Surgical decision-making in superior canal dehiscence syndrome with concomitant otosclerosis.

OBJECTIVE: The diagnosis and management of Superior Canal Dehiscence Syndrome (SCDS) with concomitant otosclerosis can be a challenge. Otosclerosis can mask SCDS symptoms and stapes surgery may reveal or exacerbate vestibular symptoms. Our aim is to present four cases of SCDS with concomitant otosclerosis and thereby informing the reader about the possibility of this dual occurrence and its implications for treatment. CASES: Four patients with SCDS and concomitant otosclerosis are presented. Two patients underwent surgical treatment for both SCDS and otosclerosis and two patients opted for conservative management. OUTCOMES: The main differences between surgically and non-surgically treated cases are the presence of autophony and pressure-induced vertigo and a more severe experience of symptoms in surgically treated cases. Surgically treated cases achieved a sizeable reduction in postoperative air-bone gap and resolution of vestibular symptoms. CONCLUSION: The subjective severity of symptoms in combination with shared decision-making is key in determining the appropriate treatment plan for SCDS and concomitant otosclerosis.

Evaluation of clinical predictors of postoperative outcomes in tegmen defect patients with and without concurrent superior semicircular canal dehiscence and cerebrospinal fluid leak.

OBJECTIVES: Tegmen and superior semicircular canal defects have been well studied, yet the factors contributing to their onset and progression are widely debated. The clinical utility of intraoperative intracranial pressure measurements has yet to be tested. This report aims to use intraoperative opening pressure and concurrent superior semicircular canal dehiscence (SSCD) to analyze factors influencing disease course and clinical outcomes in patients with tegmen dehiscence. METHODS: A retrospective analysis of 61 patients who underwent tegmen defect repair was performed. Multiple variables of interest including body mass index (BMI), presence of SSCD, presence of dural venous sinus stenosis, opening pressure, and acetazolamide therapy use were recorded. The cohort was divided into those with or without concurrent SSCD and those presenting with or without cerebrospinal fluid (CSF) leak for analysis. RESULTS: A linear relationship between opening pressure and BMI (p = 0.009) was noted; however, intraoperative opening pressure was not associated with disease outcome. Concurrent SSCD was present in 25 % of patients, while 62 % presented with CSF leak. The concurrent SSCD group exhibited higher opening pressure, higher likelihood of having dural sinus stenosis, and higher likelihood of being discharged on acetazolamide. The CSF leak group had higher likelihood of obstructive sleep apnea and persistent symptoms. CONCLUSIONS: In patients undergoing tegmen defect repair, concurrent SSCD suggests increased disease severity. The presence of preoperative CSF leak predicts persistent symptoms following repair. BMI is linearly correlated with intracranial pressure in these patients.

Unveiling the importance of the endoscope in the sealing of the superior canal dehiscence syndrome, how we do it.

The superior canal dehiscence syndrome is a pathology that affects the arcuate eminence creating a "third window" between the inner ear and the middle fossa. This condition can lead to symptoms such as hearing loss, autophony, or sound-induced vertigo. Traditionally, surgical treatment has been performed by microscope-assisted temporal craniotomy, but when the dehiscence is in the medial part of the arcuate eminence the bone defect may not be seen. We present case series treated at our institution diagnosed of superior canal dehiscence syndrome involving the medial slope of the arcuate eminence. During surgery, the bone defect could not be visible with traditional microscopic techniques. Nonetheless, by introducing the endoscope with the 0º and 30º optics, the dehiscence could be clearly observed and treated correctly. Our results show a clinical improvement without side effects or complications in the patients undergoing this technique. Endoscope-assisted surgery is a safe procedure and provides a better visualization of medial defects.

Superior semicircular canal dehiscence postoperative outcomes: a case series of 350 repairs.

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.

Impact of superior semicircular canal dehiscence on cochlear implant audiologic outcomes.

