Can routine office-based audiometry predict cochlear implant evaluation results?

OBJECTIVES/HYPOTHESIS: Determining cochlear implant candidacy requires a specific sentence-level testing paradigm in best-aided conditions. Our objective was to determine if findings on routine audiometry could predict the results of a formal cochlear implant candidacy evaluation. We hypothesize that findings on routine audiometry will accurately predict cochlear implant evaluation results in the majority of candidates. STUDY DESIGN: Retrospective, observational, diagnostic study. METHODS: The charts of all adult patients who were evaluated for implant candidacy at a tertiary care center from June 2008 through June 2013 were included. Routine, unaided audiologic measures (pure-tone hearing thresholds and recorded monosyllabic word recognition testing) were then correlated with best-aided sentence-level discrimination testing (using either the Hearing in Noise Test or AzBio sentences test). RESULTS: The degree of hearing loss at 250 to 4,000 Hz and monosyllabic word recognition scores significantly correlated with sentence-level word discrimination test results. Extrapolating from this association, we found that 86% of patients with monosyllabic word recognition scores at or below 32% (or 44% for patients with private insurance) would meet candidacy requirements for cochlear implantation. CONCLUSIONS: Routine audiometric findings can be used to identify patients who are likely to meet cochlear implant candidacy upon formal testing. For example, patients with pure-tone thresholds (250, 500, 1,000 Hz) of ≥75 dB and/or a monosyllabic word recognition test score of ≤40% have a high likelihood of meeting candidacy criteria. Utilization of these predictive patterns during routine audiometric evaluation may assist hearing health professionals in deciding when to refer patients for a formal cochlear implant evaluation. LEVEL OF EVIDENCE: 4 Laryngoscope, 127:216-222, 2017.

Flat-Panel CT for Cochlear Implant Electrode Imaging: Comparison to Multi-Detector CT.

HYPOTHESIS: Flat-panel computed tomography (FPCT) will allow more accurate localization of cochlear implants with decreased metallic artifact and decreased radiation dose when compared with multi-detector CT (MDCT). BACKGROUND: The measurement of scalar location and intra-scalar position of cochlear implantation (CI) electrodes using computed tomography (CT) is complicated by metallic image artifact and insufficient scalar resolution. FPCT has been shown to improve upon the resolution of MDCT while reducing artifact. Previous studies of FPCT imaging employed isolated temporal bones and did not compare FPCT with MDCT. METHODS: A total of 11 CI electrodes (Flex-24, MED-EL Corp, Innsbruck, Austria) were intentionally placed into either the scala tympani (ST) or scala vestibule (SV) in whole cadaver heads and imaged with MDCT and FPCT. The relative radiation dose was measured at the ocular lens for each modality. The implanted cochleae were then isolated and imaged with micro-CT which was used to assess electrode position. Images were reviewed and scored according to electrode array scalar compartment (ST, SV, scala media [SM]), intra-scalar position within each compartment (perimodiolar, mid modiolor, lateral wall) and for the presence of artifact by five readers blinded to the imaging method and approach for electrode insertion. RESULTS: FPCT showed less metallic CI artifact (p = 0.002) and decreased radiation dosage when compared with MDCT. Reviewers were able to identify the scalar compartment and intra-scalar position of all electrodes more accurately with FPCT than with MDCT (p < 0.001). CONCLUSION: FPCT more accurately resolves the scalar compartment and intra-scalar position of CI electrodes with reduced radiation exposure and metallic artifact than MDCT.

Investigating long-term effects of cochlear implantation in single-sided deafness: a best practice model for longitudinal assessment of spatial hearing abilities and tinnitus handicap.

OBJECTIVES: To evaluate methods for measuring long-term benefits of cochlear implantation in a patient with single-sided deafness (SSD) with respect to spatial hearing and to document improved quality of life because of reduced tinnitus. PATIENT: A single adult male with profound right-sided sensorineural hearing loss and normal hearing in the left ear who underwent right-sided cochlear implantation. METHODS: The subject was evaluated at 6, 9, 12, and 18 months after implantation on speech intelligibility with specific target-masker configurations, sound localization accuracy, audiologic performance, and tinnitus handicap. Testing conditions involved the acoustic (NH) ear only, the cochlear implant (CI) ear (acoustic ear plugged), and the bilateral condition (CI+NH). Measures of spatial hearing included speech intelligibility improvement because of spatial release from masking (SRM) and sound localization. In addition, traditional measures known as "head shadow," "binaural squelch," and "binaural summation" were evaluated. RESULTS: The best indicator for improved speech intelligibility was SRM, in which both ears are activated, but the relative locations of target and masker(s) are manipulated. Measures that compare performance with a single ear to performance using bilateral auditory input indicated evidence of the ability to integrate inputs across the ears, possibly reflecting early binaural processing, with 12 months of bilateral input. Sound localization accuracy improved with addition of the implant, and a large improvement with respect to tinnitus handicap was observed. CONCLUSION: Cochlear implantation resulted in improved sound localization accuracy when compared with performance using only the NH ear, and reduced tinnitus handicap was observed with use of the implant. The use of SRM addresses some of the current limitations of traditional measures of spatial and binaural hearing, as spatial cues related to target and maskers are manipulated, rather than the ear(s) tested. Sound testing methods and calculations described here are therefore recommended for assessing performance of a larger sample size of individuals with SSD who receive a CI.

