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Mekonnen M, Lum M, Duong C, Rana S, Mozaffari K, Hovis GEA, Yang I. Superior semicircular canal dehiscence postoperative outcomes: a case series of 350 repairs. Acta Neurochir (Wien) 2024; 166:230. [PMID: 38789840 PMCID: PMC11126457 DOI: 10.1007/s00701-024-06115-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 05/05/2024] [Indexed: 05/26/2024]
Abstract
BACKGROUND Superior Semicircular Canal Dehiscence (SSCD) is a dehiscence of the otic capsule which normally lies over the superior semicircular canal. This database constitutes the largest series of SSCD patients to date. OBJECTIVE To determine what preoperative factors, if any, contribute to postoperative outcomes and evaluate symptom resolution in a large SSCD patient cohort. METHODS A single-institution, retrospective chart review collected patient demographics, intraoperative findings, and pre-and postoperative symptoms. Fisher's exact t-test was performed for unpaired categorical variables, with a significance level of p < 0.05. RESULTS 350 SSCD repairs were performed. The median age was 52 years (range: 17-86 years, ± 6.4 years), and the median follow-up duration was 4.6 months (range: 0.03-59.5 months, ± 6.8 months). Preoperative hearing loss was significantly associated with female sex (p = 0.0028). The most reported preoperative symptoms were tinnitus (77.4%), dizziness (74.0%), autophony (66.3%), amplification (63.7%), and disequilibrium (62.6%). Between patients who received unilateral versus bilateral SSCD repair, the greatest postoperative symptomatic resolution was seen in autophony (74.9%, p < 0.001), amplification (77.3%, p = 0.00027), hyperacusis (77.4%, p = 0.023), hearing (62.9%, p = 0.0063), and dizziness (54.6%, p < 0.001) for patients with unilateral SSCD repair. CONCLUSION Surgical repair via the middle cranial fossa approach can significantly resolve auditory, vestibular, and neurological symptoms of patients with SSCD. Although this is one of the largest single-institution SSCD studies to date, future multi-institutional, prospective studies would be beneficial to validate these results.
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Affiliation(s)
- Mahlet Mekonnen
- Department of Neurosurgery, University of California, Los Angeles, 300 Stein Plaza, Suite 562, Los Angeles, CA, 90095-1761, USA
| | - Meachelle Lum
- Department of Neurosurgery, University of California, Los Angeles, 300 Stein Plaza, Suite 562, Los Angeles, CA, 90095-1761, USA
| | - Courtney Duong
- Department of Neurosurgery, University of California, Los Angeles, 300 Stein Plaza, Suite 562, Los Angeles, CA, 90095-1761, USA
| | - Shivam Rana
- Department of Neurosurgery, University of California, Los Angeles, 300 Stein Plaza, Suite 562, Los Angeles, CA, 90095-1761, USA
| | - Khashayar Mozaffari
- Department of Neurosurgery, University of California, Los Angeles, 300 Stein Plaza, Suite 562, Los Angeles, CA, 90095-1761, USA
| | - Gabrielle E A Hovis
- Department of Neurosurgery, University of California, Los Angeles, 300 Stein Plaza, Suite 562, Los Angeles, CA, 90095-1761, USA
| | - Isaac Yang
- Department of Neurosurgery, University of California, Los Angeles, 300 Stein Plaza, Suite 562, Los Angeles, CA, 90095-1761, USA.
- Radiation Oncology, Los Angeles (UCLA), Los Angeles, CA, USA.
- Head and Neck Surgery, Los Angeles (UCLA), Los Angeles, CA, USA.
- Jonsson Comprehensive Cancer Center, Los Angeles (UCLA), Los Angeles, CA, USA.
- Los Angeles Biomedical Research Institute, Los Angeles (UCLA), Los Angeles, CA, USA.
- Harbor-UCLA Medical Center, Los Angeles (UCLA), Los Angeles, CA, USA.
