Intraoperative Electrocochleography in Subjects Affected by Vestibular Schwannoma and Ménière's Disease: Comparison of Results.

OBJECTIVES: Histologic reports of temporal bones of ears with vestibular schwannomas (VSs) have indicated findings of endolymphatic hydrops (ELH) in some cases. The main goal of this investigation was to test ears with VSs to determine if they exhibit electrophysiological characteristics similar to those of ears expected to experience ELH. DESIGN: Fifty-three subjects with surgically confirmed VS aged ≥18 and with normal middle ear status were included in this study. In addition, a second group of adult subjects (n = 24) undergoing labyrinthectomy (n = 6) or endolymphatic sac decompression and shunt (ELS) placement (n = 18) for poorly controlled vestibular symptoms associated with Meniere's disease (MD) participated in this research. Intraoperative electrocochleography (ECochG) from the round window was performed using tone burst stimuli. Audiometric testing and word recognition scores (WRS) were performed preoperatively. ECochG amplitudes, cochlear microphonic/auditory nerve neurophonic (ANN) in the form of the "ongoing" response and summation potential, were analyzed and compared between the two groups of subjects. In addition, to evaluate any effect of auditory nerve function, the auditory nerve score was calculated for each subject. Pure-tone averages were obtained using the average air conduction thresholds at 0.5, 1, and 2 kHz while WRS was assessed using Northwestern University Auditory Test No. 6 word lists. RESULTS: In the VS group the average pure-tone averages and WRS were 59.6 dB HL and 44.8%, respectively, while in the MD group they were 52.3 dB HL and 73.8%. ECochG findings in both groups revealed a reduced trend in amplitude of the ongoing response with increased stimulus frequency. The summation potential amplitudes of subjects with VS were found to be less negative than the MD subjects for nearly all test frequencies. Finally, the VS group exhibited poorer amounts of auditory nerve function compared to the MD group. CONCLUSIONS: The current findings suggest cochlear pathology (e.g., hair cell loss) in both groups but do not support the hypothesis that VSs cause ELH.

Can an Imaging Marker of Consistency Predict Intraoperative Experience and Clinical Outcomes for Vestibular Schwannomas? A Retrospective Review.

Objective The main purpose of this article is to determine if vestibular schwannoma consistency as determined by tissue intensity on T2-weighted magnetic resonance imagings (MRIs) is predictive of intraoperative experience and postoperative clinical outcomes. Study Design Retrospective chart review. Setting Tertiary referral center. Patients Seventy-seven patients diagnosed with vestibular schwannomas who were treated with microsurgical resection. Intervention Diagnostic. Main Outcome Measures Intraoperative measures include totality of resection, surgical time and cranial nerve VII stimulation and postoperative measures include House-Brackmann grade and perioperative complications. Results Tumor consistency determined via tissue intensity on MRI was only found to correlate with surgical time, with a softer tumor being associated with a longer surgical time ( p < 0.0001). However, this was primarily driven by tumor volume with larger tumors being associated with longer surgical time based on multivariate analysis. None of the other intraoperative or postoperative measures considered were found to correlate with tumor consistency. Conclusions Tumor consistency determined by MRI is not predictive of intraoperative experience or postoperative outcomes in vestibular schwannomas. Tumor volume is the strongest driver of these outcome measures as opposed to tumor consistency.

Vestibular Thresholds: A Review of Advances and Challenges in Clinical Applications.

