Samuel C. Levine

A systematic approach to the surgical management of acoustic neuroma.

Contemporary otomicrosurgical techniques have made total removal of acoustic tumor with preservation of the seventh and sometimes the eighth cranial nerves possible. The four approaches currently used in acoustic tumor surgery are the middle cranial fossa, the translabyrinthine, the suboccipital, and the combined translabyrinthine‐suboccipital. This review examines the surgical results in the removal of more than 600 acoustic tumors and outlines a rationale for the choice of approach. Tumor size on computed tomographic scan and auditory reserve establish the parameters used in planning the surgical procedure. The translabyrinthine exposure is used most frequently followed by the combined translabyrinthine‐suboccipital. The middle fossa and suboccipital approaches are used when preservation of hearing is attempted. Total removal of tumor was accomplished in more than 99% of patients with a mortality rate of less than 1%. Anatomic preservation of the facial nerve, which is directly related to tumor size, was achieved in more than 80% of patients. Preservation of hearing is unlikely when the tumor is larger than 2 cm; anatomic preservation of the cochlear nerve was successful in 73% of hearing preservation procedures.

Effect of ear‐canal air pressure on evoked otoacoustic emissions

The effect of ear-canal air pressure on click-evoked otoacoustic emissions was measured for pressures ranging from 200 to -200 daPa and stimulus levels ranging from 60-90 dB PeSPL. Positive and negative ear-canal pressures (relative to ambient pressure) reduced the emission amplitude by 3-6 dB. A spectral analysis of the emissions revealed that the effect of ear-canal air pressure is that of a high-pass filter with a cutoff frequency of 2600 Hz and a slope of 4 dB/oct. The spectral changes are the expected effect of an increase in stiffness of the middle ear and were independent of pressure polarity and click level. Ear-canal air pressure substantially reduced the reproducibility of the emission waveform, in many cases rendering the emission indistinguishable from background noise. The implication of these findings for hearing screening applications is that a high false alarm rate may occur in normal-hearing patients with intratympanic air pressures that are significantly different from ambient pressure.

Chronic and Recurrent Otitis Media: A Genome Scan for Susceptibility Loci

Otitis media (OM) is the most common childhood disease. Almost all children experience at least one episode, but morbidity is greatest in children who experience chronic/recurrent OM (COME/ROM). There is mounting evidence that COME/ROM clusters in families and exhibits substantial heritability. Subjects who had tympanostomy tube surgery for COME/ROM (probands) and their families were recruited for the present study, and an ear examination was performed, without knowledge of the subjects history, to determine presence of OM sequelae. In addition, tympanometric testing was performed at three frequencies (226, 630 or 710, and 1,400 Hz) to detect abnormal middle-ear mechanics, and hearing was screened at 20 dB for the speech frequencies. Of these families, 121 had at least two individuals who had received the diagnosis of COME/ROM (364 affected and genotyped individuals), of whom 238 affected and informative relative pairs were used for analyses. Single-point nonparametric linkage analysis provided evidence of linkage of COME/ROM to chromosome 10q at marker D10S212 (LOD 3.78; P=3.0 x 10(-5)) and to chromosome 19q at marker D19S254 (LOD 2.61; P=5.3 x 10(-4)). Analyses conditional on support for linkage at chromosomes 10q and 19q resulted in a significant increase in LOD score support on chromosome 3p (between markers D3S4545 and D3S1259). These results suggest that risk of COME/ROM is determined by interactions between genes that reside in several candidate regions of the genome and are probably modulated by other environmental risk factors.

Acoustic neuroma surgery: The results of hearing conservation surgery

Between the years of 1978 and 1986 attempts have been made to save the hearing in 47 patients with unilateral pathologically confirmed acoustic neuromas. The middle fossa approach has been used in 32 cases and the suboccipital approach in 15 cases. Our review demonstrates an advantage using the suboccipital approach to excise most of these tumors. The success rate is higher (47% vs. 31%) and complications fewer using the suboccipital route. Despite these findings the middle fossa approach may be preferable in selected tumors located laterally in the internal auditory canal.

Cochlear implantation in the elderly: results and quality-of-life assessment.

To assess the efficacy, quality of life, and complication rate of cochlear implantation in patients over 60 years of age, we performed a retrospective chart review of 31 cochlear implant patients more than 60 years old at the time of surgery (mean, 70 years; range, 62 to 86 years). All patients had improvement in their audiological test results after operation. Twenty-eight patients (93%) are regular implant users at a median follow-up of 12 months. Major complications occurred in 2 patients (6%). We conclude that cochlear implantation in the elderly population has excellent results, with a complication rate similar to that in patients less than 60 years old, and yields an improved quality of life.

