Preoperative Word Recognition Score Research Articles

Validating an Evoked Potential Platform for Electrocochleography During Cochlear Implantation.

To validate electrocochleography (ECochG) between an auditory evoked potential (AEP) machine and an established cochlear implant (CI) manufacturer ECochG system. Intraoperative validation study at a tertiary referral center. Patients included adults and children undergoing cochlear implantation. Intraoperative ECochG was measured with both the Intelligent Hearing Systems (IHS) Duet AEP machine and Cochlear Corporation (CC) ECochG platform. Recording electrodes captured extracochlear measurements through a standard facial recess. Tone-bursts were presented from 250 Hz to 2 kHz (~110 dB SPL). A fast Fourier transform (FFT) of ECochG waveforms at key frequencies was summed into a total response (ECochG-TR). Pearson's correlation was utilized to evaluate the relationship between IHS-ECochG-TR and CC-ECochG-TR after confirming normality. Thirty patients were enrolled with an average age of 67 years (SD 18.8). In the ear that was implanted, mean preoperative pure-tone average (PTA; 0.5, 1, 2, and 4 kHz) was 87.4 dB HL (SD 19.3) and mean preoperative word-recognition scores (WRS) was 17.0% correct (SD 19.1). There was strong correlation (r = 0.905, 95% confidence interval: 0.809 to 0.954) between IHS-ECochG-TR (median 2.30 μV, range 0.1-148.26) and CC-ECochG-TR (median 3.00 μV, range 0.1-239.63). Four patients underwent transtympanic ECochG with the IHS system for feasibility evaluation and achieved similar responses. Extracochlear ECochG has been predictive of CI speech perception performance. The IHS duet system is a valid measure of extracochlear ECochG for the CI population. Future work will utilize this system for measuring transtympanic ECochG to improve preoperative estimation of CI performance. 3 Laryngoscope, 2024.

Word Recognition with a Cochlear Implant in Relation to Prediction and Electrode Position.

the word recognition score (WRS) achieved with cochlear implants (CIs) varies widely. To account for this, a predictive model was developed based on patients' age and their pre-operative WRS. This retrospective study aimed to find out whether the insertion depth of the nucleus lateral-wall electrode arrays contributes to the deviation of the CI-achieved WRS from the predicted WRS. patients with a pre-operative maximum WRS > 0 or a pure-tone audiogram ≥80 dB were included. The insertion depth was determined via digital volume tomography. fifty-three patients met the inclusion criteria. The median WRS achieved with the CI was 70%. The comparison of pre- and post-operative scores achieved with a hearing aid and a CI respectively in the aided condition showed a median improvement of 65 percentage points (pp). A total of 90% of the patients improved by at least 20 pp. The majority of patients reached or exceeded the prediction, with a median absolute error of 11 pp. No significant correlation was found between the deviation from the predicted WRS and the insertion depth. our data support a previously published model for the prediction of the WRS after cochlear implantation. For the lateral-wall electrode arrays evaluated, the insertion depth did not influence the WRS with a CI.

Cochlear coverage with lateral wall cochlear implant electrode arrays affects post-operative speech recognition.

The goal was to investigate the relationship between the insertion angle/cochlear coverage of cochlear implant electrode arrays and post-operative speech recognition scores in a large cohort of patients implanted with lateral wall electrode arrays. Pre- and post-operative cone beam computed tomography scans of 154 ears implanted with lateral wall electrode arrays were evaluated. Traces of lateral wall and electrode arrays were combined into a virtual reconstruction of the implanted cochlea. This reconstruction was used to measure insertion angles and proportional cochlear coverage. Word recognition scores and sentence recognition scores measured 12 months after implantation using electric-only stimulation were used to examine the relationship between cochlear coverage/insertion angle and implantation outcomes. Post-operative word recognition scores and the difference between post- and pre-operative word recognition scores were positively correlated with both cochlear coverage and insertion angle, however sentence recognition scores were not. A group-wise comparison of word recognition scores revealed that patients with cochlear coverage below 70% performed significantly worse than patients with coverage between 79%-82% (p = 0.003). Performance of patients with coverage above 82% was on average poorer than between 79%-82, although this finding was not statistically significant (p = 0.84). Dividing the cohort into groups based on insertion angle quadrants revealed that word recognition scores were highest above 450° insertion angle, sentence recognition scores were highest between 450° and 630° and the difference between pre- and post-operative word recognition scores was largest between 540° and 630°, however none of these differences reached statistical significance. The results of this study show that cochlear coverage has an effect on post-operative word recognition abilities and the benefit patients receive from their implant. Generally, higher coverage led to better outcomes, however there were results indicating that insertion past 82% cochlear coverage may not provide an additional benefit for word recognition. These findings can be useful for choosing the optimal electrode array and thereby improving cochlear implantation outcomes on a patient-individual basis.

