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John P. Carey - One of the best experts on this subject based on the ideXlab platform.

  • Underwater Endoscopic Repair of Superior Canal Dehiscence.
    Otology & neurotology : official publication of the American Otological Society American Neurotology Society [and] European Academy of Otology and Neu, 2020
    Co-Authors: Francis X. Creighton, Jeffrey D. Sharon, Bryan K. Ward, Samuel R. Barber, John P. Carey
    Abstract:

    : Superior Canal Dehiscence (SCD) is a bony defect of the Superior semicircular Canal (SCC). Patients with SCD Syndrome (SCDS) may experience symptoms such as aural fullness, pulsatile tinnitus, hyperacusis, autophony, or pressure or noise-induced vertigo . The defect can be repaired in various ways, but there is potential for loss of perilymphatic fluid during transmastoid approaches that could result in postoperative sensorineural hearing loss . We hypothesize that if the procedure were performed "underwater" in balanced salt solution (BSS), loss of perilymphatic fluid would be minimized. CASE REPORT:: A 55-year-old male presented with right-sided autophony, pulsatile tinnitus, and hyperacusis. Audiometric testing demonstrated a low-frequency airbone gap and a supranormal bone-conduction threshold at 4 kHz. Ocular VEMP responses were increased amplitude. Temporal bone imaging revealed a SCC Dehiscence.The patient was taken to the operating room for an underwater, endoscopic repair of the SCC using a transmastoid approach. A cortical mastoidectomy was performed using Landmarx image navigation. BSS filled the mastoid and a 0-degree endoscope with endoscrub was used to see the SCC underwater. The SCC was entered near the ampullated end with a bur. A stepwise plugging process included applying strips of wet and dried fascia and bone dust. The non-ampullated end was similarly plugged. BSS was suctioned, and under microscopic visualization, labyrinthotomies were capped with bone chips. The patient tolerated the procedure well and was discharged the next day. There was no sensorineural hearing loss postoperatively. CONCLUSION:: SCDS may be addressed surgically using multiple approaches. An underwater endoscopic repair of the SCC may be safe and effective surgical treatment.SDC video link: http://links.lww.com/MAO/A808.

  • Pressure Transmission to the Inner Ear by Mastoid Palpation After Transmastoid Surgery for Superior Canal Dehiscence.
    Otology & neurotology : official publication of the American Otological Society American Neurotology Society [and] European Academy of Otology and Neu, 2019
    Co-Authors: Ved A. Tanavde, Francis Pete X Creighton, Bryan K. Ward, John P. Carey
    Abstract:

    OBJECTIVE To discuss an effect of transmastoid repair of Superior semicircular Canal Dehiscence and its resolution using a mastoid titanium mesh plate. PATIENTS A 53-year-old woman with a history of Superior Canal Dehiscence syndrome (SCDS) and subsequent transmastoid repair experienced dizziness and a loud, drum-like sound in her repaired ear when touching the ear. Palpating the skin over the mastoid defect reproduced the symptoms and could be observed on binocular microscopy as tympanic membrane deformation synchronous with mastoid palpation. INTERVENTION (S) Surgery to place a titanium mesh cranioplasty plate over the mastoid cavity. MAIN OUTCOME MEASURE (S) Reduction in dizziness and auditory symptoms when palpating the mastoid. RESULTS In follow-up 2 months after surgery, palpation of the left mastoid no longer results in vertigo or hearing a loud sound. Hearing and vestibular function remained unchanged. CONCLUSIONS Despite resolution of SCDS symptoms after transmastoid plugging and resurfacing of the Superior semicircular Canal involving mastoidectomy, patients can be bothered by dizziness and vertigo when pressing on the mastoid soft tissue envelope. This acts like a balloon that, when compressed, changes middle ear pressure and moves the tympanic membrane and can even cause alternobaric vertigo. This can be avoided or resolved by rigidly reconstructing the defect in the mastoid bone.

  • Surgical Complications from Superior Canal Dehiscence Syndrome Repair: Two Decades of Experience.
    Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery, 2017
    Co-Authors: Yanjun Xie, Lloyd B. Minor, Charles Coleman Della Santina, Jeffrey D. Sharon, Seth E. Pross, Nicholas B. Abt, Sanskriti Varma, John P. Carey
    Abstract:

    Objective To determine the incidence of surgical complications associated with Superior Canal Dehiscence syndrome (SCDS) repair and identify the demographic, medical, and intraoperative risk factors that are associated with SCDS complications. Study Design Cases series with chart review, including patients who underwent SCDS repair between 1996 and 2015. Setting A tertiary care academic medical center. Subjects and Methods Data were collected from 220 patients, including demographic information, medical comorbidities, prior otologic surgical history, surgical approach, intraoperative findings, and postoperative complications. Relative risk analysis and multivariable logistic regression evaluated the associations between perioperative risk factors and SCDS complications. Results A total of 242 consecutive cases were performed: 95.5% middle fossa and 4.5% transmastoid approach (mean age: 47.8 ± 10.6 years; 54.5% female). Surgical complications were reported in 27 (11.2%) cases; 20 (8.3%) had Clavien-Dindo grade I complications, most commonly benign paroxysmal positional vertigo (n = 11, 4.5%) and profound sensorineural hearing loss (n = 6, 2.5%). Two cases (0.8%) had grade II; 4 cases (1.7%), grade III; and 1 case (0.4%), grade IV complications. In the analysis of comorbidities, only preoperative coagulopathy was significantly associated with increased risk of complications (relative risk = 6.4, P < .01). Following multivariate logistic regression adjusting for demographic covariates, coagulopathy was still associated with increased odds of complications (odds ratio = 15.7, P = .03). There were no significant associations between other risk factors and complications. Conclusion SCDS repair has low rates of adverse events. We observed an incidence of 11.2% complications, most commonly postoperative benign paroxysmal positional vertigo. The risk of nonotologic intracranial complications (1.7%) is low.

  • Long-Term Patient-Reported Outcomes After Surgery for Superior Canal Dehiscence Syndrome.
    Otology & neurotology : official publication of the American Otological Society American Neurotology Society [and] European Academy of Otology and Neu, 2017
    Co-Authors: Mohammed S. Alkhafaji, Lloyd B. Minor, Charles Coleman Della Santina, Jeffrey D. Sharon, Seth E. Pross, Sanskriti Varma, Jason C. Nellis, John P. Carey
    Abstract:

    Objective Evaluate the long-term patient-reported outcomes of surgery for Superior Canal Dehiscence syndrome (SCDS). Study design Cross-sectional survey. Setting Tertiary referral center. Patients Adults who have undergone surgery for SCDS with at least 1 year since surgery. Main outcome measure(s) Primary outcome: change in symptoms that led to surgery. Secondary outcomes change in 11 SCDS-associated symptoms, change in psychosocial metrics, and willingness to recommend surgery to friends with SCDS. Results Ninety-three (43%) respondents completed the survey with mean (SD) time since surgery of 5.3 (3.6) years. Ninety-five percent of respondents reported the symptoms that led them to have surgery were "somewhat better," "much better," or "completely cured." Those with unilateral symptoms were more likely to report improvement than those with bilateral symptoms. There was no difference between those with short (1-5 yr) versus long (5-20 yr) follow-up. Each of the SCDS-associated symptoms showed significant improvement. The largest improvements were for autophony, pulsatile tinnitus, audible bodily sounds, and sensitivity to loud sound. Headaches, imbalance, dizziness, and brain fog showed the least improvements. Most patients reported improvements in quality of life, mood, and ability to function at work and socially. Ninety-five percent of patients would recommend SCDS surgery. Conclusions Respondents demonstrated durable improvements in the symptoms that led them to have surgery. Auditory symptoms had the greatest improvements. Headaches, imbalance, dizziness, and brain fog showed the least improvements. Nearly, all patients would recommend SCDS surgery to others. These results can be used to counsel patients regarding the lasting benefits of surgery for SCDS.

  • Revision Surgery for Superior Canal Dehiscence Syndrome.
    Otology & neurotology : official publication of the American Otological Society American Neurotology Society [and] European Academy of Otology and Neu, 2016
    Co-Authors: Jeffrey D. Sharon, Bryan K. Ward, Seth E. Pross, John P. Carey
    Abstract:

    Objective:To identify factors associated with surgical failure for Superior Canal Dehiscence syndrome (SCDS) and define rates of complications and cure after revision SCDS repair.Study Design:Retrospective patient series.Setting:Tertiary care referral center.Patients:Adults who underwent revision su

Daniel J. Lee - One of the best experts on this subject based on the ideXlab platform.

  • Current Trends, Controversies, and Future Directions in the Evaluation and Management of Superior Canal Dehiscence Syndrome
    Frontiers in Neurology, 2021
    Co-Authors: Kristine Elisabeth Eberhard, Mads Klokker, Hideko Heidi Nakajima, Per Cayé-thomasen, Divya A. Chari, Daniel J. Lee
    Abstract:

    Patients with Superior Canal Dehiscence syndrome (SCDS) can present with a range of auditory and/or vestibular signs and symptoms that are associated with a bony defect of the Superior semicircular Canal (SSC). Over the past two decades, advances in diagnostic techniques have raised the awareness of SCDS and treatment approaches have been refined to improve patient outcomes. However, a number of challenges remain. First, there is currently no standardized clinical testing algorithm for quantifying the effects of Superior Canal Dehiscence (SCD). SCDS mimics a number of common otologic disorders and established metrics such as supranormal bone conduction thresholds and vestibular evoked myogenic potential (VEMP) measurements; although useful in certain cases, have diagnostic limitations. Second, while high-resolution computed tomography (CT) is the gold standard for the detection of SCD, a bony defect does not always result in signs and symptoms. Third, even when SCD repair is indicated, there is a lack of consensus about nomenclature to describe the SCD, ideal surgical approach, specific repair techniques, and type of materials used. Finally, there is no established algorithm in evaluation of SCDS patients who fail primary repair and may be candidates for revision surgery. Herein, we will discuss both contemporary and emerging diagnostic approaches for patients with SCDS and highlight challenges and controversies in the management of this unique patient cohort.

