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Craig A Buchman - One of the best experts on this subject based on the ideXlab platform.

  • intraoperative Cochlear Nerve monitoring for vestibular schwannoma resection and simultaneous Cochlear implantation in neurofibromatosis type 2 a case series
    Operative Neurosurgery, 2021
    Co-Authors: Margaret J Butler, Cameron C Wick, Matthew Shew, Michael R Chicoine, Amanda J Ortmann, Janet Vance, Craig A Buchman
    Abstract:

    Background Neurofibromatosis type 2 (NF2) often results in profound hearing loss and Cochlear implantation is an emerging hearing rehabilitation option. However, Cochlear implant (CI) outcomes in this population vary, and intraoperative monitoring to predict Cochlear Nerve viability and subsequent outcomes is not well-established. Objective To review the use of intraoperative electrically evoked Cochlear Nerve monitoring in patients with NF2 simultaneous translabyrinthine (TL) vestibular schwannoma (VS) resection and Cochlear implantation. Methods A retrospective review was performed of 3 patients with NF2 that underwent simultaneous TL VS resection and Cochlear implantation with electrical auditory brainstem response (eABR) measured throughout tumor resection. Patient demographics, preoperative assessments, surgical procedures, and outcomes were reviewed. Results Patients 1 and 3 had a reliable eABR throughout tumor removal. Patient 2 had eABR pretumor removal, but post-tumor removal eABR presence could not be reliably determined because of electrical artifact interference. All patients achieved auditory percepts upon CI activation. Patients 1 and 2 experienced a decline in CI performance after 1 yr and after 3 mo, respectively. Patient 3 continues to perform well at 9 mo. Patients 2 and 3 are daily users of their CI. Conclusion Cochlear implantation is attainable in cases of NF2-associated VS resection. Intraoperative eABR may facilitate Cochlear Nerve preservation during tumor removal, though more data and long-term outcomes are needed to refine eABR methodology and predictive value for this population.

  • Cochlear implantation in children with labyrinthine anomalies and Cochlear Nerve deficiency implications for auditory brainstem implantation
    Laryngoscope, 2011
    Co-Authors: Craig A Buchman, Patricia A. Roush, Holly F B Teagle, Carlton J Zdanski, Lisa R Park, Debora R Hatch, Jennifer Woodard, Oliver F Adunka
    Abstract:

    Objectives/Hypothesis: Compare outcomes among children with inner ear malformations and/or Cochlear Nerve deficiency (CND) who have received a Cochlear implant (CI). Study Design: Individual retrospective cohort study from 1993 to 2010. Methods: A select cohort of 76 children was identified. Imaging characteristics, operative findings, complications, mapping parameters, and performance were assessed. Comparisons among the different groups were undertaken. Results: Surgery was mostly uncomplicated. Nearly all children demonstrated behavioral responses to CI stimulation irrespective of inner ear morphology or the presence of CND. Children with CND had higher pure tone averages (PTAs) and required greater charge for stimulation than other malformation types. Open-set speech perception was achieved in 100% of children with incomplete partition-enlarged vestibular aqueduct (IP-EVA), 50% of those with hypoplastic malformations, and 19% of CND cases. Robust responses on eighth Nerve compound action potential (ECAP) testing through the implant was associated with higher levels of speech perception. Manually supplemented communication strategies were more common among children with hypoplastic malformations (69%) and CND (95%) than those with IP-EVA (18%). Conclusions: Children with IP-EVA malformations have an excellent prognosis for developing open-set speech perception and using oral communication modes following CI. On the contrary, children with severe malformations or CND may have elevated charge requirements for attaining sound detection alone. These children's prognosis for obtaining open-set speech understanding, using exclusive oral communication, and participating in mainstream education is more limited. These findings have important implications for considering alternative forms of intervention such as auditory brainstem implantation and/or supplementation with visually based communication strategies.