Vestibular disorders pose a substantial burden on the healthcare system due to a high prevalence and the severity of symptoms. Currently, a large portion of patients experiencing vestibular symptoms receive an ambiguous diagnosis or one that is based solely on history, unconfirmed by any objective measures. As patients primarily experience perceptual symptoms (e.g., dizziness), recent studies have investigated the use of vestibular perceptual thresholds, a quantitative measure of vestibular perception, in clinical populations. This review provides an overview of vestibular perceptual thresholds and the current literature assessing use in clinical populations as a potential diagnostic tool. Patients with peripheral and central vestibular pathologies, including bilateral vestibulopathy and vestibular migraine, show characteristic changes in vestibular thresholds. Vestibular perceptual thresholds have also been found to detect subtle, sub-clinical declines in vestibular function in asymptomatic older adults, suggesting a potential use of vestibular thresholds to augment or complement existing diagnostic methods in multiple populations. Vestibular thresholds are a reliable, sensitive, and specific assay of vestibular precision, however, continued research is needed to better understand the possible applications and limitations, especially with regard to the diagnosis of vestibular disorders.

Electrocochleography Observations in a Series of Cochlear Implant Electrode Tip Fold-Overs.

OBJECTIVE: Tip fold-over is a rare but serious complication of cochlear implant (CI) surgery. The purpose of this study was to present intraoperative electrocochleography (ECochG) observations in a series of CI electrode tip fold-overs. PATIENTS: Five pediatric subjects undergoing CI surgery through a round window (RW) approach with a perimodiolar electrode array, who were diagnosed with either auditory neuropathy spectrum disorder or enlarged vestibular aqueduct. INTERVENTIONS: Intraoperative RW ECochG during CI surgery: tone burst stimuli were presented from 95 to 110 dB SPL. MAIN OUTCOME MEASURES: Magnitude and phase characteristics of ECochG responses obtained intraoperatively before and immediately after electrode insertion were examined for patients with and without tip fold-over. RESULTS: Three subjects presented with tip fold-over and two formed the control group. Among fold-over cases, one participant exhibited an inversion in the starting phase of the cochlear microphonic response and a decrease in spectral magnitude from pre- to postinsertion. Both subjects who did not exhibit a change in phase had an increase in the ECochG-total response (ECochG-TR) magnitude. No case in the control group exhibited a change in starting phase. In regard to the ECochG-TR, all controls showed a decrease in the magnitude. CONCLUSIONS: Despite the small number of patients, heterogeneous ECochG response patterns were observed within the fold-over group. Though these results are not conclusive, they can serve as a framework to begin to understand ECochG's utility in detecting intraoperative tip fold-over.

Digital Otoscopy Videos Versus Composite Images: A Reader Study to Compare the Accuracy of ENT Physicians.

OBJECTIVES/HYPOTHESIS: With the increasing emphasis on developing effective telemedicine approaches in Otolaryngology, this study explored whether a single composite image stitched from a digital otoscopy video provides acceptable diagnostic information to make an accurate diagnosis, as compared with that provided by the full video. STUDY DESIGN: Diagnostic survey analysis. METHODS: Five Ear, Nose, and Throat (ENT) physicians reviewed the same set of 78 digital otoscope eardrum videos from four eardrum conditions: normal, effusion, retraction, and tympanosclerosis, along with the composite images generated by a SelectStitch method that selectively uses video frames with computer-assisted selection, as well as a Stitch method that incorporates all the video frames. Participants provided a diagnosis for each item along with a rating of diagnostic confidence. Diagnostic accuracy for each pathology of SelectStitch was compared with accuracy when reviewing the entire video clip and when reviewing the Stitch image. RESULTS: There were no significant differences in diagnostic accuracy for physicians reviewing SelectStitch images and full video clips, but both provided better diagnostic accuracy than Stitch images. The inter-reader agreement was moderate. CONCLUSIONS: Equal to using full video clips, composite images of eardrums generated by SelectStitch provided sufficient information for ENTs to make the correct diagnoses for most pathologies. These findings suggest that use of a composite eardrum image may be sufficient for telemedicine approaches to ear diagnosis, eliminating the need for storage and transmission of large video files, along with future applications for improved documentation in electronic medical record systems, patient/family counseling, and clinical training. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:E1668-E1676, 2021.

Intraoperative Electrocochleography of Posterior Fossa Tumors Producing Menière's Syndrome.

