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PubMed1997

Individualizing hearing preservation in acoustic neuroma surgery.

Surgical series of hearing preservation in acoustic neuroma usually emphasize a team's results with one particular technique. This report reviews acoustic neuroma outcomes of individualizing the surgical approach to patient and tumor characteristics. This study reviews 60 consecutive hearing preservation acoustic neuroma surgeries in a total series of 330 acoustic neuromas. Tumor sizes ranged from 0.3 to 4 cm in patients ranging from 23 to 74 years of age. Middle fossa surgery was performed in 57%, retrosigmoid in 43%. Overall, measurable hearing was preserved in 77%, and useful hearing in 67%. Among middle fossa cases, 85% had measurable and 74% had useful hearing. Among retrosigmoid surgeries, 65% had measurable hearing and 58% had useful hearing. Overall, long-term facial nerve function was excellent (grade I or II) in 90% and poor (grade V or VI) in 2%. There was one case of bacterial meningitis (2%), and cerebrospinal fluid leaks requiring surgery occurred in four patients (7%). The hearing preservation and other outcome parameters in this series compare favorably with other reports. We believe that individualizing the surgical approach to the patient's tumor characteristics and clinical features contributed to the high rate of hearing preservation.

Hearing Disorders↗
PubMed1998

Quality of life after acoustic neuroma surgery.

OBJECTIVE: To assess how surgery affected the quality of life of patients with acoustic neuromas and to investigate possible predictors of the functional outcome following surgery. STUDY DESIGN: A questionnaire based on the Glasgow Benefit Inventory was completed by patients randomly selected following acoustic neuroma surgery. SETTING: Skull base surgery unit of a university teaching hospital (tertiary referral center). PATIENTS: Fifty-three patients with acoustic tumors (follow-up, 1 to 3 y). RESULTS: With regard to overall quality of life, nine patients (17.4%) reported that it became better, 28 patients (53.8%) worse, and 15 patients (28.8%) that it remained the same. Four patients (7.8%) became better off financially, 15 patients (29.4%) worse, and 32 (62.8%) remained unchanged. Forty-one patients (78.8%) did not change their occupation, and 11 (21.2%) had to change their occupation, mainly because of the adverse effects of the operation. With regard to the age at operation, older patients were found to have better overall quality of life. Moreover, younger patients had worse postoperative financial status and they were more likely to change their occupation after the operation. The tumor size did not significantly affect the overall postoperative quality, but it did affect the postoperative financial status (patients with larger tumors were more likely to have worse postoperative financial status). CONCLUSION: Acoustic neuroma surgery has a significant impact on patients' overall quality of life. Surgeons proposing to operate on small tumors should not assume that the impact on patients' life will be necessarily less than that following the removal of larger tumors. All patients, especially in the younger age group, should be prepared and thoroughly informed about the consequences of the operation on their quality of life.

Adult↗
PubMed1999

Adjunctive use of endoscopy during acoustic neuroma surgery.

OBJECTIVE/HYPOTHESIS: In specific clinical situations, endoscopes offer better visualization than the microscope during acoustic neuroma (vestibular schwannoma) surgery and can therefore decrease the incidence of the postoperative complications of cerebrospinal fluid (CSF) leakage and recurrence of tumor. This study was undertaken to determine if the use of adjunctive endoscopy provides complementary information to the operating surgeon during surgery for acoustic neuromas. METHOD: Seventy-eight patients with acoustic neuromas underwent tumor excision by two neurotologists (PAW., D.S.P.), together with their respective neurosurgical partners, via a retrosigmoid (suboccipital) approach (n = 68), translabyrinthine approach (n = 7), or middle cranial fossa approach (n = 3). Endoscopy with a rigid glass lens endoscope was used during tumor removal to examine posterior fossa neurovascular structures, and after tumor excision to inspect the internal auditory canal (IAC), inner ear, and middle ear, depending on the approach used. One of the authors (D.S.P.) has not used adjunctive endoscopy during resections via the translabyrinthine and middle cranial fossa approaches, and therefore, these cases were excluded from the data collection and analysis. RESULTS: Complete tumor excision was achieved in 73 patients. Endoscopy allowed improved identification of tumor and adjacent neurovascular relationships in all cases. In addition, residual tumor at the fundus of the IAC (n = 11) and exposed air cells (n = 24) not seen with the microscope during retrosigmoid approaches were identified endoscopically. In one of the translabyrinthine cases, the endoscope allowed identification of open air cells not visualized with the microscope. None of the 78 patients developed CSF rhinorrhea. Incorporating the endoscope did not significantly increase operative time. CONCLUSIONS: Endoscopy can be performed safely during surgery to remove acoustic neuromas. The adjunctive use of endoscopy may offer some advantages including improved visualization, more complete tumor removal, and a lowered risk of CSF leakage.