  • brain stem and inner ear abnormalities in children with auditory neuropathy spectrum disorder and Cochlear Nerve deficiency
    American Journal of Neuroradiology, 2010
    Co-Authors: B Y Huang, Craig A Buchman, Joseph P Roche, Mauricio Castillo
    Abstract:

    BACKGROUND AND PURPOSE: Cranial abnormalities, including CND, are common in children with ANSD. The purpose of this study was to assess whether CND is associated with brain or inner ear abnormalities in a cohort of children with ANSD. MATERIALS AND METHODS: Two neuroradiologists retrospectively reviewed cranial MR imaging examinations in 103 children with ANSD. Brain, Cochlear Nerve, and temporal bone abnormalities were described and tabulated. Findings were stratified on the basis of the presence and laterality of CND, and differences in the presence of associated inner ear or intracranial abnormalities were assessed by using 2-tailed Fisher exact tests. RESULTS: CND was identified in 33.0% of children and 26.9% of ears with ANSD. Significantly more patients with bilateral CND had intracranial abnormalities than those with unilateral CND (60.0% versus 15.8%; P = .012). Forty percent of patients with bilateral CND, 0% of patients with unilateral CND, and 10.1% of those without CND demonstrated hindbrain malformations. Patients with bilateral CND were more likely to demonstrate hindbrain malformations than patients with normal Nerves ( P = .01) or unilateral CND ( P = .004). Labyrinthine abnormalities were significantly more common in patients with bilateral CND than in those without CND ( P ≤ .001). Cochlear anomalies were more common in patients with bilateral versus unilateral CND ( P = .01). IAC and Cochlear aperture stenosis were more common in those with unilateral and bilateral CND than those without CND (both P CONCLUSIONS: Cochlear and hindbrain abnormalities are significantly more common among patients with ANSD with bilateral CND compared with those with at least 1 intact Cochlear Nerve.

  • value of computed tomography in the evaluation of children with Cochlear Nerve deficiency
    Otology & Neurotology, 2007
    Co-Authors: Oliver F Adunka, Valerie Jewells, Craig A Buchman
    Abstract:

    Objective: To assess the predictive value of high-resolution computed tomography (HRCT) in the evaluation of children with Cochlear Nerve deficiency (CND). Study Design: Retrospective review of medical records. Setting: Tertiary referral center, hospital setting. Patients: Nineteen children (31 ears) with CND. Interventions: Magnetic resonance imaging (MRI), HRCT, and audiologic evaluation. Main Outcome Measures: Comparisons of the morphology of the internal auditory canal (IAC), the bony Cochlear Nerve canal (BCNC) as seen on HRCT, and audiologic data. Results: Of 12 ears with MRI evidence of an absent Cochlear Nerve (CN) and a normal-size IAC, all had a patent BCNC as revealed by HRCT. Four of these ears failed auditory stimulation after Cochlear implantation, confirming clinically significant CND. Of 15 ears with a narrow IAC and a single Nerve visible on MRI, 2 (13.3%) had a normal-size BCNC, 4 (26.7%) were narrow, and 9 (60.0%) were absent. One ear with a narrow IAC, normal BCNC, and a single Nerve as revealed by MRI has benefited from Cochlear implantation. Conclusion: Using BCNC patency, as revealed by HRCT, as a means of identifying CND would miss all cases of absent CNs in the setting of a normal-size IAC. Thus, MRI should be the primary modality for imaging children with severe to profound sensorineural hearing loss. When MRI demonstrates a single Nerve within a narrow IAC, the addition of HRCT can further identify more than half of these cases as involving absent CNs because of an absent BCNC. In a subset of patients, CN status remains indeterminate.

