Cochlear implants: indications and technology.

Over the last decade, the field of cochlear implants has progressed to the point where many postlinguistically deaf adults can use a multichannel device to understand speech without lipreading. The remainder are able to use their devices to aid in lipreading and to discriminate environmental sounds. It is anticipated that improved processing schemes will be developed so that the cochlear implant user can expect better speech perception with these devices. Eventually, a more sophisticated cochlear implant that has the capability of permitting good speech discrimination may supplant hearing aids for severely deafened individuals. Regardless of future developments, the present-day systems effectively restore auditory function to profoundly deafened children and adults.

Acute spontaneous otorrhagia resulting from a ruptured petrous carotid aneurysm. Case report.

A 35-year-old man experienced sudden spontaneous arterial bleeding from his left ear. Arteriography demonstrated a left petrous carotid aneurysm. The bleeding was initially controlled with packing and ultimately by left common carotid ligation and transection.

The middle cranial fossa approach to the internal auditory canal -- an anatomical study stressing critical distances between surgical landmarks.

The middle cranial fossa approach to the internal auditory canal and petrous apex has proven to be an extremely useful otologic surgical procedure. Ths historical evolution of this approach and its present day application were reviewed. The purpose of the study was to describe the normal anatomical variations encountered during the course of the middle cranial fossa approach to the internal auditory canal. Measurements between surgical landmarks were made on 20 dissected, and 41 histologically sectioned temporal bones. The values obtained were statistically analyzed. Finally, the practical implication of the observed anatomical measurements and of the statistical evaluations were discussed.

Recurrent meningitis secondary to idiopathic oval window CSF leak.

Bacterial meningitis remains a life-threatening infection even in the present antibiotic era; thus, any abnormality which predisposes a patient to a recurrence of this serious disease, must be identified and corrected. This report describes the histroy of a 12-year old boy with a profound neurosensory hearing loss, a related absence of vestibular function and a Mondini-type of temporal bone dysplasia who developed recurrent episodes of meningitis which were due to an idiopathic cerebrospinal fluid otorrhea. Even though the meningitis was labyrinthogenic in origin, the patient did not experience the associated symptoms of hearing loss and/or vertigo since the affected inner ear was clinically unreactive. By surgically exploring the middle ear, the presence of a cerebrospinal fluid otorrhea was confirmed. The leak was observed to be coming from a defect in the stapes footplate, and it was controlled by firmly packing the inner ear vestibule with muscle. A remarkable similarity exists between the patient described above and the 15 previously reported cases of meningitis due to a spontaneous cerebrospinal fluid otorrhea. Generally, the problem occurred in young children, the average age being 6.4 years; male and female were equally afflicted. All 15 previously reported cases had a severe neurosensory hearing loss which was unilateral in 10 individuals and bilateral in the other five. In 11 of the case reports, the vestibular function was evaluated, and the labyrinth was noted to be unreactive in the affected ear. An associated congenital abnormality of the inner ear was described in 11 of the patients reviewed. Anatomically, in 13 cases, the leak was observed to be coming from the oval window area. Other affected sites included one report of a fissure of the promontory and one report of a defect in the roof of the eustachian tube. Multiple surgical procedures were required in 11 of the 15 patients in order to identify the exact source of the otorrhea and to seal it permanently. In three cases, the successful procedure was a middle ear exploration with stapedectomy and packing of the inner ear vestibule. Overall, a total of 36 operations was performed in the 15 patients reviewed. In conclusion, when the physician is confronted by a case of meningitis in a patient with a unilateral or bilateral total loss of hearing and vestibular function, the possible presence of an idiopathic cerebrospinal fluid leak should be considered, expecially if radiographic studies demonstrate a temporal bone dysplasia. In these selected cases, if the etiology of the meningitis is obscure, a middle ear exploration should be performed both for diagnostic purposes as a means to ascertain definitely the presence of a leak and for therapeutic purposes to seal it effectively.

Cochlear implantation in children with enlarged vestibular aqueducts.

