Extratympanic electrocochleography: diagnostic and predictive value.

OBJECTIVE: To define the clinical value of extratympanic electrocochleography (ECoG) in the diagnosis of Meniere's disease. STUDY DESIGN: Retrospective case review. SETTING: An otology/neurotology referral center. PATIENTS: A group of 252 patients with symptoms consistent with Meniere's disease and 20 normal-hearing control subjects. INTERVENTION: All patients underwent audiologic testing and extratympanic ECoG at the time of initial evaluation and, when possible, following treatment. MAIN OUTCOME MEASURES: Audiologic thresholds and summating and action potential ratios (SP:AP). RESULTS: Patients were classified into definite, probable, possible, and bilateral Meniere's disease groups according to American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guidelines. The definite Meniere's group demonstrated an elevated SP:AP ratio in 74% of cases, the possible Meniere's group in 64%, and the bilateral group demonstrated elevated ratios in both ears in 66%. Contralateral ears produced elevated ratios in 42% for unilateral cases, whereas 40% of these ears reported at least one contralateral symptom. All 40 control ears were normal (SP:AP > or = 0.50). Results statistically correlated (p = 0.004) with the Meniere's staging system set forth in the 1995 AAO-HNS guidelines. No correlation was found between ECoG results and disease duration. Although 72% of the 86 follow-up patients reported complete or substantial vertigo control, changes from initial ECoG results did not specifically correlate to vertigo, tinnitus, or aural fullness improvement. CONCLUSIONS: Extratympanic ECoG can be useful in the diagnosis of Meniere's disease, lending promise to possible cases where objective audiologic data are lacking. Each testing center should study its own results to establish meaningful parameters and confidence levels.

Round window atresia in association with congenital stapes fixation.

OBJECTIVE: To document an association of round window atresia with congenital stapes fixation, discuss the diagnostic role of computed tomography, and implicate the clinical significance of these anomalies. STUDY DESIGN: Retrospective chart review and review of the literature. RESULTS: The authors report three pediatric cases of round window atresia. All cases presented with hearing loss of a conductive nature (two cases bilateral, one unilateral). Two patients underwent middle ear exploration, demonstrating stapes fixation and the absence of a round window. Stapedectomy was performed in both cases without postoperative hearing improvement. Subsequent revision stapedectomy was also unsuccessful in one of these cases. The unoperated case represents the fraternal twin of one patient. In all cases, computed tomography scanning demonstrated findings consistent with atresia of the round window niche without cochlear anomaly. CONCLUSIONS: An association of round window atresia and congenital stapes fixation is apparent. The mechanism of the conductive hearing loss following stapedectomy remains poorly understood. Computed tomography imaging and surgical confirmation are probably both necessary to establish the diagnosis of round window atresia.

Vestibular nerve section: long-term follow-up.

Vestibular nerve section is considered an effective modality in the treatment of refractory and incapacitating vertigo. Typically nerve section results are described on the basis of short-term follow-up. We have reviewed 41 cases of vestibular nerve section spanning an 18-year period. Although the majority of cases involved classic Meniere's disease, delayed endolymphatic hydrops, vestibular neuritis, and Meniere's syndrome secondary to head trauma were also included. Surgical approaches included translabyrinthine (20 cases), retrolabyrinthine (14 cases), retrosigmoid (six cases), and middle fossa (one case) procedures. Postoperative follow-up time averaged 102 months, with 46% of patients followed for a minimum of 9 years. Results are reported according to standards set forth by the American Academy of Otolaryngology--Head and Neck Surgery. Vertigo was cured or markedly improved in 88% of cases (90% in patients with Meniere's disease) at 18 to 24 months postoperatively. These vertigo results were sustained at the time of latest follow-up. Functional level was also preserved over time despite the development of bilateral symptoms in several cases. The rate of bilateral disease reached 22% of cases. Although vertigo results remained stable, long-term follow-up of successful hearing preservation cases demonstrated deterioration over time. Postoperative continuation of medical treatment is urged to optimize and sustain the vestibular neurectomy result.

Brain herniation into the middle ear and mastoid: concepts in diagnosis and surgical management.

