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Jose N Fayad

Publications and source records attributed to Jose N Fayad.

At least 19 recordsLinked to original sources
PubMed2006

Clinical performance of children following revision surgery for a cochlear implant.

OBJECTIVES: The purpose of this study was to describe the causes for revision surgery and to compare clinical performance before and after surgery in children who required electrode reinsertion. STUDY DESIGN AND SETTINGS: Soundfield thresholds and speech recognition scores were compared before device failure and following electrode reinsertion. Temporal bones from a deceased adult implant user who underwent bilateral revision implantation were analyzed. RESULTS: Histopathology in the adult temporal bones revealed new bone formation in the scala tympani and substantially reduced spiral ganglion counts, with open-set speech recognition realized. Of 28 children undergoing revision surgery, 18 required electrode reinsertion. With the exception of 1 patient with severe cochlear malformation, new electrode arrays were fully inserted without difficulty. Clinical outcomes between pre-device failure and post-electrode reinsertion did not differ statistically. CONCLUSION AND SIGNIFICANCE: Electrode reinsertion is technically feasible in the pediatric population. The majority of children recover their prerevision clinical performance. EBM RATING: C-4.

Adolescent↗
PubMed2006

Distribution of low-frequency nerve fibers in the auditory nerve: Temporal bone findings and clinical implications.

HYPOTHESIS: Low-frequency cochlear fibers are on the outer surface of the auditory nerve adjacent to the vestibular nerve in the distal part of the internal auditory canal. BACKGROUND: There is a misconception that low-frequency cochlear fibers are in the core of the cochlear nerve and are surrounded by high-frequency fibers. METHODS: We analyzed temporal bones with a loss of upper spiral ganglion cells caused by different etiologies (n = 6) and traced the corresponding fibers into the distal internal auditory canal. Spiral ganglion cells for each segment (I-IV) of the cochlea were counted, and we defined the location of nerve fibers from the various segments. RESULTS: There was total or near-total degeneration of the upper spiral ganglion cells in these bones. Corresponding low-frequency fibers were on the outer surface of the cochlear nerve adjacent to the vestibular nerve in the distal segment of the internal auditory canal. CONCLUSION: Low-frequency fibers seem to be located at the periphery of the cochlear nerve. These findings provide one possible explanation for the low-frequency sensorineural hearing loss found in 10% of patients with vestibular nerve schwannomas and may have clinical relevance in the diagnosis of these lesions.

Adult↗
PubMed2006

Human cochleae with three turns: an unreported malformation.

OBJECTIVE: The objective of this histologic study of archival temporal bone sections was to describe the morphology of human cochleae found with three turns, a previously unreported anomaly, found in three pairs of temporal bones. METHODS: The authors conducted histopathologic processing and measurement of basilar membrane length. Basilar membrane length was compared with that found in six normal control bones. RESULTS: Cochleae with three complete turns, rather than the usual two and a half turns, are described for the first time. All had longer than normal basilar membranes, with a mean length of 40.6 mm compared with a mean of 33.8 mm in the normal bones. CONCLUSIONS: Human cochleae with three turns exist as an unreported anomaly. This is a new category of anomaly, not likely based on interruption of development.

Aged↗
PubMed2006

Multichannel cochlear implants: relation of histopathology to performance.