Radiographic features of superior semicircular canal dehiscence in the setting of chronic ear disease.

OBJECTIVE: To determine if radiologic chronic otitis media (COM), both with and without cholesteatoma, is associated with superior semicircular canal dehiscence (SSCD). STUDY DESIGN: Retrospective review of consecutive high-resolution computed tomography (HRCT) scans of the temporal bone. SETTING: Tertiary care medical center. PATIENTS: Two hundred consecutive patients undergoing HRCT of the temporal bone beginning January 1, 2012. INTERVENTION: Imaging was evaluated by 3 reviewers (2 neuroradiologists and 1 neurotologist). All scans were assessed for the presence of SSCD, cholesteatoma, chronic otomastoiditis, tegmen dehiscence, and for abnormalities of the cochlea, vestibule, facial nerve, and temporal bone vasculature. MAIN OUTCOME MEASURE: Ears with COM associated with chronic otomastoiditis or cholesteatoma were compared with those without COM with respect to the presence of SSCD or other temporal bone abnormalities. Statistical analysis was performed to assess for differences between the groups studied. RESULTS: One-hundred ninety-four patients (388 ears) were included. Cholesteatoma was identified in 48 ears (12.4%) and chronic otomastoiditis in 62 ears (16%). Ten ears with cholesteatoma had ipsilateral SSCD, and 8 ears with chronic otomastoiditis had ipsilateral SSCD. In 340 ears without either cholesteatoma or chronic otomastoiditis, SSCD was found in 18 (5.3%). SSCD was found to occur significantly more often in patients with ipsilateral radiologic cholesteatoma. No cases of SSCD were associated with cochlear, facial nerve, or vascular abnormalities. CONCLUSION: Our findings suggest that COM with cholesteatoma is associated with the presence of SSCD, although the nature of this association is unclear.

Bilateral duplicated internal carotid arteries presenting as middle ear masses: a case report and review of the literature.

OBJECTIVES: We seek to describe an individual with bilateral duplicated internal carotid arteries (ICAs) presenting as middle ear masses, to discuss the anatomy and characteristic imaging findings associated with this condition, and to familiarize clinicians with effective methods to prevent and manage complications related to this entity. METHODS: The clinical presentation of an individual with this unusual vascular anomaly was reviewed. A literature search was then performed to identify previously reported studies describing aberrant ICAs in order to characterize the presentation, anatomy, imaging findings, and management of this condition. RESULTS: An aberrant ICA presenting as a middle ear mass is uncommon; there are only approximately 45 reported cases to date. The majority of these cases presented as a unilateral anomaly without a duplication, were associated with pulsatile tinnitus and hearing loss, and were diagnosed during middle ear procedures. Bilateral aberrant ICAs are exceedingly rare, with only 14 existing reports. Only 1 of these cases presented with duplicated ICAs. Our report demonstrates an unusual presentation of aberrant ICAs, as pulsatile tinnitus was absent and previous middle ear surgery had been performed without establishing this diagnosis and without any resulting complications. Furthermore, this case represents the first known instance of a bilateral duplicated ICA system without persistent stapedial arteries. Although vascular middle ear anomalies are unusual, complications of surgical manipulation have been documented. CONCLUSIONS: The clinician must have a high index of suspicion for vascular lesions in patients presenting with a retrotympanic mass. Appropriate diagnostic imaging studies should be performed to exclude this diagnosis before middle ear exploration. Should injury to the carotid artery occur, surgeons should follow specific guidelines to avoid potentially serious complications.

Facial and lower cranial neuropathies after preoperative embolization of jugular foramen lesions with ethylene vinyl alcohol.

OBJECTIVE: To report 3 unique cases of cranial neuropathy after super-selective arterial embolization of jugular foramen vascular tumors with ethylene vinyl alcohol. STUDY DESIGN: Clinical capsule report. SETTING: Three tertiary academic referral hospitals. PATIENTS: Three patients who underwent superselective arterial embolization (SSE) of head and neck paragangliomas with ethylene vinyl alcohol are described. One individual was treated with primary SSE, whereas the remaining tumors were treated with preoperative SSE followed by surgical extirpation within 72 hours. All patients were found to have new cranial nerve deficits after SSE. RESULTS: One patient with isolated complete cranial nerve VII palsy demonstrated partial return of function at 8 months. One individual experienced cranial nerve VII, X, and XII palsies and demonstrated partial recovery of function of the involved facial nerve after 19 months. One subject experienced ipsilateral cranial nerve X and XI palsies after SSE and recovered full function of the spinal accessory nerve within 1 week but failed to demonstrate mobility of the ipsilateral true vocal fold. CONCLUSION: We present the first report documenting facial and lower cranial neuropathies after super-selective embolization of head and neck paragangliomas with EVA. Although it is difficult to draw conclusions from this small number of cases, it is plausible that the use of ethylene vinyl alcohol during SSE may result in a higher risk of permanent cranial neuropathy than the use of other well-established and more temporary agents. Knowledge of the arterial supply to the cranial nerves can help the clinician to choose the embolization agent that will provide maximal occlusion while minimizing the risk of complications.