Adolescent↗
PubMed2000

An objective method of analyzing cochlear versus noncochlear patterns of distortion-product otoacoustic emissions in patients with acoustic neuromas.

OBJECTIVES: To objectify the effects of retrocochlear disease on distortion-product otoacoustic emissions (DPOAEs) by developing a computer-based software strategy for classifying DPOAE patterns as cochlear or noncochlear and to evaluate the sensitivities of these techniques in a large series of patients with unilateral acoustic neuromas. STUDY DESIGN: Development of a novel, software-based method of DPOAE analysis, which was evaluated with data obtained from a retrospective review of the results from audiometric tests performed in a series of patients. METHODS: A computer-based software strategy was developed, using frequency-specific data from normal-hearing adults, for the purpose of distinguishing cochlear from noncochlear patterns of hearing loss, by determining the discrepancies between DPOAEs and behavioral audiometry. Preoperative pure-tone thresholds and DPOAEs from 97 patients with surgically confirmed acoustic neuroma were compared using an objective method and a standard, subjective technique that was considered to be the gold standard. The effects of bilateral hearing losses, such as noise-induced hearing loss and presbycusis, were accounted for during the analysis to isolate the effects of the tumors on hearing thresholds and DPOAEs. RESULTS: Overall, 55 (57%) of the tumor ears were assigned to the cochlear group (i.e., DPOAEs consistent with hearing thresholds), 40 (41%) to the noncochlear group (i.e., DPOAEs inconsistent with hearing thresholds), and 2 (2%) to an indeterminate group, using the subjective technique for classifying DPOAEs. There was no significant difference in the categorization of the patients with acoustic neuroma when employing the objective strategy. The objective algorithm, when modified to maximize the number of noncochlear identifications, led to assignments of 36 (37%) to the cochlear, 57 (59%) to the noncochlear, and 4 (4%) to the indeterminate categories. CONCLUSIONS: Subjective analysis of a large series patients with acoustic neuromas showed that the majority of ears with tumors demonstrated cochlear (57%), rather than non-cochlear (41%), patterns of DPOAEs. The computerized, software-based algorithm developed for differentiating cochlear from noncochlear patterns of DPOAEs in patients with retrocochlear disease had a maximum sensitivity of 59%. This value was significantly higher than that reported in previous studies.

Adult↗
PubMed2000

Impact of facial paralysis on patients with acoustic neuroma.

OBJECTIVE: To assess the psychological distress, the ways of coping with that stress, and the self-esteem of patients with facial paralysis after acoustic neuroma surgery. Possible predictors and associations between these measures were also explored. STUDY DESIGN: Four validated questionnaires were completed by patients with facial paralysis after acoustic neuroma surgery: 1) the Derriford Appearance Scale (DAS) to measure psychological distress, 2) the COPE questionnaire to measure how patients cope with facial paralysis, 3) the Personal Report questionnaire to measure the self-esteem of patients, and 4) the Facial Paralysis Questionnaire (FPQ) to measure the severity of facial paralysis. PATIENTS: One hundred three patients with facial paralysis after surgical removal of acoustic tumors. RESULTS: Distress spanned a wide range in these patients. There was no statistically significant association between the level of distress and the grade of facial paralysis or between time since operation and levels of distress. Women had higher levels of distress (P = .02) and a significant negative correlation was found between levels of distress and age (r = -0.28, P = .005). High levels of distress were associated with low levels of self-esteem, as shown by the significant negative correlation between level of distress and self-esteem (r = -0.59, P = .01). A significant correlation between distress and maladaptive coping (r = 0.31, P = .002) was also found. Stepwise multiple regression of the distress scores revealed that self-esteem was the most important contributing factor (standardized coefficient beta -0.60, P = .0001), followed by age (beta -0.24, P = .006) and sex (beta -0.21, P = .04). This model explained 44% of the distress variance. CONCLUSION: Clinicians must be aware of the distress felt by some patients experiencing facial palsy after acoustic neuroma surgery and that the level of distress may not be related to the clinical grade of the facial nerve paralysis. People with low self-esteem, young people, and women suffer from more distress due to the facial palsy. Clinicians should thoroughly counsel patients before and after surgery and should implement measures that increase patients' self-esteem and decrease their distress, especially in these high-risk groups.