- David Geffen School of Medicine, Los Angeles (UCLA), Los Angeles, CA, USA.
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Yang HH, Yang I, Gopen QS. Narrowing of Low-Frequency Air-Bone Gap and Its Association with Symptom Resolution Following Superior Canal Dehiscence Repair. Otolaryngol Head Neck Surg 2024; 170:1133-1139. [PMID: 38149698 DOI: 10.1002/ohn.588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/19/2023] [Accepted: 10/28/2023] [Indexed: 12/28/2023]
Abstract
OBJECTIVE Low-frequency air-bone gap (LABG) on pure tone audiometry is an expected clinical finding of superior canal dehiscence (SCD) syndrome. We investigate how narrowing of LABG following SCD repairs translates to symptom resolution. STUDY DESIGN Cohort study. SETTING Tertiary Care Center. METHODS We analyzed consecutive SCD repairs at an institution between 2012 and 2022. Pure tone audiometry and symptom questionnaires were administered pre- and post-operatively. The independent variable assessed whether the LABG narrowed (≥5 dB) following surgery. Outcome measures were rates of Overall Symptom Improvement (OSI, net resolution of ≥1 symptom) and Symptom Resolution Score (SRS, % symptoms resolved). We conducted multivariable regression analyses with LABG narrowing as the primary predictor. All models controlled for demographics, bilateral disease, prior ear surgery, and follow-up. RESULTS Among total of 217 repairs analyzed, 161 (74%) reached OSI, and mean SRS was 39 (out of 100). LABG narrowing at 250 Hz (65%), 500 Hz (52%), and 1000 Hz (47%) was associated with a 41-point (β 95% confidence interval [CI] 5-77) increase in auditory, 15-point (β 95% CI 1-30) increase in auditory, and 23-point (β 95% CI 2-45) increase in vestibular SRS, respectively. However, LABG narrowing was not significantly associated with the rates of auditory and vestibular OSI at all frequencies assessed. CONCLUSION Lack of LABG narrowing following repair was associated with the persistence of a greater proportion of preoperative symptoms but similar likelihood of OSI. This relationship was more prominent for auditory symptoms at 250 to 500 Hz and for vestibular symptoms at 1000 Hz. Additional research is warranted to elucidate the mechanism through which symptoms resolve despite LABG persistence.
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Affiliation(s)
- Hong-Ho Yang
- Department of Head and Neck Surgery, David Geffen School of Medicine at University of California, Los Angeles, California, USA
| | - Isaac Yang
- Department of Neurosurgery, David Geffen School of Medicine at University of California, Los Angeles, California, USA
| | - Quinton S Gopen
- Department of Head and Neck Surgery, David Geffen School of Medicine at University of California, Los Angeles, California, USA
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Yang HH, Yang I, Gopen QS. First-Side and Second-Side Repair of Bilateral Superior Canal Dehiscence. Laryngoscope 2024; 134:1882-1888. [PMID: 37937741 DOI: 10.1002/lary.31118] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 08/16/2023] [Accepted: 10/04/2023] [Indexed: 11/09/2023]
Abstract
OBJECTIVE Bilateral superior canal dehiscence (SCD) may warrant surgeries on both sides. With repairs of unilateral SCD as reference, we investigate the comparative effectiveness of first-side and second-side repairs, in hopes of establishing knowledge that can guide clinical decision-making pertaining the appropriateness of second-side surgeries. METHODS Middle fossa SCD repairs at an institution between 2011 and 2022 were analyzed. Multivariable regression models assessed symptom resolution and audiometric improvement with surgery cohort (unilateral SCD repair vs. first-side repair vs. second-side repair) as the primary predictor. All models controlled for patient age, sex, surgery duration, prior ear surgery, and follow-up. RESULTS A total of 407 repairs (180 unilateral SCD, 172 first-side, and 55 second-side repairs) were analyzed. The rates of overall symptom improvement for auditory and vestibular symptoms were as follows: 81% and 67% for unilateral SCD repairs; 73% and 54% for first-side repairs; and 43% and 51% for second-side repairs, respectively. Compared with first-side repairs, which resolved auditory symptoms at similar rates (aOR 95% C.I. 0.36-1.07) but resolved vestibular symptoms at significantly lower rates (aOR 95% C.I. 0.35-0.93) compared with unilateral SCD repairs, second-side repairs resolved auditory symptoms at significantly lower rates (aOR 95% C.I. 0.10-0.51) but resolved vestibular symptoms at similar rates (aOR 95% C.I. 0.45-2.01). CONCLUSIONS Careful consideration of perioperative symptomatology may inform the appropriateness of second-side surgeries. If auditory symptoms persisted following first-side surgeries, second-side surgeries are less likely to yield resolution. If vestibular symptoms persisted following first-side repairs, second-side repairs may lead to resolution at similar rates as first-side repairs. LEVEL OF EVIDENCE 3 Laryngoscope, 134:1882-1888, 2024.