Hearing Outcomes Following Endolymphatic Duct Blockage Surgery and Factors Associated with Improved Audition at Two Years Follow-Up.

Objective: To evaluate hearing outcomes at 2 years post endolymphatic duct blockage (EDB) surgery, with an analysis of factors that may predict hearing improvement. Study Design: Retrospective comparative study. Setting: Tertiary care center. Subjects: Definite Ménière's Disease (MD) patients undergoing EDB for refractory disease. Methods: Chart review was conducted to assign cases to one of the three hearing outcome groups (deteriorated, stable, and improved). All cases that met our inclusion criteria were selected. Preoperative data collected were audiograms, bithermal caloric tests, preoperative vertigo episodes, history of previous ear surgery for Ménière, intratympanic steroid injections (ITS) and intraoperative endolymphatic sac (ELS) tear or opening. Postoperative data collected at 24 months were audiograms, vertigo episodes and bithermal caloric testing. Results: Preoperative vertigo episodes, caloric paresis and history of surgery, ITS injections or ELS integrity, as well as postoperative vertigo class distribution and caloric paresis changes were not different between our groups. Preoperative word recognition score (WRS) was lowest in the improved hearing group (p = 0.032). The persistence of tinnitus at 2 years postoperatively was associated with deteriorated hearing (p = 0.033). Conclusions: There are no strong predictors of hearing improvement on presentation pre-EDB, but low preoperative WRS may be the best estimator available. Therefore, ablative interventions should be considered very carefully in patients presenting with low WRS, as they may benefit more from EDB; there is a fair chance of a good hearing outcome with EDB surgery. Persistence of tinnitus can reflect deteriorating audition. Vertigo control and hearing preservation are independent outcomes of EDB surgery, making it desirable as an early intervention for refractory MD cases.

The Effect of Immediate Microsurgical Resection of Vestibular Schwannoma on Hearing Preservation.

Evaluate for differences in postoperative hearing in patients who undergo immediate versus delayed hearing preservation microsurgical resection of vestibular schwannomas (VS). Retrospective single-institution cohort study spanning November 2017 to November 2021. Single-institution tertiary care hospital. Sporadic VS in patients with American Academy of Otolaryngology-Head and Neck Surgery hearing classification A or B, with tumor size less than or equal to 2 cm and undergoing hearing preservation microsurgical resection. Delayed surgical intervention defined by time from first diagnostic MRI to date of surgery being greater than 3 months. Preoperative and postoperative audiometric performance. In total, 193 patients met inclusion criteria. Within the cohort, 70 (36%) proceeded with surgery within 3 months of diagnostic MRI with a mean observation time of 62 days, whereas 123 (63%) underwent surgery after 3 months with a mean observation time of 301 days. There was no difference in preoperative hearing between the two groups with word recognition score 99% in early intervention group and 100% in delayed intervention group (p = 0.6). However, 64% of those who proceeded with immediate surgery had successful hearing preservation, compared to a 42% of those who had delayed intervention (p < 0.01). In a multivariable logistic regression accounting for preoperative word recognition score, tumor size, and age at diagnosis, the odds of hearing preservation were lower in those who delayed surgery compared to immediate surgery (odds ratio, 0.31; 95% confidence interval, 0.15-0.61). Patients who underwent microsurgical resection within 3 months of diagnosis demonstrated a hearing preservation advantage compared to those who did not. Findings of this study highlight the counseling challenges associated with the timing of surgical treatment of VS in patients presenting with good preoperative hearing and small tumors.

Analysis of Hearing Preservation in Middle Cranial Fossa Resection of Vestibular Schwannoma.

