Autoimmune inner ear disease--a real entity?

Involvement of autoimmune mechanisms in sudden-onset, rapidly progressive, bilateral inner ear disease is supported by the following evidence: (1) the inner ear contains immune cells and mediators (immunoglobulins); (2) animal models demonstrate inner ear damage after immunization with inner ear tissue; (3) experimental autoimmune inner ear disease appears to be transferable with sensitized T cells; (4) human SNHL can occur in the context of systemic immunologic disease; (5) SNHL can be improved by immunosuppressive therapy; and (6) patients with SNHL demonstrate elevated immune responses to inner ear proteins/tissue preparations. There are also several reasons, however, why the above inner ear disease cannot be termed "autoimmune": (1) in experimental models, inner ear damage may be produced during an in situ immune response to an irrelevant antigen; (2) histopathology is not yet extensive enough to confirm the role of immune cells and mediators in human disease; (3) immune reactivity to an organ-specific antigen associated with the inner ear has not yet been identified. At this time, therefore, clinical inner ear disease with evidence of immunologic involvement is termed "immune-mediated" rather than "autoimmune." IMIED is likely to represent a heterogeneous group of diseases with multifactorial causes but a common endpoint. Diagnosis is made primarily by clinical profile in association with laboratory testing to rule out neoplasia or infection. Investigational laboratory immunoassays for antibodies to inner ear proteins or hsp 70 appear to have promise for diagnosis or predicting clinical response to immunosuppressive treatment. Sensitivity and specificity of such assays have not yet been established.

Can sensitized lymphocytes retain reactivity to inner ear antigens after retrieval from frozen storage?

Immune inner ear disease results in rapidly progressive, bilateral sensorineural hearing loss and is one of the few forms of sensorineural hearing loss that can be treated medically. The purpose of this study is to identify and preserve several populations of sensitized lymphocytes from patients with immune inner ear disease as a first step toward cloning autoreactive T cells, in order to study the pathogenesis of disease. Lymphocytes from four patients with high reactivity (stimulation index of 2.5 or greater) were placed in frozen storage. At 8 to 14 months they were thawed and restimulated. All four samples were viable. Two reacted again to inner ear homogenate, but with different intensities. Some lymphocytes sensitized to inner ear antigens can retain reactivity after frozen storage. This methodology may be useful to clone highly reactive T cells.

Hearing and Sjögren's syndrome.

Immune sensorineural hearing loss is manifested in several systemic immune diseases. Although hearing loss has been previously documented in patients with Sjögren's syndrome (SS), the effect of SS on hearing is unclear. This prospective study was designed to assess the presence of hearing loss in 14 patients with SS and, if sensorineural hearing loss was present, to determine if the hearing loss was immune-mediated. Patients were evaluated with basic audiologic tests as well as for cellular immune inner ear reactivity as measured by the lymphocyte transformation test (LTT). Three patients had evidence of sensorineural hearing loss. Two patients had a positive LTT without evidence of sensorineural hearing loss. This preliminary study suggests that SS may not directly cause sensorineural hearing loss, immuno-mediated or otherwise.

Sudden sensorineural hearing loss.

Approximately 4000 new cases of sudden hearing loss (SHL) occur annually in the United States, and 15,000 annually worldwide, accounting for approximately 1% of all cases of SHL. Although prevalence studies do not necessarily distinguish between idiopathic and acquired SHL, most cases of spontaneous SHL have no identifiable cause. In this article, the authors assess the cause, history, diagnosis, and treatment of SHL.

Cochleosacculotomy for the treatment of Menière's disease in the elderly patient.

Cochleosacculotomy is a surgical option for the treatment of incapacitating vertigo in elderly patients with Menière's disease. This procedure was performed in nine patients (mean age: 73 years) for control of vertigo and/or drop attacks. The average follow-up period was 29 months. Vertigo was controlled in eight of nine patients, but hearing worsened in all but one patient. No patient developed a transient increase in vertigo in the postoperative period. Cochleosacculotomy should be considered in elderly patients with recurrent vertigo and severe non-fluctuating sensorineural hearing loss who would otherwise be candidates for labyrinthectomy.

Adenomatous lesions of the temporal bone immunohistochemical analysis and theories of histogenesis.