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Affiliation(s)
- Hong-Ho Yang
- Department of Head and Neck Surgery, David Geffen School of Medicine at University of California, Los Angeles, California, USA
| | - Isaac Yang
- Department of Neurosurgery, David Geffen School of Medicine at University of California, Los Angeles, California, USA
| | - Quinton S Gopen
- Department of Head and Neck Surgery, David Geffen School of Medicine at University of California, Los Angeles, California, USA
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Benchetrit L, Shave S, Garcia A, Chung JJ, Suresh K, Lee DJ. Predictors of non-primary auditory and vestibular symptom persistence following surgical repair of superior canal dehiscence syndrome. Front Neurol 2024; 15:1336627. [PMID: 38469592 PMCID: PMC10925929 DOI: 10.3389/fneur.2024.1336627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 02/06/2024] [Indexed: 03/13/2024] Open
Abstract
Objective Patients with superior canal dehiscence syndrome (SCDS) can present with a plethora of auditory and/or vestibular symptoms associated with a bony defect of the superior semicircular canal. While surgical repair is a reasonable option for patients with significant localizing symptoms, the degree of clinical improvement will vary among patients and poses challenges in outcome prediction. This study aims to assess the relationship between preoperative and postoperative symptoms and identify predictors of symptom persistence following repair. Study design Retrospective chart review. Setting Tertiary neurotology single-institution care center. Main outcome measures The primary outcome was to determine the proportion of resolved and persistent primary (most bothersome) and non-primary audiologic and vestibular symptoms following SCD repair. Secondary outcomes included comparison of patient, operative and radiologic characteristics between patients with resolved vs. persistent symptoms. Standardized patient questionnaires including 11 auditory and 8 vestibular symptoms were administered to patients at their preoperative and follow-up visits. Patient pre- vs. postoperative survey results, demographic and clinical characteristics, operative characteristics, audiometric data and cervical vestibular evoked myogenic potential (cVEMP) thresholds were compared via univariate χ2 and multivariate binary logistic regression analyses between those patients reporting full postoperative resolution of symptoms and persistence of one or more symptoms. Radiologic computed tomography (CT) measurements of superior canal dehiscence (SCD) defect size, location, and laterality were also compared between these two groups. Results Of 126 patients (132 ears) included in our study, 119 patients (90.2%) reported postoperative resolution (n = 82, 62.1%) or improvement (n = 37, 28.0%) of primary (most bothersome) symptoms, while 13 patients (9.8%) reported persistence of primary symptoms. The median (interquartile range) and range between surgery and questionnaire completion were 9 (4-28), 1-124 months, respectively. Analyzing all symptoms (primary and non-primary) 69 (52.3%) and 68 (51.1%) patients reported complete postoperative auditory and vestibular symptom resolution, respectively. The most likely persistent symptoms included imbalance (33/65/67, 50.8%), positional dizziness (7/20, 35.0%) and oscillopsia (44/15, 26.7%). Factors associated with persistent auditory symptoms included history of seizures (0% vs. 7.6%, p = 0.023), auditory chief complaint (50.0% vs. 70.5%), higher PTA (mean 19.6 vs. 25.1 dB, p = 0.043) and higher cervical vestibular evoked myogenic potential (cVEMP) thresholds at 1000 Hz (mean 66.5 vs. 71.4, p = 0.033). A migraine diagnosis (14.0% vs. 41.9% p < 