OBJECTIVES: This report details our experience with cochlear implantation in children with both profound sensorineural HL (SNHL) and enlarged vestibular aqueducts (EVAs). It seeks to determine if the abnormal anatomy of EVA predisposes to any adverse events during or after cochlear implantation. STUDY DESIGN: A retrospective review. METHODS: Charts were reviewed for details of the procedure, complications, and audiologic outcome. RESULTS: Between 8/25/93 and 9/16/98, 10 children with EVAs received cochlear implants, of whom 8 children (5 males, 3 females; mean age 7.8 y) had audiologic follow-up of at least 6 months. The implant was inserted without difficulty in all patients. Pulsatile clear fluid via the cochleostomy was observed in five patients, but was easily controlled in each instance. There have been no major complications, although two patient had short-lived postoperative vestibular symptoms and one child has experienced an intermittent pulsing sensation in her head. Speech perception measures were obtained using a battery of tests that assessed the children's ability to perceive speech in both open- and closed-set formats. Two patients were excluded because the implant was placed within the last 6 months. Of the remaining eight children identified with EVAs, seven (86%) demonstrated open-set word recognition. CONCLUSIONS: These favorable results may be attributed in part to HL that occurs relatively late in childhood, allowing implantation in postlingual candidates. Cochlear implantation can be safely and effectively performed in children with SNHL associated with EVAs.

Beta-2 transferrin: limitations of use as a clinical marker for perilymph.

Beta-2 transferrin is a protein marker that can be used in the clinical setting to reliably identify the presence of cerebrospinal fluid (CSF). Recent literature has suggested that beta-2 transferrin can also be used as a clinical marker for perilymph. This study investigates the use of a beta-2 transferrin assay as a method to identify the presence of perilymph. Twenty-two patients were enrolled in the study. Fluid samples were obtained intraoperatively and tested for the presence of beta-2 transferrin. As expected, four CSF samples collected were positive for beta-2 transferrin; however, four known perilymph samples collected from patients undergoing cochlear implantation were negative for beta-2 transferrin, seven of nine known perilymph samples obtained during stapedectomies were negative for beta-2 transferrin, and four of five samples collected during middle ear explorations for fistula were negative for beta-2 transferrin. With current methodology beta-2 transferrin does not appear to be a reliable clinical marker for perilymph in the operative setting.

Ciprofloxacin: drug of choice in the treatment of malignant external otitis (MEO).

Ciprofloxacin, a fluorinated quinolone with high efficacy against Pseudomonas aeruginosa, was used in the treatment of 10 consecutive patients with malignant external otitis. All patients had skull base osteomyelitis documented by nuclear and computed tomography (CT) scans. Dosages of 1.5 g of ciprofloxacin daily were used for a mean average of 10 weeks. All patients were considered cured with a minimum follow-up of 18 months after completion of therapy. A new classification of malignant external otitis (MEO) is presented.

Congenital cholesteatomas in children: an embryologic correlation.

The clinical findings in 37 children with congenital cholesteatoma of the middle ear, 17 of which have not been previously reported, are presented. Clinical findings and surgical observations are correlated with recent developmental studies. It is hypothesized that congenital cholesteatoma may originate from an epidermoid formation, which has been identified in the anterior superior lateral tympanic cavity adjacent to the anterior annulus during fetal development, and which normally is present early in development, involuting by 33 weeks' gestation. It is proposed that the epidermoid formation may not always involute, and could serve as an embryologic anlage of congenital cholesteatomas.

Complications of the treatment of malignant external otitis.

Malignant external otitis is an aggressive, potentially lethal infection of the temporal bone, the treatment of which is often fraught with complications. Among the reasons for these complications are the difficulty in assessing the extent of this disease, the uncertainty in determining the point at which treatment can be terminated, the toxic nature of the antibiotics used, and the technical difficulty of performing any surgery on the infected tissues. In those patients who receive inadequate initial therapy, the further extension of the disease itself represents a complication of treatment.

A clinical-radiographic classification of skull base lesions.

Lesions involving the base of the skull can be divided into primary and secondary disease processes. The primary group consists of bone lesions more often seen elsewhere in the skeletal system while the secondary group consist of those lesions extending to the base of the skull by direct extension from adjacent intracranial or extracranial sites. The purpose of this paper will be to arrive at a classification of skull base lesions based on the roentgen localization of the disease process. The base of the skull because of its anatomically variable curvature can be difficult to evaluate on good quality conventional radiographs. In addition to the changing angles of the bone itself, the overlying soft tissues of the pharynx and neck only serve to further conceal areas of bone pathology. The advent of polytomography and CAT scanning has greatly aided the evaluation of this region which clinically is extremely difficult to assess. In some instances invasive modalities such as angiography and posterior fossa myelography are necessary to define the lesion. With these diagnostic methods available, rather than discovering classical patterns of disease, a variety of disease processes have been found that radiographically mimic each other. Similarly, on a purely clinical basis, many of the disease entities present in a similar fashion. It is only by a combined approach that an intelligent differential diagnosis can be offered.