Adaptation, Psychological↗
PubMed2000

Vocal fold vibrations: high-speed imaging, kymography, and acoustic analysis: a preliminary report.

OBJECTIVES: To evaluate a new analysis system, High-Speed Tool Box (H. Larsson, custom-made program for image analysis, version 1.1, Department of Logopedics and Phoniatrics, Huddinge University Hospital, Huddinge, Sweden, 1998) for studying vocal fold vibrations using a high-speed camera and to relate findings from these analyses to sound characteristics. STUDY DESIGN: A Weinberger Speedcam + 500 system (Weinberger AG, Dietikon, Switzerland) was used with a frame rate of 1,904 frames per second. Images were stored and analyzed digitally. Analysis included automatic glottal edge detection and calculation of glottal area variations, as well as kymography. These signals were compared with acoustic waveforms using the Soundswell program (Hitech Development AB, Stockholm, Sweden). METHODS: The High-Speed Tool Box was applied on two types of high-speed recordings: a diplophonic phonation and a tremor voice. Relations between glottal vibratory patterns and the sound waveform were analyzed. RESULTS: In the diplophonic phonation, the glottal area waveform, as well as the kymogram, showed a specific pattern of repetitive glottal closures, which was also seen in the acoustic waveform. In the tremor voice, fundamental frequency (F0) fluctuations in the acoustic waveform were reflected in slow variations in amplitude in the glottal area waveform. For studying details of mucosal movements during these kinds of abnormal vibrations, the glottal area waveform was particularly useful. CONCLUSIONS: Our results suggest that this combined high-speed acoustic-kymographic analysis package is a promising aid for separating and specifying different voice qualities such as diplophonia and voice tremor. Apart from clinical use, this finding should be of help for specification of the terminology of different voice qualities.

Acoustics↗
PubMed2001

Accuracy of acoustic rhinometry measurements.

OBJECTIVES: To identify the factors that influence the accuracy of acoustic rhinometry measurements recorded with commercially available equipment. STUDY DESIGN: A simple model was used which consisted of a metal pipe and cylindrical inserts. These inserts comprised various lengths, and aperture dimensions were comparable to, or smaller than, the nasal valve areas of both adults and children. METHODS: Accuracy of the acoustic rhinometry technique was evaluated by comparing the measured and actual cross-sectional areas. The results were discussed in terms of the calculated acoustic transmission, reflection, and attenuation coefficients of the pipe model variations. RESULTS: Reducing the inner diameter of the insert increased the degree of measurement error. As the length of the insert was increased, the measured cross-sectional area gradually decreased, approaching the actual area of the experimental passageway. For larger inserts, level of error was not highly dependent on passageway length compared with the narrower inserts. CONCLUSION: Our results show that both the cross-sectional area and passageway length of the narrow segment are the most significant factors that influence the accuracy in acoustic rhinometry measurements.

Acoustics↗
PubMed2002

Acoustic properties of different cartilage reconstruction techniques of the tympanic membrane.