0.010), bilateral radiologic SCD (17.5% vs. 38.1%, p = 0.034) and revision cases (0.0% vs. 14.0%, p = 0.002) were associated with persistent vestibular symptoms. Neither SCD defect size nor location were significantly associated with symptom persistence (P > 0.05). Conclusions Surgical repair for SCDS offers meaningful reduction in the majority of auditory and vestibular symptoms. However, the persistence of certain, mostly non-primary, symptoms and the identification of potential associated factors including migraines, PTA thresholds, cVEMP threshold, bilateral SCD, and revision cases emphasize the importance of individualized patient counseling and management strategies.
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Affiliation(s)
- Liliya Benchetrit
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
- Department of Otolaryngology-Head, and Neck Surgery, Boston University, Boston, MA, United States
| | - Samantha Shave
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
- Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States
| | - Alejandro Garcia
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
- Department of Otolaryngology-Head, and Neck Surgery, University of Iowa, Iowa City, IA, United States
| | - Janice J Chung
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
| | - Krish Suresh
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
| | - Daniel J Lee
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
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Suresh K, Garcia A, Bartholomew RA, Song Y, Lee DJ. Auditory and Vestibular Symptom Improvement With Surgery for Superior Canal Dehiscence Syndrome. Otolaryngol Head Neck Surg 2023; 169:1005-1011. [PMID: 37125629 DOI: 10.1002/ohn.359] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/02/2023] [Accepted: 04/15/2023] [Indexed: 05/02/2023]
Abstract
OBJECTIVE (1) To measure the change in auditory and vestibular symptoms following superior canal dehiscence (SCD) surgery, and (2) to determine differences in clinical features and surgical outcomes between superior canal dehiscence syndrome (SCDS) patients with primarily auditory or vestibular complaints. STUDY DESIGN Retrospective cohort study. SETTING Single surgeon series at the tertiary academic medical center from 2002 to 2021. METHODS Retrospective review of SCDS patients who underwent surgical repair. (1) Patients were administered a standardized symptom questionnaire at preoperative and follow-up visits, and results were compared with paired statistical testing. (2) Patients were divided into 2 cohorts based on either auditory or vestibular chief complaint and differences in demographic, clinical, and outcome variables were examined. RESULTS Our study included 113 patients with 118 operated ears. Twenty-seven patients (24%) had radiographic bilateral dehiscence. 10/11 auditory symptoms (91%) and 5/8 vestibular symptoms (63%) solicited on the questionnaire improved significantly with surgery, except for nonpulsatile tinnitus, sense of imbalance, positional dizziness, and oscillopsia. Analyses stratified by chief complaint (auditory vs vestibular) revealed overall similar characteristics and surgical outcomes. Patients with chief vestibular complaints underwent surgery at an earlier age (45.5 vs 53.9 years, p < 0.05). CONCLUSION SCD surgery alleviates a wide range of auditory and vestibular symptoms. Overall, we did not find significant differences between patients with chief auditory versus vestibular complaints, and both groups benefited from surgery. Symptoms are not directly linked to third-window physiology and certain vestibular symptoms may be more likely to persist. Bilateral dehiscence may play an important role in persistent symptoms as well.