Describe the effect of preoperative hearing on the likelihood of hearing preservation after middle cranial fossa (MCF) approach for resection of vestibular schwannoma (VS) and the effect of hearing preservation on disease-specific quality of life (QOL). Retrospective chart review. Academic tertiary care skull base surgery program. Sixty three adult patients with preoperative word recognition score (WRS) ≥50% who underwent MCF resection of VS between 2017 and 2020. All patients underwent MCF VS resection with attempted hearing preservation. Hearing preservation (postoperative WRS ≥50%), hearing-related Penn Acoustic Neuroma Quality of Life (PANQOL) score. Sixty three patients with mean age 47.4 (±9.6) years and tumor size 11.5 (±0.5) mm were analyzed. Hearing was preserved (+HP) and lost (-HP) in 37 (58.7%) and 26 (41.3%) patients, respectively. Preoperatively, pure tone average audiometry was significantly lower among the +HP group (20.0 dB) versus -HP (31.0 dB, p < 0.003). WRS was higher among +HP versus -HP (94% vs. 84%, respectively; p < 0.002). Linear regression showed that intra- versus extra-canalicular tumor location, sudden hearing loss history, fundal fluid cap thickness, and tumor size had no relationship to hearing preservation outcomes. When evaluating postoperative QOL data (n = 37) hearing-related PANQOL score differed between +HP and -HP (t35 = 2.458, p = 0.0191) groups. In this cohort of patients undergoing MCF resection of VS, rates of HP were higher for patients with excellent preoperative hearing. Postoperatively, +HP patients reported improved hearing-related PANQOL scores compared to -HP patients.

Cochlear T2 Signal May Predict Hearing Outcomes After Resection of Acoustic Neuroma.

Examine the impact of preoperative cochlear Fast Imaging Employing Steady-state Acquisition (FIESTA) and Constructive Interference in Steady State (CISS) signal intensity on hearing outcomes after middle cranial fossa (MCF) resection of acoustic neuroma (AN). Adult patients (≥18 years) who underwent MCF AN resection for hearing preservation (HP) between November 2017 and September 2019 were retrospectively reviewed. All patients had preoperative word recognition score (WRS) ≥50%. HP was defined as postoperative WRS ≥50%. A neuroradiologist blinded to patients' clinical and audiometric outcomes reviewed patients' preoperative magnetic resonance images. Ipsilateral-to-contralateral cochlear FIESTA/CISS signal intensity ratios were determined using hand-drawn regions of interest focused on the cochlear fluid. Preoperative and postoperative pure tone average (PTA) and WRS were reviewed. Fifty-one patients were reviewed (60.8% female). Mean age was 47 years and mean tumor size 9.2 mm (±3.8). Hearing was preserved in 56.9% (n = 29). FIESTA/CISS signal ratios did not significantly differ between patients with and without HP. Lower FIESTA/CISS signal ratios correlated with greater declines in hearing (r = 0.322, p = 0.011 for PTA; and r = 0.384, p = 0.004 for WRS). On multivariate analysis accounting for tumor size and preoperative PTA/WRS, decreases in FIESTA/CISS signal ratios independently predicted greater declines in hearing by PTA (b = -100.9, p = 0.012) and WRS (b = 76.208), although the latter result was not statistically significant (p = 0.078). Cochlear FIESTA/CISS signal intensity may be a predictor of postoperative hearing loss after MCF AN resection. In this cohort, degraded preoperative cochlear FIESTA/CISS signal strongly predicted postoperative hearing loss.Level of Evidence: IV.

Preoperative Sudden Hearing Loss May Predict Hearing Preservation After Retrosigmoid Resection of Vestibular Schwannoma.

Describe the effect of preoperative sudden hearing loss (SHL) on likelihood of hearing preservation (HP) after surgical resection of vestibular schwannoma (VS). Retrospective chart review. Tertiary referral center. Adult patients (≥18 years) who underwent retrosigmoid VS resection for HP between February 2008 and December 2018 were reviewed. All patients had preoperative word recognition score (WRS) of at least 50%. Similarly, HP was defined as postoperative WRS of more than or equal to 50%. Regression analysis was used to describe the effect of SHL on HP, accounting for tumor size, and preoperative hearing quality. All patients underwent retrosigmoid VS resection for HP. WRS of at least 50%. Of 160 patients who underwent retrosigmoid VS resection during the study period, 153 met inclusion criteria. Mean tumor size was 14.0 (±6) mm. Hearing was preserved in 41.8% (n = 64). Forty patients (26.1%) had a history of preoperative SHL. Among 138 patients (90.2%) in whom the cochlear nerve was anatomically preserved during surgery, HP was achieved in 61.8% of those with SHL (21 of 34) and 41.3% of those without SHL (43 of 104) (p = 0.0480). On univariate and multivariate analysis (accounting for tumor size and preoperative hearing quality), SHL was a significant positive predictor of HP (odds ratio 2.292, p = 0.0407 and odds ratio 2.778, p = 0.0032, respectively). In patients with VS and retained serviceable hearing, SHL is an independent predictor of HP after retrosigmoid microsurgical resection when the cochlear nerve is preserved.

