Superior Canal Dehiscence Research Articles

SURG-55. NOVEL IQ-DOME APPROACH FOR SUPERIOR SEMICIRCULAR CANAL DEHISCENCE REPAIR REDUCES REVISIONAL SURGERY RATE

Abstract Superior Semicircular Canal Dehiscence (SSCD) is characterized by a thinning of the bony ceiling of the superior semicircular canal, manifesting in auditory and vestibular deficits. Surgical repair is the standard treatment modality of SSCD, with conventional methods including plugging or recapping the defective canal with bone wax, bone chips, muscle, and others. Previous research has shown multiple complications with these conventional materials, including a high rate of failure of the primary repair and the need for revisional surgeries. To address this challenge, we investigated a novel surgical sealing technique using IQ-Dome, a titanium mesh plate overlying the arcuate eminence. We aim to assess the efficacy of IQ-Dome in the repair of SSCD compared to conventional material while evaluating outcome measures including postoperative symptom resolution, complication, and revisional surgery rates. We performed a retrospective analysis of patients undergoing SSCD repair via the middle cranial fossa approach at UCLA between 2017 and 2021. We compared demographics and post-operative outcomes between the application of IQ-Dome and conventional materials. A total of 160 patients undergoing SSCD repair were included in our study, with 80 patients receiving IQ-Dome and 80 patients receiving non-IQ-Dome approaches. 60% of patients in the IQ-Dome cohort and 66.7% of patients in the non-IQ-Dome cohort were female. The mean ages of patients were 45.7 years (range 13-78) in the IQ-Dome cohort and 48.9 years (range 17-69) in the non-IQ-Dome cohort. The surgical revision rates for the IQ-Dome and non-IQ-Dome cohorts were 5.7% and 8.5%, respectively. There was no significant difference in postoperative complications between groups. Thus, IQ-Dome is a safe approach for the surgical management of SSCD, decreasing failure and revision rate by nearly 3% in our patient population and offering an alternative surgical sealing repair intervention. Future studies with larger sample sizes are warranted to further assess the efficacy of IQ-Dome.

Model of superior semicircular canal dehiscence: asymmetrical vestibular dysfunction induces reversible balance impairment.

Superior semicircular canal dehiscence (SSCD) is a vestibular-cochlear disorder in humans in which a pathological third mobile window of the otic capsule creates changes to the flow of sound pressure energy through the perilymph/endolymph. The primary symptoms include sound-induced dizziness/vertigo, inner ear conductive hearing loss, autophony, headaches, and visual problems. We have developed an animal model of this human condition in the Mongolian Gerbil that uses surgically created SSCD to induce the condition. A feature that is unique in this model is that spontaneous resurfacing of the dehiscence occurs via osteoneogenesis without a subsequent intervention. In this study, we completed our assessment of this model to include reversible asymmetrical vestibular impairments that interfere with balance. Adult Mongolian gerbils (N = 6) were trained to complete a balance beam task. They were also trained to perform a Rotarod task. After 10 days of training, preoperative ABR and c+VEMP testing was followed by a surgical fenestration of the left superior semicircular canal. Balance beam testing recommenced at postoperative day 6 and continued through postoperative day 15 at which point final ABR and c+VEMP testing was carried out. Behavioral comparison of preoperative and postoperative performance show a significant decrease in Rotarod performance, increased rates of falling, and an increase in time to cross the balance beam. Impairments were the most significant at postoperative day 7 with a return toward preoperative performance by postoperative day 14. This behavioral impairment was correlated with residual impairments to auditory thresholds and vestibular myogenic amplitudes at postoperative day 14. These results confirm that aberrant asymmetric vestibular output in our model of SSCD results in reversible balance impairments. The level of these behavioral impairments is directly correlated with severity of the vestibular dysfunction as we have previously reported for peripheral ear physiology and cognition.