  • Bone-conduction hyperacusis induced by Superior Canal Dehiscence in human: the underlying mechanism
    Scientific Reports, 2020
    Co-Authors: Xiying Guan, John J. Rosowski, Daniel J. Lee, Y. Song Cheng, Deepa J. Galaiya, Hideko Heidi Nakajima
    Abstract:

    Our ability to hear through bone conduction (BC) has long been recognized, but the underlying mechanism is poorly understood. Why certain perturbations affect BC hearing is also unclear. An example is BC hyperacusis (hypersensitive BC hearing)—an unnerving symptom experienced by patients with Superior Canal Dehiscence (SCD). We measured BC-evoked sound pressures in scala vestibuli ( P _ SV ) and scala tympani ( P _ ST ) at the basal cochlea in cadaveric human ears, and estimated hearing by the cochlear input drive ( P _ DIFF  =  P _ SV  –  P _ ST ) before and after creating an SCD. Consistent with clinical audiograms, SCD increased BC-driven P _ DIFF below 1 kHz. However, SCD affected the individual scalae pressures in unexpected ways: SCD increased P _ SV below 1 kHz, but had little effect on P _ ST . These new findings are inconsistent with the inner-ear compression mechanism that some have used to explain BC hyperacusis. We developed a computational BC model based on the inner-ear fluid-inertia mechanism, and the simulated effects of SCD were similar to the experimental findings. This experimental-modeling study suggests that (1) inner-ear fluid inertia is an important mechanism for BC hearing, and (2) SCD facilitates the flow of sound volume velocity through the cochlear partition at low frequencies, resulting in BC hyperacusis.

  • Endoscopic-assisted surgical repair of Superior Canal Dehiscence using a keyhole middle fossa craniotomy approach
    Operative Techniques in Otolaryngology-Head and Neck Surgery, 2019
    Co-Authors: Elliott D. Kozin, Daniel J. Lee
    Abstract:

    Superior Canal Dehiscence (SCD) is a bony defect of the Superior semicircular Canal that is called SCD syndrome (SCDS) when associated with vestibular and auditory dysfunction. Surgical management of SCD is reserved for patients with intractable auditory and/or vestibular symptoms. As direct visualization of an arcuate eminence defect is most easily achieved from above, the majority of cases use a microscope-assisted middle fossa craniotomy. However, approximately 30% of SCD cases have a medial arcuate eminence defect along a downsloping tegmen. These defects can be difficult to visualize without a large cranial window, drilling down a prominent lateral skull base ridge, and/or prolonged brain retraction. In line with recent development of endoscopic ear surgery, the endoscope has been employed at our institution via a middle fossa craniotomy approach to repair a SCD. We believe that skull base endoscopy is a safe and effective way to identify and repair a medial or blue-lined SCD when used with a middle fossa craniotomy approach. The angled endoscope enhances visualization and transillumination of the SCD and reduces temporal lobe retraction. The following chapter highlights an endoscopic-assisted middle fossa craniotomy repair of SCD.

  • Superior Canal Dehiscence Surgery Outcomes Following Failed Round Window Surgery.
    Otology & neurotology : official publication of the American Otological Society American Neurotology Society [and] European Academy of Otology and Neu, 2019
    Co-Authors: Raphaelle A Chemtob, Kimberley S. Noij, Ahad A. Qureshi, Mads Klokker, Hideko Heidi Nakajima, Daniel J. Lee
    Abstract:

    Objective:Round window (RW) occlusion or reinforcement is a less-invasive option compared with direct repair approaches to improve symptoms of Superior Canal Dehiscence (SCD) syndrome. However, RW surgery is associated with variable outcomes. Middle fossa craniotomy or transmastoid repair is an opti

  • Utility of Postoperative Magnetic Resonance Imaging in Patients Who Fail Superior Canal Dehiscence Surgery
    Otology & neurotology : official publication of the American Otological Society American Neurotology Society [and] European Academy of Otology and Neu, 2019
    Co-Authors: Raphaelle A Chemtob, Hideko Heidi Nakajima, Lorenz Epprecht, Katherine L. Reinshagen, Alexander M. Huber, Per Cayé-thomasen, Daniel J. Lee
    Abstract:

    Objective:The etiology of symptoms following primary repair of Superior Canal Dehiscence (SCD) may be due to a persistent third window. However, the extent of surgery cannot be seen on postoperative computed tomography (CT) since most repair materials are not radiopaque. We hypothesize that the exte

Lloyd B. Minor - One of the best experts on this subject based on the ideXlab platform.