OBJECTIVES: Intraoperative electrocochleography (ECochG) has provided insight regarding inner ear pathophysiology during neurotologic procedures. In this study, intraoperative ECochG findings are reported in patients who presented with episodic aural and vestibular symptoms during resection of posterior fossa neoplasms. PATIENTS: Three patients with episodic vertigo who underwent resection of posterior fossa tumors. INTERVENTION: Intraoperative ECochG was performed before and after tumor resection with the active electrode at the round window. Acoustic stimuli consisted of click and tone bursts presented in alternating polarity. MAIN OUTCOME MEASURE: ECochG responses including summation potential (SP), action potential (AP), and SP:AP ratio values to evaluate for endolymphatic hydrops. RESULTS: All subjects presented with asymmetric sensorineural hearing loss (SNHL), episodic vertigo, and tinnitus. Subject 1 was a 63-year-old woman who underwent left translabyrinthine excision of an endolymphatic sac (ELS) tumor and demonstrated no measurable responses until fenestration of the lateral semicircular canal, suggesting severe hydrops relieved by labyrinthotomy. Subject 2 was a 44-year-old woman who underwent right ELS tumor resection and exhibited an elevated SP:AP ratio. Subject 3 was a 55-year-old woman who underwent right retrolabyrinthine resection of a meningioma and exhibited robust responses without hydrops. CONCLUSIONS: Endolymphatic hydrops secondary to mechanical obstruction by a posterior fossa neoplasm may be demonstrated using intraoperative ECochG. Immediate improvement of hydrops may not be demonstrated after tumor resection.

Therapeutic challenges and clinical characteristics of single-sided deafness in children.

INTRODUCTION: The clinical implications of single-sided deafness (SSD) in children has historically been underappreciated by patients and providers alike, despite a large body of literature on the wide-ranging neurocognitive, language, scholastic, and functional impairments that occur. Conventional amplification options are marked by variable results and frequent loss of follow-up. METHODS: Retrospective case series for pediatric SSD from 2008 to 2018. RESULTS: 88 children with congenital SSD were identified. Seventeen (N = 17/88, 23.9%) passed their newborn hearing screen. Median age at first otolaryngology evaluation was 0.65 years (range 0.1-16.9 years). Most common etiologies included cochlear nerve deficiency (N = 39, CND, 44.3%), unknown (N = 30, 35.2%), inner ear malformation (N = 7, 8.0%), and congenital cytomegalovirus (N = 6, 6.8%). 32.5% of patients elected for continued observation only, followed by bone conduction hearing aid (27.7%), contralateral routing of sound aid (20.5%), conventional hearing aid (13.3%), or cochlear implant (6%). Lack of follow-up at ≥1 year was common (39.8%). Of those with device use data (N = 39), 84.7% reported either discontinued or <6 h of daily use. CONCLUSIONS: Despite early diagnosis and evaluation, the pediatric SSD cohort is characterized by high rates of loss of follow-up and amplification discontinuation. Cochlear nerve deficiency is commonly seen in congenital SSD. Early specialist referral is critical for habilitation evaluation. Patients and caregivers should be educated on the significant implications of unilateral hearing loss.

Electrocochleography and Cochlear Implantation: A Systematic Review.

OBJECTIVE: Given the heterogeneity of papers about electrocochleography (ECochG) and cochlear implantation (CI) and the absence of a systematic review in the current literature, the aim of this work was to analyze the uses of ECochG in the different stages of CI. DATA SOURCES: A search of PubMed from inception to December 8, 2019, with cross-references, was executed. Keywords were: "Cochlear Implant" OR "Cochlear Implantation" AND "Electrocochleography" OR "ECochG." The main eligibility criteria were English-language articles, investigating the use of ECochG in the different phases of CI. STUDY SELECTION: Literature reviews, editorials, case reports, conference papers were excluded, as were papers in which ECochG was just sporadically executed. DATA EXTRACTION: The quality of the included studies was assessed using "The Strengthening the Reporting of Observational Studies in Epidemiology" (STROBE) Statement. DATA SYNTHESIS: A total of 95 articles were identified and 60 papers were included. The included articles covered a timeframe from 2003 to 2019. Of the 60 papers, 46 were human studies, 12 animal studies, and two involved more data sets. Eleven related to the diagnostic phase, 43 described intraoperative monitoring, and 10 were regarding follow-up testing. Hearing preservation was the most discussed topic with 25 included articles. CONCLUSIONS AND RELEVANCE: ECochG measurements appeared to be useful in many aspects of CI, such as hearing preservation. Our review is the first that shows the evolution of the technique and how much has been achieved from the earliest experiments to the most recent signal process refinements and device implementation in CI.