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Affiliation(s)
- Krish Suresh
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Alejandro Garcia
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Ryan A Bartholomew
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Yohan Song
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Daniel J Lee
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA
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Yang HH, Patel VS, Yang I, Gopen QS. Computed tomography approximated superior semicircular canal dehiscence size and location and their association with clinical presentation. J Clin Neurosci 2023; 112:30-37. [PMID: 37037168 DOI: 10.1016/j.jocn.2023.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/31/2023] [Accepted: 04/03/2023] [Indexed: 04/12/2023]
Abstract
OBJECTIVE This study investigates the relationship of superior semicircular canal dehiscence (SSCD) size and location with patient symptomatology and audiometry. METHODS We retrospectively reviewed SSCD cases presented to a tertiary institution between 2011 and 2022. Dehiscence length and width measured on high-resolution temporal bone computed tomography imaging were used to calculate an approximate dehiscence area (ADA). Dehiscence location was classified employing a six-grade system. Multivariable regression analyses were performed with symptomatology and audiogram metrics as outcome variables and ADA and dehiscence location as the primary covariates of interest. RESULTS A total of 402 SSCD were included in the analysis. Controlling for patient age, sex, dehiscence laterality, and location, greater ADA was independently associated higher rates of autophony (aOR 1.39; 95% C.I. 1.14-1.71; P = 0.004) and hyper-amplification (aOR 1.39; 1.14-1.70; P = 0.004). Additionally, dehiscences with greater ADA exhibited significantly lower bone conduction threshold at 500 Hz (adjusted β -1.75, P = 0.006) and 1000 Hz (adjusted β -1.61, P = 0.018) and significantly wider air-bone gap at 500 Hz (adjusted β 2.22, P < 0.001) and 1000 Hz (adjusted β 1.00, P = 0.039). Dehiscence location was not independently associated with any outcome variable examined when accounting for dehiscence size. CONCLUSION The size of dehiscence is more independently related to clinical presentations than the anatomical location of the dehiscence in the superior semicircular canal. Greater dehiscence size is associated with symptomatology and audiometry consistent with more severe bone conduction hyperacusis.
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Affiliation(s)
- Hong-Ho Yang
- Department of Head and Neck Surgery, David Geffen School of Medicine at University of California, Los Angeles, USA.
| | - Vishal S Patel
- Department of Head and Neck Surgery, David Geffen School of Medicine at University of California, Los Angeles, USA
| | - Isaac Yang
- Department of Neurosurgery, David Geffen School of Medicine at University of California, Los Angeles, USA
| | - Quinton S Gopen
- Department of Head and Neck Surgery, David Geffen School of Medicine at University of California, Los Angeles, USA
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Yang HH, Lum M, Kaur T, Yang I, Gopen QS. Postoperative Pneumolabyrinth Following the Middle Cranial Fossa Approach for Superior Semicircular Canal Dehiscence Repair, 2014-2020. Otolaryngol Head Neck Surg 2023; 168:453-461. [PMID: 35727631 DOI: 10.1177/01945998221106688] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 05/25/2022] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The present study investigates risk factors and clinical outcomes of postoperative pneumolabyrinth following the middle cranial fossa approach for superior semicircular canal dehiscence repair, a complication that has not been documented previously. STUDY DESIGN Retrospective cohort study. SETTING Tertiary/quaternary care referral center. METHODS We conducted a retrospective review of 332 middle cranial fossa procedures from 2014 to 2020 at a tertiary/quaternary care institution. Upon identifying pneumolabyrinth cases from postoperative computed tomography temporal bone scans, we conducted multivariable logistic regression analysis to explore demographic and clinical factors that were independently linked to this complication. We also compared the rates of postoperative symptoms among patients with different grades of pneumolabyrinth. RESULTS We identified 41 (12.3%) pneumolabyrinth cases. Patients with older age, higher preoperative pure tone average, and frank dehiscence were at higher risk for pneumolabyrinth. Furthermore, patients with pneumolabyrinth reported significantly higher rates of postoperative dizziness and exhibited significantly greater pure tone average and air-bone gap postoperatively as compared with patients without pneumolabyrinth. Finally, higher-grade pneumolabyrinth was associated with increased rates of postoperative hearing loss, and grade III pneumolabyrinth was associated with higher rates of postoperative tinnitus vs grade I and II cases. CONCLUSION Pneumolabyrinth following the middle cranial fossa approach was associated with poor clinical outcomes, including dizziness and auditory impairment. Old age, high preoperative pure tone average, and frank dehiscence were risk factors for this complication. The highlighted parameters may be important to note when considering this approach as a treatment option and while monitoring postoperative recovery.