  • Surgical Complications from Superior Canal Dehiscence Syndrome Repair: Two Decades of Experience.
    Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery, 2017
    Co-Authors: Yanjun Xie, Lloyd B. Minor, Charles Coleman Della Santina, Jeffrey D. Sharon, Seth E. Pross, Nicholas B. Abt, Sanskriti Varma, John P. Carey
    Abstract:

    Objective To determine the incidence of surgical complications associated with Superior Canal Dehiscence syndrome (SCDS) repair and identify the demographic, medical, and intraoperative risk factors that are associated with SCDS complications. Study Design Cases series with chart review, including patients who underwent SCDS repair between 1996 and 2015. Setting A tertiary care academic medical center. Subjects and Methods Data were collected from 220 patients, including demographic information, medical comorbidities, prior otologic surgical history, surgical approach, intraoperative findings, and postoperative complications. Relative risk analysis and multivariable logistic regression evaluated the associations between perioperative risk factors and SCDS complications. Results A total of 242 consecutive cases were performed: 95.5% middle fossa and 4.5% transmastoid approach (mean age: 47.8 ± 10.6 years; 54.5% female). Surgical complications were reported in 27 (11.2%) cases; 20 (8.3%) had Clavien-Dindo grade I complications, most commonly benign paroxysmal positional vertigo (n = 11, 4.5%) and profound sensorineural hearing loss (n = 6, 2.5%). Two cases (0.8%) had grade II; 4 cases (1.7%), grade III; and 1 case (0.4%), grade IV complications. In the analysis of comorbidities, only preoperative coagulopathy was significantly associated with increased risk of complications (relative risk = 6.4, P < .01). Following multivariate logistic regression adjusting for demographic covariates, coagulopathy was still associated with increased odds of complications (odds ratio = 15.7, P = .03). There were no significant associations between other risk factors and complications. Conclusion SCDS repair has low rates of adverse events. We observed an incidence of 11.2% complications, most commonly postoperative benign paroxysmal positional vertigo. The risk of nonotologic intracranial complications (1.7%) is low.

  • Long-Term Patient-Reported Outcomes After Surgery for Superior Canal Dehiscence Syndrome.
    Otology & neurotology : official publication of the American Otological Society American Neurotology Society [and] European Academy of Otology and Neu, 2017
    Co-Authors: Mohammed S. Alkhafaji, Lloyd B. Minor, Charles Coleman Della Santina, Jeffrey D. Sharon, Seth E. Pross, Sanskriti Varma, Jason C. Nellis, John P. Carey
    Abstract:

    Objective Evaluate the long-term patient-reported outcomes of surgery for Superior Canal Dehiscence syndrome (SCDS). Study design Cross-sectional survey. Setting Tertiary referral center. Patients Adults who have undergone surgery for SCDS with at least 1 year since surgery. Main outcome measure(s) Primary outcome: change in symptoms that led to surgery. Secondary outcomes change in 11 SCDS-associated symptoms, change in psychosocial metrics, and willingness to recommend surgery to friends with SCDS. Results Ninety-three (43%) respondents completed the survey with mean (SD) time since surgery of 5.3 (3.6) years. Ninety-five percent of respondents reported the symptoms that led them to have surgery were "somewhat better," "much better," or "completely cured." Those with unilateral symptoms were more likely to report improvement than those with bilateral symptoms. There was no difference between those with short (1-5 yr) versus long (5-20 yr) follow-up. Each of the SCDS-associated symptoms showed significant improvement. The largest improvements were for autophony, pulsatile tinnitus, audible bodily sounds, and sensitivity to loud sound. Headaches, imbalance, dizziness, and brain fog showed the least improvements. Most patients reported improvements in quality of life, mood, and ability to function at work and socially. Ninety-five percent of patients would recommend SCDS surgery. Conclusions Respondents demonstrated durable improvements in the symptoms that led them to have surgery. Auditory symptoms had the greatest improvements. Headaches, imbalance, dizziness, and brain fog showed the least improvements. Nearly, all patients would recommend SCDS surgery to others. These results can be used to counsel patients regarding the lasting benefits of surgery for SCDS.

  • Improvement in autophony symptoms after Superior Canal Dehiscence repair.
    Otology & neurotology : official publication of the American Otological Society American Neurotology Society [and] European Academy of Otology and Neu, 2010
    Co-Authors: Benjamin T. Crane, Lloyd B. Minor, Frank R. Lin, John P. Carey
    Abstract:

    Objective:Autophony, or the unusually loud or disturbing sound of a patient's own voice, can be a prominent and disabling symptom of Superior Canal Dehiscence (SCD) syndrome. The current study measures autophony symptoms before and after SCD plugging to quantify the benefits of surgery.Study Design:

  • Superior Canal Dehiscence plugging reduces dizziness handicap
    Laryngoscope, 2008
    Co-Authors: Benjamin T. Crane, Lloyd B. Minor, John P. Carey
    Abstract:

    Objectives/Hypothesis: To compare dizziness handicap inventory (DHI) scores before and after surgery for plugging of Superior Canal Dehiscence (SCD). The size of the Dehiscence as measured during surgery, subject age, vestibular-evoked myogenic potentials threshold, and degree of conductive hearing loss (CHL) were also considered. Study Design: Retrospective. Methods: Nineteen adults with SCD who underwent surgery to plug the SCD via middle fossa approach were studied. Pre- and postoperative DHI scores were compared, and correlations between DHI scores and other clinical measures were assessed. Results: Average preoperative DHI score was 44 ± 24 (mean ± SD). Postoperative DHI score was significantly lower at 18 ± 15 (P < .01). Only two subjects had a higher DHI score after surgery. Subjects who had a preoperative DHI score below 30 did not have any significant change in their DHI score after surgery, whereas those with a preoperative DHI score ≥30 had an improvement by an average of 39 ± 16 after surgery. There were no correlations between either preoperative DHI score or the change in DHI score after surgery and HL, age, vestibular-evoked myogenic potentials threshold, or Dehiscence size. Conclusions: DHI scores significantly decreased after SCD plugging. Subjects who had the largest decrease in DHI scores were those with high preoperative DHI scores. Subjects who chose to undergo SCD plugging because of nonvestibular symptoms such as conductive HL, tinnitus, or autophony generally had lower preoperative DHI scores and did not experience large improvements in DHI scores. The SCD plugging procedure offers an improvement in DHI score that is comparable with that of other procedures for peripheral vestibular dysfunction.

  • vestibular evoked myogenic potential thresholds normalize on plugging Superior Canal Dehiscence
    Neurology, 2008
    Co-Authors: Miriam S Welgampola, Lloyd B. Minor, Oluwaseun A Myrie, John P. Carey
    Abstract:

    Background: Diagnosis of the Superior Canal Dehiscence syndrome (SCDS) relies on symptoms such as sound- or pressure-induced vertigo or oscillopsia, demonstration of sound or pressure-evoked vertical/torsional eye movements, and the presence of a defect in the bony roof overlying the Superior semicircular Canal. Lowered thresholds for eliciting vestibular-evoked myogenic potentials (VEMPs) provide additional conformation. Objective: To examine VEMP characteristics before and after Canal plugging for SCDS. Methods: VEMPs evoked by air- and bone-conducted tones were measured from the sternocleidomastoid muscles (cVEMP) and periocular sites (oVEMP) of 20 normal volunteers, 10 newly diagnosed subjects with SCDS, and 12 subjects who underwent successful Superior Canal plugging. Results: In all SCDS ears, thresholds for evoking VEMP using air-conducted tones were pathologically lowered, with average values of 83.85 ± 1.40 dB sound pressure level (SPL) for cVEMP and 85.38 ± 1.32 dB SPL for oVEMP, 20 to 30 dB below those of controls. Successful Canal plugging resulted in normal reflex thresholds. For bone vibration, average thresholds in SCDS ears were 114.62 ± 1.54 dB FL (force level) for cVEMP and 116.0 ± 1.52 dB FL for oVEMP, 10 to 20 dB below controls, yet three SCDS ears had normal thresholds. Conclusions: Ocular and cervical vestibular-evoked myogenic potentials evoked by air-conducted sound are equally useful in the diagnosis and follow-up of Superior Canal Dehiscence syndrome. Stimulus thresholds are consistently lowered upon presentation and normalize after corrective surgery. Thresholds for bone vibration, in contrast, have a lower diagnostic yield.

James G. Colebatch - One of the best experts on this subject based on the ideXlab platform.

  • Properties of 500Hz air- and bone-conducted vestibular evoked myogenic potentials (VEMPs) in Superior Canal Dehiscence.
    Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, 2016
    Co-Authors: Sendhil Govender, Miriam S Welgampola, Tavish Fernando, Danielle L. Dennis, James G. Colebatch
    Abstract:

    Abstract Objectives To compare threshold and amplitude properties for air- (AC) and mastoid bone-conducted (BC) cervical (cVEMP) and ocular (oVEMP) vestibular evoked myogenic potentials in Superior Canal Dehiscence (SCD). Methods Thirteen patients (53±14yrs) clinically diagnosed with SCD were tested using AC 500Hz sound and BC 500Hz transmastoid vibration. Baseline intensities of 135dBpSPL and 138dBpFL respectively were used and reduced until the response amplitudes were less than 2.5 standard deviations of the prestimulus baseline mean. SCD VEMP amplitudes, response gradients and threshold parameters for the initial peaks for the cVEMP (ipsilateral) and the oVEMP (contralateral) were compared with results for normal subjects over a range of intensities. Results Despite higher amplitudes, reflex gradients against intensity for AC and BC cVEMPs were significantly less in SCD than normals ( P ≪0.001) while AC and BC oVEMP gradients were not significantly different between the groups. Abnormally low thresholds for AC 500Hz were present for 85% of cVEMPs and 62% of oVEMPs. Abnormally low BC 500Hz thresholds were seen for 33% of cVEMPs and 83% of oVEMPs. Amplitudes for AC 500Hz were compared over the 135–105dBpSPL intensity range. The cVEMP showed more pathologically large amplitude responses with the lower stimulus intensities (135dBpSPL: 5%, 105dBpSPL: 100%) whereas the oVEMP demonstrated high rates of amplitude increases for all intensities (129–111dBpSPL: 92%). The pattern of pathologically large amplitudes evoked by BC 500Hz was similar for both reflexes such that both cVEMPs and oVEMPs showed maximum prevalence of abnormally large responses around 117dBpFL (cVEMP: 58%, oVEMP: 83%). Conclusions In SCD, both AC and BC evoked cVEMPs show evidence of saturation but this is not evident for oVEMPs. Both cVEMPs and oVEMPs show frequent abnormalities of amplitudes and thresholds in SCD compared to normal subjects but the sensitivities differed between measures. Significance Previous evidence of saturation of cVEMP responses in SCD was confirmed. For diagnosis, AC cVEMP amplitudes at 105dBpSPL or AC-evoked oVEMP amplitudes both have over 90% sensitivity in separating SCD from normal responses.

