Prognostic factors for hearing preservation in vestibular schwannoma surgery.

OBJECTIVE: To determine whether prognostic indicators for hearing preservation could be identified in patients with vestibular schwannoma undergoing middle fossa craniotomy resection. STUDY DESIGN: Prospective case review. SETTING: Private practice tertiary referral center. PATIENTS: 333 patients with serviceable hearing and vestibular schwannoma resected by middle fossa craniotomy from 1992 to 1998. MAIN OUTCOME MEASURES: Potential prognostic indicators, including tumor size and nerve of origin, preoperative pure-tone average, speech discrimination, distortion product otoacoustic emission testing, age, auditory brainstem response (ABR), and electronystagmography. RESULTS: Postoperative hearing near preoperative levels was attained in 167 patients (50%), with an American Academy of Otolaryngology-Head and Neck Surgery Class A hearing result in 33% and a Class B result in 26%. Comparison of potential prognostic indicators between groups with hearing preserved and the group with no measurable hearing revealed significant differences in preoperative hearing, ABR, and tumor origin data. Better preoperative hearing, shorter intraaural wave V latency, shorter absolute wave V latency, and superior vestibular nerve origin were associated with higher rates of hearing preservation. CONCLUSIONS: Preoperative hearing status, ABR, and intraoperative tumor origin data were shown to be of value as prognostic indicators.

Profound hearing loss associated with hydrocodone/acetaminophen abuse.

OBJECTIVES: To describe profound hearing loss associated with hydrocodone overuse and the successful rehabilitation of these patients with cochlear implantation. STUDY DESIGN: Retrospective review. SETTING: A tertiary otologic referral center. PATIENTS: Twelve patients with rapidly progressive hearing loss and a concurrent history of hydrocodone overuse. INTERVENTIONS: Comprehensive medical histories, physical findings, audiometric tests, and, in those patients undergoing cochlear implantation, postimplantation performance data were reviewed. MAIN OUTCOME MEASURES: Clinical characteristics of hydrocodone-related hearing loss and open set word and sentence performance in those patients undergoing cochlear implantation. RESULTS: Hydrocodone overuse was associated with rapidly progressive sensorineural hearing loss in 12 patients. In four patients the initial presentation was unilateral, and two of the patients experienced vestibular symptoms. None of the 12 patients experienced improved thresholds after high-dose prednisone. Seven of the eight patients undergoing cochlear implantation have demonstrated early success with their devices. CONCLUSIONS: Hydrocodone is frequently prescribed in combination with acetaminophen for the relief of pain and has a side effects profile similar to other medications in its class. Although not described previously, overuse or abuse can be associated with a rapidly progressive sensorineural hearing loss. These patients can be successfully rehabilitated with cochlear implantation.

Cochlear implants in the geriatric population: benefits outweigh risks.

Cochlear implantation has become widely accepted as an effective means of hearing rehabilitation in severely and profoundly deaf individuals. In the elderly, cochlear implantation involves a number of unique issues that can affect patient outcomes. These factors include age-related changes in the auditory system, prolonged durations of deafness, diminished communication abilities, and coexisting medical and psychosocial problems. In general, the results of cochlear implantation in the elderly have been comparable with those of younger adults. Perioperative attention to medical and surgical details allows for safe insertion and a minimum of postoperative complications. Patients older than 65 have obtained excellent results by both audiologic and quality-of-life measures.

Sensorineural hearing loss after occlusion of the enlarged vestibular aqueduct.