Minor's Syndrome or Dehiscence of the Superior Semicircular Canal: A Case Report

Semicircular canal dehiscence is a congenital syndrome that mainly affects the superior and, less commonly, the posterior semicircular canal in the temporal bone. This syndrome was first reported by Minor et al. in 1998. The prevalence is about 0.5% in the general population. The most characteristic symptom is the Tullio phenomenon, predominantly vertigo and nystagmus. Hearing loss (in particular conductive loss) often completes overall clinical picture. The dehiscence may be completely asymptomatic, in which case it is seen as an incidental finding on radiological investigations. Audiological evaluation includes audiometry and vestibular evoked myogenic potentials (VEMPs). Clinical symptoms are based on the pathophysiological concept of a third mobile window within the inner ear. Diagnosis is confirmed by high resolution petrous temporal bone CT with multiplanar reconstructions (MPRs) in the plane of the canal (Pöschls’ plane for the superior semicircular canal) and 3-D surface reconstructions. MR findings are less sensitive for this entity. The most common differential diagnosis is otosclerosis. Clinical–radiological correlations have therapeutic applications even though the indication for surgery depends on the severity of the vestibular symptoms.

Perilymphatic fistula: a historical overview of publication trends

BackgroundPerilymph fistula (PLF) can cause symptoms of dizziness, vertigo, and fluctuating hearing. We hypothesized that publications on PLF have decreased in recent years relative to other inner ear disorders with overlapping symptoms.MethodsWe performed a Scopus search using the terms “perilymphatic fistula” OR “perilymph fistula,” limited to original studies or reviews involving human subjects published in English before 2022. We noted the senior author's institution, country affiliation, and publishing journal. The Kendall rank correlation coefficient test was used to analyze the trend of each variable over the past 30 years. Using the same search strategy, we compared these data to those from vestibular neuritis (VN), Meniere's disease (MD), superior semicircular canal dehiscence (SSCD), and benign paroxysmal positional vertigo (BPPV).ResultsSix hundred and ninety-eight PLF publications were returned. The top publishing country was the United States (n = 334), the top publishing journal was the American Journal of Otology/Otology and Neurotology (n = 68), and the top publishing institution was the University of Pittsburgh (n = 15). In the past 30 years (n = 501), there was no trend in the frequency of annual PLF publications (τ = −0.150, p = 0.265). Still there were positive trends in publications on vestibular neuritis (τ = 0.724, p < 0.001), Meniere's disease (τ = 0.587, p < 0.001), superior canal dehiscence syndrome (τ = 0.840, p < 0.001), and benign paroxysmal positional vertigo (τ = 0.882, p < 0.001) 5,398 PLF cases were identified, of which 4,356 specified the etiology; the majority identified an inciting insult (74.8%, n = 3,257).ConclusionsThe absence of diagnostic criteria for PLF may hinder its appeal to researchers as similar syndromes have had diagnostic consensus documents set forth. Given the greater number of cases with inciting insults, efforts to define a diagnostic criterion should focus on this subtype.

Radiographic Estimation of Superior Canal Dehiscence Area in a Prediction Model of Surgical Outcome.

Computed tomography (CT) imaging of the temporal bone constitutes an integral element in the diagnostic workup of superior canal dehiscence (SCD). This study explores the utility of a clinically efficient method of manually estimating SCD size on CT imaging in predicting surgical outcomes. Cohort study. Tertiary center. Consecutive middle fossa repairs of SCD between 2011 and 2022 were included. Measurements of approximate dehiscence area (ADA), a previously established estimation method, on temporal bone CT imaging were performed by trained raters blind to clinical information. Surgical outcomes, evaluated with symptom resolution and audiometric improvement following repair, were assessed in multivariable regression models with ADA as the primary predictor and patient demographics and other history factors as covariates. Among 311 cases included, mean ADA was 2.68 mm2, and 71% of cases achieved overall symptom improvement (OSI). Every 1 mm2 rise in ADA predicted on average 3 dB greater narrowing of low-frequency air-bone gap (β 95% confidence interval, CI [-5.4, -0.7]) but 50% lower odds of OSI (adjusted odds ratio: 95% CI [0.32, 0.78]) among unilateral SCD cases. A model incorporating ADA, patient demographics, and history factors predicted OSI with a sensitivity, specificity combination as high as 85%, 73% and a positive predictive value, negative predictive value combination as high as 85%, 82% (area under the curve: 95% CI: 0.76-0.93). Increased ADA predicts more pronounced audiometric improvement but poorer symptomatic response among unilateral SCD cases. ADA is an efficient and practical method of estimating SCD size and demonstrated clinical utility in accurately predicting surgical outcomes.

Audio-Vestibular Evaluation of Pediatric Pseudo-Conductive Hearing Loss: Third Window Syndromes.