  • internal auditory canal morphology in children with Cochlear Nerve deficiency
    Otology & Neurotology, 2006
    Co-Authors: Oliver F Adunka, Patricia A. Roush, Carolyn J Brown, Holly F B Teagle, Carlton J Zdanski, Valerie Jewells, Craig A Buchman
    Abstract:

    Objective: To describe the internal auditory canal (IAC) and inner ear morphologic characteristics of children with Cochlear Nerve (CN) deficiency. Study Design: Retrospective case series. Setting: Tertiary referral center. Patients: Fourteen children with small or absent (deficient) CNs have been identified by means of high-resolution magnetic resonance imaging (MRI). Interventions: MRI of the brain. Clinical evaluation. Main Outcome Measures: Review of medical records, audiological testing results, and imaging studies. Images were evaluated for the structure of the Cochlear, vestibular and facial Nerves, IACs and inner ears. Audiometric thresholds were evaluated in all subjects. Methods: Fourteen children with small or absent (deficient) CNs have been identified by means of high-resolution MRI. A review of the medical records, audiologic testing results, and imaging studies was undertaken. The images were evaluated for the structure of the Cochlear, vestibular and facial Nerves, IACs, and inner ears. The audiometric thresholds were evaluated in all subjects. Results: Among the 14 patients, 5 had known syndromes. MRI allowed an exact specification of the nervous structures within all ears with normal-size IACs. Precise characterization of the Nerves in ears with small IACs was more difficult, requiring a consideration of both imaging findings and functional parameters. Five children had bilateral deficient CNs, whereas the remaining 9 subjects were affected unilaterally. Thus, 19 ears had CN deficiency (absent CN, 16; small CN, 3). Eleven ears had normal-size IACs and deficient CNs. Of the 9 ears with small IACs, 8 had deficient CNs (absent, 7; small, 1) on the basis of both MRI and functional assessments. Two ears with small IACs had clear morphologic and/or functional evidence for the presence of a CN: one had a small-size CN on MRI, whereas another had a single Nerve in a small IAC with present facial and auditory functions. Conclusion: The findings of this study suggest that CN deficiency is not an uncommon cause of congenital hearing loss. The findings that most ears with CN deficiency had normal IAC morphology and that two ears with small IACs had CNs present indicate that IAC morphology is an unreliable surrogate marker of CN integrity. On the basis of these findings, we think that high-resolution MRI, rather than CT imaging, should be performed in all cases of pediatric hearing loss, especially in those cases where profound hearing

David L Horn - One of the best experts on this subject based on the ideXlab platform.

  • progression of unilateral hearing loss in children with and without ipsilateral Cochlear Nerve canal stenosis a hazard analysis
    Otology & Neurotology, 2017
    Co-Authors: Patricia L Purcell, Grace S Phillips, Angelisa M Paladin, Kathleen C Y Sie, Justin R Shinn, Scott S Coggeshall, David L Horn
    Abstract:

    Objective:To investigate the risk of hearing loss progression in each ear among children with unilateral hearing loss associated with ipsilateral bony Cochlear Nerve canal (BCNC) stenosis.Setting:Tertiary pediatric referral center.Patients:Children diagnosed with unilateral hearing loss who had unde

  • bony Cochlear Nerve canal stenosis and speech discrimination in pediatric unilateral hearing loss
    Laryngoscope, 2015
    Co-Authors: Patricia L Purcell, David L Horn, Ayaka J Iwata, Grace S Phillips, Angelisa M Paladin, Kathleen C Y Sie
    Abstract:

    Objectives/Hypothesis To examine the relationship between bony Cochlear Nerve canal (BCNC) width, degree of hearing loss, and speech discrimination in children with unilateral sensorineural hearing loss (USNHL). Study Design Retrospective chart review (case-control study). Methods Audiometric database was cross-referenced with radiologic database at pediatric tertiary care facility to identify children with USNHL and temporal bone computed tomography. BCNC widths were measured independently by two radiologists blinded to affected ear. Regression analyses investigated associations among variables. Results One hundred and sixty children with USNHL had temporal bone imaging. Mean BCNC width was significantly smaller in affected ears, P = 0.0001. Narrower width was associated with more severe hearing loss, P = 0.01. Among children who had narrower Cochlear Nerve canals in affected ears compared to unaffected ears, smaller width was associated with lower speech discrimination score, P = 0.03. Increasing asymmetry in BCNC width between affected and unaffected ears was associated with poorer discrimination scores, P = 0.02. Among ears with asymmetrically smaller Cochlear Nerve canals, a 1-mm reduction in Cochlear canal width between the normal and affected ear was associated with 30.4% lower word recognition score percentage in the affected ear, P = <0.001. Conclusion There is a significant association between BCNC stenosis and impaired speech discrimination, independent of degree of hearing loss. Further investigation is needed to determine whether BCNC stenosis is a poor prognostic factor for auditory rehabilitation. Level of Evidence 3b. Laryngoscope, 125:1691–1696, 2015

Mauricio Castillo - One of the best experts on this subject based on the ideXlab platform.