PURPOSE: Determine whether adult cochlear implant users with radiographic superior semicircular canal dehiscence experience clinically significant differences in audiological outcomes when compared to cochlear implant users with normal temporal bone anatomy. MATERIALS AND METHODS: Retrospective, single institution review. Adult, post-lingual deaf patients implanted between 2010 and 2020. Inclusion criteria included age 18 years or older, available preoperative computed tomography imaging, and preoperative and postoperative AzBio audiological data for at least 6 months of cochlear implant use. Preoperative and postoperative AzBio Sentence Test scores were compared between patients with normal temporal bone anatomy and those with radiographic superior semicircular canal dehiscence or near dehiscence. RESULTS: 110 patients met inclusion criteria. Mean AzBio score for normal temporal bone anatomy group improved from 35.2 % (SD 28.2) preoperatively to 70.3 % (SD 25.7) postoperatively, an improvement of 35.1 % (SD 28.6). Mean AzBio score for near dehiscent temporal bone anatomy group improved from 26.6 % (SD 28.9) preoperatively to 64.5 % (SD 30.6) postoperatively, an improvement of 37.9 % (SD 27.9). Mean AzBio score for dehiscent temporal bone anatomy group improved from 26.3 % (SD 20.4) preoperatively to 65.1 % (SD 27.6) postoperatively, an improvement of 38.7 % (SD 26.9). Utilizing the one-way analysis of variance test, there was no significant difference in audiologic outcomes between the three groups. CONCLUSIONS: Patients with complete or near complete radiographic superior canal dehiscence at the time of cochlear implantation achieve similar improvements in speech perception scores compared to normal anatomy adult cochlear implant users.

Traumatic Events Preceding the Development of Superior Canal Dehiscence Syndrome.

OBJECTIVE: To describe the features of antecedent head trauma in patients with superior canal dehiscence syndrome (SCDS). STUDY DESIGN: Cross-sectional survey. SETTING: Tertiary referral center. METHODS: An online survey was sent to 450 adult patients who underwent surgical repair for SCDS patients asking questions about the nature of internal or external traumatic events preceding symptoms. RESULTS: One-hundred and thirty-six patients (avg. age, 51.9 years, 62.8% female) completed the survey, of which 61 (44.9%) described either preceding external head trauma (n = 35, 26%), preceding internal pressure event (n = 33, 25%), or both (8, 6%). Of those endorsing external trauma, 22 (63%) described a singular event (head hit by object (n = 8); head hit ground (n = 5); motor vehicle accident (n = 4); assault (n = 2); other (n = 3). One-third experienced loss of consciousness because of the trauma. For those describing internal pressure events (n = 33), the most common events were heavy physical exertion (9, 27%); pressure changes while flying (6, 18%); coughing, nose blowing with illness (5, 15%); childbirth (5, 15%); and self contained underwater breathing apparatus diving events (3, 9%). The interval between trauma and onset of symptoms averaged 5.6 years (SD, 10.7 years). One-third (n = 19) described onset of symptoms immediately after the external trauma or internal pressure event. Symptoms began on the side ipsilateral to the trauma in 91%. Sound- and pressure-induced vertigo/oscillopsia developed more commonly after external trauma versus internal pressure events (68% and 61% vs 44% and 32%, respectively). CONCLUSION: Trauma or internal pressure-related events precede SCDS symptoms in nearly half of cases, with roughly half of preceding events being external.

The History of Superior Semicircular Canal Dehiscence: A Bibliometric Analysis.

OBJECTIVE: The treatment and understanding of superior semicircular canal dehiscence (SSCD) has seen significant developments over the past 25 years. Bibliographic analysis can provide insight into the evolution of research as well as highlight emerging areas. Reviewing a large volume of publications provides valuable insights into the citation patterns and collaborations of research groups. This study seeks to offer a comprehensive historical overview of SSCD and leading authors. DATABASE REVIEWED: Web of Science Core Collection. METHODS: A bibliometric analysis of the current literature on SSCD was conducted. A performance analysis and science mapping of the top 100 most cited articles was completed using a citation analysis. Two independent reviewers evaluated articles for relevance and adjugated by a third reviewer. Author and institution networks were examined. RESULTS: Seven hundred ninety-one articles on the topic of SSCD were identified. The top 100 articles spanned over 23 years from 1998 to 2019 and were published in 30 different journals. The top 100 articles were cited 8253 times in literature. The document contents revealed 233 keywords and 238 author keywords. The articles were authored by a total of 291 authors, with only 4 single-authored documents. CONCLUSIONS: SSCD has been highly researched in aspects of symptomatology, diagnosis, and treatment, as indicated by many highly cited articles that relate. However, the production of highly cited articles on SSCD displays a significant decrease after 2013, with only 17 of the top cited articles published since then.