Enlarged vestibular aqueduct: Intraoperative electrocochleography findings during cochlear implantation.

Enlarged vestibular aqueduct (EVA) is the most frequent inner ear abnormality found on computed tomography in children with sensorineural hearing loss. The effects EVA abnormalities have on electrocochleography (ECochG) are unknown. Positive deflections in summation potential evoked by tone bursts were observed in 3/5 subjects, while a large negative deflection, similar to endolymphatic hydrops (EH), was observed for 2/5 subjects. The presence of an enlarged summation potential, with and without a compound action potential, was observed in response to a broadband click stimulus. Results suggest likely effects of a third window on ECochG responses and presence of EH in EVA.

Utilizing Electrocochleography as a Microphone for Fully Implantable Cochlear Implants.

Current cochlear implants (CIs) are semi-implantable devices with an externally worn sound processor that hosts the microphone and sound processor. A fully implantable device, however, would ultimately be desirable as it would be of great benefit to recipients. While some prototypes have been designed and used in a few select cases, one main stumbling block is the sound input. Specifically, subdermal implantable microphone technology has been poised with physiologic issues such as sound distortion and signal attenuation under the skin. Here we propose an alternative method that utilizes a physiologic response composed of an electrical field generated by the sensory cells of the inner ear to serve as a sound source microphone for fully implantable hearing technology such as CIs. Electrophysiological results obtained from 14 participants (adult and pediatric) document the feasibility of capturing speech properties within the electrocochleography (ECochG) response. Degradation of formant properties of the stimuli /da/ and /ba/ are evaluated across various degrees of hearing loss. Preliminary results suggest proof-of-concept of using the ECochG response as a microphone is feasible to capture vital properties of speech. However, further signal processing refinement is needed in addition to utilization of an intracochlear recording location to likely improve signal fidelity.

Electrocochleography During Translabyrinthine Approach for Vestibular Schwannoma Removal.

HYPOTHESIS: Intraoperative electrocochleography (ECochG) can differentiate hair cell and neural dysfunction caused by a vestibular schwannoma (VS) and help define the site of lesion as peripheral or central to the spiral ganglion. BACKGROUND: Hearing loss in patients with a VS can be caused by both sensory (cochlear) and neural dysfunction. METHODS: Round-window ECochG using low and high-frequency tone bursts was performed in 49 subjects with a VS. Responses were analyzed for magnitude, spectrum, and shape of the time waveform. Components examined included the cochlear microphonic, auditory nerve neurophonic, compound action potential (CAP), and summating potential (SP). RESULTS: Variability in the summed response magnitudes across frequency, or "total response" (ECochG-TR), varied from 0.1 to 100 µV. Responses were larger for lower frequencies. Subjective estimates revealed a wide range of neural contributions from the auditory nerve neurophonic to low frequencies and the CAP to high frequencies. Cases with larger CAPs had smaller SPs. The correlation of ECochG-TR, with word recognition score (WRS), was moderate (r = 0.67), as well as the correlation between pure-tone averages and ECochG (r = 0.63). The cochlea remained functional in two cases of sudden sensorineural hearing loss with 0% WRS. CONCLUSION: Reduced ECochG-TR and neural activity in many cases indicates both sensory and neural deficits. Smaller SPs when CAPs are present indicate a neural contribution to the SP. Good cochlear function with 0% WRS, and cases of sudden sensorineural hearing loss with retained cochlear function, indicate retrocochlear effects, typically proximal to the spiral ganglion cells.

