Biomedical subjects

F M Rizer

Publications and source records attributed to F M Rizer.

12 recordsLinked to original sources

PubMed1991

Perilymph fistulas: the House Ear Clinic experience.

The diagnosis, evaluation, and surgical treatment of perilymph fistulas has recently been the focus of a great deal of attention in otology. Authors have focused on perilymph fistulas as the cause of hearing loss and vertigo in many diverse situations. Additionally, surgical repair has been suggested when there is little objective support for intervention. To address some of the problems inherent in the diagnosis and treatment of perilymph fistulas, records of patients operated on at the House Ear Clinic during the past 12 years were reviewed retrospectively. Eighty-six patients were surgically explored for fistulas during this period. Thirty-five (40.7%) fistulas were found, and 51 ears were patched whether fistulas were found or not. Of the 80 patients who were seen for follow-up, 35 (43.8%) were subjectively better, and 45 (56.2%) were the same. Although the number of fistulas found and the number of patients improved were similar, the composition of the two groups was different. On the basis of audiometric results, improvement in hearing occurred in only 18.7% of the patients. None of the demographic factors or diagnostic tests were predictive of either the presence of a fistula or the therapeutic outcome. Further work is required to facilitate the preoperative diagnosis of fistulas and to design appropriate surgical intervention.

Adolescent↗

PubMed1990

Staging for cholesteatoma in the child, adolescent, and adult.

A closed tympanomastoidectomy with subsequent staged surgical procedures leading to the excision of cholesteatoma was validated as described. All elements of staging with a 10-year experience of 354 patients are covered according to categories of child (0 to 9 years), adolescent (10 to 15 years), and adult. The child differed from the adolescent and adult in the following manner: more recurring cholesteatomas, greater ossicular necrosis, poorer hearing results, less aggressive residual cholesteatoma, and significantly poorer results with pars flaccida cholesteatoma than pars tensa cholesteatoma. After the end stage, 90% of the cases remained closed, with acceptable hearing in 60% of the patients.

Adolescent↗

PubMed1989

Perilymph fistulas in children: experience of the Otologic Medical Group.

We reviewed records of 86 consecutive fistula explorations over 12 years. Four cases were children under age 18. There were 35 fistulas, all in adults. Since this series, we have identified five more children with fistula explorations for a total of nine patients. Two had bilateral explorations. Presenting symptoms were hearing loss and dizziness. None of the children had a definite fistula. Of the nine patients, one patient had a significant improvement in hearing postoperatively, five had no change, and two had worse hearing. There was no follow-up in two patients or in the second ear of a bilateral case. We feel that a fistula should be considered in any case of progressive or fluctuating sensorineural hearing loss, especially in cases with a congenital inner ear deformity. In such cases, an exploration may be reasonable to rule out a fistula. Otherwise, we are hesitant to explore patients for fistulas regardless of whether they are children or adults. Sudden, progressive, and fluctuating sensorineural hearing loss, dizziness, and meningitis have been attributed to perilymph fistulas in both adults and children. The literature reports fistulas in all types of conditions. The incidence and degree of success of treatment have varied widely. When Goodhill first reported round window rupture as a cause of sudden sensorineural hearing loss (SNHL), the Otologic Medical Group (OMG) began routine exploration of all cases of sudden SNHL for the presence of fistulas. After 50 consecutive cases were explored and no fistulas were found, we became selective in our exploration candidates.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1988

A postoperative audiometric evaluation of cochlear implant patients.

As the benefits of the cochlear implantation become more defined, many investigators hope that these devices can be offered to patients with a lesser degree of hearing loss. Accordingly, it is necessary to investigate the audiometric thresholds in the implanted ear after surgery. Preservation of the residual hearing after implantation would support the claims that surgery and the presence of a cochlear implant do not adversely affect the implanted ear.

Audiometry↗

PubMed1988

The management of congenital cholesteatoma: surgical results of 42 cases.

Radical surgery for congenital cholesteatoma leaves the patient, usually a child, with an ear that requires care for life. At the Otologic Medical Group, the intact canal wall technique has been used for many patients with cholesteatoma. To determine results of this management in the treatment of congenital cholesteatoma, we reviewed records of all patients treated between 1974 and 1985. Forty-two ears were studied in 41 patients. A closed middle-ear space was achieved in all cases, and an intact canal wall was maintained in 41 (98%). Follow-up averaged 4.3 years. Of the 41 cases with serviceable hearing before surgery, 28 (68%) had postoperative hearing within 10 dB of the best preoperative bone conduction threshold. Thirty-eight of the 41 achieved a final hearing result within 20 dB of the best bone conduction threshold.