Differences in dendritic cells in congenital and acquired cholesteatomas.

Cholesteatomas are histologically benign, though biologically invasive lesions that arise from the migration of squamous epithelium of the ear. Acquired cholesteatomas usually arise in an antigenically active environment, i.e., a chronically and/or recurrently inflamed middle ear. In contrast, congenital cholesteatomas occur in an uninflamed environment. The potential role of dendritic cells (DCs) in the evolution of this lesion has not been thoroughly studied. By staining for S-100 protein, the authors evaluated the presence and distribution of DCs in cholesteatomas. Sixteen cases of cholesteatomas diagnosed from 1987 to 1989 were selected for this study. The formalin-fixed, paraffin-embedded sections were processed by a standard avidin-biotin peroxidase-antiperoxidase method for S-100 protein and for leukocyte common antigen (LCA). The presence and distribution of S-100 protein-positive DCs was evaluated and compared to canal wall skin. DCs were present in all cases. Nine acquired cholesteatomas had 5 to 16 epithelial DCs per high-power field (HPF). Seven congenital cholesteatomas were examined. Four with isolated congenital pearl-like cholesteatomas had 1 to 3/HPF epithelial DCs. In contrast, the three inflamed congenital cholesteatomas had 6 to 12/HPF DCs. The control uninflamed canal wall skin had only 1 to 3/HPF DCs. All DCs were LCA negative, as expected.

Surgery for recurrent and residual cholesteatoma.

One hundred twelve patients (116 ears) were treated for recurrent and residual cholesteatoma. A retrospective review revealed that 66% had undergone canal wall down mastoidectomy at the previous surgery. The surgical procedure at revision was selected on the basis of an intraoperative assessment of the extent of disease, and clinical prediction of eustachian tube function. The average period of follow-up was 3.4 years. Revision surgery was successful in providing the patient with a safe, dry ear in 105 (91%) of 116 cases. Surgical principles and hearing results are presented.

Complications in the management of large glomus jugulare tumors.

This study analyzes the complications encountered in the surgical treatment of 17 patients with large glomus jugulare tumors. All 17 patients sustained either new cranial nerve palsies or exacerbation of preexisting palsies. These involved, in descending order of frequency, the facial nerve, the vagus and glossopharyngeal nerves, and the hypoglossal nerve. Postoperative palsies of the facial nerve involved 17 patients, as compared to 5 preoperatively. Fifteen patients had postoperative partial or complete paralysis of the vagus nerve as compared to eight preoperatively. Ten patients had postoperative palsies of the hypoglossal nerve as compared to six preoperatively. Other complications included CSF leak, meningitis, and wound infection. Aspiration and dysphagia were encountered postoperatively in 13 patients. Teflon injection of paretic vocal cords and cricopharyngeal myotomy effectively improved the ability to swallow and the quality of the voice. Prompt recognition and treatment of complications is essential for effective surgical management of large glomus jugulare tumors.

Tuberculous otitis media.

Tuberculous otitis media is a variable and puzzling infectious disease which may remain undiagnosed or confused with other acute or chronic middle ear conditions if appropriate diagnostic studies are not performed. Among the common clinical findings are insiduous onset of painless watery drainage, severe hearing loss, multiple perforations of the tympanic membrane and subsequent appearance of profuse granulation tissue. As the disease progresses destruction of the middle ear conductive apparatus, facial paralysis, cochlear involvement with labyrinthitis and further hearing loss, and finally intracranial dissemination of infection may occur. The case histories of two patients recently treated at Mount Sinai Hospital illustrate some of the clinical problems encountered with this disease.

The evaluation of middle ear meningiomas using computerized axial tomography.

Meningiomas localized within the middle ear and mastoid which have no intracranial component are rare tumors. Three patients with meningiomas which were thought to involve only the middle ear were treated surgically, were followed for two to six years and were thought to have been cured. However, when computerized axial tomography became clinically available, these patients were examined using this radiographic technique. Unexpectedly, all three patients were found to have a large intracranial meningiomatous extension. A review of the literature reveals only 13 primary meningiomas; these case reports are summarized. It was noted that definitive tests for an intracranial extension of the meningioma were performed in only 2 of the 13 cases. Therefore, in view of our recent clinical experience, it is recommended that a patient presenting with a middle ear meningioma should have a computerized axial tomographic examination of the head to detect the possible presence of a clinical silent intracranial involvement.