OBJECTIVE: To review the occurrence characteristics of and clinical repair experience with brain herniation in to the middle ear and mastoid from 1970-1995. STUDY DESIGN: Retrospective chart/case review. SETTING: Private Otology/Neurotology referral practice. PATIENTS: Thirty-five patients with temporal bone brain herniation diagnosed and treated from 1970-1995. INTERVENTION: Diagnosis confirmed by CT and/or MRI. Treatment was surgical. MAIN OUTCOME MEASURES: Success of surgical repair of the problem in a large experience with follow-up of up to 180 months (mean, 48.7 months). RESULTS: Diagnosis is most effectively made by both (computed tomography (CT) and magnetic resonance imaging (MRI). In this series diagnosis was accurate in 89% with MRI. Primary repair was successful in all but three patients, two of whom required a second repair. One was unreconstructable. CONCLUSIONS: Temporal bone encephaloceles occur after ear surgery and in chronic otitis media. Prompt and effective surgical repair is successful and integral to complication avoidance.

Management of acoustic neuroma in the elderly population.

OBJECTIVE: Ongoing controversy regarding the optimal treatment of acoustic neuromas in the elderly population has prompted us to examine the our experience in order to arrive at a treatment algorithm. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: The records of 48 elderly patients ranging from age 70 to 90 years with acoustic tumors were reviewed. INTERVENTIONS: In 34 cases, tumor size was followed through serial imaging for a mean 28.5 months (range 5-108 months). Eight of these patients subsequently required surgery for significant tumor growth. An additional 12 patients were managed surgically from the time of diagnosis. MAIN OUTCOME MEASURE: The natural history of acoustic neuromas in the elderly population. RESULTS: The mean tumor growth rate for the watched group was 0.29 cm/y. Fifteen patients demonstrated no growth whereas accelerated growth was noted in eight cases. Ten patients with tumors confined to the internal auditory canal demonstrated an average growth rate of only 0.06 cm/y over a mean interval of 38 months. For the surgically treated group, the mean tumor size at the time of resection was 2.8 cm. Resection was described as complete in 17 cases and near-total in three cases. Perioperative complication rates and facial nerve results were comparable to our figures for all age groups. There was one perioperative death. CONCLUSIONS: Elderly patients with small acoustic neuromas should be offered a trial of observation. When significant tumor growth, size, or neurologic deterioration are demonstrated, early surgical intervention is required to avoid complications associated with the removal of larger tumors.

Pediatric neurotologic skull base surgery.

The objectives of neurotologic skull base surgery are complete resection of the lesion and high-grade function following surgery. There is a perception that these goals are more difficult to achieve in children than in adults. Skull base disease in children and adolescents is rare. Of the 292 skull base tumors treated from 1970 to 1995 by The Otology Group in Nashville, 15 were in patients 21 years of age or younger, with only 5 patients under 10 years old. In this retrospective study, the authors review these 15 cases and compare them to their adult series. The pathology encountered in the 15 young patients with skull base tumors included 8 glomus lesions and 4 schwannomas. In these patients, 13 tumors occurred sporadically, and 2 tumors were related to neurofibromatosis type 2. Advanced-stage disease and malignancy were prevalent in this younger patient group. All patients underwent excision of their skull base tumor, with one procedure considered a subtotal resection. As compared with an adult glomus tumor series, postoperative cranial nerve function and complication rates were generally worse in the young glomus patients. However, postoperative function and complications were consistent with the extensive procedures required for the treatment of advanced disease. Despite the advances that have been made in imaging and treatment modalities, this study illustrates the need for more timely diagnosis in younger patients with skull base tumors.

Mutational spectrum in the neurofibromatosis type 2 gene in sporadic and familial schwannomas.

Using a heteroduplex approach and direct sequencing, we have completed the screening of approximately 88% of the neurofibromatosis type 2 (NF2)-coding sequence of DNA extracted from 33 schwannomas from NF2 patients and from 29 patients with sporadic schwannomas. The extensive screening has resulted in the identification of 33 unique mutations. Similarly to other human genes, we have shown that the CpG sites are more highly mutable in the NF2 gene. The frequency, distribution, and types of mutations were shown to differ between the sporadic and familial tumors. The majority of the mutations resulted in protein truncation and were consistent with more severe phenotype, however three missense mutations were identified during this study and were all associated with milder manifestations of the disease.

Otology through the ages.

Recounted are some, not all, of the most significant contributions to otology. The history of otology has, for the most part, followed the history of medicine: Little was known of otology by the ancient physicians, but their work must be reviewed to appreciate the progress that has been made. Most of the otology produced during the Middle Ages was limited to those structures that were readily accessible; otologic surgery was confined to trauma and removal of foreign bodies from the external auditory canals. Examination of the ear began after studies of the ear by Italian anatomists during the seventeenth century. It was not until the end of the eighteenth century that magnification was used so that the minute anatomic details could be observed. The clinical specialty of otology started in France (1850s), emerged as a scientific specialty in England, and received explosive progress from the German-speaking countries at the end of the nineteenth century. Otology has a remarkable background.