OBJECTIVE: This study aimed to report the hearing results of endolymphatic sac occlusion in patients with enlarged vestibular aqueduct syndrome. STUDY DESIGN: The study design was a multiinstitutional retrospective case series. SETTING: The study was conducted at tertiary otologic referral centers. PATIENTS: The study included 10 previously unreported patients with progressive sensorineural hearing loss and vestibular aqueducts greater than 1.5 mm in diameter on computerized tomography. INTERVENTION: Occlusion of the enlarged vestibular aqueduct was performed by means of a transmastoid surgical approach. Either intraluminal endolymphatic sac obliteration (five patients) or extraluminal extradural endolymphatic sac obliteration (five patients) was accomplished with temporalis fascia. MAIN OUTCOME MEASURES: The postoperative pure tone average (PTA) and speech discrimination scores were compared with the preoperative levels using conventional audiometry. RESULTS: Nine of 10 patients experienced some degree of sensorineural hearing loss. The median change in PTA was a loss of 21 decibels (dB), and 50% of the patients experienced a sensorineural hearing loss greater than 25 dB. Postoperative change in PTA ranged from +10 dB to -59 dB. The median change in speech discrimination score was a loss of 27.5%. Only one patient had an improvement in both speech discrimination score and pure tone averages after surgery. Patients who underwent extraluminal occlusion had a median PTA loss of 12 dB, and patients who underwent open sac occlusion had a median PTA loss of 34 dB. These were not statistically different. CONCLUSION: In this series of 10 patients, 5 had a greater than 25 dB decrease in hearing after occlusion of the enlarged vestibular aqueduct. Surgical occlusion of the enlarged vestibular aqueduct showed no significant benefit in hearing preservation. The otologic surgeon is alerted to the potential for severe sensiorineural hearing loss after occlusion of the enlarged vestibular aqueduct.

Beta-2 transferrin assay in the identification of perilymph.

HYPOTHESIS: Western blot assay for beta-2 transferrin protein is a clinically useful method for the detection of human perilymph and should be used for the diagnosis of perilymph fistulas (PLFs). BACKGROUND: Considerable controversy exists regarding the diagnosis of PLF. Recent studies suggest that the detection of beta-2 transferrin protein may be useful in the identification of perilymph. METHODS: To evaluate the usefulness of the beta-2 transferrin assay for identifying human perilymph, paired perilymph samples and negative controls were collected on Gelfoam pledgets from 20 patients who had surgery that opened the inner ear. Blinded immunoelectrophoretic assay (Western blot) for beta-2 transferrin was performed on each specimen. RESULTS: Only one (5%) of the known perilymph samples and none of the control specimens were definitely positive for beta-2 transferrin. Combined with historical data, this assay has 29% sensitivity, 100% specificity, 100% positive predictive value, and 31% negative predictive value. CONCLUSIONS: These findings suggest that the beta-2 transferrin protein assay may not be a reliable method for detecting human perilymph when performed using this technique.

Cochlear implant performance after reimplantation: a multicenter study.

OBJECTIVE: This study compares auditory performance between original and replacement cochlear implants. STUDY DESIGN AND SETTING: Data from 18 U.S. cochlear implant programs were obtained by retrospective chart review. Patients received and returned subjective questionnaires. PATIENTS: Twenty-eight adults with once-functioning Nucleus 22 cochlear implants that failed received replacement Nucleus 22 cochlear implants in the same ears. MAIN OUTCOME MEASURES: Objective measures included sentence (CID Everyday Sentences or Iowa Sentences) and monosyllabic word (NU-6 Words or CNC Words) speech discrimination scores. Patients also rated and compared performance using subjective scales. RESULTS: Thirty-seven percent of patients had significantly higher sentence or word scores with their replacement cochlear implants than with their original implants, 26% had no significant change, and 37% had significantly poorer scores. Subjectively, 57% of patients reported that the performance of their replacement device was better or the same and 43% reported that it was poorer. There was no correlation between performance with the replacement cochlear implant and cause of the original device failure, duration of original device use before failure, surgical complications with either implantation, changes in electrode insertion depths, or preoperative variables, such as age, etiology, or duration of deafness. CONCLUSIONS: Speech recognition ability with a replacement cochlear implant may significantly increase or decrease from that with the original implant. Experienced cochlear implant patients facing reimplantation must be counseled regarding the possibility of differences in sound quality and speech recognition performance with their replacement device.

Automobile airbag impulse noise: otologic symptoms in six patients.

Automobile airbag safety systems have successfully reduced the number of occupant injuries from motor vehicle accidents. Unfortunately, airbags are also associated with some inherent risk, including a high-amplitude, short-duration noise from airbag deployment. A review of the available research in the automobile industry indicates that the peak amplitude of this noise may exceed 170 dB sound pressure level. Despite the increasingly wide application of airbags in automobiles, there have been no previous reports of airbag-related otologic injuries. We have encountered six patients with otologic symptoms that appear to be related to airbag impulse noise. Five of these patients have documented hearing loss, one patient reported persistent tinnitus, and two patients have significant dysequilibrium. Although permanent hearing loss from airbag noise appears to be rare, temporary threshold shifts are probably much more common. It is important, therefore, that the clinician be aware of the noise associated with airbag inflation and the possibility of acoustic trauma from these safety devices.

