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Biomedical subjects

T Balkany

Publications and source records attributed to T Balkany.

15 recordsLinked to original sources
PubMed1991

Intrinsic vasculature of the labyrinthine segment of the facial nerve--implications for site of lesion in Bell's palsy.

Recent studies of the intrinsic vasculature of the cat facial nerve have demonstrated relatively poor blood supply to the labyrinthine segment. In this study, the intrinsic vasculature of the human facial nerve was systematically evaluated in 25 temporal bones and three fresh cadaver nerves. Cross-sectional vessel counts were obtained for the labyrinthine, tympanic, and mastoid segments. Capillary densities for each segment were derived from these data. The labyrinthine segment of the human facial nerve, like that in the cat, contains fewer and smaller intrinsic blood vessels than do the mastoid and tympanic segments. This may indicate that the labyrinthine segment of the facial nerve may be more vulnerable to ischemic damage. In conjunction with the previously demonstrated narrowness of the labyrinthine fallopian canal, these findings support the contention that the labyrinthine segment is a likely site of lesion in Bell's palsy.

Ear, Inner↗
PubMed1991

Flexible fiberoptic endoscopy of the cochlea: human temporal bone studies.

New bone formation within the cochlea has been found more frequently than expected during cochlear implantation. Although implantation of partially ossified cochleas with long multichannel electrodes is possible, in practicality it may be difficult to determine whether electrode insertion is feasible prior to attempting it. In spite of use of high resolution computerized tomography, the presence, nature, and extent of new bone formation in the scala tympani is often difficult to ascertain. Flexible fiberoptic otologic endoscopes, 0.7 mm and 1.0 mm in diameter, were developed for the purpose of visualizing the fluid-containing scalae of the cochlea. In order to determine the efficacy of the device in visualizing the interior of the cochlea, as well as determining possible damage caused by its use, ten formalin fixed human temporal bones were studied. The flexible fiberoptic otologic endoscope was found to be capable of passage through the scala tympani of the cochlea in the inferior segment and of identifying normal and abnormal structures. Passage beyond this point resulted in damage to the spiral ligament. We conclude that human trials of use of the endoscope during cochlear implantation on previously deafened individuals is feasible.

Cochlear Implants↗
PubMed1990

Endoscopy of the cochlea during cochlear implantation.

We have previously demonstrated that multichannel cochlear implants may be effective in partially obstructed cochleas. In practice, however, it may be difficult to determine whether electrode insertion is feasible prior to attempting it. Initial trials with a flexible fiberoptic otologic endoscope on 10 cadaver temporal bones were previously reported. On the basis of these trials, endoscopy of the inferior segment of the cochlea during cochlear implantation seemed feasible. In the present study, the same endoscope was used on eight subjects undergoing cochlear implantation, six of whom had partially obstructed cochleas. Endoscopy was found to be helpful in visualizing obstructed segments, determining patency after the obstruction was removed, and identifying normal structures of the cochlea. Documentation with videotape and 35-mm photography constitutes the majority of this paper.

Adolescent↗
PubMed1988

Binaural cochlear implantation: comparison of 3M/House and Nucleus 22 devices with evidence of sensory integration.

Direct comparison of the efficacy of cochlear implant designs has been difficult for several reasons. There have been wide variations in patients implanted and many differences in testing protocols for each device. In most instances, even a single patient may have unequal degrees of pathology and duration of deafness in the two ears. Implantation of a 3M/House device in the left ear and a Nucleus 22 device in the right ear of a 55-year-old woman, deafened to a similar degree and simultaneously in both ears by streptomycin, allows an opportunity to compare function under presumably similar circumstances. The Nucleus 22 cochlear implant was superior in this case in providing speech discrimination. Perhaps of greater interest, however, is evidence of a binaural effect. Presumably, central integration of sensory stimuli presented through two dissimilar processing strategies resulted in enhanced function on certain measures.

Cochlear Implants↗
PubMed1986

The intrinsic vasculature of the cat facial nerve.