Conductive hearing loss caused by external or middle ear problems prevents the transmission of sound waves from the external auditory canal to the cochlea, and it is a common condition, especially in pediatric patients aged 1-5 years. The most common etiological factors are otitis media and cerumen during childhood. In some patients, external and middle ear functions and structures may be normal bilaterally despite the air-bone gap on the audiogram. This condition, which is often a missed diagnosis in children, is defined as a pseudo-conductive hearing loss (PCHL) caused by third window syndromes (TWSs) such as semicircular canal dehiscence, inner ear malformations with third window effect, and perilymphatic fistula. In this review of the literature, the authors emphasize the pitfalls of pediatric audio-vestibular evaluation on TWSs as well as the key aspects of this evaluation for the differential diagnosis of PCHL brought on by TWSs. This literature review will provide audiologists and otologists with early diagnostic guidance for TWSs in pediatric patients.

Insights from therapeutic strategies in superior canal dehiscence syndrome: is there anything beyond surgical treatment?

Superior semicircular canal dehiscence syndrome (SCDS) is a clinical syndrome that can cause instability, vertigo, fullness, tinnitus, autophony, hearing loss (HL), Tullio phenomenon, or Hennebert's sign. Historically, surgery has been the primary treatment reported in the literature, although some medical treatments may also be proposed. This study aims to comprehensively characterize SCDS in a large series of patients from clinical, auditory, and vestibular perspectives, and explore medical alternatives to conventional surgical treatments by comparing their results and evolution. A retrospective observational study was designed in a tertiary care center. Audiovestibular tests evaluated included pure-tone audiometry (PTA), VEMPs, video head impulse test (vHIT), and CT imaging. Improvement was assessed over a follow-up period of up to 6 months for seven cardinal symptoms to verify the efficacy of the proposed treatments. 71 subjects with SCDS and a mean age of 51.20 ± 12.22 years were included in the study. The most common symptom found in our sample was instability in 31 patients (43.66%), followed by aural fullness or tinnitus in 29 subjects (40.85%). 36 patients (43.66%) received medical treatment, with 28 of them (77.78%) showing symptom reduction. Surgical repair was indicated in five patients, with all showing symptom improvement. Statistically significant improvement (p < 0.05) was observed, particularly with surgical treatment and acetazolamide, in both symptoms and objective tests such as pure-tone audiometry and VEMPs. SCDS shows significant similarities with other otic capsule dehiscences. It is essential to perform VEMPs and CT scans to complete the diagnosis, which is usually accompanied by clearly recognizable clinical criteria. Surgery for SCDS is effective, safe, and without complications. However, in cases where symptoms are mild to moderate, addressing this condition with medical treatment using diuretics such as acetazolamide has shown promising results.

Superior Canal Dehiscence and the Risk of Additional Dehiscences: A Retrospective CT Cohort Study.

Determine if superior canal dehiscence (SCD) found on flat-panel CT increases the risk for other defects in the otic capsule. Retrospective cohort study. Tertiary care center. One hundred ears (50 with SCD and 50 matched controls without SCD). Flat-panel CT imaging. (1) Prevalence of other dehiscences in SCD ears, (2) dehiscences in controls, and (3) otic capsule thickness in other reported dehiscence locations (cochlea-carotid, lateral semicircular canal [SCC] and mastoid, facial nerve-lateral SCC, vestibular aqueduct, posterior SCC-jugular bulb, posterior SCC-posterior fossa). Between-group comparisons were considered significant at p < 0.007 after applying the Bonferroni correction for multiple comparisons. Not including the SCD, there was a mean of 0.04 additional dehiscences in the SCD group (n = 2/50, 4%) and 0.04 non-SCD dehiscences in the controls (n = 2/50, 4%, p > 0.007). In the SCD group, there was one dehiscence between the cochlea and carotid artery and one between the posterior SCC and posterior fossa. The control group had one enlarged vestibular aqueduct and one dehiscence between the facial nerve and lateral SCC. As a group, SCD ears had wider vestibular aqueducts (0.68 ± 0.20 vs 0.51 ± 0.30 mm, p < 0.007) and thinner bone between the posterior SCC and posterior fossa (3.12 ± 1.43 vs 4.34 ± 1.67 mm, p < 0.007). The bone between the facial nerve and lateral SCC was thicker in SCD ears (0.77 ± 0.23 vs 0.55 ± 0.27 mm, p < 0.007) and no different for cochlea-carotid, and lateral SCC and mastoid (p > 0.007). SCD does not increase the likelihood of a second dehiscence in the same otic capsule. SCD patients may have congenitally thinner otic capsule bones compared to controls, particularly near the posterior SCC, where the vestibular aqueduct may be enlarged.

