for the combined tensor function is discussed in distinction to the stapedius mediated acoustic reflex. The concept of a single tensor muscle, with two anatomic divisions, a common nerve supply, and parallel function, is therefore submitted.

Ear, Middle↗
PubMed1977

Secondary phase nystagmus--revisited.

A prospective clinical study of secondary phase nystagmus (SPN) is presented. The tracings of 200 patients referred for ENG evaluation and eight normal control subjects were anlyzed under all caloric conditions, within a prolonged postirrigation tracing time frame. The spontaneous direction reversal (SPN) was observed in a majority of the control subjects under all four conditions. The occurrence of post-caloric SPN in the patient group varied considerably among various diagnostic categories. However, SPN was observed far less frequently in the total patient group as compared to the control group. Thus, the absence of SPN may be taken to be a general indication of vestibular pathology.

Electronystagmography↗
PubMed1976

Perilymphatic fistula and its interest to audiologists.

Forty-one patients who had sudden hearing loss associated with spontaneous perilymphatic fistllas were reviewed in this investigation. A history of physical exertion or an upper respiratory infection prior to the onset of hearing loss strongly suggests the presence of spontaneous perilymphatic fistula. However, absence of such a history does not necessarily preclude the possibility of membrane rupture. A great variation in audiologic and vestibular findings was observed. Tinnitus was present for most patients and vertigo or disequilibrium was reported by some. Findings support the need for surgical exploration in patients with sudden hearing loss when a perilymphatic fistula is suspected. Postoperative success in restoring hearing function in cases with perilymphatic fistula is good if the fistula is closed within two weeks after the initial insult. Delay in closure of such fistulas can cause irreversible loss of hearing.

Adolescent↗
PubMedDate not supplied

Preservation of vestibular nerves in surgery of the cerebellopontine angle: effect on hearing and balance function.

INTRODUCTION: Small tumors of the cerebellopontine angle (CPA) can frequently be removed with preservation of the auditory and the vestibular portion of the eighth cranial nerve. This study was undertaken to estimate the effect of vestibular nerve preservation on both balance and hearing following surgery. MATERIALS AND METHODS: A retrospective study of all cases of CPA lesions between 1987 and 1991 was undertaken. This identified 11 patients in whom either the superior and/or inferior vestibular nerves were preserved. This included eight acoustic neuromas and three meningiomas. The retrosigmoid approach and total tumor extirpation was undertaken in all cases. Patients undertook a vestibular questionnaire, audiometric testing, and evaluation of vestibulo-ocular responses preoperatively and postoperatively. Additionally, static and dynamic platform posturography was performed postoperatively in 9 of 11 patients. RESULTS: Follow-up ranged from 6 to 44 months. Of the eight patients with acoustic neuroma, four had a preoperative balance disorder that resolved postoperatively. One patient died of unrelated causes. Of the remaining seven patients with caloric testings, one maintained normal caloric responses. A persistent postoperative phase shift was noted in 4 of the 7 cases with rotatory testing. Three patients were treated for a meningioma. All had a preoperative balance disorder that resolved postoperatively. Two patients showed vestibular response indicative of residual but compromised function on the involved side. The third patient showed absent responses indicating an anatomically intact nerve that does not necessarily predict functional activity. Preservation of the vestibular nerve was associated with preservation of preoperative hearing in five of the patients. This included four of the eight acoustic patients and one of the three meningioma patients. CONCLUSIONS: Preservation of the vestibular nerve did not result in a chronic balance disorder in this patient population. This study does not allow the authors to conclude if vestibular nerve preservation improves overall hearing after CPA surgery; however, these data suggest that preservation of the inferior vestibular nerve may result in less damage to the cochlear nerve in some patients. Accordingly, preservation of the vestibular nerve in CPA meningioma surgery can be recommended.

Adult↗
PubMedDate not supplied

Hypercoagulability in otologic patients.

INTRODUCTION: Three patients with otologic disorders developed complications related to hypercoagulability. This report was prepared to increase the awareness among otolaryngologists of the diagnosis and management of hypercoagulable states, and to encourage expert consultation when indicated. MATERIALS AND METHODS: One patient with dural venous sinus thrombosis complicating an otitis media, one patient with a large glomus jugulare tumor, and one patient with a sudden sensorineural hearing loss were treated by the otolaryngology service. Suspicious thromboembolic events were evaluated by the hematology service, and appropriate anticoagulative therapy was recommended. RESULTS: One patient with an inherited hypercoagulopathy and two patients with acquired hypercoagulopathies were treated for otologic problems. Two of the patients were stabilized and discharged on life-long anticoagulation therapy. The third patient, in spite of intensive medical and surgical support, eventually succumbed to complications to which an acquired hypercoagulable state made a significant contribution. Expert consultants made the hematologic diagnoses and treatment recommendations. CONCLUSION: Otolaryngologists should be aware that hypercoagulable states may now be more accurately diagnosed and characterized, and that thorough investigation of thromboembolic events may affect treatment decisions.

Adult↗
PubMedDate not supplied

Alternate and simultaneous binaural bithermal caloric testing: a comparison.

This study compares the results from simultaneous binaural bithermal and alternate binaural bithermal caloric testing of 652 patients with dizziness. Also compared are the abilities of these tests to distinguish between a population of healthy asymptomatic subjects and our patient population. Caloric testing used a closed-loop irrigation system. Eye movements were monitored with electro-oculography. The agreement between the results from the two tests was low. Also, while the simultaneous test was more sensitive, the alternate test was more specific. Using receiver-operator characteristic methodology, it was found that the ability of the alternate test to distinguish between a healthy population and a patient population was superior to that of the simultaneous test. There was no improvement in the ability to distinguish between a healthy population and a patient population when the results from the two tests were combined as compared to using the alternate caloric test alone.

Algorithms↗
PubMedDate not supplied

Gamma knife: an alternative treatment for acoustic neurinomas.

Despite surgical advances and technologic means of better monitoring seventh and eighth nerve function intraoperatively, there remains a group of patients for whom alternative methods of treatment are desirable. These include the elderly, those with bilateral tumors or tumors in only hearing ears, individuals with medical contraindications to major surgery, and those who refuse surgical resection. The University of Pittsburgh became the fifth world center and the first in the United States to install the "gamma knife" for stereotactic radiosurgery. On the basis of the pioneering work done at the Karolinska Institute in Stockholm, acoustic tumor patients who fulfill the above criteria are being treated. A tumoricidal single treatment closed-skull radiation dose is given through 201 sharply focused cobalt 60 sources, minimizing the effects on surrounding brain or other tissues. Our early results are discussed and compared to those from more than 200 cases in Stockholm. Complications and expected long-term results are presented.

Cobalt Radioisotopes↗
PubMedDate not supplied

The tensor tympani, stapedius, and tensor veli palatini muscles--an electromyographic study.

Electromyographic recordings of the activity of the tensor veli palatini, tensor tympani, and stapedius muscles were obtained from several adult human subjects. Muscle responses were recorded under four stimulus conditions, ie, contralateral intense wide-band noise, air jet to the eye, swallow, and electrical stimulation of the tongue. The results indicated that the two tensor muscles responded to the same stimuli in similar patterns. The latter muscle differed from the response of the stapedius.

Acoustic Stimulation↗