A Comparison of Intracochlear Pressures During Ipsilateral and Contralateral Stimulation With a Bone Conduction Implant.

OBJECTIVES: To compare contralateral to ipsilateral stimulation with percutaneous and transcutaneous bone conduction implants. BACKGROUND: Bone conduction implants (BCIs) effectively treat conductive and mixed hearing losses. In some cases, such as in single-sided deafness, the BCI is implanted contralateral to the remaining healthy ear in an attempt to restore some of the benefits provided by binaural hearing. While the benefit of contralateral stimulation has been shown in at least some patients, it is not clear what cues or mechanisms contribute to this function. Previous studies have investigated the motion of the ossicular chain, skull, and round window in response to bone vibration. Here, we extend those reports by reporting simultaneous measurements of cochlear promontory velocity and intracochlear pressures during bone conduction stimulation with two common BCI attachments, and directly compare ipsilateral to contralateral stimulation. METHODS: Fresh-frozen whole human heads were prepared bilaterally with mastoidectomies. Intracochlear pressure (PIC) in the scala vestibuli (PSV) and tympani (PST) was measured with fiber optic pressure probes concurrently with cochlear promontory velocity (VProm) via laser Doppler vibrometry during stimulation provided with a closed-field loudspeaker or a BCI. Stimuli were pure tones between 120 and 10,240 Hz, and response magnitudes and phases for PIC and VProm were measured for air and bone conducted sound presentation. RESULTS: Contralateral stimulation produced lower response magnitudes and longer delays than ipsilateral in all measures, particularly for high-frequency stimulation. Contralateral response magnitudes were lower than ipsilateral response magnitudes by up to 10 to 15 dB above ~2 kHz for a skin-penetrating abutment, which increased to 25 to 30 dB and extended to lower frequencies when applied with a transcutaneous (skin drive) attachment. CONCLUSIONS: Transcranial attenuation and delay suggest that ipsilateral stimulation will be dominant for frequencies over ~1 kHz, and that complex phase interactions will occur during bilateral or bimodal stimulation. These effects indicate a mechanism by which bilateral users could gain some bilateral advantage.

Intraoperative Monitoring of Auditory Function During Lateral Skull Base Surgery.

OBJECTIVE: We present a unique case of a patient with a jugular foramen tumor with serviceable hearing. This study discusses the audiometric results and intraoperative electrocochleographic (ECochG) findings recorded during tumor removal to illustrate the potential utility of this technique in skull base surgery. PATIENTS: A 22-year-old female patient presented with a jugular foramen schwannoma and associated symptoms of right-sided otalgia, mild hearing loss, and blurry vision. INTERVENTIONS: Intraoperative ECochG responses during an infratemporal fossa approach: click and tone burst (1, 2, 4 kHz) stimuli were used and presented at 90 dB nHL. MAIN OUTCOME MEASURES: Intraoperative ECochG testing using frequency-specific tone bursts and clicks before and after tumor resection. RESULTS: The compound action potential magnitudes, cochlear microphonic, and summation potential were recorded pre- and post-tumor removal. For statistical analysis, a paired t test with significance set at p < 0.05 was used. The compound action potential magnitudes increased at all test frequencies (p < 0.01) while the summation potential and cochlear microphonic remained relatively stable (p > 0.05). Audiometric testing demonstrated an improvement of the preoperative mild right-sided hearing loss after tumor resection (pure-tone average for 0.5, 1, 2, and 4 kHz of 30 dB HL preoperation and 7.5 dB HL after tumor resection). CONCLUSIONS: Intraoperative ECochG may allow for real-time monitoring during complex skull base surgery.

Fibrous dysplasia mimicking a pediatric endolymphatic sac tumor.