Patient Sex Mediates the Influence of Patient Age on Superior Canal Dehiscence Repair Outcome.

OBJECTIVE: To investigate the independent and interactive effects of patient age and sex on superior canal dehiscence (SCD) repair outcomes. METHODS: This was a cohort study of consecutive SCD repairs via the middle fossa approach at an institution between 2011 and 2022. We constructed multivariable regression models assessing surgical outcomes with age and sex as the primary predictors. Models controlled for surgery duration, follow-up duration, and relevant surgical and medical history. Subsequently, we repeated each model with the incorporation of an interaction term between patient age and sex. RESULTS: Among 402 repairs, average age was 50 years, and 63% of cases were females. There was a significant interaction between patient age and sex with respect to symptom resolution score (SRS) (adj. ß 0.80, 95% C.I. 0.04-1.56). Older age was associated with lower SRS among females (-0.84, -1.29 to -0.39 point per year) but not significantly associated with SRS among males (0.04, -0.65 to 0.56 point per year). Furthermore, older age independently predicted a greater magnitude of increase in air conduction at 8000 Hz following surgery regardless of sex (adj. ß 2.1, 0.2-4.0 dB per 10-year increase). CONCLUSIONS: This is the first study on the interactive effect between patient age and sex with respect to SCD repair outcomes. Older age predicted poorer symptomatic response among female patients but did not predict symptomatic response among male patients. Furthermore, older age predicted more severe high-frequency hearing loss following SCD repairs among both female and male patients. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:3363-3370, 2024.

Scuba Diving-Induced Inner-Ear Pathology: Imaging Findings of Superior Semicircular Canal and Tegmen Tympani Dehiscence.

BACKGROUND Superior semicircular canal dehiscence is an inner-ear pathology which presents with vertigo, disequilibrium, and hearing loss. Although the exact etiology of superior semicircular canal dehiscence is unknown, it is thought that an increase in middle-ear pressure disrupts a thin overlying temporal bone. Superior semicircular canal dehiscence is frequently seen in association with dehiscence of the tegmen tympani, which overlies the middle ear. Here, we present a case report of a 52-year-old Puerto Rican man with vertigo, dizziness, vomiting, and mild hearing loss associated with superior semicircular canal and tegmen tympani dehiscence after performing improper scuba diving techniques. CASE REPORT A 52-year-old Puerto Rican man presented to the emergency department with vertigo, dizziness, vomiting, and mild hearing loss in the right ear. The symptoms began shortly after scuba diving with inadequate decompression techniques on ascent. He was treated with recompression therapy with mild but incomplete improvement in symptoms. Bilateral temporal magnetic resonance imaging was suggestive of segmental dehiscence of the right superior semicircular canal and tegmen tympani. High-resolution computed tomography of the temporal bone confirmed right superior semicircular canal and tegmen tympani dehiscence with an intact left inner ear. CONCLUSIONS The increased inner-ear pressure that occurs during scuba diving can lead to dehiscence of the superior semicircular canal and tegmen tympani, causing vertigo and hearing loss. Performance of improper diving techniques can further increase the risk of dehiscence. Therefore, appropriate radiologic evaluation of the inner ear should be performed in such patients.

Probabilities of Isolated and Co-Occurring Vestibular Disorder Symptom Clusters Identified Using the Dizziness Symptom Profile.

