Bone conduction impairment in chronic ear disease.

The preoperative and postoperative bone conduction (BC) thresholds were prospectively investigated in 24 patients with chronic ear disease in the form of cholesteatoma, chronic suppurative otitis media, or adhesive otitis media. All underwent tympanoplasty with mastoidectomy. Ossicular reconstruction was performed in 14, and the remaining 10 were still awaiting second-stage ossicular reconstruction at the time of this investigation. In each group, the postoperative results were compared with the preoperative results by the paired-samples t-test. In the ossicular reconstruction group, the results revealed a significant improvement in the postoperative BC thresholds, as compared with the preoperative BC thresholds, at 250, 1,000, and 2,000 Hz, with the largest mean improvement observed at 2,000 Hz. No significant improvement was observed at any frequency for the group without ossicular reconstruction. Postoperative improvement of at least 10 dB at 2 or more frequencies was observed in 71% of the ossicular reconstruction group, as compared with 0% of the group that did not undergo ossicular reconstruction. The results support the theory that the elevated BC thresholds of patients with chronic ear disease result from the elimination, due to disease, of the middle ear contribution (from the inertial ossicular component and ossicular resonance) to the BC response. The results also suggest that the middle ear contribution to the BC response is restored with ossicular reconstruction.

Eustachian tube endoscopy in patients with chronic ear disease.

OBJECTIVES/HYPOTHESIS: A paucity of research exists on trans-eustachian tube endoscopy to evaluate the status of the eustachian tube. Fuller examination of the role of the eustachian tube in chronic ear disease is needed, particularly because the eustachian tube has been implicated in the chronicity and pathogenesis of chronic ear disease. Therefore the purpose of this study was to evaluate the eustachian tube, based on observations from trans-eustachian tube endoscopy. STUDY DESIGN: Twenty-two adult patients with chronic ear disease gave informed consent to participate in a prospective, trans-eustachian tube endoscopic investigation. METHODS: Flexible, fiberoptic, nonarticulating (outside diameter of 0.5 mm) and articulating (outside diameter of 1.0 mm) endoscopes (coherent fused bundle of 3,000 pixels) were employed. The eustachian tube endoscopy was performed under general endotracheal anesthesia as the initial part of a larger, otological surgical procedure for chronic ear disease. The endoscope was passed from the middle ear (transtympanic approach) to the nasopharynx. RESULTS: The 0.5-mm endoscope passed entirely through the eustachian tube from the tympanic orifice into the pharyngeal orifice in 16% of the cases. Stenotic blockage occurred at the infundibulum in 37%, isthmus in 42%, and fossa of Rosenmuller in 5% of cases. The eustachian tube mucosa was abnormal in 64% of cases. The risk for abnormal eustachian tube mucosa was four times greater for persons with long-standing disease (> or = 20 y) than for persons without long-standing disease (<20 y). The mean therapeutic efficiency of ossicular reconstruction was higher for the subgroup with normal than for the subgroup with abnormal eustachian tube mucosa. CONCLUSIONS: The findings of trans-eustachian tube endoscopy provide objective evidence concerning eustachian tube status in persons with chronic ear disease and have implications for the timing of surgical intervention (ossicular reconstruction).

Cochlear implant device failure: diagnosis and management.

Complete, irreversible failure of the implanted receiver-stimulator of the Cochlear Corporation multichannel implant are relatively rare. However, as the implanted patient population grows, malfunctions may be expected. From the over 200 patients implanted at the University of Michigan Medical Center, 6 patients with a complete and irreversible cochlear implant receiver-stimulator failure have been identified and treated. This represents a 3% failure rate. The amount of time between initial implantation and device failure ranged from 6 months to 3.5 years. Determination of device failure was made using psychophysical, electrophysiologic, and averaged electrode voltage measurements. The measurement of the average electrode voltages proved to be useful in determining the condition of the implant. Physiologic changes causing reduced electrical excitability were ruled out using psychophysical or electrophysiologic promontory testing. All patients were successfully explanted and reimplanted.

Scar formation in the vestibular sensory epithelium after aminoglycoside toxicity.

Hair cell degeneration and the repair process due to differing types of trauma have been studied extensively in the organ of Corti. It has been determined that, during scar formation, after differing types of trauma to the auditory sensory system, the reticular lamina is maintained with adherens junctions and tight junctions. We investigated the repair process within the vestibular epithelium. Hair cell degeneration was induced by the unilateral application of streptomycin to the inner ears of guinea pigs. Whole mount preparations of all five vestibular organs were processed and examined by fluorescence, light and electron microscopy. Scar formation was seen as early as 4 days post-treatment with streptomycin and was noted to coincide with hair cell degeneration. Neighboring supporting cells swelled and filled the space beneath the degenerating hair cell. Between three and five supporting cells participate in the reparative process. The distribution of cytokeratin is also altered during scar formation. The area once occupied by the hair cell becomes filled with cytokeratin-rich processes of supporting cells. It appears that differing numbers of supporting cells are involved in the reparative process within the vestibular sensory epithelium as compared to the auditory system. The reticular lamina remains intact at all times. This may possibly prevent mixing of fluids between different compartments in the inner ear and dysfunction of the vestibular sensory organs.