The rehabilitation of conductive hearing impairment.

Conductive hearing loss (CHL) usually is amenable to surgical correction. At times, patients with CHL may not be candidates for surgical correction, or they may refuse to undergo the procedure. In such a situation, the patient should be encouraged to try hearing aids, either conventional or bone conduction, depending on the pathologic condition. After a discussion of bone-conduction implantable hearing aids, the article discusses congenital aural atresia, otosclerosis, and the management of CHL after infratemporal fossa approach and transtemporal approaches.

A five-generation family with late-onset progressive hereditary hearing impairment due to cochleosaccular degeneration.

Cochleosaccular dysplasia or degeneration (Scheibe degeneration) is considered the most common cause of profound congenital hearing impairment, and accounts for approximately 70% of cases 2 with hereditary deafness. A five-generation family with hereditary hearing impairment associated with cochleosaccular degeneration has recently been identified. The diagnosis of classical Scheibe degeneration was based on histopathological findings in the temporal bones of the proband, a 61-year-old profoundly deaf male. Auditory structures in the brainstem of the proband were also studied. Twenty-two members of the family were contacted for surveys and blood samples. Of these, 6 males and 2 females have hearing impairment. Complete audiological evaluation was done on 12 family members, and prior audiologic records of the proband and affected family members were available for study. Affected family members suffer a mild bilateral high-frequency hearing loss during childhood and adolescence, and progress to moderate-to-profound deafness in the second and third decades of life. The family is suitable for linkage analysis and does not map to previously reported loci harboring autosomal dominant, nonsyndromic hereditary hearing impairment genes. The genetic study of this family will be helpful in identifying the genes which, when mutated, result in Scheibe degeneration.

Preoperative electroneuronography and facial nerve outcome in acoustic neuroma surgery.

OBJECTIVE: To determine whether preoperative electroneuronography (ENoG) predicts facial nerve outcome in patients undergoing acoustic neuroma surgery. STUDY DESIGN: Prospective, consecutive patients undergoing surgery for acoustic neuroma. SETTING: A private tertiary otology and neurotology practice. PATIENTS: One hundred consecutive patients presented for surgical removal of an acoustic neuroma between May 1992 and September 1993. The mean patient age was 49 years (range 17-77). Forty-three percent were male and 57% were female. The mean tumor size was 1.77 cm (range 3 mm to 5 cm). The tumors were removed by a translabyrinthine approach in 59% of patients, via the middle fossa in 40%, and retrosigmoid in 1%. The facial nerve was anatomically intact at the conclusion of the operation in all but one patient. INTERVENTION: Preoperative ENoG in all patients undergoing surgical removal of their acoustic neuromas. MAIN OUTCOME MEASURES: Facial nerve outcome was measured using the House-Brackmann scale immediately after the operation. 5-7 days after surgery, and > 1 year after surgical resection. RESULTS: Preoperative ENoG had no predictive value in determining immediate or eventual facial nerve outcome. CONCLUSIONS: ENoG has no value in predicting the facial nerve outcome in acoustic neuroma patients. The results of this study are similar to reports with smaller series in the literature. Preoperative ENoG has proven useful, in another study from this institution, in predicting the possible presence of a facial nerve neuroma. This test may be helpful in determining the possible etiology of an intracanalicular mass.

Sudden bilateral sensorineural hearing loss.

Most cases of sudden sensorineural hearing loss (SHL) remain idiopathic, and the majority are unilateral. From 1989 to 1993, 823 patients with sudden SHL were evaluated. Of these, 14 (1.7%) had sudden bilateral SHL. We reviewed the charts of these 14 patients to compare sudden bilateral SHL with sudden unilateral SHL. Usually, bilateral SHL was asymmetric. Most bilateral cases received combined steroid and vasodilator treatment, while unilateral cases were more likely to receive only one of these treatments. By audiological criteria, 67% of bilateral SHL cases improved, while the improvement rate in unilateral SHL was 52%; however, this difference was not statistically significant. In bilateral SHL patients showing improvement, both ears responded. Bilateral SHL patients were older at the onset of hearing loss, had a higher incidence of vascular disease, and were more likely to have positive antinuclear antibody titer. Recognition of similarities and differences between sudden unilateral and bilateral SHL can help in counseling patients.