A 15-year-old female presented for evaluation of progressive hearing loss over a year. Computed tomographic imaging revealed a 11 x 6 × 6 mm osseous lesion with 'groundglass' appearance within the left posterior petrous bone lateral to vestibular aqueduct suspicious for an endolymphatic sac tumor. Surgical excision revealed fibrous dysplasia on histological analysis. Fibrous dysplasia of the temporal bone is not uncommon, but few cases of extension causing sensorineural hearing loss exist in the literature. We describe the first reported case of fibrous dysplasia mimicking an endolymphatic sac tumor; interestingly, the patient also showed hearing improvement immediately following removal.

Comparison of Opioid Prescription Patterns and Consumption Following Otologic Surgery.

OBJECTIVE: To examine opioid prescribing patterns and consumption among patients undergoing common otologic surgeries. STUDY DESIGN: Retrospective cohort study with chart review and telephone survey. SETTING: Tertiary academic medical center. METHODS: Retrospective chart review and telephone survey of those undergoing tympanoplasty, tympanomastoidectomy, stapedectomy, and cochlear implantation in 2018. The survey consisted of questions regarding the details of the number of pills taken, duration of opioid use, subjective pain control, the use of over-the-counter pain medications, opioid disposal, and their history of substance abuse. RESULTS: Sixty-one patients were able to be contacted and agreed to participate in the study. Fifty-nine (96.7%) stated that their pain was controlled, and 10 (16.4%) did not take any opioids postoperatively despite their prescription. The mean morphine milligram equivalent (MME) prescribed was 99.9 (44.3) and MME taken was 45.2 (SD 46.3) (p < 0.001). Similarly, the mean number of pills prescribed was 17.8 (SD 8.6) and mean taken was 7.9 (SD 8.3) (p < 0.001). Comparison between males and females regarding MME and pills prescribed and taken were not statistically significantly different (p > 0.05). Analysis of the MME and pills prescribed and taken among the different surgeries (tympanoplasty, stapes surgery, tympanomastoidectomy, and cochlear implantation) revealed no statistically significant interactions (p > 0.05). Pain control was achieved for 50% of patients with 5 pills (MME = 25 mg), for 75% with 12 pills (MME = 60 mg), and for 90% with 24 pills (MME = 135 mg). CONCLUSION: The opioid epidemic continues to be an ongoing issue in the United States, and prescription opioid abuse is a large contributor. There is increasing literature to suggest a practice of overprescribing in multiple surgical specialties. This same finding appears to be present in common otologic surgeries, where on average patients took less than half of the prescribed MME/pills, and 75% of patients had their pain controlled with 12 pills or fewer. Otolaryngologists performing otologic surgery should strongly consider adjusting their postoperative regimens to reflect these findings. LEVEL OF EVIDENCE: 2b.

Intraoperative Electrocochleography in Patients With Menière's Disease Undergoing Endolymphatic Sac Decompression and Shunt Surgery.

HYPOTHESIS: Objective physiologic changes measured using electrocochleography at the round window (ECOG) are observable during endolymphatic sac decompression and shunt surgery (ELS). BACKGROUND: Limited effective treatment options are available to patients with Menière's disease (MD) who have failed conservative management, experience persistent vertigo symptoms, and have substantial residual hearing. ELS is a feasible therapeutic option for these patients. However, the efficacy of this procedure has been questioned, and objective measures assessing inner ear physiologic alterations are lacking. METHODS: ECOG was measured in patients with MD undergoing ELS. Stimuli consisted of tone bursts (250, 500, 1000, 2000, 4000 Hz) and 100 µs broadband clicks at various intensities (60-90 dB nHL). Cochlear microphonic (CM), summation potential (SP), compound action potential (AP), SP:AP ratio, and CM harmonic distortions were measured. RESULTS: ECOG was completed in 18 patients. The mean SP magnitude at 500 Hz changed significantly from -7.1 µV before to -5.1 µV after ELS (p < 0.05). However, the mean SP:AP ratio in those tested (n = 13) did not significantly change after ELS. CM harmonic magnitudes remained unchanged from pre- to post-ELS (n = 12) across all frequencies. CONCLUSION: ECOG allows detection of acute electrophysiological changes in the cochlea. However, our results indicate only small objective changes in the low-frequency SP magnitude (500 Hz) immediately after ELS, but not in other frequencies or measures tested (CM, SP:AP, CM harmonic distortions). These results suggest minimal electrophysiological changes occur in the cochlea as a result of ELS.