The Effect of Tumor Size on Likelihood of Hearing Preservation After Retrosigmoid Vestibular Schwannoma Resection.

1) Describe the effect of tumor size on the likelihood of hearing preservation after retrosigmoid approach for resection of vestibular schwannoma (VS).2) Describe the effect of preoperative hearing status on the likelihood of hearing preservation. Retrospective chart review. Tertiary referral center. Adult (18 years or older) patients underwent retrosigmoid VS resection and postoperative audiometry between 2008 and 2018 and had a preoperative word recognition score (WRS) of at least 50%. Patients with a history of neurofibromatosis 2, radiation, or previous resection were excluded. All patients underwent retrosigmoid VS resection with attempted hearing preservation. WRS of at least 50%. Data from 153 patients were analyzed. Mean age was 50.8 (±11.3) years and mean tumor size 14 (±6) mm. Hearing was preserved and lost in 64 (41.8%) and 89 (58.2%) patients, respectively. Hearing preservation rates were higher for intrameatal tumors than for tumors with extrameatal extension (57.6% versus 29.4%, p = 0.0005). On univariate and multivariate regression analysis, tumor size (per mm increase) was a negative predictor of hearing preservation (odds ratio [OR] 0.893, p = 0.0002 and 0.841, p = 0.0005, respectively). Preoperative American Academy of Otolaryngology-Head & Neck Surgery Hearing Class was also predictive of hearing preservation (p = 0.0044). Class A hearing (compared with class B hearing) was the strongest positive risk factor for hearing preservation (OR 3.149, p = 0.0048 and 1.236, p = 0.0005, respectively). Small tumor size and preoperative class A hearing are positive predictors of hearing preservation in patients undergoing the retrosigmoid approach for VS resection.

Transmastoid Labyrinthectomy for Menière's Disease: Experience and Outcomes.

To characterize presurgical symptoms and treatment history and postoperative course in patients with medically recalcitrant Menière's disease undergoing transmastoid labyrinthectomy in the post-intratympanic gentamicin era. Retrospective case series. Tertiary academic medical center. All patients who underwent transmastoid labyrinthectomy for medically recalcitrant Menière's disease in 2003 to 2019 by the senior author. Review of patients' medical records for: preoperative history of drop attacks, gentamicin injections, endolymphatic sac decompression or vestibular neurectomy, preoperative audiograms, length of hospital stay, postoperative complications, and persistent symptoms or challenging recovery. Presurgical clinical history and proximal postoperative outcomes. Seventy-two patients with a mean age of 56.7 (standard deviation [SD] 10.7) were included. All cases were unilateral. Forty-three patients (59.7%) suffered from drop attacks. Sixty-two (86.1%) had failed sufficient symptom control with gentamicin injections. The mean preoperative word recognition score was 36.4% (SD 23.7) versus 95.1% (SD 8.5) in the contralateral ear. The mean pure-tone average (PTA) of the ipsilateral ear before surgery was 65.5 dB (SD 18.0) versus 16.2 (SD 13.5) for the contralateral ear. Mean hospital stay was 2.0 days (SD 0.87 days, range of 1-5 d). Three patients (4.2%) had prolonged postoperative vertigo. Transmastoid labyrinthectomy at our center is performed for unilateral Menière's disease, generally when intratympanic gentamicin has failed. A majority of surgical patients suffer from drop attacks preoperatively. Hospital stay is typically brief.

Outcomes for a clinically representative cohort of hearing-impaired adults using the Nucleus\xae CI532 cochlear implant