Outcomes at 6 months after isolated or non-isolated surgery for temporal bone cerebrospinal fluid leak in adults: A STROBE analysis

AimThe main aim of this study was to evaluate 6-month closure success in surgery for isolated or non-isolated temporal bone osteomeningeal breach (OMB). Secondary objectives were to analyze complications of closure and correlations between success and breach, treatment and patient data. Material and methodThis was a single-center retrospective observational study of patients who underwent surgery for temporal bone OMB via a middle cranial fossa or transmastoid approach in a French university teaching hospital between 2007 and 2022, with follow-up of at least 6months. Patients with superior semicircular canal dehiscence were excluded. Study data comprised gender, age, body mass index, OMB etiology, mode of discovery, audiometric and radiological data, surgical technique, length of hospital stay and postoperative complications. The primary endpoint was absence of a cerebrospinal fluid leak on MRI at 6months. Fisher's exact test or Chi2 test were used for qualitative data and Student t-test for quantitative data. ResultsThe closure success rate was 87%: 81% (3 recurrences) in the middle cranial fossa group of 16 patients and 93% in the transmastoid group of 14 patients. Postoperative audiometry showed significant improvement (P=0.0016) for air conduction in the middle cranial fossa group. Five patients (17%) operated on via the middle cranial fossa approach and 1 (7%) operated on via the transmastoid approach had postoperative complications. OMB was in the tegmen mastoideum in 8 patients (29%), tegmen tympani in 7 (25%), tegmen antri in 4 (14%), tegmina antri and tympani in 3 (11%), antri and mastoideum in 1 (8%) and in the whole tegmen in 5 (18%). Eleven OMBs were lateral to the superior semicircular canal, 13 medial and 4 on either side. ConclusionThe transmastoid approach is indicated in case of associated middle-ear procedures, patients aged over 75years or OMB lateral to the superior semicircular canal. The middle cranial fossa approach is reserved for OMB located medial to the superior semicircular canal patients under 75years of age without associated ossicular procedures. For patients with OMB medial to the superior semicircular canal who require middle-ear surgery, a combined approach can be used.

Symptomatology in Unilateral Versus Bilateral Superior Canal Dehiscence Patients Undergoing Unilateral Surgery.

To compare symptomatology in patients with unilateral versusbilateral superior semicircular canal dehiscence who underwent unilateral surgical repair. Retrospective cohort study. Single surgeon series at tertiary academic medical center from 2002 to 2021. Patients were administered a standardized questionnaire regarding the presence or absence of 16 symptoms (11 auditory and 8 vestibular) pre- and postoperatively. Symptom rates were compared between patients with unilateral and bilateral dehiscence, and paired statistical testing was used to analyze symptom improvement with surgery. Our final cohort included 125 patients, 93 (74%) with unilateral superior canal dehiscence syndrome(SCDS) and 32 (26%) with bilateral SCDS. Bilateral patients had an increased burden of auditory and vestibular symptoms compared to unilateral patients before surgery (7.6 vs 6.2, P = .03) and after surgery (3.1 vs 1.9, P = .02). Both groups experienced a significant reduction of symptoms following repair (P < .01 for both). Our study has 2key findings: First, patients with bilateral dehiscence seem to be more symptomatic, reporting more auditory and vestibular symptoms both before and after surgery. Second, bilateral patients still seem to benefit from unilateral repair, demonstrating a significant reduction in the number of symptoms with surgery. Our findings may help inform the management of the sizable proportion of SCDS patients with bilateral defects.