How Does Nonverbal Reasoning Affect Sentence Recognition in Adults with Cochlear Implants and Normal-Hearing Peers?

BACKGROUND: Previous research has demonstrated an association of scores on a visual test of nonverbal reasoning, Raven's Progressive Matrices (RPM), with scores on open-set sentence recognition in quiet for adult cochlear implant (CI) users as well as for adults with normal hearing (NH) listening to noise-vocoded sentence materials. Moreover, in that study, CI users demonstrated poorer nonverbal reasoning when compared with NH peers. However, it remains unclear what underlying neurocognitive processes contributed to the association of nonverbal reasoning scores with sentence recognition, and to the poorer scores demonstrated by CI users. OBJECTIVES: Three hypotheses were tested: (1) nonverbal reasoning abilities of adult CI users and normal-hearing (NH) age-matched peers would be predicted by performance on more basic neurocognitive measures of working memory capacity, information-processing speed, inhibitory control, and concentration; (2) nonverbal reasoning would mediate the effects of more basic neurocognitive functions on sentence recognition in both groups; and (3) group differences in more basic neurocognitive functions would explain the group differences previously demonstrated in nonverbal reasoning. METHOD: Eighty-three participants (40 CI and 43 NH) underwent testing of sentence recognition using two sets of sentence materials: sentences produced by a single male talker (Harvard sentences) and high-variability sentences produced by multiple talkers (Perceptually Robust English Sentence Test Open-set, PRESTO). Participants also completed testing of nonverbal reasoning using a visual computerized RPM test, and additional neurocognitive assessments were collected using a visual Digit Span test and a Stroop Color-Word task. Multivariate regression analyses were performed to test our hypotheses while treating age as a covariate. RESULTS: In the CI group, information processing speed on the Stroop task predicted RPM performance, and RPM scores mediated the effects of information processing speed on sentence recognition abilities for both Harvard and PRESTO sentences. In contrast, for the NH group, Stroop inhibitory control predicted RPM performance, and a trend was seen towards RPM scores mediating the effects of inhibitory control on sentence recognition, but only for PRESTO sentences. Poorer RPM performance in CI users than NH controls could be partially attributed to slower information processing speed. CONCLUSIONS: Neurocognitive functions contributed differentially to nonverbal reasoning performance in CI users as compared with NH peers, and nonverbal reasoning appeared to partially mediate the effects of these different neurocognitive functions on sentence recognition in both groups, at least for PRESTO sentences. Slower information processing speed accounted for poorer nonverbal reasoning scores in CI users. Thus, it may be that prolonged auditory deprivation contributes to cognitive decline through slower information processing.

Intracochlear Electrocochleography: Influence of Scalar Position of the Cochlear Implant Electrode on Postinsertion Results.

HYPOTHESIS: Electrocochleography (ECochG) recorded during cochlear implant (CI) insertion from the apical electrode in conjunction with postinsertion ECochG can identify electrophysiologic differences that exist between groups with and without a translocation of the array from the scala tympani (ST) into the scala vestibuli (SV). BACKGROUND: Translocation of the CI electrode from ST into SV can limit performance postoperatively. ECochG markers of trauma may be able to aid in the ability to detect electrode array-induced trauma/scalar translocation intraoperatively. METHODS: Twenty-one adult CI patients were included. Subjects were postoperatively parsed into two groups based on analysis of postoperative imaging: 1) ST (n = 14) insertion; 2) SV (n = 7) insertion, indicating translocation of the electrode. The ECochG response elicited from a 500 Hz acoustic stimulus was recorded from the lead electrode during insertion when the distal electrode marker was at the round window, and was compared to the response recorded from a basal electrode (e13) after complete insertion. RESULTS: No statistically significant change in mean ECochG magnitude was found in either group between recording intervals. There was a mean loss of preoperative pure-tone average of 52% for the nontranslocation group and 94% for the translocation group. CONCLUSIONS: Intraoperative intracochlear ECochG through the CI array provides a unique opportunity to explore the impact of the CI electrode on the inner ear. Specifically, a translocation of the array from ST to SV does not seem to change the biomechanics of the cochlear region that lies basal to the area of translocation in the acute period.