OBJECTIVES/HYPOTHESIS: The use of cartilage in reconstruction of the tympanic membrane has been established especially in cases such as tubal dysfunction and adhesive processes. Cartilage offers the advantage of higher mechanical stability compared with membranous transplants but may alter the acoustic transfer characteristics of the graft. Apart from material properties, it can be assumed that, also, the microsurgical reconstruction technique might influence the sound transmission properties of the reconstructed tympanic membrane. The purpose of the study was to investigate the acoustic transfer characteristics of different cartilage transplants being typically used in different reconstruction techniques of the tympanic membrane. METHODS: Cartilage plates of different thicknesses (1.0, 0.7, 0.5, and 0.3 mm), cartilage palisades, and cartilage island transplants of varying size were investigated by means of an ear canal-tympanic membrane model. In contrast to former single-point measurements, sound-induced vibrational amplitudes of the entire transplant were measured by scanning laser Doppler vibrometry (measuring points, n = 133) (PSV-200, Polytec, Waldbronn, Germany). Frequency response functions (displacement vs. sound pressure) of all measured points were determined in the frequency range of 200 Hz to 4 kHz for the different transplants. RESULTS: Cutting thick cartilage transplants into thin plates or palisades decreased the first resonance frequency and increased its amplitude, reflecting improved sound transmission properties of the transplant. From an acoustical point of view, the 0.5-mm cartilage plate seems preferable compared with the palisade technique. Cartilage island techniques showed vibration characteristics superior to plate or palisade techniques. CONCLUSIONS: Apart from material characteristics, the sound transmission properties of the reconstructed tympanic membrane are strongly influenced by the reconstruction technique. The choice of the surgical technique should consider requirements based on mechanical stability and acoustic transfer characteristics of the transplant.

Acoustics↗
PubMed2003

Postural stability of preoperative acoustic neuroma patients assessed by sway magnetometry: are they unsteady?

OBJECTIVE: The objective was to evaluate the preoperative postural stability of acoustic neuroma patients using sway magnetometry. STUDY DESIGN: Prospective two-center study. METHODS: Fifty-one patients (mean age, 53 years) diagnosed with unilateral acoustic neuroma on magnetic resonance imaging at two tertiary referral centers were studied. Preoperatively, each patient had sway patterns (with eyes open and with eyes closed, and standing on foam) recorded for 120 seconds by sway magnetometry. Path length for 30 seconds was calculated. The Romberg coefficient (path length with eyes open divided by path length with eyes closed) was calculated. RESULTS: Forty-four percent of patients had abnormal path lengths with eyes open, and 49% with eyes closed. The Romberg coefficients were significantly lower than normal (P <.001; 95% CI, 0.19-0.87). Mean Romberg coefficient was 0.59 (normal value = 0.73), and all patients had a coefficient of less than 1. CONCLUSIONS: Half of preoperative acoustic neuroma patients are unsteady, exhibiting abnormal sway patterns based on path length measurements. The increase in sway path length demonstrable in normal subjects with eyes closed was significantly exaggerated in patients with acoustic neuroma.

Adolescent↗
PubMed2003

Combining acoustic and electrical hearing.

OBJECTIVES/HYPOTHESIS: The concept of combining electrical stimulation for high-frequency sound with acoustic hearing for low-frequency information was tested. In addition, whether residual hearing can be preserved when an electrode is placed into the inner ear up to 10 mm and whether place of electrical stimulation influences speech perception were tested. STUDY DESIGN: A single-subject clinical trial design was employed. METHODS: Six postlingual adults with severe high-frequency hearing impairment were recruited to participate in the study. A new six-channel cochlear implant was designed for the clinical trial. The intracochlear electrodes were either 6 or 10 mm in length based on a Nucleus CI-24 multichannel implant. Monosyllabic word understanding and consonant identification testing in a recorded sound-only condition were used to assess changes in speech perception. Follow-up was greater than 12 months. RESULTS: Acoustic hearing was preserved in all six subjects (n = 3, 6-mm electrodes; n = 3, 10-mm electrodes). Preoperative monosyllabic word and sentence scores were unchanged in all subjects following implantation. A 30% to 40% improvement in consonant recognition occurred with the 10-mm electrode. The subjects with 10-mm electrodes were able to understand 83% to 90% of the monosyllabic words using the implant plus binaural hearing aids. Scores were more than doubled when compared with preoperative scores with hearing aids only. CONCLUSION: The human ear has the capability to integrate both acoustic and high-frequency electrically processed speech information. Placement of a short, 10-mm electrode does not appear to damage residual low-frequency inner ear hair cell function, interfere with the micro mechanics of normal cochlear vibration, or decrease residual speech perception. The improvement in speech recognition was due primarily to the increased perception of higher-frequency consonantal speech cues, and this improvement took several months to become apparent. Such a device can provide a substantial benefit in speech understanding to individuals with severe high-frequency hearing loss, while still maintaining the benefits of the residual lower-frequency acoustic hearing. The position of the electrode and the place of frequency information within the cochlea were shown to be important factors in the success of such a device.