Prognosis and treatment of sudden sensorineural hearing loss.

Most cases of sudden sensorineural hearing loss (SHL) are idiopathic. Consequently, the otologist may be asked to predict hearing recovery and select a treatment strategy without fully understanding the disease process. We retrospectively reviewed the charts of 837 patients with SHL to evaluate the prognostic value of specific clinical parameters and the effectiveness of steroid and vasodilator treatments. Treatment response was defined by the patient's subjective response and audiological criteria. Patients who were treated with steroids and/or vasodilators were more likely to improve. Patients who improved had a worse initial pure-tone average (PTA) than those who did not improve. In addition, those with poorer initial speech discrimination scores, worse initial thresholds at 4,000 Hz, younger age, and greater number of treatments were more likely to improve. Neither the electronystagmogram results nor the initial audiogram shape were valuable indicators. Recognition of prognostic indicators can help in counselling patients and in the evaluation of treatment response.

Cochlear implantation in the congenital malformed cochlea.

Cochlear implantation has proven beneficial for numerous children with profound congenital hearing impairments. Some congenitally deaf ears, however, may have anatomical malformations. This study reports the authors' recent experience with cochlear implants in patients with cogenital inner ear malformations. Since 1987, 10 patients with congenital abnormal inner ear structures have been implanted at the House Ear Clinic; 8 with abnormal cochleas and 2 with enlarged vestibular aqueducts. Nine patients received the Nucleus 22 device and 1 patient was implanted with the 3M/House device. Some modifications of the routine surgical approach were required in 5 patients. A cerebrospinal fluid (CSF) leak occurred in 4 of the 10 cases. There was a relationship between the degree of abnormality and the number of electrodes that could be inserted. All 10 patients can perceive sound and are active users of their implants.

Consonant perception by users of Nucleus and Clarion multichannel cochlear implants.

A study was carried out to compare the consonant perceptions of five Nucleus multichannel cochlear implant users, five Clarion-CIS users, and four Clarion-CA users. All subjects were administered the Iowa Medical Consonant Recognition Test in the auditory-only condition. The groups averaged approximately 1 year of implant use at the time of testing, and the average age at implantation was 47 years for the Nucleus users, 60 years for the Clarion-CIS users, and 56 years for the Clarion-CA users. The percent-corrected scores for all three devices were variable and ranged from 34% to 84%, with each group averaging about 50% correct consonant recognition. Consonant feature information transmission was calculated for five features: manner of articulation, nasality, place of articulation, duration, and voicing. The highest information transmission in the Nucleus group was for the features of duration (71%), nasality (60%), and voicing (57%), which agrees with previous studies. The Clarion-CIS group had the highest information transmission for duration, place of articulation, manner of articulation, and nasality (50%, 29%, 28%, and 27%). The Clarion-CA group had the highest information transmission for the features voicing, place of articulation, and duration (41%, 40%, and 37%). This study indicates that the Clarion device may carry some acoustic information related to place of articulation, a feature that has not been found to be encoded well by other multichannel cochlear implants.

Sudden hearing loss in acoustic neuroma patients.

Patients with acoustic neuroma may have sudden sensorineural hearing loss. Most patients with sudden hearing loss seek medical attention promptly, but the diagnosis of an acoustic neuroma may be delayed for months or years because sudden hearing loss is an unusual initial symptom of an acoustic neuroma. In a retrospective review of 836 cases of sudden hearing loss, we found 13 patients with acoustic neuromas. The prevalence of acoustic neuromas for those screened with auditory brain stem response or magnetic resonance imaging was 2.5%. In addition to these 13 patients, 79 acoustic neuroma patients treated in our clinic had well-documented sudden hearing loss as the initial symptom. Hearing loss in these 92 patients ranged from mild to profound. Associated symptoms of pain, facial paresthesia, or unilateral tinnitus preceding the sudden hearing loss were suggestive of an acoustic neuroma, as was a midfrequency (U-shaped) hearing loss. A history of other diseases or events that might explain the sudden hearing loss, a normal electronystagmogram, or recovery of hearing does not eliminate the possibility of a tumor. Because there are no clinical findings that clearly distinguish those patients with acoustic neuromas from other patients with sudden hearing loss, we recommend either an evaluation with auditory brain stem response or gadolinium-enhanced magnetic resonance imaging for any patient with sudden hearing loss.