PurposeHearing performance data was collected from a large heterogeneous group of subjects implanted with the Cochlear™ Nucleus® CI532 with Slim Modiolar Electrode, for the purposes of postmarket clinical follow-up. Data was analysed for factors which may predict postoperative speech recognition scores.MethodsData was collected retrospectively from five German clinics for 159 subjects from March 2017 to August 2018. Hearing thresholds and recognition scores for monosyllabic words in quiet and sentences in noise were measured preoperatively and at 3 and 6 months postoperatively.ResultsThere was a mean gain of 44% points (95% CI 39–49%) at 6 months in monosyllable scores in quiet for implanted ears. Preoperative hearing thresholds in implant ears increased systematically with decreasing age; however, younger subjects had better baseline monosyllable scores with hearing aids compared with older subjects. Baseline performance alone explained 14% of the variation in postoperative scores. Residual hearing was preserved on average to within 22 dB at 250 Hz and 30 dB at 500 Hz of preoperative levels.ConclusionsIn a large and varied cohort of routinely treated hearing-impaired adults, speech recognition with the CI532 for German monosyllabic words in quiet at 6 months was equivalent to performance reported at one year or more in other published studies. Although younger subjects had poorer preoperative pure-tone thresholds, they had better preoperative word recognition scores compared with older subjects, and also had higher post implant scores. Further research is required to identify if this phenomenon is just applicable to German health system assessment and referral practices.

Decisive criteria between stapedotomy and cochlear implantation in patients with far advanced otosclerosis.

To describe the hearing outcomes in patients with far-advanced otosclerosis and to identify the best initial approach based on preoperative word recognition scores (WRS), pure tone averages (PTA), and radiological classification. Retrospective case review. Academic neurotology tertiary referral center. All patients (n = 58) with preoperative air conduction PTA less than 85 dB (HL), disyllabic WRS less than or equal to 50% at 60 dB (HL) with well-fitted hearing aids, and evidence of otosclerosis on CT scan, treated in our department over the past 20 years. Stapedotomy, cochlear implantation, or both. Postoperative WRS after a minimum of 12 months' follow-up, percentage of patients with WRS greater than 50%. Reliability of air and bone conduction PTAs and WRS in predicting failure of stapedotomy. Fifty-eight patients were divided into three groups: group I, primary stapedotomy (n = 32); group II, primary cochlear implantation (n = 9); and group III, secondary cochlear implantation (with a previous history of stapedotomy) (n = 25). The mean postoperative WRS were 50.6% (± 34), 75% (± 17), and 72% (± 20), respectively. Sixty percent of patients in the stapedotomy group had a postoperative WRS greater than 50% requiring no further treatment, compared to 85% for cochlear implant recipients. No specific predictive factors for stapedotomy outcome could be identified. Surgical difficulties during cochlear implantation were significantly higher in patients with advanced radiological stage. Although cochlear implantation gives better overall results, stapedotomy with hearing aids can still be very effective in the management of patients with far-advanced otosclerosis. It should therefore be proposed as a first-line treatment.

Cochlear Implantation for Single‐Sided Deafness: Early Outcomes for 12 Patients

Objectives: (1) Summarize hearing status in the nonimplant ear. (2) Report audiometric and subjective outcomes. Methods: Multi-institutional retrospective chart review. We report outcomes of cochlear implantation in 12 patients with single-sided deafness. Hearing status in the nonimplant ear included: 6 patients with American Academy of Otolaryngology—Head and Neck Surgery Class A, 4 with Class B, and 2 with Class C (1 with WRS 90%). Five of 12 (42%) patients had normal hearing in the nonimplanted ear. There were 6 male and 6 female patients. Average age was 51.5 years (range, 9-75 years). Average preoperative word recognition score in the nonimplanted ear was 82% (range, 52%-100%). Average preoperative pure tone average was 30.4 dB (range, 2-60 dB). Results: Average post-implantation follow-up was 8 months (range, 1-36 months). Etiologies of deafness included 5 idiopathic sudden-sensorineural, 3 Ménière’s Disease, 2 idiopathic progressive, 1 labyrinthitis, and 1 iatrogenic. Audiometric results for the implant-only condition demonstrated mean consonant-nucleus-consonant score of 67% (range, 10%-88%) and mean AzBio score of 83% (range, 73%-97%). Objective testing in noise also showed substantial improvement compared to the preoperative condition. All are daily users. Conclusions: Although cochlear implantation for asymmetric hearing loss and single-sided deafness is not Food and Drug Administration approved in the United States, our patients report a high level of satisfaction. Early audiometric data indicate that these patients score similarly to standard implant users in the CI only condition. In addition, they show substantial improvement in noise since preoperative testing. More data are needed to determine future candidacy for this intervention.