Cochlear Implants↗
PubMed1990

Radiosurgery for acoustic neurinomas: early experience.

We reviewed our early experience with the first 26 patients with acoustic neurinomas (21 unilateral, 5 bilateral) treated by stereotactic radiosurgery using the first North American 201-source cobalt-60 gamma knife. Follow-up ranged from 6 to 19 months (median, 13 months). Serial postoperative imaging showed either a decrease in tumor size (11 patients) or growth arrest (15 patients). Loss of central contrast enhancement was a characteristic change (18 patients). Seven patients had good or serviceable hearing preoperatively. In all 7 the preoperative hearing status was retained immediately after radiosurgery. At follow-up, 3 had preserved hearing, 1 had reduced hearing, and 3 had lost all hearing in the treated ear. Hearing in 1 patient that was nonserviceable preoperatively later improved to a serviceable hearing level. Delayed facial paresis developed in 6 patients, and delayed trigeminal sensory loss developed in 7 patients, none of whom had significant deficits before radiosurgery. Both facial and trigeminal deficits tended to improve within 3 to 6 months of onset with excellent recovery anticipated. Lower cranial nerve dysfunction was not observed. All 26 patients remain at their preoperative employment or functional status. At present, stereotactic radiosurgery is an alternative treatment for acoustic neurinomas in patients who are elderly, have significant concomitant medical problems, have a tumor in their only hearing ear, have bilateral acoustic neurinomas, refuse microsurgical excision, or have recurrent tumor despite surgical resection. Although longer and more extensive follow-up is required, the control of tumor growth and the acceptable rate of complications in this early experience testifies to the future expanding role of this technique in the management of selected acoustic neurinomas.

Adolescent↗
PubMed1993

Clinical correlates of acoustic neuroma volume.

A computer-assisted, MRI-based technique of tumor volume determination was used to correlate preoperative hearing levels and long-term postoperative facial function with acoustic neuroma volume. Preoperative hearing was studied in a group of 41 patients subjected to direct tumor volume calculations and in another group of 131 patients in whom volume was extrapolated from the acoustic neuroma volume-diameter relation. Similarly postoperative facial function was correlated with acoustic neuroma volume in another 864 patients in whom long-term follow-up was available. Preoperative hearing levels were found not to be significantly related to tumor volume. However, postoperative facial function was significantly associated with tumor volume and was best predicted as a nonlinear function of diameter. Thus, tumor volume changes are important considerations in the clinical management of acoustic neuromas. Patients should be advised that even small changes in tumor diameter (especially in larger tumors) can result in tumor volume changes that may be associated with significant changes in postoperative facial function.

Auditory Threshold↗
PubMed2001

Perioperative morbidity of acoustic neuroma surgery.

OBJECTIVE: To review complications that occur during the course of acoustic neuroma surgery. STUDY DESIGN: Database and retrospective case review. SETTING: Tertiary referral center, private neurotologic practice. PATIENTS: A series of 1,687 patients undergoing acoustic neuroma surgery between 1987 and 1997. The 822 male and 865 female patients ranged in age from 10 to 87 years (mean age at time of surgery, 50 yr; standard deviation, 14 yr). The most common surgical approach was translabyrinthine (72.5%), followed by middle fossa (25.7%). The tumors ranged in size from 3 to 7 cm in diameter (mean, 2.0 cm; SD, 1.1 cm). MAIN OUTCOME MEASURE: Frequency of occurrence of all surgical and medical complications. RESULTS: The most common complications were cerebrospinal fluid leaks (9.4%; 2.1% requiring reoperation) and meningitis (1.5%). Other surgical complications included cerebral edema, hydrocephalus, pneumocephalus, lower cranial nerve dysfunction, and wound infection. Medical complications in order of frequency included cystitis, sacral root syndrome, anemia, and pneumonia/bronchitis. Complications were related to tumor size and diagnosis of neurofibromatosis type 2. CONCLUSIONS: Perioperative complications will occur with acoustic neuroma surgery, but the overall rate in this large series was low. The authors believe that this supports an aggressive treatment approach for management of acoustic tumors. The findings of this study provide a basis for comparison with other treatment approaches and also are useful for preoperative patient counseling.

