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Biomedical subjects

W F House

Publications and source records attributed to W F House.

At least 55 records · Page 3Linked to original sources
PubMed1989

An immunohistochemical study of the endolymphatic sac in patients with acoustic tumors.

Intraosseous endolymphatic sacs obtained from patients with acoustic neuromas who had undergone total labyrinthectomy during tumor removal were examined for the presence of T helper/inducer and T suppressor/cytotoxic lymphocytes, B lymphocytes, plasma cells, and macrophages. Immunoperoxidase staining of cryostat sections revealed the presence of T helper/inducer lymphocytes, T suppressor/cytotoxic lymphocytes, and macrophages. The number of B lymphocytes and plasma cells was much smaller than the number of T lymphocytes. The number of T suppressor/cytotoxic lymphocytes was higher than the number of T helper/inducer lymphocytes. This study supports the notion of local immune responsiveness in the human inner ear. This is the first immunohistochemical study to analyze lymphocyte subpopulations; specifically, to provide insight into T-cell function in the endolymphatic sac.

Antigens, Differentiation↗
PubMed1989

Biocompatibility of the central electroauditory prosthesis and the human cochlear nuclei.

Previous studies from the House Ear Institute have reported the possibility of sound sensation from the central electroauditory prosthesis (CEP) implanted in patients during removal of bilateral acoustic neuromas. This study describes histologic features of tissues formed around a CEP that was removed due to infection in the area of the electrical plug on the external surface of the skull. We found a layer of compact collagen tissue around the CEP. The tissue penetrated spaces of the Dacron mesh matrix, preventing our determination of the precise place of the electrode-tissue interface. We also found a layer of connective tissue on the Silastic covering on the CEP leads. Histopathologic analysis showed no unusual pathologic changes around the CEP except for degeneration of the abdominal fat used for placement and stabilization of the CEP on the surface of the cochlear nuclei.

Biocompatible Materials↗
PubMed1988

Histopathologic study of the cochlear nuclei after 10 years of electrical stimulation of the human cochlea.

This report provides histologic data on the cochlear nuclei of a patient who used a cochlear implant in the right ear for about 10 years and in the left ear for about 1 year. The most pronounced abnormality in the cochlear nuclei is sites of gliosis. However, since areas of necrosis with similar size, shape, and content of cells were observed outside the nuclei, the gliosis was not specific to the nuclei. There were no other unusual changes in the cochlear nuclei, such as excessive chromatolysis, excessive accumulation of lipofuscin, swollen neurons, or accumulation of glial cells. Comparison showed no statistically significant differences in sizes of cell bodies, size of nuclei, and total density of neurons in cochlear nuclei between the right and left sides. However, the density of normal-looking neurons (with visible nucleoli and without visible pathologic features) was noticeably less on the longer-stimulated side. Some differences between the longer- and shorter-stimulated sides may be due to differences before implantation or other factors, as well as to effects of stimulation.

Cochlea↗
PubMed1987

Congenital malformations of the inner ear: a classification based on embryogenesis.

Approximately 20% of patients with congenital sensorineural hearing loss have radiographic abnormalities of the inner ear. A broad spectrum of anomalous patterns have been described, most of which have been lumped together under the term "Mondini's dysplasia." We feel that this grouping of many dissimilar entities under a single umbrella term is unwarranted. Based on a review of 63 patients with 98 congenitally malformed ears, we have been able to recognize a number of distinct anatomic patterns from their radiographic appearance. A remarkable similarity between these morphologies and the appearance of the inner ear at various stages of embryogenesis was found. This led us to propose a classification system based upon the theory that these deformities result from an arrest of development during varying stages of inner ear organogenesis.

Congenital Abnormalities↗
PubMed1987

Sound detection with the cochlear implant in five ears of four children with congenital malformations of the cochlea.

To determine if the cochlear implant can enable sound detection in children with a congenitally deformed cochlea, we reviewed warble-tone thresholds in five ears of four children in the implant clinical trials program. Of the five ears, there were two common cavity deformities, two cochlear hypoplasias, and one incomplete partition. Four of the five ears had an auditory response to stimulation by the implant at the same level as ears deafened by other disorders. One ear that had an auditory response to stimulation also produced facial stimulation that precluded use of the implant. The one ear that did not stimulate was the incomplete partition. This ear had a very narrow internal auditory canal. Three patients are now using the implant in three ears to detect sound. Results show that a cochlear implant may enable sound detection in a patient with a malformed cochlea but that a very narrow internal auditory canal (less than 1.5 mm) detected preoperatively on radiographs may contraindicate an implant. Such anatomy suggests only a rudimentary audiovestibular nerve or no such nerve and only a facial nerve.

Audiometry↗
PubMed1987

Cochlear implants in deaf children.