Adenomatous lesions of the temporal bone represent a diverse group of neoplasms. At least three histopathologic patterns have been described: glandular; ribbon-like, or "festooning;" and aggressive papillary. Combinations of glandular and ribbon-like histologies in the same lesion are not uncommon. The glandular and ribbon-like histologies have been associated with carcinoid tumors, and the aggressive papillary tumor has been considered a separate entity. Recently, the endolymphatic sac has been proposed as the site of origin of the aggressive papillary lesions. Previous reports have described neuroendocrine properties with characteristics embracing the three histologic types. The authors postulate that the neural crest is the site of origin of this unusual group of neoplasms. Immunohistochemical analysis on the pathologic specimens of patients with adenomatous lesions of the temporal bone was performed to test this hypothesis. From 1975 to 1992 seven patients were treated at the Cleveland Clinic Foundation with a diagnosis of middle ear adenoma. A panel of special stains for neuroectodermal markers, including synaptophysin, chromogranin, neuron specific enolase, calcitonin, and serotonin was used on the paraffin-embedded formalin-fixed specimens. Three lesions were also evaluated by electron microscopy, all demonstrating dense core, intracytoplasmic granules. Three ribbon-like tumors were positive for synaptophysin and chromogranin, and two of these were positive for serotonin. One glandular tumor was positive for synaptophysin, and an aggressive papillary tumor was positive for synaptophysin and neuron specific enolase. An additional papillary tumor was referred following a third recurrence without accompanying immunohistochemical data. Cholesteatoma-like material was identified with a few glandular cells interspersed, all negative by immunohistochemical evaluation. The seventh specimen, initially diagnosed as papillary adenoma on light microscopy, was not studied by the aforementioned stains, and was later identified as a papilloma of sinonasal origin. The neural crest gives rise to pluripotential stem cells with widespread anatomic distribution, including the temporal bone. Because immunomarkers used in this study are specific for neuroectodermal differentiation, results suggest that temporal bone adenomas have neuroendocrine characteristics and could be derived from the specialized neuroectoderm of the neural crest.

Surgical treatment of incapacitating peripheral vertigo. Criteria for the evaluation of surgical results.

This brief article presents general criteria for evaluating results of different operations for hearing, vertigo, and disability. Also reviewed are the 1985 guidelines of the Committee on Hearing and Equilibrium of the American Academy of Ophthalmology and Otolaryngology, which are currently being revised.

Update of reparative granuloma: survey of the American Otological Society and the American Neurotology Society.

Members of the American Otological Society and the American Neurotology Society were polled regarding stapes surgery and reparative granuloma. Of 467 questionnaires, 176 (38%) were returned, and 319,410 stapes cases were statistically analyzed: 329 reparative granulomas were reported after stapedectomy (incidence = 0.1%) and 29 after stapedotomy (incidence = 0.07%); 77 surgeons reported having encountered at least one reparative granuloma; and 50 surgeons related the occurrence of a reparative granuloma to a specific graft material. Gelfoam was the most common graft material reported when a reparative granuloma was encountered, followed by fat, and vertigo was the most frequently reported presenting symptom. Reported operative techniques as well as manifestations, management, and outcome are discussed.

Laboratory diagnosis of immune inner ear disease.

Immune inner ear disease is a relatively new and distinct clinical entity that produces unexplained, rapidly progressive, bilateral sensorineural hearing loss. The diagnosis is based on clinical manifestations, positive immune laboratory testing, and beneficial response to a trial of corticosteroids. Immune laboratory tests are used to confirm a presumptive clinical diagnosis. The two tests most commonly used are the lymphocyte transformation test and Western blot immune assay. The rationale behind these tests is presented, and the role they play in laboratory diagnosis of immune inner ear disease is discussed.

Objective measurement of normal facial movement with video microscaling.

This study examines variability in facial movements in normal subjects using a new objective method of measuring facial movement, video microscaling. Video microscaling superimposes a computer-generated measuring scale over a video recorded image of facial movements. Distances moved are determined digitally. Eleven subjects were tested raising the eyebrows and smiling five times on two separate days. Test-retest, day-to-day, side-to-side, and intersubject variability were evaluated. Average variability was relatively low; however, some normal subjects exhibited considerable variability, particularly from day-to-day and from side-to-side. Because of this, a facial nerve grading system based solely on objective measurements of facial movements may be invalid. Video microscaling is a promising research technique.

Retrolabyrinthine transtentorial approach to lesions of the anterior cerebellopontine angle.

Various surgical approaches to the cerebellopontine angle have been used for removal of acoustic neuromas. A retrolabyrinthine transtentorial approach has been developed that allows (1) access to the anterior cerebellopontine angle and all portions of the basilar artery, (2) extra dural retraction of the lateral sinus and cerebellum while avoiding the vein of Labbé, and (3) preservation of hearing. This approach allows good exposure of tumor and accurate visualization of cranial nerves. To avoid complications, control of spinal fluid is mandatory and great care must be taken to avoid injury of the cranial nerves. The retrolabyrinthine or translabyrinthine transtentorial approach enables skilled neurosurgeons and neurotologists to gain access to lesions that are located in areas difficult to approach.

The learning curve in stapes surgery.

Fewer stapes operations are available to train residents and to maintain individual competence. Most residents in the United States perform 0 to 10 cases during training, and produce results which are not as good as expert results, even with close supervision. After graduation, fewer cases are available to achieve expert results in private or academic practice. The authors' conclusions and recommendations are based on his own learning curve. Residents who have below average skills in middle ear surgery, and residents who do not wish to practice otology, should watch but not perform stapes surgery. Program directors, collectively or separately, should develop more formal guidelines for teaching stapes surgery during residency.