An algorithm for the surgical approach to spontaneous temporal bone CSF leak

ObjectiveTo suggest a comprehensive algorithm for the surgical approach for correcting of sources of temporal bone CSF leaks. MethodsA case series for patients operated in a single academic tertiary referral center between 2011 and 4.2022. Included in the study were 46 patients, 5 of whom had a bilateral problem, resulting in 51 pathologic temporal bones. The presentation was an active CSF leak (38 patients) or bacterial otogenic meningitis (8 patients). Follow up ranged from 8 months to 5 years. ResultsOf the 42 ears operated via the default middle fossa approach, 37 were successful (88 %) in controlling CSF leak. None had intracranial complications or sensorineural hearing loss. Location, number and size of the defects, hearing status, associated superior semicircular canal dehiscence, additional intra-temporal or intra-cranial pathologies may indicate a transmastoid approach. Of the six ears that had a canal wall up mastoidectomy as a primary procedure, one required revision due to ongoing CSF leak. Five revision cases and three primary cases were effectively sealed with a subtotal petrosectomy and obliteration. One was lost to follow-up. Hearing was reconstructed with bone-anchored hearing implants in 6 out of these 8 ears. ConclusionsThe middle fossa approach could be used as a default approach for sealing TD. There are a number of indications for transmastoid approaches in both primary and revision cases. Obliteration of the ear was used in all revision cases. The suggested algorithm can help in planning surgery for temporal bone CSF leaks or a history of otogenic meningitis.

Development and Standardization of Modified Simultaneous Multifrequency (SiMFy) Stimulus for Recording oVEMP And Its Interaction with the Alternate Electrode Montages.

Simultaneous Multifrequency (SiMFy) is a time-saving and reliable stimulus to determine the frequency tuning of ocular vestibular-evoked myogenic potential (oVEMP); however, the absence of 4000 Hz in SiMFy potentially makes it a less potent tool for the diagnosis of Superior semicircular canal dehiscence, a pathology with an ever-increasing prevalence. Further, SiMFy was validated using only the infra-orbital (IO) electrode montage. However, the recordings obtained using the IO montage might be susceptible to reference contamination introduced by a small separation between the recording electrodes, and also susceptible to reflex impurity due to the spatially displaced reference electrode from the inferior oblique muscle (IOM), rendering it vulnerable to picking up responses from other muscles. Nonetheless, little is known about the similarities/differences between the SiMFy-induced oVEMPs using alternate montages [belly-tendon (BT), chin-reference (CR), and sternum-reference (SR)] and the non-simultaneous multifrequency oVEMPs (NSM-oVEMPs) using the IO montage. To develop a modified SiMFy stimulus and investigate its effects on frequency tuning of oVEMP using various electrode montages. Within-subject experimental design. Thirty-three healthy adults aged 20-30 years. Tone bursts of octave and mid-octave frequencies from 250 Hz to 4000 Hz were generated and concatenated to create the modified SiMFy stimulus. All participants underwent non-simultaneous multifrequency oVEMPs and modified SiMFy oVEMPs using BT, CR, SR, and IO montages simultaneously. The response rate, peak-to-peak amplitude, and frequency tuning were compared between NSM-oVEMP and modified SiMFy oVEMP and also between the electrode montages. BT montage recorded the largest amplitude among the montages in non-simultaneous multifrequency stimulation and modified SiMFy stimulation. Although the response rates were comparable, the modified SiMFy produced significantly lower oVEMP amplitudes than the non-simultaneous multifrequency stimulation within each electrode montage (p < 0.05). A moderate-to-strong agreement on frequency tuning existed between the non-simultaneous multifrequency stimuli and modified SiMFy stimulus for all the montages, except for the SR montage. Although the modified SiMFy produces smaller amplitude oVEMPs than the non-simultaneous multifrequency stimulation for the respective montages, its use in combination with the BT montage yields higher response rates and larger peak-to-peak amplitudes than the non-simultaneous multifrequency recording using IO montage.

Association Between Superior Canal Dehiscence Syndrome and Anxiety and Depressive Disorders.

Association Between Superior Canal Dehiscence Syndrome and Anxiety and Depressive Disorders.

Diagnosis and Management of Unexplained Conductive Hearing Loss With Intact Tympanic Membrane: A Systematic Review.