Distribution of cytokeratins in the vestibular epithelium of the guinea pig.

Cytokeratin expression in the vestibular labyrinth of the guinea pig was investigated with immunofluorescence and immunoperoxidase staining on surface preparations of the vestibular epithelium. Phalloidin, an F-actin-specific probe, was used to distinguish between hair cells and supporting cells. Cytokeratin expression was not found in the cytoplasmic domain of hair cells of the crista ampullaris, utricle, or saccule. Cytokeratin expression was abundant in supporting cells of the vestibular sensory epithelium. Electron microscopy revealed the presence of desmosomes, which are associated with cytokeratins, within type 2 hair cells of the vestibular epithelium. It appears that cytokeratins are absent within the cytoplasmic domain of hair cells, but are present in association with intercellular junctions. The functional significance of this unique pattern of cytokeratin expression within the vestibular epithelium is discussed.

Squamous cell carcinoma of the temporal bone arising 43 years after fenestration procedure.

Squamous cell carcinoma originating in the middle ear cleft is a rare tumor that tends to be diagnosed late in its course. The presenting symptoms mimic inflammatory disease of the middle ear space, and hence biopsy is often delayed. Herein we present a case of squamous cell carcinoma of the temporal bone arising 43 years after fenestration procedure. Operative findings were significant for complete dissolution of the tegmen tympani, tegmen mastoideum, and posterior fossa dura plate with dural exposure and sigmoid sinus exposure. Tumor was noted to invade the labyrinth at the horizontal semicircular canal. This case report highlights the aggressiveness of this particular tumor in a previously exenterated mastoid cavity and its proclivity to penetrate the otic capsule via pre-formed pathways. The treatment of choice is aggressive surgical resection followed by radiotherapy.

Facial nerve monitoring in surgery for congenital auricular atresia.

Surgery for congenital auricular atresia places the facial nerve at risk because of its potential aberrancy; iatrogenic facial paralysis is a well-known potential risk. Five cases of congenital auricular atresia are presented. All patients had intraoperative monitoring of the facial nerve. The facial nerve was found to be abnormally displaced, usually due to hypoplasia of the tympanic ring. Preoperative and postoperative facial nerve function was unchanged by surgery. Facial nerve monitoring is an important adjunct in congenital ear surgery because it allows for early and precise identification of the nerve in the absence of normal surgical landmarks and provides for continuous monitoring of the nerve.

An anatomic study of the external laryngeal framework with surgical implications.

Precise knowledge of the level of the vocal fold as projected on the external thyroid cartilage is of critical importance for the performance of thyroplasty type I and supraglottic laryngectomy. Measurements of the external laryngeal framework were made on the larynges of 18 human cadavers in order to identify landmarks that will aid the surgeon in determining endolaryngeal anatomy. On the basis of our results, the following guidelines are recommended: (1) Thyroid cartilage incision for supraglottic laryngectomy should be made on a line joining the juncture of the upper one third and lower two thirds of the midline length and the juncture of the upper one third and lower two thirds of the oblique line. This will ensure a position above the level of the anterior commissure and the true vocal cord; (2) In thyroplasty type I, the superior border of the thyroid cartilage window should be made at a line joining the midpoint of the midline length and the juncture of the upper two thirds and lower one third of the oblique line. Formation of the cartilage window according to this guideline will ensure its placement lateral to the vocalis muscle.

Sinus and nasal manifestations of the acquired immunodeficiency syndrome.

The AIDS epidemic has made previously uncommon infectious diseases and tumors commonplace in HIV-infected individuals. In this article we discuss specific cases of various infections and tumors of the sinonasal tract. Several of these diseases may be the presenting signs of HIV-seropositivity and AIDS. As a result, the clinician first to see such patients must be aware of the diagnosis of these diseases and tumors so that proper testing and treatment may ensue.

Bronchoesophageal manifestations of acquired immunodeficiency syndrome.

Among the more common manifestations of acquired immunodeficiency syndrome (AIDS) are tumors and infections that occur in regions treated by the bronchoesophagologist. In reviewing our institutional experience in the diagnosis and treatment of 396 patients with AIDS in 1987, we have noted that 226 (57%) had some form of pneumonia and 133 (34%) had candidiasis. In this communication we discuss the various types of bronchopulmonary, oropharyngeal, and esophageal infections that have been reported among AIDS patients. We also review the universal precautions and specific guidelines recommended for safeguarding the bronchoesophagologist and other health care workers who treat these patients.