  • brain stem and inner ear abnormalities in children with auditory neuropathy spectrum disorder and Cochlear Nerve deficiency
    American Journal of Neuroradiology, 2010
    Co-Authors: B Y Huang, Craig A Buchman, Joseph P Roche, Mauricio Castillo
    Abstract:

    BACKGROUND AND PURPOSE: Cranial abnormalities, including CND, are common in children with ANSD. The purpose of this study was to assess whether CND is associated with brain or inner ear abnormalities in a cohort of children with ANSD. MATERIALS AND METHODS: Two neuroradiologists retrospectively reviewed cranial MR imaging examinations in 103 children with ANSD. Brain, Cochlear Nerve, and temporal bone abnormalities were described and tabulated. Findings were stratified on the basis of the presence and laterality of CND, and differences in the presence of associated inner ear or intracranial abnormalities were assessed by using 2-tailed Fisher exact tests. RESULTS: CND was identified in 33.0% of children and 26.9% of ears with ANSD. Significantly more patients with bilateral CND had intracranial abnormalities than those with unilateral CND (60.0% versus 15.8%; P = .012). Forty percent of patients with bilateral CND, 0% of patients with unilateral CND, and 10.1% of those without CND demonstrated hindbrain malformations. Patients with bilateral CND were more likely to demonstrate hindbrain malformations than patients with normal Nerves ( P = .01) or unilateral CND ( P = .004). Labyrinthine abnormalities were significantly more common in patients with bilateral CND than in those without CND ( P ≤ .001). Cochlear anomalies were more common in patients with bilateral versus unilateral CND ( P = .01). IAC and Cochlear aperture stenosis were more common in those with unilateral and bilateral CND than those without CND (both P CONCLUSIONS: Cochlear and hindbrain abnormalities are significantly more common among patients with ANSD with bilateral CND compared with those with at least 1 intact Cochlear Nerve.

  • hypoplasia of the bony canal for the Cochlear Nerve in patients with congenital sensorineural hearing loss initial observations
    Radiology, 2000
    Co-Authors: Girish M Fatterpekar, Suresh K Mukherji, Jay Alley, Mauricio Castillo
    Abstract:

    PURPOSE: To evaluate the length and width of the bony canal of the Cochlear Nerve in patients with congenital sensorineural hearing loss (SNHL) who have “normal” findings at thin-section computed tomography (CT) of the temporal bone. MATERIALS AND METHODS: The authors retrospectively evaluated the length and width of the bony canal for the Cochlear Nerve in two groups of patients. The first group was composed of 33 patients with profound SNHL and no demonstrable abnormality at thin-section CT. The control group was composed of 50 patients who underwent temporal bone CT for causes unrelated to SNHL. The mean value ± SD was calculated for both cohorts. Statistical analysis consisted of the nonparametric Wilcoxon rank sum test with the npar1way program. RESULTS: The length and width of the bony canal for the Cochlear Nerve were significantly smaller in patients with SNHL than in the control group (P < .05) CONCLUSION: The hypoplastic bony canal for the Cochlear Nerve in patients with SNHL may be indicative o...

Vittorio Colletti - One of the best experts on this subject based on the ideXlab platform.