Objective: To analyze the etiology, diagnosis, and treatment of unexplained conductive hearing loss (UCHL) with intact tympanic membrane. Methods: A systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 642 articles were retrieved from databases such as PubMed, Embase, Web of Science, and Cochrane. Fifty-four research articles and 21 case reports were screened out according to the inclusion and exclusion criteria for analysis of the etiology of UCHL. Seven research articles with UCHL who underwent exploratory tympanotomy were selected for data extraction and analysis of clinical characteristics. Results: UCHL is a common manifestation of various diseases, including congenital ossicular anomalies (COA), otosclerosis (OTS), congenital middle ear cholesteatoma (CMEC), oval window atresia, superior semicircular-canal dehiscence, congenital stapedial footplate fixation, middle ear osteoma or adenoma, congenital ossification of stapedial tendon, and so on. A total of 522 patients were included in the 7 articles; among whom OTS showed a tendency to increase with age. The main symptoms were hearing loss, followed by tinnitus, dizziness, ear fullness, ear pain, facial paralysis. A total of 87.5% to 93.0% patients with COA manifested as nonprogressive deafness that occurred since childhood, with tinnitus incidence of 15.6% to 30.2%, and 86.4% to 96.4% patients with OTS presented with progressive hearing loss, with tinnitus incidence of 60.1% to 90.9%. The diagnosis positive rate of high-resolution computed tomography (HRCT) was 33.8% to 87.1%, and CMEC was higher than that of COA (83.3%-100% vs 28.6%-64%). All the articles reported good hearing recovery. The most common surgical complications included taste abnormalities, tinnitus, and dizziness. Conclusion: UCHL presents with similar clinical manifestations and poses challenges in preoperative diagnosis. Exploratory tympanotomy is the primary method for diagnosis and treatment, with good prognosis after removing the lesion and reconstructing hearing during the operation. Children can also safely undergo the surgery.

Clinico-radiologic discordance: A case of superior semicircular canal dehiscence by superior petrosal sinus

Clinico-radiologic discordance: A case of superior semicircular canal dehiscence by superior petrosal sinus

Pulsatile Tinnitus: Differential Diagnosis and Approach to Management.

The purpose of this review is to provide an updated approach to the evaluation and management of pulsatile tinnitus (PT), an uncommon but often treatable subtype of tinnitus. Secondary PT can be due to either vascular or non-vascular etiologies, including, but not limited to: neoplasm, arteriovenous malformation or fistula, idiopathic intracranial hypertension, dural venous sinus stenosis, otoacoustic etiologies (e.g., otosclerosis, patulous eustachian tube) and bony defects (e.g., superior semicircular canal dehiscence). Computed tomography (CT) and magnetic resonance imaging (MRI) imaging have comparable diagnostic yield, though each may be more sensitive to specific etiologies. If initial vascular imaging is negative and a vascular etiology is strongly suspected, digital subtraction angiography (DSA) may further aid in the diagnosis. Many vascular etiologies of PT can be managed endovascularly, often leading to PT improvement or resolution. Notably, venous sinus stenting is an emerging therapy for PT secondary to idiopathic intracranial hypertension with venous sinus stenosis. Careful history and physical exam can help establish the differential diagnosis for PT and guide subsequent evaluation and management. Additional studies on the efficacy and long-term outcome of venous sinus stenting for venous stenosis are warranted.

What is known about superior semicircular canal dehiscence syndrome

Introdução: A origem da síndrome foi levantada através do estudo de tomografias computadorizadas onde os sintomas eram acompanhados de falha na cobertura óssea do canal semicircular superior, na fossa craniana média, próximo à dura-máter. Essa doença ainda não é de conhecimento da maioria dos médicos. Objetivo: Atualizar o conhecimento sobre ela para despertar a possibilidade de sua existência durante atendimento médico. Método: Revisão narrativa feita nas plataformas Pubmed e Scielo visando artigos ao tema, incluindo relatos de casos, estudos, revisões e metanálises publicados entre 1998 e 2023. Foram incluídos artigos em inglês, português e espanhol. Os descritores usados foram “superior canal dehiscence syndrome”, “superior canal dehiscence” e “síndrome da deiscência do canal semicircular superior”. Resultado: Foram analisados 47 artigos. Conclusão: O entendimento dessa síndrome é complexo e pouco conhecido, e aprimoramento das estratégias de tratamento requerem abordagem multidisciplinar com investigação contínua na intenção de oferecer melhor qualidade de vida ao portador. Tentativas evolutivas na orientação terapêutica até que se tenha confirmação por evidências de qual é melhor forma de tratamento, é o que na atualidade deve ser feito.

Comparing Approaches for Repair of Superior Semicircular Canal Dehiscence.