Use of electrocochleography in the diagnosis of meniere's disease†

Objective: The diagnosis of Menieres disease has always been a source of confusion. There is no single test that is definitive for the diagnosis. Recent advances have enabled clinicians to noninvasively test the function of the inner ear and its associated neural pathways. The electrocochleogram (ECOG) has been advocated as a reliable test that is diagnostic for Menieres disease. This study was undertaken to assess the value of ECOG in establishing the diagnosis of Menieres disease. Study Design: Patients who were suspected of having Menieres disease were prospectively entered into a study of the diagnostic value of ECOG. Each patient had a complete evaluation including a detailed history, physical examination, laboratory studies, and audiometric tests. Setting: University otolaryngology clinic. Patients: A group of 199 patients who presented to a neurotology clinic and were suspected to have symptoms consistent with Menieres disease. Intervention: ECOG testing. Main Outcome Measures: Audiometric thresholds, action potential magnitude (AP), summating potential amplitude (SP), AP latency, and clinical evaluations were assessed. Results: The ECOG was found to correlate with historical and audiometric criteria that are used to diagnose the disease. The percentage of abnormal ECOG did not correlate with stage of disease or duration of time that symptoms were present. Conclusions: The ECOG has limited value in the diagnosis of Menieres disease. It appears to correlate with the length of time patients experience symptoms and their audiometric findings. It was not correlated with the number of symptoms that the patient experienced at the time that the study was conducted.

The family study of otitis media: Design and disease and risk factor profiles

Recurrent acute otitis media (RAOM) and chronic otitis media with effusion (COME) exhibit familial aggregation, but environmental risk factors (day care attendance, cigarette smoke exposure, and bottle feeding) are also important in their development. The Family Study of OM was designed to ascertain the RAOM/COME status of families whose children participated in Otitis Media Research Center studies between 1978 and 1984. Probands were treated with tympanostomy tubes, and had their RAOM/COME status ascertained as criteria for entry into these studies. For the Family Study of OM parents were interviewed about their otitis media and risk factor history; mothers were interviewed about their childrens history, and pertinent medical records were obtained. Members of 173 families were examined with otomicroscopy and multifrequency tympanometry; 19% of parents and 32% of siblings were classified as affected, which is substantially higher than RAOM/COME rates from previous reports. Risk factor profiles differed significantly (P < .001) between parents and their children. Younger generation (adjusted odds ratio [OR] = 4.18, 95% confidence interval [Cl], 2.74, 6.36), day care attendance (OR = 1.96, 95% Cl, 1.32, 2.91) and male gender (OR = 1.42, 95% Cl, 1.03, 1.97) were significantly related to RAOM/COME using logistic regression. Analyses confirm (1) higher disease rates in families with an affected member compared to existing studies of the general population, (2) increased risk of RAOM/COME associated with known risk factors, and (3) increased risk for parents irrespective of risk factors. Additional analyses will explore competing models of disease susceptibility using genetic models and known risk factors.

Infectious complications in pediatric cochlear implants

Objectives: Infectious complications may cause significant delay in cochlear implant device initiation and programming and be a source of additional morbidity. We reviewed our experience with infectious complications in the pediatric age group to determine specific sources that may not be seen in adults.

Tympanic electrocochleography for evaluation of endolymphatic hydrops

There has been increased interest in electrocochleography for the diagnosis and intraoperative monitoring of patients with endolymphatic hydrops. Attention has been focused on the determination of the summating potential: action potential (SP:AP) ratio from alternating polarity clicks. Review of this technique at the University of Minnesota led to a reevaluation of the usual interpretation of these recordings. Separate examination of the rarefaction and condensation click recordings provides insight into abnormal response patterns. Cases are presented to illustrate a variety of normal and abnormal patterns including abnormal differences in the latency of condensation and rarefaction‐click‐generated action potentials, increased summating potential, uncanceled cochlear microphonic, and reduced action potential and summating potential amplitudes. These response categories may be useful in understanding the pathophysiology of Menieres disease.

Safety and clinical performance of acoustic reflex tests.

OBJECTIVE Safety and effectiveness of acoustic reflex tests are important issues because these tests are widely applied to screen for retrocochlear pathology. Previous studies have reported moderately high sensitivity and specificity for detection of acoustic neuroma. However, there have been reports of possible iatrogenic hearing loss resulting from acoustic reflex threshold (ART) and decay (ARD) tests. This study assessed safety and clinical performance of ART tests for detection of acoustic neuroma. DESIGN We report a case in which ARD testing resulted in a significant bilateral permanent threshold shift. This case was the impetus for us to investigate the clinical utility of ART and ARD tests. We analyzed sensitivity and specificity of ART, as well as asymmetry in pure-tone thresholds (PTT) for detection of acoustic neuroma in 56 tumor and 108 non-tumor ears. RESULTS AND CONCLUSIONS Sensitivity and specificity were higher for PTT asymmetry than for ART. Ipsilateral ART at 1000 Hz had poor sensitivity and specificity for detection of acoustic neuroma, and involves some potential risk to residual hearing for presentation levels higher than 115 dB SPL. Approximately half of the acoustic neuroma group had ipsilateral ARTs that would require administration of ARD tests at levels exceeding 115 dB SPL. Therefore, we conclude that PTT asymmetry is a more effective test for detection of acoustic neuroma, and involves no risk to residual hearing. Future studies of contralateral reflex threshold and ARD in combination with PTT asymmetry are recommended.