The results to date with the 3M/House cochlear implant in children have been extremely encouraging. Statistically and clinically significant changes show that the implant can provide improvements in auditory detection and discrimination as well as in speech production. As with any intervention, results range from outstanding for some children (open-set speech discrimination and/or intelligible speech) to minimal for others (no stimulation or little improvement in speech). Until long-term studies can be completed, the implant will undoubtedly remain controversial. However, professionals involved in the care of a child who is hearing-impaired should be informed that the field of cochlear implantation is rapidly expanding. A number of different cochlear implants are currently undergoing clinical trials in adults. Besides the 3M/House device, the FDA has recently approved a second device, the Nucleus Multichannel Cochlear Implant, for investigation in children. The treatment of profound deafness is changing in children with the cochlear implant as an option for those not benefiting significantly from hearing aids. However, some important aspects of a deaf child's management have not changed and will not change: the need for early diagnosis and multidisciplinary management. The first five years of life are the language acquisition years. Proper management during these years is critical if the hearing-impaired child's handicap is not to dominate his or her future and limit potential for a successful, happy life.

Adolescent↗
PubMed1987

Surgical accessibility of the cochlear nuclear complex in man: surgical landmarks.

Patients deafened by bilateral acoustic tumors or by transections of both cochlear nerves are excluded as candidates for cochlear implantation. These patients require more proximal stimulation of the auditory pathway. One potential area for such stimulation is the cochlear nuclear complex (CNC) in the lateral recess of the fourth ventricle. If animal studies establish the safety and efficacy of such stimulation, electrical stimulation of the human cochlear nuclear complex may become an accepted treatment modality for this select group of patients. Such implantation requires that the surgeon accurately locate the cochlear nuclear complex without destruction of vital surrounding neural and vascular structures. With ten fresh human brains, oriented for a translabyrinthine approach, we determined key anatomical landmarks to the exposed surface of the CNC on both sides of each brain. Using a combination of anatomical landmarks--including the flocculus, eighth nerve root, choroid plexus, and taenia--we located the cochlear nuclear complex (without disruption of surrounding neural or vascular structures) and marked it with colloidal carbon. Access to the CNC was obtained in all 20 specimens, and histologic sections confirmed the carbon marker in the CNC in 19 of 20 specimens.

Cochlea↗
PubMed1987

Anatomical relationships of the cochlear nuclei and the pontobulbar body: possible significance for neuroprosthesis placement.

The pontobulbar body (PBB) is located in the cerebellopontine angle caudally to the cochlear nuclear complex (CN). We found the common boundary between these two structures on the surface of the brain stem as well as within it. We used the Kluver-Barrera staining technique to characterize different neuronal types adjacent to the boundary. Although the majority of them in the CN were globular, we also saw a substantial number of spherical neurons. Neurons in the PBB were substantially different in shape and were mainly angular. The boundary between the PBB and CN at their closest contact runs around the caudal side of the ventral cochlear nucleus and the most proximal part of the eighth nerve. In the more dorsal region, the PBB is completely separated from the CN by the brain stem tissue. In the ventral region, the PBB runs between the seventh and eighth nerves, and it is adjacent to both. These results might aid accurate placement of the central electroauditory prosthesis and further understanding of the general anatomy of the cerebellopontine angle.

Adult↗
PubMed1987

Electrical stimulation of the auditory brain stem structure in deafened adults.

Electrical stimulation of the cochlear nuclear complex in the brain stem was first accomplished in a female adult deafened by bilateral acoustic tumors. The central electroauditory prosthesis (CEP) was surgically placed at the time of the second tumor removal. The patient has now been receiving electrical stimulation for 5 years. Six more adults have received the CEP at the time of tumor surgery. Clinical results indicate fluctuations in electrical measurements over time, particularly in the first weeks following surgery. Patients are able to sustain tone perception for one minute at all frequencies tested. Auditory discrimination test results reveal above-chance performance on suprasegmental measures, similar to scores achieved by cochlear implant users. No serious complications have occurred to date.

Adult↗
PubMed1987

Early detection of small bilateral acoustic tumors.

Bilateral acoustic tumors are one of the most difficult problems in acoustic tumor surgery. Total tumor removal with preservation of hearing has seldom been achieved in the past. Recently, hearing has been successfully preserved if the tumors are small when removed. We present the case of a child with a family history of von Recklinghausen's disease associated with bilateral acoustic tumors. A high index of suspicion of bilateral tumors and a thorough work-up resulted in the early diagnosis of small tumors. The tumors were removed with preservation of normal hearing.

Adolescent↗
PubMed1987

Topography of vestibulocochlear nerve fibers in the posterior cranial fossa.