Residual Hearing Conservation and Electroacoustic Stimulation with the Nucleus 24 Contour Advance Cochlear Implant

To assess the conservation of residual hearing in recipients of the Nucleus 24 Contour Advance cochlear implant (CI) and the benefits of combined electrical and acoustic stimulation. Prospective multicenter study. CI clinics in Western Europe. Adult candidates for conventional cochlear implantation with a minimum preoperative word recognition score of 10% in the ear to be implanted. "Soft-surgery" protocol, including a 1- to 1.2-mm anterior and inferior cochleostomy hole with the electrode array, inserted 17 mm using the "advance-off-stylet" technique. Patients with postoperative pure-tone hearing threshold levels (HTLs) of 80 dB hearing loss or less at 125 and 250 Hz and 90 dB hearing loss or less at 500 Hz were refitted with an in-the-ear hearing aid for combined ipsilateral electrical and acoustic (El-Ac) stimulation. A questionnaire to collect information regarding surgery. Pure-tone HTLs measured at intervals. Word recognition tested in quiet and sentence recognition tested in noise at 10 and 5 dB signal-to-noise ratio (SNR). HEARING CONSERVATION RESULTS: HTL data were available for 27 patients. HTLs were conserved within 20 dB of preoperative levels for 33, 26, and 19% of patients for 125, 250, and 500 Hz, respectively. However, the recommended soft-surgery protocol was strictly followed in only 12 of 27 patients. For these 12 patients, hearing thresholds were conserved within 20 dB for 50, 50, and 33% of patients. Median threshold increases were 40 dB (range, 250-500 Hz) for the whole group and 23 dB for the strict surgery group. Ten patients retained sufficient HTLs to enter the El-Ac user group. SPEECH RECOGNITION RESULTS: Group mean recognition scores for nine El-Ac users for words presented at 65 dB sound pressure level were 45% for CI alone and 55% for CI + ipsilateral hearing aid (p < 0.05, paired t). For sentences presented in noise at 5 dB SNR, mean word scores were 46% CI alone and 56% CI + ipsilateral hearing aid (p < 0.01, paired t). Hearing was conserved for conventional candidates for cochlear implantation where the recommended soft-surgery protocol was strictly adhered. Combined ipsilateral electrical and acoustic stimulation provided considerable benefits for speech recognition in noise, equivalent to between 3 and 5 dB SNR, compared with CI alone.

Small Acoustic Neuromas

Evaluate factors affecting outcomes of small acoustic neuroma (AN) removal via a middle cranial fossa (MCF) approach, and compare results to published data on observation and radiation therapy. Retrospective chart review. Academic tertiary referral center. 162 consecutive patients (ages 19-70) with unilateral AN (0.2-2.5 cm in largest dimension) removed through a MCF approach were reviewed focusing on preservation of hearing, facial nerve function and complications. One hundred thirteen patients had pre-operative word recognition scores (WRS)>70%. Both tumor size and pre-operative WRS were related to post-operative WRS (p<0.01). Overall, at least some hearing was preserved in 94 (60%) of the 156 patients who had hearing before surgery. If the WRS was also >70% (N=113), 56 (50%) maintained WRS>70%. Importantly, WRS for 12 others improved to >70% after surgery. When the patients were stratified by tumor size, the patients with small tumors (2-10 mm) faired better than the overall group. At least some hearing was preserved in 65 (72%) of the 90 patients. If the WRS was also >70% (N=66), 39 (59%) maintained WRS>70%. WRS for eight others improved to >70% after surgery. When the tumor was 1.1-1.4 cm (N=34), the chance of preserving some hearing decreased to 42% (14/33). If the WRS was also >70% (N=23), 9 (39%) maintained WRS>70%. WRS for three others improved to >70% after surgery. When the tumor reached 1.5-2.5 cm (N=35), the hearing preservation rate was 43%. If the WRS was also >70% (N=24), only eight (33%) maintained WRS of 70%, and one other improved to >70%. The addition of intra-operative whole eighth nerve near field monitoring improved results during small tumor (<or=1.0 cm) removal preserving some hearing in 80% (32/40) and preserving >70% WRS in 76% (22/29) of those with >70% pre-operative WRS. Good facial nerve function (HB I-II) was achieved in 97% (86% HB I). When tumor size was <or=1.0 cm (N=93), however, good facial nerve function was obtained in 100% (94% HB I). Complications included CSF leak: 9 (5.5%); seizure: 2 (1.2%); and recurrence: 1 (0.6%). Our results suggest that removal of unilateral AN through an MCF approach when the tumor is small and hearing is good provides the best opportunity for hearing preservation and normal facial nerve function. Observation historically results in tumor growth in young and middle-age patients with subsequent hearing loss. Radiation may prevent most tumors from growing, and more data are needed to determine long-term tumor control and hearing preservation rates.