Child↗

PubMed1988

Cochlear histopathology in the labyrinthectomized ear: implications for cochlear implantation.

Limited damage to the cochlea and preservation of hearing after labyrinthectomy have been the subject of many case reports. One might hypothesize that, even when hearing is lost, there may be less damage to the cochlea than anticipated, and some neural elements that can be electrically stimulated may be preserved. Four labyrinthectomized temporal bones on file at the House Ear Institute were evaluated histopathologically. All had some remaining spiral ganglion cell population, the neural element that we think is stimulated by the intracochlear electrode. We also examined the population of hair cells and dendrites and the presence and extent of cochlear ossification, factors that may influence the performance of a cochlear implant. This is the first study of its type. Results indicate that cochlear implantation in the labyrinthectomized ear may be feasible.

Cochlea↗

PubMed1987

Induced temporary threshold shift in guinea pigs.

The etiology of an incidentally discovered temporary threshold shift observed in an experimental animal (Harley guinea pig) is discussed with its potential implications for auditory research.

Animals↗

PubMed1987

Reconstructing the absent lenticular process.

When a surgeon encounters an absent lenticular process of the incus, he must either reposition the incus or attempt to bridge the small gap between the remaining incus long process and the stapes capitulum. Our solution to this problem is to place a Lippy modified Robinson stapes prosthesis on the stapes footplate and attach it to the remaining long process, thus bypassing the stapes superstructure. This modified Robinson prosthesis has a portion of the well removed allowing the eroded long process to enter from the side. The hearing results of 63 cases at 6 months (two-thirds of which had a concurrent tympanoplasty) are 67% within 10 dB and 91% within 20 dB of the preoperative bone hearing level. The use of an existing and proven prosthesis provides both stability and, to date, the most successful hearing results for reconstructing the absent lenticular process.

Ear Ossicles↗

PubMed1987

Lateral sinus thrombosis: diagnosis and treatment--a case report.

Lateral sinus thrombosis is a difficult diagnostic problem. Specialized computerized tomography allows non-invasive preoperative visualization of sinus contents enabling the surgeon to make a definitive diagnosis with appropriate preoperative planning. This case report details these specialized techniques and their application to a case of lateral sinus thrombosis.

Child↗

PubMed1985

Macroglossia: etiologic considerations and management techniques.

Tongue enlargement of varying degrees occurs in many people and often requires no therapy. However, marked tongue enlargement, when present, requires direct intervention. In this case, the otolaryngologist is presented with a dilemma, for the etiology of the problem is often obscure. In many cases, the tongue enlargement is secondary to systemic disease, and medical management is indicated. When tongue reduction is indicated, there are many modalities available. Of these, only excision offers an acceptable functional result with minimal morbidity. Even large protuberant tongues can be reduced with minimum difficulty. The type of tongue excision can be tailored to the involved area and to special patient requirements. The problem of macroglossia is explored and management techniques are reviewed to present an alternative for optimal management of the enlarged tongue.

Acromegaly↗

PubMed1984

Voice quality and intelligibility characteristics of the reconstructed larynx and pseudolarynx.

The ideal laryngeal substitute would provide a voice with good intelligibility, volume, and character. The basic components of these qualities are being studied in our laboratories to refine laryngeal reconstruction and replacement techniques. Exact definition of these characteristics may then be translated into specific requirements for reconstruction. In this study the phonation of laryngectomees using hand-held artificial laryngeal devices and patients with reconstructed larynges was compared with that of normal speakers. Presentations were evaluated by adult listeners with normal voice and hearing, and intelligibility scores were developed. These studies show, in part, that the fundamental frequencies at which various artificial speech aids are used do not significantly correlate with user intelligibility. Computerized spectral analysis was then utilized to ascertain the unique acoustic characteristics of the voices. Further computer analysis was carried out to determine what characteristics of the normal speakers' voices were shared in common with patients using artificial devices and patients with reconstructed larynges. Initial attempts at using these findings in laryngeal reconstruction based on computer modeling will be presented.

Humans↗

PubMed1983

Comparison of geometric and "real" surface areas of cochlear electrodes.

The destructive potential of the electrically active electrode is believed to be related to charge density at the electrode-tissue surface. Charge density has been calculated with the use of both geometric and electrochemical "real" values for surface area. To further assess the accuracy of surface area measurements determined by means of the previously mentioned methods, an eight-electrode modiolar array cochlear implant was examined. Electrode surface areas were measured first electrochemically, then by means of a light microscope, and finally with the use of the scanning electron microscope. Comparison of these measurements demonstrated a high correlation between the scanning and light microscopic values. However, there was no correlation between the surface areas determined by light and scanning electron microscopy and the electrochemical measurements.

Cochlear Implants↗