Programming the cochlear implant based on electrical acoustic reflex thresholds: patient performance.

The electrical acoustic reflex threshold (EART) has been shown to be a reliable estimate of behavioral comfort levels in both child and adult cochlear implant patients. The purpose of this study was to investigate the potential for using EARTs for programming the Nucleus cochlear implant. EARTs and behavioral comfort levels were obtained from 7 adult implant patients. Two programs or "maps" were made for each patient, one based on behavioral comfort levels and one based on EARTs. Performance on open set tests of speech recognition was measured with each map. Mean data suggest that speech perception is similar with both maps. Analysis of individual data revealed that, whereas 2 subjects performed better with the C-level maps, the remaining 5 subjects tended to perform either better with the EART map or equally well with both maps. These results suggest that EARTs may be an adequate substitute for comfort levels when programming the implant for patients who are unable to make reliable psychophysical judgments.

Radiographic findings in progressive necrotizing "malignant" external otitis.

Twenty-three cases of progressive necrotizing (malignant) external otitis were reviewed. Radiographic evaluation was correlated with clinical disease. CT scanning accurately demonstrated subtle foci of involvement in the skull base which may be clinically unsuspected or go undetected with other studies. Central skull base erosion indicates advanced disease and selects those patients requiring extended antibiotic therapy. Soft tissue thickening of the parapharyngeal space and roof of the nasopharynx also implies advanced disease requiring prolonged therapy. Soft tissue improvement can be visualized on CT. While CT scanning demonstrates the progression of bony disease, it cannot be used to follow resolution of central skull base osteomyelitis. Radionuclide scans provide information regarding the overall extent of the inflammatory process.

Primary adenomatous neoplasm of the middle ear.

Adenomatous lesions of the temporal bone are seldom encountered in clinical practice. Four cases of primary adenocarcinoma of the middle ear are reported. All four patients presented with a mass behind an intact tympanic membrane. Two of the four patients had received radiation to the head and neck area 10 or more years prior to their developing adenocarcinoma of the middle ear space. Although this tumor is locally invasive, it does not appear to be highly aggressive and can be treated by local excision, i.e., mastoidectomy with tympanoplasty.

A matched-pairs comparison of single and multichannel cochlear implants in children.

Auditory capabilities of Nucleus 22 multichannel cochlear implant users were compared to those of matched 3M/House single-channel users. Six children who received either the 3M/House or Nucleus 22 cochlear implants were separated into three matched pairs. Group 1 consisted of two postlinguistically deafened adolescents, group 2 consisted of two prelinguistically deafened school-age children, and group 3 consisted of two perilinguistically deafened preschoolers. Participants were evaluated using auditory comprehension and discrimination tasks as indicated by the 3M/House and Nucleus 22 protocols. However, only tasks common to both were included here. While the 3M/House single-channel device has been under an IDE for children under the age of 18 years since 1984, the Nucleus 22 multichannel implant only recently became available for this age group. Thus, short-term evaluations at 6 months and 1 year postimplantation have been used for comparison. Two of the three groups indicated that the multichannel users performed as early as the 6-month level; the children in the third group performed equally. These results indicate that multichannel cochlear implants show great promise in deaf children.

Outcome analysis of cochlear implant reimplantation in children.

OBJECTIVES: We review our experience gained in performing cochlear reimplantation in 25 children who have had multichannel cochlear implant device failure at the Cochlear Implant Center of the Manhattan Eye, Ear and Throat Hospital and Lenox Hill Hospital (New York, NY), to assess the feasibility of cochlear reimplantation in children and the effect of reinsertion on audiological performance. STUDY DESIGN: We retrospectively analyzed the outcome of 27 consecutive multichannel cochlear implant reinsertions performed in 25 children at the Manhattan Eye, Ear and Throat Hospital and Lenox Hill Hospital. These reimplantations were performed between 1990 and 1999, with a minimum follow-up of 6 months for both surgical and audiological performance. METHODS: Charts were reviewed for patient factors, findings at the time of initial operation and repeat operation, and results of audiological testing both before and after reimplantation. RESULTS: Surgical complications of reimplantation included two intraoperative cerebral spinal fluid leaks and two late postoperative flap breakdowns with implant extrusions. For the most part, depth of electrode insertion was unchanged. Open-set speech recognition scores and speech perception abilities remained stable or improved compared with results before reimplantation. CONCLUSION: Our results confirm that cochlear implant reimplantation is technically feasible and allows for continued auditory development for the child who has a cochlear implant device failure.