OBJECTIVES: Dizziness is among the most common reasons people seek medical care. There are data indicating patients with dizziness, unsteadiness, or vertigo may have multiple underlying vestibular disorders simultaneously contributing to the overall symptoms. Greater awareness of the probability that a patient will present with symptoms of co-occurring vestibular disorders has the potential to improve assessment and management, which could reduce healthcare costs and improve patient quality of life. The purpose of the current investigation was to determine the probabilities that a patient presenting to a clinic for vestibular function testing has symptoms of an isolated vestibular disorder or co-occurring vestibular disorders. DESIGN: All patients who are seen for vestibular function testing in our center complete the dizziness symptom profile, a validated self-report measure, before evaluation with the clinician. For this retrospective study, patient scores on the dizziness symptom profile, patient age, and patient gender were extracted from the medical record. The dizziness symptom profile includes symptom clusters specific to six disorders that cause vestibular symptoms, specifically: benign paroxysmal positional vertigo, vestibular migraine, vestibular neuritis, superior canal dehiscence, Meniere disease, and persistent postural perceptual dizziness. For the present study, data were collected from 617 participants (mean age = 56 years, 376 women, and 241 men) presenting with complaints of vertigo, dizziness, or imbalance. Patients were evaluated in a tertiary care dizziness specialty clinic from October 2020 to October 2021. Self-report data were analyzed using a Bayesian framework to determine the probabilities of reporting symptom clusters specific to an isolated disorder and co-occurring vestibular disorders. RESULTS: There was a 42% probability of a participant reporting symptoms that were not consistent with any of the six vestibular disorders represented in the dizziness symptom profile. Participants were nearly as likely to report symptom clusters of co-occurring disorders (28%) as they were to report symptom clusters of an isolated disorder (30%). When in isolation, participants were most likely to report symptom clusters consistent with benign paroxysmal positional vertigo and vestibular migraine, with estimated probabilities of 12% and 10%, respectively. The combination of co-occurring disorders with the highest probability was benign paroxysmal positional vertigo + vestibular migraine (~5%). Probabilities decreased as number of symptom clusters on the dizziness symptom profile increased. The probability of endorsing vestibular migraine increased with the number of symptom clusters reported. CONCLUSIONS: Many patients reported symptoms of more than one vestibular disorder, suggesting their symptoms were not sufficiently captured by the symptom clusters used to summarize any single vestibular disorder covered by the dizziness symptom profile. Our results indicate that probability of symptom clusters indicated by the dizziness symptom profile is comparable to prior published work on the prevalence of vestibular disorders. These findings support use of this tool by clinicians to assist with identification of symptom clusters consistent with isolated and co-occurring vestibular disorders.

The importance of bone density and anatomical structure in superior semicircular canal dehiscence.

OBJECTIVE: This study investigates the importance of bone density, surface area, and diameter of anatomical structures of the superior semicircular canal (SSC), lateral semicircular canal (LSC), posterior semicircular canal (PSC), utricle, and saccule in patients diagnosed with superior semicircular canal dehiscence (SSCD). MATERIALS AND METHODS: The bone density, surface area, and diameter of SSC, LSC, PSC, utricle, and saccule were measured and compared between the SSCD group and control group. Fifteen ears in the SSCD group and 60 ears in the control group were evaluated. Additionally, within the SSCD group, the dehiscent and healthy sides were evaluated independently. RESULTS: SSC's bone density was significantly lower in the SSCD group compared to the control group (p = 0.008). No significant differences were found in surface area and diameter between the groups (p > 0.05). While most of the anatomical structures showed no significant difference in bone density between dehiscent and healthy ears (p > 0.05), SSC bone density was significantly lower in affected ears (p = 0.000) in SSCD group. CONCLUSION: Based on the data obtained in this study, bone density and anatomical structure may be useful in patients diagnosed with SSCD.

Superior canal dehiscence syndrome: A review.

Superior canal dehiscence syndrome (SCDS) is a vestibular disorder in which the presence of a pathological third window in the labyrinth causes several vestibular and cochlear symptoms. Herein, we review the diagnostic criteria and treatment of SCDS. The cause of SCDS is considered to be congenital or acquired; however, its etiology is not well known. Symptoms: Vertigo and/or oscillopsia induced by loud sounds (Tullio phenomenon) or stimuli that change the middle ear or intracranial pressure (fistula symptoms) with vestibular symptoms and hyperacusis and aural fullness with cochlear symptoms are characteristic clinical complaints of this syndrome. Neurological tests: Vertical-torsional eye movements can be observed when the Tullio phenomenon or fistula symptoms are induced. Conductive hearing loss with both a decrease in the bone conduction threshold at lower frequencies and an increase in the air conduction threshold at lower frequencies may be present on audiometry. Cervical and/or ocular vestibular evoked myogenic potentials are effective in strongly suspecting the presence of a pathologic third window in the labyrinth. Computed tomography (CT) imaging: High-resolution CT findings with multiplanar reconstruction in the plane of the superior semicircular canal consistent with dehiscence indicate SCDS. The Pöschl view along the plane of the superior semicircular canal and the Stenvers view perpendicular to it are recommended as CT imaging conditions. Findings from all three major diagnostic categories (symptoms, neurological tests, and/or CT imaging) are needed to diagnose SCDS. The surgical approaches for SCDS are as follows: the 1) middle cranial fossa approach, 2) transmastoid approach, and 3) round window and oval window reinforcement. Each technique has advantages and disadvantages.