  • Tuning of the ocular vestibular evoked myogenic potential (oVEMP) to air- and bone-conducted sound stimulation in Superior Canal Dehiscence
    Experimental Brain Research, 2012
    Co-Authors: Alexander S. Zhang, Sendhil Govender, James G. Colebatch
    Abstract:

    Recent studies have demonstrated the frequency selectivity of air-conducted (AC) and bone-conducted (BC) stimuli in eliciting ocular vestibular evoked myogenic potentials (oVEMPs). In this study, frequency tuning of the oVEMP was assessed in patients with Superior Canal Dehiscence (SCD) and compared with responses previously reported for healthy subjects. Six (five unilateral) SCD patients were stimulated using AC sound (50–1,200 Hz) and BC transmastoid vibration (50–1,000 Hz). Stimuli were delivered at two standardized intensities: one the same as previously used for healthy controls and the other at 10 dB above vestibular threshold (a similar relative intensity to that used in controls). For AC stimulation, SCD patients had larger oVEMP amplitudes across all frequencies tested for both stimulus intensities. Normalized tuning curves demonstrated greater high-frequency responses with the stronger stimulus. For BC stimulation, larger oVEMP amplitudes were produced at frequencies at and above 100 Hz using standard intensity stimuli. For the matched intensity above vestibular threshold, enhancement of the oVEMP response was present in SCD patients for 500–800 Hz only. We conclude that SCD causes greater facilitation for AC than BC stimuli. The high-frequency response is likely to originate from the Superior (anterior) Canal and is consistent with models of inner ear changes occurring in SCD.

  • Superior Canal Dehiscence causes abnormal vestibular bone-conducted tuning.
    Neurology, 2011
    Co-Authors: Alexander S. Zhang, Sendhil Govender, James G. Colebatch
    Abstract:

    The sensitivity of patients with Superior Canal Dehiscence (SCD) to air-conducted (AC) sound is a widely documented phenomenon. Dehiscence of the Superior semicircular Canal is thought to change the dynamics of the endolymphatic channels of the membranous labyrinth, causing oscillopsia, vertigo, and disequilibrium when AC sound stimulates the ear.1 AC sound is now widely used for diagnosis of SCD through cervical vestibular evoked myogenic potential (cVEMP) testing2 and, more recently, ocular vestibular evoked myogenic potential (oVEMP) testing.3,4 Mechanical bone-conducted (BC) vibration has also been shown to elicit abnormal cVEMPs and oVEMPs in SCD. However, not all patients show a low threshold,3 and the relationship to the clinical symptomatology of SCD is less clear. Tuning of vestibular-evoked responses to BC stimulation has been demonstrated in normal subjects and is proposed to arise from resonance properties of the vestibular end organs.5 In this study, the frequency tuning of BC oVEMPs was examined to explore whether SCD affects this fundamental property. ### Case report. A 39-year-old man developed oscillopsia and disequilibrium triggered by loud sounds and the Valsalva maneuver approximately 5 months before presentation. He also reported mild oscillopsia and disequilibrium associated with vigorous movement such as running and riding in elevators as well as …

  • Vestibular hypersensitivity to sound in Superior Canal Dehiscence: Large evoked responses in the legs produce little postural sway
    Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, 2008
    Co-Authors: Sally M. Rosengren, Gabor Michael Halmagyi, James G. Colebatch
    Abstract:

    Abstract Objective Patients with Superior Canal Dehiscence (SCD) typically have enhanced sound-evoked vestibular reflexes, such as vestibulo-collic and vestibulo-ocular reflexes. We wished to investigate whether sound-evoked lower limb EMG responses and postural sway are also enhanced in this condition. Methods Eight patients with CT confirmed SCD (11 affected ears) and 8 age-matched normal controls participated. Three sound-evoked responses were measured; vestibulo-collic reflexes (i.e. vestibular-evoked myogenic potentials, VEMPs), lower limb vestibulo-spinal reflexes and body sway (centre of pressure in mm). Sound stimuli were 500 Hz air-conducted tone bursts of varying lengths (VEMPs: 2 ms; vestibulo-spinal: 20 ms; sway: 1 s and 200 ms) set at fixed levels above each subject’s VEMP threshold. Results SCD patients had very large VEMP and vestibulo-spinal responses following high intensity stimulation, but at the matched intensity of 15 dB above threshold amplitudes were similar in both SCD patients and controls. The amplitude of both responses increased linearly with increasing stimulus intensity in both groups. Large (∼20 mm), stereotyped sway responses were present in only one (atypical) patient with high intensity stimulation. Small (∼2 mm) sway responses were present in the remaining patients, and began immediately following the vestibulo-spinal responses. Conclusions Despite the presence of large vestibular reflexes, there is usually very little body sway in response to loud sounds in SCD patients. Significance Large short-latency vestibulo-spinal reflexes in SCD do not necessarily evoke large sway responses.