  • Nervus intermedius guides auditory brainstem implant surgery in children with Cochlear Nerve deficiency
    'SAGE Publications', 2016
    Co-Authors: G. Colletti, M. Mandal&#224, L. Colletti, Vittorio Colletti
    Abstract:

    OBJECTIVE: To investigate the anatomic features of the nervus intermedius and cranial Nerve VII in children with Cochlear Nerve deficiency and to verify whether the nervus intermedius can provide an additional landmark to help guide placement of the auditory brainstem implant electrode. STUDY DESIGN: Case series with chart review. SETTING: Tertiary referral center. SUBJECTS AND METHODS: High-definition video was captured during retrosigmoid surgery in 64 children (mean age, 3.91 \ub1 2.83 years) undergoing auditory brainstem implant placement. These videos were examined with particular reference to the number and variety of nervus intermedius bundles and any associated facial Nerve anomalies. RESULTS: Absence of cranial Nerves VI, VII, and VIII was observed in 3, 6, and all 64 children, respectively. Fifteen children had several abnormalities of the facial Nerve in the cerebellopontine angle. Anatomic identification of the facial Nerve and the bundles composing the nervus intermedius was possible in 46 children. In 12 children, identification was possible with the assistance of intraoperative monitoring. The number of bundles composing the nervus intermedius varied from 1 to 6. The nervus intermedius and cranial Nerve IX were useful landmarks for identifying the foramen of Luschka of the lateral recess. CONCLUSION: The nervus intermedius provides an additional landmark during auditory brainstem microsurgery since it was identified in all subjects. The nervus intermedius anatomy and its topographic relationship with the neurovascular structures around the foramen of Luschka have been described for the first time in children with Cochlear Nerve deficiency

  • the therapeutic dilemma of Cochlear Nerve deficiency Cochlear or brainstem implantation
    Otolaryngology-Head and Neck Surgery, 2014
    Co-Authors: L. Colletti, G. Colletti, Marco Mandala, Vittorio Colletti
    Abstract:

    ObjectiveTo compare the outcomes between 2 age-matched cohorts of children with Cochlear Nerve deficiency: those receiving auditory brainstem implants (group A) or Cochlear implants (group B).Study DesignRetrospective cohort study.SettingTertiary referral center.Subjects and MethodsSubjects were selected from a pool of 537 children fitted with Cochlear implants (n = 443) or auditory brainstem implants (n = 94) over the past 14 years. Performance, examined with the Category of Auditory Performance scale, and complications were compared with a mean follow-up of 5 years.ResultsAll children had bilateral profound sensorineural hearing loss and Cochlear Nerve deficiency. Magnetic resonance imaging documented an absent Cochlear Nerve (n = 12) and a small Cochlear Nerve (n = 8) in group A and an absent Cochlear Nerve (n = 11) and a small Cochlear Nerve (n = 9) in group B (P = 1.000). Children with Cochlear implants had Category of Auditory Performance scores spanning from 0 to 3 levels of performance, and all re...

  • auditory brainstem implantation after unsuccessful Cochlear implantation of children with clinical diagnosis of Cochlear Nerve deficiency
    Annals of Otology Rhinology and Laryngology, 2013
    Co-Authors: L. Colletti, Eric P Wilkinson, Vittorio Colletti
    Abstract:

    ObjectivesWe compared the perceptual auditory abilities of 21 children with suspected Cochlear Nerve deficiency (CND) and a surgically verified absent Cochlear Nerve (CN) who first underwent cochle...

  • imaging in 28 children with Cochlear Nerve aplasia
    Acta Oto-laryngologica, 2009
    Co-Authors: Marco Carner, L. Colletti, Robert V Shannon, Roberto Cerini, Marco Barillari, Roberto Pozzi Mucelli, Vittorio Colletti
    Abstract:

    Conclusion. Preoperative CT and MRI assessment of children with severe or profound sensorineural hearing loss (SNHL) is critical for determining implant candidacy. Objectives. There are a significant number of children who do not show any auditory development with a Cochlear implant (CI), possibly due to Cochlear Nerve (CN) aplasia/hypoplasia. Regardless of the suspected etiology, if a CI is not providing auditory development the clinician should carefully evaluate the possibility of a CN malformation and re-evaluate the child with detailed neuroimaging studies. If the imaging evaluation shows severe Cochlear malformation or CN aplasia there is some developmental urgency to consider auditory brainstem implant (ABI) surgery. Subjects and methods. Twenty-eight children affected by congenital SNHL were examined by CT and MRI. Evaluation of the cerebellopontine angle (CPA), internal auditory canal (IAC), cranial Nerves, and membranous labyrinth was performed. Six children had been previously fitted elsewhere ...