Trans-mastoid plugging of superior semicircular canal dehiscence: long-term follow-up.

OBJECTIVE: To evaluate the long-term outcomes of trans-mastoid plugging of superior semicircular canal dehiscence (SSCD), focusing on complicated cases. METHODS: In this cohort study, we included all patients who underwent trans-mastoid plugging of SSCD between 2009 and 2019. We evaluated the symptoms (autophony, sound-/pressure-induced vertigo, disequilibrium, aural fullness and pulsatile tinnitus) before and 1 year after surgery in the medical records. We systematically assessed the current symptoms 6.2 ± 3 years postoperative (range 2.2-12.3 years) using questionnaires sent by post and validated by telephone interviews. We also documented any complications and the need for further procedures. We compared pure tone and speech audiometry before and 1 year after surgery. Finally, the degree of mastoid pneumatisation and mastoid tegmen anatomy were reviewed on preoperative CT scans. RESULTS: We included 24 ears in 23 patients. No complications were recorded, and none required a second procedure for SSCD. Following surgery, oscillopsia and Tullio phenomena resolved in all patients. Hyperacusis, autophony, and aural fullness were also settled in all patients except one. Balance impairment persisted to some degree in 35% of patients. No deterioration over the years was reported regarding the above symptoms. On average, bone conduction pure tone average pre- and 1 year postoperative were 13.7 ± 17 and 20.5 ± 18 dB, respectively (P = 0.002). Air bone gaps were reduced from 12.7 ± 8 to 5.9 ± 6 (P = 0.001). Two patients had a significant sclerotic mastoid, three had a prominent low-lying mastoid tegmen, and two had both. Anatomy had no effect on outcome. CONCLUSION: Trans-mastoid plugging of SSCD is a reliable and effective technique which achieves long-lasting symptom control, even in cases with sclerotic mastoid or low-lying mastoid tegmen.

Photon Counting Versus Energy-integrated Detector CT in Detection of Superior Semicircular Canal Dehiscence.

BACKGROUND: Superior semicircular canal dehiscence (SSCD), an osseous defect overlying the SSC, is associated with a constellation of audiovestibular symptoms. This study sought to compare conventional energy-integrated detector (EID) computed tomography (CT) to photon-counting detector (PCD)-CT in the detection of SSCD. MATERIAL AND METHODS: Included patients were prospectively recruited to undergo a temporal bone CT on both EID-CT and PCD-CT scanners. Two blinded neuroradiologists reviewed both sets of images for 1) the presence or absence of SSCD (graded as present, absent, or indeterminate), and 2) the width of the bone overlying the SSC (if present). Any discrepancies in the presence or absence of SSCD were agreed upon by consensus. RESULTS: In the study 31 patients were evaluated, for a total of 60 individual temporal bones (2 were excluded). Regarding SSCD presence or absence, there was substantial agreement between EID-CT and PCD-CT (k = 0.76; 95% confidence interval, CI 0.54-0.97); however, SSCD was present in only 9 (15.0%) temporal bones on PCD-CT, while EID-CT examinations were interpreted as being positive in 14 (23.3%) temporal bones. This yielded a false positive rate of 8.3% on EID-CT. The bone overlying the SSC was thinner on EID-CT images (0.66 mm; SD = 0.64) than on PCD-CT images (0.72 mm; SD = 0.66) (p < 0.001). CONCLUSION: The EID-CT examinations tend to overcall the presence of SSCD compared to PCD-CT and also underestimate the thickness of bone overlying the SSC.

Third window lesions of the inner ear: A pictorial review.