Compare outcomes for subjects who underwent middle cranial fossa (MCF) or transmastoid (TM) repair of superior semicircular canal dehiscence (SSCD). Retrospective cohort study. Quaternary-care, academic neurotology practice. Subjects who underwent MCF or TM repair of SSCD between December 1999 and April 2023 were identified. Main outcome measures included demographic data, length of surgery and hospital stay, clinical presentation, and audiometric testing. Ninety-three subjects (97 ears) who underwent surgery for SSCD met inclusion criteria: 58.8% (57) via MCF, 39.2% (38) via TM, and 2.0% (2) via TM + MCF. Median operative time was shorter for the TM (35) compared to the MCF (29) approach (118 vs 151 minutes, P < .001). Additionally, median hospital stays were shorter for TM (36) compared to the MCF (56) approach (15.3 vs 67.7 hours, P < .001). Overall, 92% (49/53) of MCF and 92% (33/36) of TM surgeries resulted in an improvement or resolution of one or more symptoms (P = .84). There was no significant preoperative to postoperative change in the median air conduction pure-tone average (PTA), air-bone gap, or word recognition score in both the MCF and TM groups (P > .05). Improvements of >10 dB in the pre- to postoperative absolute change in bone conduction PTA were noted in 3 subjects in the MCF group and 4 subjects in the TM group (P = .49). The TM approach for SSCD demonstrates shorter operative times and length of hospital stay. The TM and MCF approaches have comparable audiometric and clinical outcomes.

Toward Automating Diagnosis of Middle- and Inner-ear Mechanical Pathologies With a Wideband Absorbance Regression Model.

During an initial diagnostic assessment of an ear with normal otoscopic exam, it can be difficult to determine the specific pathology if there is a mechanical lesion. The audiogram can inform of a conductive hearing loss but not the underlying cause. For example, audiograms can be similar between the inner-ear condition superior canal dehiscence (SCD) and the middle-ear lesion stapes fixation (SF), despite differences in pathologies and sites of lesion. To gain mechanical information, wideband tympanometry (WBT) can be easily performed noninvasively. Absorbance, the most common WBT metric, is related to the absorbed sound energy and can provide information about specific mechanical pathologies. However, absorbance measurements are challenging to analyze and interpret. This study develops a prototype classification method to automate diagnostic estimates. Three predictive models are considered: one to identify ears with SCD versus SF, another to identify SCD versus normal, and finally, a three-way classification model to differentiate among SCD, SF, and normal ears. Absorbance was measured in ears with SCD and SF as well as normal ears at both tympanometric peak pressure (TPP) and 0 daPa. Characteristic impedance was estimated by two methods: the conventional method (based on a constant ear-canal area) and the surge method, which estimates ear-canal area acoustically.Classification models using multivariate logistic regression predicted the probability of each condition. To quantify expected performance, the condition with the highest probability was selected as the likely diagnosis. Model features included: absorbance-only, air-bone gap (ABG)-only, and absorbance+ABG. Absorbance was transformed into principal components of absorbance to reduce the dimensionality of the data and avoid collinearity. To minimize overfitting, regularization, controlled by a parameter lambda, was introduced into the regression. Average ABG across multiple frequencies was a single feature.Model performance was optimized by adjusting the number of principal components, the magnitude of lambda, and the frequencies included in the ABG average. Finally, model performances using absorbance at TPP versus 0 daPa, and using the surge method versus constant ear-canal area were compared. To estimate model performance on a population unknown by the model, the regression model was repeatedly trained on 70% of the data and validated on the remaining 30%. Cross-validation with randomized training/validation splits was repeated 1000 times. The model differentiating between SCD and SF based on absorbance-only feature resulted in sensitivities of 77% for SCD and 82% for SF. Combining absorbance+ABG improved sensitivities to 96% and 97%. Differentiating between SCD and normal using absorbance-only provided SCD sensitivity of 40%, which improved to 89% by absorbance+ABG. A three-way model using absorbance-only correctly classified 31% of SCD, 20% of SF and 81% of normal ears. Absorbance+ABG improved sensitivities to 82% for SCD, 97% for SF and 98% for normal. In general, classification performance was better using absorbance at TPP than at 0 daPa. The combination of wideband absorbance and ABG as features for a multivariate logistic regression model can provide good diagnostic estimates for mechanical ear pathologies at initial assessment. Such diagnostic automation can enable faster workup and increase efficiency of resources.

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

BackgroundSuperior 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.ObjectiveTo determine what preoperative factors, if any, contribute to postoperative outcomes and evaluate symptom resolution in a large SSCD patient cohort.MethodsA 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.Results350 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.ConclusionSurgical 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.