  • hearing restoration with auditory brainstem implant in three children with Cochlear Nerve aplasia
    Otology & Neurotology, 2002
    Co-Authors: Vittorio Colletti, Francesco G Fiorino, Luca Sacchetto, Veronica Miorelli, Marco Carne, Alessandro Orsi, Francesco Cilurzo, Lorenzo Pacini
    Abstract:

    ObjectiveTo verify the possibility of auditory habilitation in children with aplasia and hypoplasia of the Cochlear Nerve by direct electrical stimulation of the Cochlear nuclei with an auditory brainstem implant.Study DesignRetrospective case review.SettingStudy conducted at the Ear, Nose, and Thro

Seung Ha Oh - One of the best experts on this subject based on the ideXlab platform.

  • A Predictive Model for Cochlear Implant Outcome in Children with Cochlear Nerve Deficiency
    Scientific Reports, 2019
    Co-Authors: Moo Kyun Park, Seung Ha Oh
    Abstract:

    The outcome of Cochlear implantation (CI) in patients with Cochlear Nerve deficiency (CND) is variable, resulting in a wide range of speech perception performance, from degrees of environmental sound perception to conversation without lip-reading. Twenty-five Cochlear implantees with CND were enrolled retrospectively to determine the factors correlated with CI outcome in patients with CND and to develop a predictive model for CI outcome. CI outcome was evaluated using the Categories of Auditory Performance (CAP) score at 2 years after CI. Patients with negative auditory brainstem response (ABR) showed a significantly lower CAP score than those with positive ABR (2.5 ± 1.7, 4.8 ± 0.7; p = 0.001). The area ratio of vestibuloCochlear Nerve (VCN) to facial Nerve (FN) at the cerebellopontine angle on magnetic resonance images was positively correlated with CI outcome (p 

  • implication of bony Cochlear Nerve canal on hearing in patients with congenital unilateral sensorineural hearing loss
    Audiology and Neuro-otology, 2012
    Co-Authors: Jeong Hun Jang, Sun O Chang, Seung Ha Oh
    Abstract:

    This study was designed to evaluate the dimensions of the bony Cochlear Nerve canal (BCNC) in congenital unilateral sensorineural hearing loss (USNHL) patients with normal inner ears, and to analyze the correlation between BCNC and hearing status. Medical records and temporal bone computed tomography (TBCT) findings of 380 patients who visited Seoul National University Hospital between January 1999 and December 2007 were reviewed retrospectively. The length and width of the BCNC at the fundus of the internal auditory canal were measured in millimeters based on the axial view of TBCT for three ear groups: normal inner ears of control group subjects (group A, 179 ears), normal inner ears on the contralateral side of USNHL patients (group B, 201 ears), and the affected inner ears in USNHL (group C, 201 ears). The mean values of length and width in group C (0.79 ± 0.36 and 1.58 ± 0.83 mm, respectively) were significantly smaller than those in group A (1.07 ± 0.10 and 2.38 ± 0.28 mm, respectively; p < 0.001) and group B (1.04 ± 0.23 and 2.33 ± 0.39 mm, respectively; p < 0.001). The receiver operating characteristic curves for BCNC were conducted to estimate the cutoff values from which the proportions of profound hearing loss increased, compared to those of mild to severe hearing loss. The areas under the curve were 0.487 ± 0.044 (p = 0.781) and 0.622 ± 0.041 (p = 0.011) for length and width, respectively. The cutoff value of width with a sensitivity of 90% for profound USNHL was 1.16 mm in otherwise normal inner ears. Clinicians would be recommended to take a close look at BCNC as one of the possible causes of hearing loss in otherwise normal inner ears of USNHL on TBCT.