PURPOSE: Radiographic review of pathologies that associate with third window syndrome. METHODS: Case series and literature review. RESULTS: Eight unique third window conditions are described and illustrated, including superior, lateral, and posterior semicircular canal dehiscence; carotid-cochlear, facial-cochlear, and internal auditory canal-cochlear dehiscence, labyrinthine erosion from endolymphatic sac tumor, and enlarged vestibular aqueduct. CONCLUSION: The present study highlights the characteristic imaging features and symptoms to differentiate third window pathologies for expedient diagnosis and management planning.

Prevalence of Cochlear-Facial and Other Non-Superior Semicircular Canal Third Window Dehiscence on High-Resolution Temporal Bone CT.

BACKGROUND AND PURPOSE: The radiologic prevalence of superior semicircular canal dehiscence in the asymptomatic population has been widely studied, but less is known about the rates of other forms of third window dehiscence. Per the existing literature, the radiologic prevalence of cochlear-facial nerve dehiscence, for example, exceeds that seen in histologic studies, suggesting that conventional CT is unreliable for cochlear-facial dehiscence. These studies relied on nonisometric CT acquisitions, however, and underused multiplanar reformatting techniques, leading to false-positive findings. Our purpose was to determine the rate of cochlear-facial dehiscence and other non-superior semicircular canal third window dehiscences on optimized CT in asymptomatic patients. MATERIALS AND METHODS: Sixty-four-channel temporal bone CT scans from 602 patients in emergency departments were assessed for cochlear-facial and other non-superior semicircular canal third window dehiscences by using high-resolution, multiplanar oblique reformats. Confidence intervals for dehiscence prevalence were calculated using the Newcombe 95% interval confidence method. RESULTS: Of 602 patients, 500 were asymptomatic, while 102 had an imaging indication consistent with possible third window syndrome (symptomatic). Eight asymptomatic patients (1.6%) had cochlear-facial dehiscence, while 43 (8.4%) had jugular bulb-vestibular aqueduct dehiscence. There was no statistically significant difference between the prevalence of cochlear-facial dehiscence or jugular bulb-vestibular aqueduct dehiscence in asymptomatic patients compared with symptomatic patients. Cochlear-carotid canal, cochlear-internal auditory canal, and cochlear-petrosal sinus dehiscences were not observed. CONCLUSIONS: Sixty-four-channel CT with multioblique reformatting is sensitive and specific for identifying cochlear-facial dehiscence, with rates similar to those in postmortem series. Jugular bulb-vestibular aqueduct dehiscence is a common incidental finding and is unlikely to produce third window physiology. Other non-superior semicircular canal third window dehiscences are rare in asymptomatic patients.

Auditory and Vestibular Symptom Improvement With Surgery for Superior Canal Dehiscence Syndrome.

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.

Audiometric Outcomes After the Middle Cranial Fossa Repair of Superior Semicircular Canal Dehiscence.

OBJECTIVE: To evaluate the audiometric outcomes after the middle cranial fossa approach (MCF) for superior canal dehiscence (SCD) repair. STUDY DESIGN: Retrospective review. SETTING: Tertiary referral center. PATIENTS: SCD cases presented to a single institution between 2012 and 2022. INTERVENTIONS: The MCF repair of SCD. MAIN OUTCOME MEASURES: Air conduction (AC) threshold (250-8,000 Hz), bone conduction threshold (BC) (250-4,000 Hz), and air bone gap (ABG) (250-4,000 Hz) at each frequency, pure tone average (PTA) (500, 1,000, 2,000, 3,000 Hz). RESULTS: Among 202 repairs, 57% were bilateral SCD disease and 9% had previous surgery on the affected ear. The approach significantly narrowed ABG at 250, 500, and 1,000 Hz. The narrowing of ABG was achieved by both decreased AC and increased BC at 250 Hz, but mediated primarily by increased BC at 500 Hz and 1,000 Hz. Among cases without previous ear surgery, mean PTA remained in the normal hearing range (mean: preop, 21 dB; postop, 24 dB) and clinically important hearing loss (PTA increased by ≥10 dB) after the approach was noted in 15% of cases. Among cases with previous ear surgery, mean PTA remained in the mild hearing loss range (mean: preop, 33 dB; postop, 35 dB) and clinically important hearing loss after the approach was noted in 5% of cases. CONCLUSION: This is the largest study to date examining the audiometric outcomes after the middle cranial fossa approach for SCD repair. Findings of this investigation support that the approach is effective and safe with long-term hearing preservation for most.