Spontaneous cerebrospinal fluid leaks originating from multiple skull base defects.

Spontaneous cerebrospinal fluid (CSF) leaks of temporal bone origin are more prevalent than once believed. Twenty-eight of the 61 cases documented in the world literature have been reported since 1992. All but four of these cases involved unilateral defects. The authors have previously reported experiences with 12 cases, with the vast majority of defects localized to the tegmen tympani. These patients also had demonstrated a single area of bone and dural dehiscence. We report two additional cases of spontaneous CSF leak originating from multiple/distant skull base defects. As in previously reported multisite cases, one of our patients demonstrated an elevated opening pressure on lumbar puncture. Significant time intervals existed between leak site presentations, which emphasizes the importance of careful follow-up for treated patients. Potential etiologies and associated factors are also discussed. This patient subset contributes another dimension to the evolving natural history of spontaneous CSF leakage.

Ultrastructural findings in the vestibular end-organs of AIDS cases.

Neurotologic manifestations are apparent in human immunodeficiency virus (HIV) infection, but are poorly understood. Symptoms related to the vestibular system include episodes of vertigo, imbalance, ataxia, and nausea. Although patients present more often with hearing impairment, vestibular complaints are described and electrophysiologic studies indicate vestibular dysfunction in HIV-infected patients. Whether the disease involvement includes the central, or the peripheral nervous system has not been established. Ultrastructural analysis of vestibular end-organs obtained from HIV autopsy cases revealed pathologic changes in the labyrinth wall, the epithelial lining, and the receptor maculae and cristae. Cytologic changes in hair cells included inclusion bodies, viral-like particles, and hair bundle malformations. Epithelial lining cells, supporting cells, and connective tissue cells had inclusions and viral-like particles. These findings are consistent with those of a previous cochlear study demonstrating intracellular viral-like particles with the morphologic characteristics of HIV. Further cytologic evaluation of decalcified temporal bones and immunohistochemical analysis of freshly harvested HIV-infected temporal bones may provide further insight into the pathogenesis of viral-induced hearing loss and vestibular impairment.

Evaluation and management of spontaneous temporal bone cerebrospinal fluid leaks.

Spontaneous temporal bone cerebrospinal fluid leak may be defined as a leak without an apparent precipitating cause. These transdural fistulas occur rarely, and diagnosis is predicated upon a high index of suspicion. Leaks have been reported through both middle and posterior fossa defects, although the vast majority involve the middle fossa plate. In a previous study we reported 7 cases of spontaneous temporal bone cerebrospinal fluid leaks, all involving the middle fossa tegmen. Upon further review of these cases and 5 previously unreported cases, the defect was localized to the tegmen tympani in 9 of the total 12 cases. Diagnostic methods are discussed, with the importance of high-resolution computed tomography stressed. The role of contrast cisternography is also evaluated. An outline for surgical management is presented based upon residual hearing and defect location and accessibility. A transmastoid procedure offers the advantage of visualization of both the middle and posterior fossa plates, and this approach can be supplemented with an obliterative procedure when indicated. The middle fossa approach provides optimal exposure of the tegmen plate with less likelihood of ossicular injury when dealing with tegmen tympani defects. Adjuncts to surgical therapy include intrathecal fluorescein dye and continuous postoperative lumbar cerebrospinal fluid drainage.

Otological and habilitative management of children with Down syndrome.

It has been well-established that children with Down syndrome experience a high incidence of persistent conductive hearing loss because of their predisposition to stenosis of the external auditory canal (EAC), cerumen impaction, serous otitis media (SOM), and cholesteatoma. Because this hearing problem may be a primary cause of the spoken communication skills in these children being far below their cognitive ability, assertive management is required. The authors present an aggressive multi-discipline treatment model that is instituted during the first year of life in an infant with Down syndrome. Reconstruction of the EAC, amplification technology, and speech/language intervention that emphasizes auditory-verbal (A/V) therapy are discussed. In a pilot study, we compared the language development of six infants with Down syndrome who received aggressive treatment during their first year of life (group A) to six infants who did not (group B). The results showed age-appropriate oral language development for the infants in group A.