  • Ocular vestibular evoked myogenic potentials in Superior Canal Dehiscence.
    Journal of neurology neurosurgery and psychiatry, 2007
    Co-Authors: Sally M. Rosengren, G.m. Halmagyi, N. P Mcangus Todd, James G. Colebatch
    Abstract:

    Objective: Patients with Superior Canal Dehiscence (SCD) have large sound-evoked vestibular reflexes with pathologically low threshold. We wished to determine whether a recently discovered measure of the vestibulo-ocular reflex—the ocular vestibular evoked myogenic potential (OVEMP)—produced similar high-amplitude, low-threshold responses in SCD, and could differentiate patients with SCD from normal control patients. Methods: Nine patients with CT-confirmed SCD and 10 normal controls were stimulated with 500 Hz, 2 ms tone bursts and 0.1 ms clicks at intensities up to 142 dB peak SPL. Conventional VEMPs were recorded from the ipsilateral sternocleidomastoid muscle to determine threshold, and OVEMPs were recorded from electrode pairs placed Superior and inferior to the eyes. Three-dimensional eye movements were measured with scleral dual-search coils. Results: In patients with SCD, OVEMP amplitudes were significantly larger than normal (p Conclusions: OVEMP amplitude and threshold (particularly the contralateral inferior n10 response) differentiated patients with SCD from normal controls. Our findings suggest that both the OVEMPs and induced eye movements in SCD are a result of intense saccular activation in addition to Superior Canal stimulation.

Elliott D. Kozin - One of the best experts on this subject based on the ideXlab platform.

  • Endoscopic-assisted surgical repair of Superior Canal Dehiscence using a keyhole middle fossa craniotomy approach
    Operative Techniques in Otolaryngology-Head and Neck Surgery, 2019
    Co-Authors: Elliott D. Kozin, Daniel J. Lee
    Abstract:

    Superior Canal Dehiscence (SCD) is a bony defect of the Superior semicircular Canal that is called SCD syndrome (SCDS) when associated with vestibular and auditory dysfunction. Surgical management of SCD is reserved for patients with intractable auditory and/or vestibular symptoms. As direct visualization of an arcuate eminence defect is most easily achieved from above, the majority of cases use a microscope-assisted middle fossa craniotomy. However, approximately 30% of SCD cases have a medial arcuate eminence defect along a downsloping tegmen. These defects can be difficult to visualize without a large cranial window, drilling down a prominent lateral skull base ridge, and/or prolonged brain retraction. In line with recent development of endoscopic ear surgery, the endoscope has been employed at our institution via a middle fossa craniotomy approach to repair a SCD. We believe that skull base endoscopy is a safe and effective way to identify and repair a medial or blue-lined SCD when used with a middle fossa craniotomy approach. The angled endoscope enhances visualization and transillumination of the SCD and reduces temporal lobe retraction. The following chapter highlights an endoscopic-assisted middle fossa craniotomy repair of SCD.

  • Transmastoid approach for surgical repair of Superior Canal Dehiscence syndrome
    Operative Techniques in Otolaryngology-Head and Neck Surgery, 2019
    Co-Authors: Raphaelle A Chemtob, Samuel R. Barber, Angela W. Zhu, Elliott D. Kozin, Daniel J. Lee
    Abstract:

    Patients with Superior Canal Dehiscence syndrome may present with a myriad of auditory and/or vestibular complaints. Treatment of Superior Canal Dehiscence syndrome depends on severity of symptoms and impact on quality of life. Surgery is recommended for patients with debilitating auditory and/or vestibular symptoms. The goal of surgery is to create a durable and watertight seal of the bony Superior semicircular Canal defect, thereby eliminating the “third window”. Repair involves either resurfacing and/or plugging of the dehiscent Superior Canal to eliminate the third window and reduce symptoms. Surgical options include middle fossa craniotomy or transmastoid (TM) approach. The main advantages of a TM approach includes (1) avoidance of a craniotomy, (2) lower risk of CSF leak, and (3) no brain retraction. The TM approach is ideal for Superior petrosal sinus Superior Canal Dehiscence cases as the defect is found medial along the skull base and can be isolated indirectly without direct manipulation of the brain and sinus. This chapter discusses the surgical technique of TM approach.