Adolescent↗
PubMed2001

Internal auditory canal involvement of acoustic neuromas: surgical correlates to magnetic resonance imaging findings.

OBJECTIVE: Factors that play a role in the selection of surgical approach for acoustic neuromas include patient health and age, size of tumor, hearing status, and location of tumor in the internal auditory canal (IAC) and the cerebellopontine angle. Deep extension into the IAC makes hearing preservation extremely difficult when a retrosigmoid craniotomy is used, and the best approach is a middle fossa subtemporal route. Modern gadolinium-enhanced magnetic resonance imaging (MRI) can be inaccurate in identifying the presence of tumor laterally in the IAC. This may affect the selection of a surgical approach. STUDY DESIGN: This study was a retrospective case review. SETTING: Patients were accrued from a tertiary referral otologic practice. PATIENTS: From 1997 through 2000, the authors identified six patients who had undergone acoustic neuroma surgery, had adequate imaging and intraoperative data, and demonstrated a lack of correlation between MRI and intraoperative findings of the lateral IAC. INTERVENTION: The interventions were preoperative MRI of the IAC and surgical resection of an acoustic neuroma. MAIN OUTCOME MEASURE: Comparison of MRI and intraoperative findings of the lateral IAC were the main outcome measures. RESULTS: Six patients demonstrated a lack of correlation between MRI and intraoperative findings of the lateral IAC. CONCLUSIONS: Gadolinium-enhanced T1-weighted MRI findings of the depth of penetration into the lateral aspect of the IAC do not always correlate with intraoperative findings and thus may have implications in the selection of surgical approaches to acoustic neuromas.

Cerebellopontine Angle↗
PubMed2002

Vestibular function after acoustic neuroma removal with preservation of one branch of the vestibular nerve.

BACKGROUND: Vestibular compensation after acoustic neuroma surgery is affected by many parameters. Apart from surgical approach, age of the patient, and comorbidity, the use of rehabilitative vestibular training and the degree of preoperative vestibular compensation play their respective roles. OBJECTIVE: To examine whether and how surgical preservation of one branch of the vestibular nerve affects the compensation process in patients after acoustic neuroma removal. STUDY DESIGN: Prospective study involving 29 patients with acoustic neuromas. In 15 patients operated on by the middle fossa or retrosigmoid approach, one branch of the vestibular nerve could be preserved intraoperatively, and the course of the compensation process was followed (Group 1). Fourteen other patients with acoustic neuroma, who were operated on via a translabyrinthine approach, served as a control group (Group 2). MAIN OUTCOME MEASURE: The evaluation of vestibular compensation was accomplished clinically, by electronystagmography, and by dynamic posturography. RESULTS: An accelerated vestibular compensation was found in all examinations for Group 1, and 3 months after surgery 47% of the patients in this group were back to work without substantial restrictions, compared with 29% of Group 2. At the end of 6 months, however, there was no more significant difference between the two groups. CONCLUSION: The long-term results of vestibular compensation do not seem to be influenced by partial preservation of the vestibular nerve, whereas the compensation process seems to be accelerated when the nerve is partially preserved.

Electronystagmography↗
PubMed2004

Gamma knife radiosurgery for acoustic neuromas performed by a neurotologist: early experiences and outcomes.

OBJECTIVE: To assess early outcomes after Gamma knife radiosurgery of acoustic neuromas and other skull base tumors. BACKGROUND: Gamma knife radiosurgery is one of the available methods to treat acoustic neuromas, in addition to micro-surgical resection. Neuro-otologists have long been associated with microsurgical resection of these tumors; however, the application of Gamma knife radiosurgery to the treatment of these tumors by neuro-otologists has not been previously described. SETTING: Acoustic Neuroma and Skull Base Surgery Program / Tertiary Referral Center. STUDY DESIGN/PATIENTS/INTERVENTION: Prospective clinical study of all patients treated by the senior author and our gamma knife team beginning in June 2000. MAIN OUTCOME MEASURES: Preoperative MRI, audiometry, vestibular testing and facial nerve electromyography were completed. At six-month intervals postoperatively, audiometry, caloric testing and MRI were performed to determine thresholds and speech discrimination ability, vestibular function, and the size of the tumor. RESULTS: From June 2000 until March 2004, 38 patients were treated, and these included 33 acoustic neuromas, two meningiomas, one glomus jugulare tumor, and two facial neuromas. Greater than 36 month follow-up was available in 7 patients, > 24 months in 24, > 12 months in 31, and > 6 months in 34 patients. Statistically significant reduction in tumor size was seen over time, and tumor control was achieved in all but two patients. Various patterns of changes in auditory function, both in threshold and speech discrimination were observed in either positive or negative directions. CONCLUSIONS: Preliminary experience with Gamma knife radiosurgery indicates that this treatment method represents another option for neuro-otologists to use in managing patients with skull base tumors.