Treatment of facial nerve disorders is based in part on assumptions regarding the intrinsic blood supply of the nerve. This study was designed to comprehensively delineate the intrinsic facial nerve microcirculation and its relation to the extrinsic circulation in an animal model. Twenty-eight cat facial nerves were removed intact from brain stem to stylomastoid foramen following intravital fixation. Specimens were studied by gross dissection, silicone injection and tissue clearing, complete vessel counts on serial cross sections of individual nerves, and scanning electron microscopy or transmission electron microscopy. The labyrinthine segment of the cat facial nerve contains strikingly fewer intrinsic blood vessels than the mastoid and tympanic segments. The geniculate ganglion, however, has a distinct, rich vascular plexus. The ultrastructure of the intrinsic facial nerve vessels is similar to other small vessels of the body with tight junctions of the endothelium and overlapping spiral smooth muscle fibers of arterioles, as well as surrounding pericytes.

Animals↗
PubMed1986

Behavioral effects of cochlear prosthesis on deafened monkeys.

No deleterious effects of electrical stimulation on deafened young monkeys were noted using the behavioral techniques described. Due to the small size of this study and the variability of individual monkey behavior, it is impossible to draw definitive conclusions from this study. However, the results strongly suggest that deafened young monkeys with functioning cochlear implants showed apparent improvement in social behavior over deafened nonimplanted subjects. These changes may result from environmental and vocalization sound awareness and/or prevention of auditory deprivation provided by the prosthesis.

Animals↗
PubMed1978

Idiopathic pleomorphic midfacial granuloma (Stewart's type).

Idiopathic mid-facial granuloma is an unusual highly destructive disease which was virtually unknown prior to 1955. Great confusion exists, due in large part to the terminology applied to this entity as well as the clinical similarity of the process to other destructive mid-facial lesions. A classical case of idiopathic mid-facial granuloma of Stewart's type is presented, with characteristic lesions limited to the mid-face. Definitive histopathological features consist of pleomorphic inflammatory granulation tissue with patchy necrosis and no system lesions or neoplasia in the autopsy tissues.

Face↗
PubMedDate not supplied

Unilateral endolymphatic hydrops and associated abnormalities.

A case of unilateral endolymphatic hydrops is presented in which several significant histopathological findings are observed in the affected inner ear and are absent in the opposite ear. Moderate endolymphatic hydrops is present in all cochlear turns on the involved side. Atrophic changes in the cochlear and vestibular end-organs, partial collapse and infolding of Reissner's and the saccular membranes, and collapse of the posterior canal membrane are also seen. There is also marked narrowing of the proximal rugose portion of the endolymphatic sac, associated with a flattened, epithelial lining, dense fibrotic connective tissue, brown pigment deposition, and poor vascularity in a relatively narrowed and straightened vestibular aqueduct. Fibrosis, loss of vascularity, and brown pigment deposition are also observed in the bony channels surrounding the vestibular aqueduct.

Cochlea↗
PubMedDate not supplied

Multichannel cochlear implants in partially ossified cochleas.

Deposition of bone within the fluid spaces of the cochlea is encountered commonly in cochlear implant candidates and previously has been considered a relative contraindication to the use of multichannel intracochlear electrodes. This contraindication has been based on possible mechanical difficulty with electrode insertion as well as uncertainty about the potential benefit of the multichannel device in the patient. Fifteen profoundly deaf patients with partial ossification of the basal turn of the cochlea received implants with long intracochlear electrodes (11, Nucleus; 1, University of California at San Francisco/Storz; and 3, Symbion/Inneraid). In 11 cases, ossification had been predicted preoperatively by computed tomographic scan. Electrodes were completely inserted in 14 patients, and partial insertion was accomplished in one patient. All patients currently are using their devices and nine of 12 postlingually deaf patients have achieved some degree of open-set speech discrimination. This series demonstrates that in experienced hands, insertion of long multichannel electrodes into partially ossified cochleas is possible and that results are similar to those achieved in patients who have nonossified cochleas.

Adolescent↗