Isolated malleus fixation: A pediatric case series.

OBJECTIVES: The goal of this review was to review our series of isolated malleus fixation in pediatric patients, a rare entity causing conductive hearing loss. Malleolar fixation is poorly described in this patient population. METHODS: A retrospective review of pediatric tympanoplasties by the senior author over a four-year period was performed. Only cases with isolated fixation of the malleus were reviewed. Primary outcome of interest was post-operative hearing. Paired t-tests were used to calculate pre- and post-operative hearing outcomes. RESULTS: Five cases were analyzed. Mean age at time of surgery was 9.1 years (range 4.4-16.0 years). Average follow-up after surgery was 13.9 months (range 4.4-31.2 months). Patients were otherwise healthy and typically presented after a failed school hearing test despite previously good hearing. Three out of five cases showed radiographic evidence of bony fixation (60%) on computerized tomography (CT). Otoscopy was unremarkable in all cases. Average procedure time was 41.2 min and consisted of transcanal tympanoplasty with excision of fixed bony segment. A significant improvement in both pre- and post-operative air bone gaps was observed (p = 0.005)., with average ABG of 14.75 dB. CONCLUSIONS: Isolated pediatric malleolar fixation is an uncommon cause of pediatric conductive hearing loss. CT scan is useful for identifying this abnormality, and surgical correction results in improved post-operative hearing outcomes, potentially obviating the need for hearing amplification.

Audiometric findings in children with unilateral enlarged vestibular aqueduct.

OBJECTIVE: To evaluate the prevalence of bilateral hearing loss in children with unilateral enlarged vestibular aqueduct (EVA) at a single institution. METHODS: A retrospective case review was performed at a tertiary care pediatric referral center involving children with radiologic findings of unilateral EVA and normal labyrinthine anatomy of the contralateral ear diagnosed via CT and/or MRI. The main outcome measure of interest is the number of patients with unilateral EVA who were diagnosed with bilateral hearing loss. RESULTS: Sixty-one pediatric patients were identified. The mean audiometric follow-up was 48.2 months (0-150). Three (4.9%) patients with unilateral EVA were noted to have bilateral hearing loss, and this rate was not significantly different (p = 1.0) from the rate reported in a comparison group of patients with contralateral hearing loss (6.0%) without an EVA. The pure-tone average (defined as the average dB HL at 500, 1000, 2000, and 4000 Hz) in the group with bilateral hearing loss was 31.3 dB HL in the better hearing ear and 79.6 dB HL in the worse hearing ear, with the difference being statistically significant (p = 0.02). In the unilateral EVA patients without contralateral hearing loss (n = 56, 91.8%), the PTA was 9.4 dB HL in the better hearing ear and 51.9 dB HL in the worse hearing ear, with the difference being statistically significant (p < 0.001). Two patients (3.3%) with unilateral EVA were found to have hearing within normal limits bilaterally. The EVA was ipsilateral to the worse hearing ear in all cases. CONCLUSION: The prevalence of bilateral hearing loss in children with unilateral EVA appears to be low. Specifically, it may be no different than the rate of contralateral hearing loss in children with unilateral hearing loss without an EVA. The present report is somewhat different than the previously described prevalence in the literature. This difference could be related to the imaging type and diagnostic criteria used, the patients included, the source of the identified patents, and the overall population of patients studied.