OBJECTIVES: To determine the relationship of surviving neural elements to auditory function in multichannel cochlear implant temporal bones. STUDY DESIGN: Case series of all 14 existing multichannel cochlear implants in our temporal bone collection. METHODS: Devices included Nucleus 22 (n = 11), Nucleus 24 (n = 1), Ineraid (n = 1), and Clarion (n = 1). Morphologic evaluation of structural elements including spiral ligament, stria vascularis, hair cells, peripheral processes, and spiral ganglion cells was performed. Clinical performance data were obtained from patient charts. For eight patients, nonimplanted contralateral temporal bones were available and paired comparisons were made. RESULTS: Despite frequent absence of hair cells and peripheral processes, all bones had at least some remaining spiral ganglion cells. Percent of normal remaining structures were unrelated to auditory performance with the implant for any of the structural elements. Ganglion cell count in segment III showed significant negative correlations to speech discrimination scores for words and sentences (Rhos = -.687 and -.661, P < or = .03 and .04) as did segment IV and total ganglion cell count with word score (Rhos = -.632 and -.638; P < or = .05). Spiral ganglion cell survival did not differ between implanted and nonimplanted ears, with the exception of segment I, which had fewer cells in the implanted ear (P < or = .028). CONCLUSIONS: Performance variability of cochlear implants cannot be explained on the basis of cochlear neuronal survival. Although hair cells and peripheral processes were frequently absent or greatly diminished from normal, all subjects had at least some spiral ganglion cells. And, in this series, there was an inverse relationship between survival of ganglion cells and performance.

Adult↗
PubMed2006

Auditory brainstem implants: surgical aspects.

Patients with neurofibromatosis type 2 often develop bilateral life-threatening vestibular schwannoma necessitating tumor removal, which results in deafness. We developed the auditory brainstem implant (ABI) in order to be able to electrically stimulate the cochlear nucleus complex in patients with bilateral cochlear nerve injury from bilateral schwannoma. After tumor removal, the electrode array of the ABI is inserted into the lateral recess of the fourth ventricle and placed over the surface of the ventral and dorsal cochlear nuclei. The ABI is designed to stimulate auditory neural structures within the cochlear nucleus in order to convey salient cues about the frequency, amplitude, and temporal characteristics of sounds. To date, more than 200 patients have received an ABI device at our institution. Recently, penetrating ABIs were introduced, and preliminary results of penetrating ABIs are discussed in this paper. The surgical anatomy of the nucleus and surgical placement of the ABI in patients with neurofibromatosis type 2 are described, and surgical considerations in this group of challenging patients are detailed.

Auditory Brain Stem Implants↗
PubMed2006

Understanding drug ototoxicity: molecular insights for prevention and clinical management.

Ototoxicity is a trait shared by aminoglycoside and macrolide antibiotics, loop diuretics, platinum-based chemotherapeutic agents, some NSAIDs and antimalarial medications. Because their benefits in combating certain life-threatening diseases often outweigh the risks, the use of these ototoxic drugs cannot simply be avoided. In this review, the authors discuss some of the most frequently used ototoxic drugs and what is currently known about the cell and molecular mechanisms underlying their noxious effects. The authors also provide suggestions for the clinical management of ototoxic medications, including ototoxic detection and drug monitoring. Understanding the mechanisms of drug ototoxicity may lead to new strategies for preventing and curing drug-induced hearing loss, as well as developing new pharmacological drugs with less toxic side effects.

Aminoglycosides↗
PubMed2005

Glomus tympanicum.

Explore the source record for details and available documents.

Ear Neoplasms↗
PubMed2004

Revision cochlear implant surgery: causes and outcome.

OBJECTIVE: To review experience with cochlear implant reimplantations, including effect of reinsertion on audiological performance. STUDY DESIGN AND SETTING: Retrospective review of cochlear implant reinsertions in patients seen in a private tertiary neurotologic practice. Forty-three patients (8 adults and 35 children) underwent revision cochlear implant surgery for device failure or upgrade. Findings at initial and repeat operations were noted, including number of electrodes inserted, and speech perception performance data were obtained when available. RESULTS: Five complications occurred in the reinsertion operations, 2 (6%) intraoperative cerebral spinal fluid leaks and 3 (7%) postoperative flap breakdowns with implant extrusion. Number of electrodes inserted was unchanged in 40/43 patients. Speech perception abilities remained stable or improved. CONCLUSION: Cochlear reimplantation is technically feasible and allows for continued auditory stimulation. SIGNIFICANCE: Patients facing reimplantation must be aware of the possibility of differences in sound quality and speech recognition performance with their replacement device, but speech perception ability will typically remain the same or improve.

Adult↗