In the posterior cranial fossa, the separation of the vestibular and cochlear subdivisions of the eighth nerve is clear in about 75% of cases. Although in the remaining cases the vestibulocochlear cleavage plane is not visible macroscopically, the large-fibered vestibular subdivision and the small-fibered cochlear subdivision are well recognized in histological sections. Within the cochlear subdivision, some fibers of large caliber are mixed with fibers of small caliber in a region we named the "overlapping zone." We studied, histologically, cross sections of the intracranial portion of six eighth nerves at about 5 mm proximal to the porus acusticus. A computerized video system was used to measure the diameters of the fibers of the vestibular and cochlear subdivisions localized at different distances from the vestibulocochlear cleavage plane. The overlapping zone is located within the cochlear subdivision adjacent to the vestibulocochlear cleavage plane. It has a pear-like shape, with the larger part occupying the anterosuperior part of the cochlear subdivision. The mean cross-sectional area of this zone in our six samples is about 0.4 mm2, which is approximately 23% of the area of the cochlear subdivision. The thickness of the zone in the superior-inferior direction ranges from 0.23 mm to 0.55 mm. The parameters of the described overlapping zone should be taken into consideration in vestibular neurectomy, in which complete sectioning of the vestibular fibers is important.

Adult↗
PubMed1987

Surgical approaches to the human cochlear nuclear complex.

Patients with bilateral neural deafness may be candidates for rehabilitation with a device that provides direct electrical stimulation of the central nervous system. The cochlear nuclear complex at the pons-medulla junction is a logical site to implant because it is in the surgical field exposed for acoustic tumor surgery. In this study we compared four surgical approaches commonly used to reach the cerebellopontine angle for ease of access to the cochlear nuclear complex. We found the translabyrinthine approach to be the most satisfactory because the anterior approach facilitates identification of key landmarks, such as the tenia of the choroid plexus and the lateral recess of the fourth ventricle. The suboccipital, or retrosigmoid, approach would be satisfactory after removal of a large acoutic tumor; however, the amount of cerebellar retraction necessary may preclude its use in nontumor cases.

Cochlea↗
PubMed1986

Chondrosarcoma of the skull base.

Chondrosarcoma of the skull base is an uncommon neoplasm that comprises 0.15% of all intracranial tumors and 6% of skull base lesions. Compression of vital neurologic structures by tumor expansion as well as the histologic characteristics contribute to the malignant potential of these neoplasms. Tumor recurrence has been associated with incomplete resection in this traditionally surgically inaccessible region. This review of five cases of chondrosarcoma of the skull base examines the surgical approaches to resection in a chronologic fashion to emphasize that total gross resection of these lesions has become possible through the evolution of lateral skull base techniques. The difficulty in pathologic diagnosis and the efficacy of postoperative radiotherapy in enhancing survival are also addressed.

Adult↗
PubMed1986

The middle fossa transpetrous approach to the anterior-superior cerebellopontine angle.

We present a new approach to the skull base, medial and superior to the internal auditory canal, for tumors involving the anterior-superior cerebellopontine angle, petrous apex, and clivus. This approach is accomplished through a middle fossa craniotomy and involves removal of the bone anterior and medial to the internal auditory canal and medial to the cochlea and carotid artery. It combines the advantages of complete tumor removal, low mortality rate, and hearing preservation.

Cerebellar Neoplasms↗
PubMed1986

Safety and efficacy of the House/3M cochlear implant in profoundly deaf adults.

The House/3M cochlear implant system is no longer considered investigational. Many years of clinical experience led to development of a clinically feasible program for selecting patients, fitting the device, training patients in its use, and evaluating results. Both laboratory and clinical data support the conclusion that this device is safe and provides significant benefits for profoundly deaf adults. The House/3M cochlear implant has had a significant impact in the treatment of the profoundly deaf, even while in the investigational stage. First and foremost, patients who were previously turned away as "untreatable" were provided with a new option. Furthermore, the professionals--otologists and audiologists--had a new set of tools, including assessment and rehabilitation materials, to use in dealing with the profoundly deaf patient. These patients can now be provided more effective care whether they obtain an implant or a hearing aid. Finally, the introduction of this device stimulated the development of better devices, better assessment tools, and other alternatives. The future calls for device improvements, objective methods for selection of candidates, and expansion of the application of electrical stimulation of hearing to children, to patients with more residual hearing, and to those who require a central electroauditory prosthesis for stimulation in the brain stem. Cochlear implants are rapidly becoming a part of clinical otology and audiology. It is important that accurate information be disseminated among these professionals, that professional training programs teach their students about this area, and that other professionals, such as educators of the deaf, speech/language pathologists, and psychologists who deal with the hearing impaired, become knowledgeable in dealing effectively with the implanted child or adult.

Adult↗