  • Toward Optimizing Cervical Vestibular Evoked Myogenic Potentials (cVEMP): Combining Air-Bone Gap and cVEMP Thresholds to Improve Diagnosis of Superior Canal Dehiscence.
    Otology & neurotology : official publication of the American Otological Society American Neurotology Society [and] European Academy of Otology and Neu, 2018
    Co-Authors: Kimberley S. Noij, Hugh D. Curtin, Barbara S. Herrmann, Y. Song Cheng, Maria J. Duarte, Kevin Wong, Salwa Masud, Vivek V. Kanumuri, John J. Guinan, Elliott D. Kozin
    Abstract:

    Objective To develop a novel approach combining low-frequency air-bone gap (ABG) and cervical vestibular evoked myogenic potential (cVEMP) thresholds to improve screening for Superior Canal Dehiscence (SCD) syndrome. Study design Retrospective study. Setting Tertiary care center. Patients One hundred forty patients with SCD and 21 healthy age-matched controls were included. Ears for each patient were divided into three groups based on computed tomography (CT) findings: 1) dehiscent, 2) thin, or 3) unaffected. Main outcome measures cVEMP and audiometric thresholds were analyzed and differences among groups were evaluated. Results We define the third window indicator (TWI) as the cVEMP thresholds at 500, 750, and 1000 Hz adjusted for the ABG at 250 Hz (i.e., subtracting ABG from cVEMP threshold). The TWI differentiates between dehiscent and nondehiscent control ears with a sensitivity of 82% and specificity of 100%, corresponding to a positive predictive value of 100%. ABGs and cVEMP thresholds were similar for healthy controls and patients with thin bone over the Superior Canal. Conclusion This is the largest study to date examining the usefulness of cVEMPs in the diagnosis of SCD. Our "third window indicator" (TWI) combines cVEMP thresholds with the ABG at 250 Hz to improve the ability to screen patients with SCD symptoms.

  • Minimally invasive middle fossa craniotomy approach with endoscopic repair of Superior Canal Dehiscence
    Operative Techniques in Otolaryngology-Head and Neck Surgery, 2017
    Co-Authors: Elliott D. Kozin, Daniel J. Lee
    Abstract:

    Superior Canal Dehiscence (SCD) is a bony defect of the Superior semicircular Canal. SCD syndrome occurs when vestibular or auditory dysfunction accompanies SCD. Although not all patients with SCD are symptomatic, surgical repair is an option in patients with incapacitating symptoms and are unresponsive to conservative treatment. Traditionally, repair of SCD when involving the arcuate eminence can be achieved using a middle fossa craniotomy approach. However, approximately 30% of SCD cases have a medial arcuate eminence defect along a downsloping tegmen, making the defect difficult to visualize with the binocular microscope without a large craniotomy, extensive temporal lobe retraction, and drilling of the skull base. As complete visualization of an arcuate eminence defect is essential for successful repair, we describe an operative approach to visualize the SCD that combines a small middle fossa craniotomy and rigid endoscopy. The wide-field view and Superior transillumination with skull base endoscopy can be achieved with a minimal access skin incision, small bony window, less dural dissection, and reduced brain retraction, resulting in unequivocal identification of the entire arcuate eminence defect.

  • benign paroxysmal positional vertigo commonly occurs following repair of Superior Canal Dehiscence
    Laryngoscope, 2016
    Co-Authors: Samuel R. Barber, Elliott D. Kozin, Yew Song Cheng, Maryanna Owoc, Aaron K. Remenschneider
    Abstract:

    Objectives/Hypothesis Repair of Superior Canal Dehiscence (SCD) often results in the resolution of preoperative auditory and vestibular symptoms; however, many patients experience dizziness in the postoperative period. Postoperative dizziness may be the result of new-onset benign paroxysmal positional vertigo (BPPV). This study aims to investigate the prevalence of BPPV before and following SCD repair. Study Design Retrospective chart review at a tertiary care center. Methods Electronic medical records were reviewed for patients with a diagnosis of SCD syndrome (SCDS) between January 2002 and May 2015. Collected information included demographic data, incidence of BPPV diagnosed by Dix-Hallpike maneuver before and following surgery, operative technique, repair material, and the duration of time to BPPV onset. Results A total of 180 patients with a diagnosis of SCDS were identified: 84 patients underwent surgery (operated subjects) and 96 were observed (nonoperated, control group). In operated subjects, 20 of 84 (23.8%) developed BPPV following SCD repair versus 6.2% of nonoperated (P < 0.005). Benign paroxysmal positional vertigo lateralized to the operated side in all but one subject whose laterality was unknown (P < 0.0001). There were no associations of BPPV with surgical approach (P = 0.50) or repair material (P = 0.33). The majority of subjects (58%) were diagnosed with BPPV within 3 months of surgery. Conclusion New-onset BPPV occurs commonly after SCD repair and may be the result of mobilized otoliths from inner ear pressure changes. Although the exact etiology of post-SCD repair BPPV remains unknown, postoperative dizziness is important to discuss with patients during preoperative counseling. Level of Evidence 4. Laryngoscope, 2015