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Affiliation(s)
- Hong-Ho Yang
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Meachelle Lum
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Taranjit Kaur
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Isaac Yang
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Quinton S Gopen
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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Wackym PA, Balaban CD, Van Osch OJ, Morris BT, Tamakloe MA, Salvatore VL, Duwadi S, Gay JD, Mowery TM. New model of superior semicircular canal dehiscence with reversible diagnostic findings characteristic of patients with the disorder. Front Neurol 2023; 13:1035478. [PMID: 36742050 PMCID: PMC9892720 DOI: 10.3389/fneur.2022.1035478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 11/15/2022] [Indexed: 01/20/2023] Open
Abstract
Background Third window syndrome is a vestibular-cochlear disorder in humans in which a third mobile window of the otic capsule creates changes to the flow of sound pressure energy through the perilymph/endolymph. The nature and location of this third mobile window can occur at many different sites (or multiple sites); however, the most common third mobile window is superior semicircular canal dehiscence (SSCD). There are two essential objective diagnostic characteristics needed to validate a model of SSCD: the creation of a pseudoconductive hearing loss and cVEMP increased amplitude and decreased threshold. Methods Adult Mongolian gerbils (n = 36) received surgical fenestration of the superior semicircular canal of the left inner ear. ABR and c+VEMP testing were carried out prior to surgery and over acute (small 1 mm SSCD, 1-10 days) or prolonged (large 2 mm SSCD, 28 days) recovery. Because recovery of function occurred quickly, condenser brightfield stereomicroscopic examination of the dehiscence site was carried out for the small SSCD animals post-hoc and compared to both ABRs and c+VEMPs. Micro-CT analysis was also completed with representative samples of control, day 3 and 10 post-SSCD animals. Results The SSCD created a significant worsening of hearing thresholds of the left ear; especially in the lower frequency domain (1-4 kHz). Left (EXP)/right (CTL) ear comparisons via ABR show significant worsening thresholds at the same frequency representations, which is a proxy for the human pseudoconductive hearing loss seen in SSCD. For the c+VEMP measurements, increased amplitude of the sound-induced response (N1 2.5 ms and P1 3.2 ms) was observed in animals that received larger fenestrations. As the bone regrew, the c+VEMP and ABR responses returned toward preoperative values. For small SSCD animals, micro-CT data show that progressive osteoneogenesis results in resurfacing of the SSCD without bony obliteration. Conclusion The large (2 mm) SSCD used in our gerbil model results in similar electrophysiologic findings observed in patients with SSCD. The changes observed also reverse and return to baseline as the SSCD heals by bone resurfacing (with the lumen intact). Hence, this model does not require a second surgical procedure to plug the SSCD.