Follow-Up Studies↗
PubMed2003

Alpha 4 beta 2* nicotinic acetylcholine receptors modulate the effects of ethanol and nicotine on the acoustic startle response.

BACKGROUND: Ethanol modulates the functional activity of alpha4beta2 neuronal nicotinic cholinergic receptors (nAChR) when measured in vitro, but the potential role of alpha4beta2 nAChRs in regulating behavioral effects of ethanol is unknown. Recently, Tritto et al. (Tritto T, Stitzel JA, Marks MJ, Romm E, Collins AC (2002) Variability in response to nicotine in the LSxSS RI strains: potential role of polymorphisms in alpha4 and alpha6 nicotinic receptor genes. Pharmacogenetics 12:197-208) reported that a polymorphism (A529T) in the alpha4 nAChR subunit gene is associated with variability in nicotine's effects on startle in the LSxSS recombinant inbred (RI) strains. Ethanol also alters the acoustic startle response. Thus, we evaluated the potential role of alpha4beta2 nAChRs in modulating ethanol's effects on acoustic startle. METHODS: The effects of ethanol on acoustic startle were determined in the LSxSS RI strains. In addition, the effects of ethanol and nicotine were also measured in alpha4 gain of function and beta2 null mutant mice. The beta2 mutants do not express the major variant of alpha4 nAChRs, alpha4beta2. RESULTS: An association between the alpha4 A529T polymorphism and ethanol's effects on startle was found in the LSxSS RI strains; those strains that express the A529 variant of alpha4 were more sensitive to ethanol-induced depression of startle. The alpha4 gain of function mutants were more sensitive to the effects of both nicotine and ethanol and the beta2 null mutants were less sensitive to both drugs. CONCLUSIONS: alpha4beta2-containing nAChRs may play important roles in modulating the effects of both ethanol and nicotine on the acoustic startle response. We suggest that nAChR subunit genes should be evaluated as potential contributors to both alcoholism and tobacco abuse.

Acoustic Stimulation↗
PubMed2006

Unilateral deafness after acoustic neuroma surgery: subjective hearing handicap and the effect of the bone-anchored hearing aid.

OBJECTIVE: To evaluate the subjective hearing handicap in patients with unilateral deafness after acoustic neuroma surgery and the effect of the Bone-anchored Hearing Aid (BAHA) on test band. STUDY DESIGN: Fifty-nine consecutive patients with unilateral deafness after translabyrintine removal of an acoustic neuroma, treated in Denmark in 2001 and 2002, were included. The patients were asked to complete a questionnaire, which addressed the subjective handicap of unilateral deafness; 90% responded. These patients were invited to test the BAHA on test band, and the subjective and objective effects were recorded. RESULTS: Eighty percent of the patients thought that they had a subjective hearing handicap of some significance. However, only 50% accepted the invitation to test the BAHA. The overall subjective effect was positive, and a significant improvement in speech discrimination in noise with the BAHA was demonstrated. After the test, however, only about 50%, that is, 25% of all patients wished implantation for BAHA treatment. CONCLUSION: This study shows that unilateral deafness after acoustic neuroma surgery is thought as a handicap in most of the patients and confirms that treatment with the BAHA has positive subjective effects and improves speech discrimination in noise. However, only 25% of the patients wished implantation for BAHA treatment. The implications of these findings are discussed. Data from centers that perform simultaneous acoustic neuroma surgery and implantation for BAHA are necessary for firm conclusions.

Adult↗