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Affiliation(s)
- P. Ashley Wackym
- Department of Otolaryngology – Head and Neck Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States,Rutgers Brain Health Institute, New Brunswick, NJ, United States
| | - Carey D. Balaban
- Departments of Otolaryngology, Neurobiology, Communication Sciences and Disorders, Bioengineering and Mechanical Engineering and Materials Science, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Olivia J. Van Osch
- Department of Otolaryngology – Head and Neck Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States
| | - Brian T. Morris
- Department of Otolaryngology – Head and Neck Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States
| | - Mark-Avery Tamakloe
- Department of Otolaryngology – Head and Neck Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States
| | - Victoria L. Salvatore
- Department of Otolaryngology – Head and Neck Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States
| | - Sudan Duwadi
- Department of Otolaryngology – Head and Neck Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States
| | - Jennifer D. Gay
- Department of Otolaryngology – Head and Neck Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States
| | - Todd M. Mowery
- Department of Otolaryngology – Head and Neck Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States,Rutgers Brain Health Institute, New Brunswick, NJ, United States,*Correspondence: Todd M. Mowery ✉
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Hong M, Mozaffari K, Uy B, Kim WJ, Umesh A, Chandla A, Unterberger A, Yang I, Gopen Q. Postoperative Outcomes of Patients with Thin Bone Overlying the Superior Semicircular Canal: A Single Institution's Experience. World Neurosurg 2022; 166:e93-e98. [PMID: 35779752 DOI: 10.1016/j.wneu.2022.06.118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND Superior semicircular canal dehiscence (SSCD) is defined by a bony defect overlying the superior semicircular canal (SSC) in the middle cranial fossa floor, causing a myriad of vestibular and auditory symptoms. Patients with thin bone without full dehiscence overlying the SSC also present with similar symptoms. There are currently no guidelines for surgical management of patients with thin bone. The authors offer their experience with thin bone patients to characterize their symptomatology and explore whether these patients benefit from surgical intervention typically offered to SSCD patients. METHODS Two hundred fifty-six patients evaluated for SSCD from 2011 to 2019 were reviewed. High-resolution coronal computed tomography scans with 0.6-mm slice thickness of the temporal bones were assessed to determine whether the patient had a true dehiscence or a thin bone covering overlying the SSC. Bone that was ≤0.5 mm was considered to be "thin bone." Parameters of interest included patient demographics as well as preoperative and postoperative symptomatology. A P value < 0.05 was considered statistically significant. RESULTS Forty-eight patients met inclusion criteria of having "thin bone." The mean age was 48.13 ± 12.03 years, and 65.5% of patients were female. Of the preoperative symptoms evaluated, the greatest postoperative symptomatic resolution was noted in hearing loss (92.3%), vertigo (94.4%), and oscillopsia (100%). Dizziness (56.5%) had the lowest symptomatic resolution rate. CONCLUSIONS Surgical management of thin bone patients via middle fossa craniotomy, a similar technique to SSCD repair, provides significant symptomatic resolution. Therefore, surgery should be considered in thin bone patients with debilitating symptoms, albeit not having a true dehiscence.
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Affiliation(s)
- Michelle Hong
- UCLA Department of Head and Neck Surgery, Los Angeles, California, USA
| | | | - Benjamin Uy
- UCLA Department of Neurosurgery, Los Angeles, California, USA
| | - Wi Jin Kim
- UCLA Department of Neurosurgery, Los Angeles, California, USA
| | - Amith Umesh
- UCLA Department of Neurosurgery, Los Angeles, California, USA
| | - Anubhav Chandla
- UCLA Department of Neurosurgery, Los Angeles, California, USA
| | | | - Isaac Yang
- UCLA Department of Head and Neck Surgery, Los Angeles, California, USA; UCLA Department of Neurosurgery, Los Angeles, California, USA; Office of the Patient Experience at UCLA, Los Angeles, California, USA; UCLA Department of Radiation Oncology, Los Angeles, California, USA; UCLA Jonsson Comprehensive Cancer Center, Los Angeles, California, USA; Los Angeles Biomedical Research Institute (LA BioMed) at Harbor-UCLA Medical Center, Torrance, California, USA.
| | - Quinton Gopen
- UCLA Department of Head and Neck Surgery, Los Angeles, California, USA; UCLA Department of Radiation Oncology, Los Angeles, California, USA; UCLA Jonsson Comprehensive Cancer Center, Los Angeles, California, USA
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