Superior Canal Dehiscence Research Articles

Practicality of multilayer round window reinforcement in the surgical management of superior semicircular canal dehiscence syndrome: a case report of long-term follow-up.

Several surgical techniques have been documented for approaching and repairing superior semicircular canal dehiscence syndrome (SCDS). These techniques encompass the trans-middle cranial fossa, transmastoid, endoscopic approaches, and round window reinforcement (RWR). RWR entails the placement of connective tissue with or without cartilage and around the round window niche, restricting the round window's movement to minimize the 3rd window effect and restore the bony labyrinth closer to its normal state. We employed the multilayer RWR technique, resulting in significant postoperative improvement and long-lasting effects for 3.7 years in 2 cases. Here, we present the clinical findings, surgical procedures, and the effectiveness of multilayer RWR. This technique can be the initial choice for surgical treatments of SCDS due to its high effectiveness, longer-lasting effect, and minimal risk of surgical complications.

Primary Stapedectomy: A Retrospective Review of Surgical Results Using a Cold Steel Technique and Pre-Operative CT Correlates.

Stapedectomy is an effective treatment option for patients with symptomatic otosclerosis. A common surgical technique today is laser stapedotomy, although the equipment required adds a significant cost to the procedure and may not be available in certain, particularly remote, centers. This study aimed to evaluate cold steel stapedectomy in a modern otology practice as a cost-effective and versatile alternative. The primary objective was to evaluate the efficacy and safety of cold steel stapedectomy. The secondary objectives included characterizing the prevalence of relevant computed tomography (CT) findings and evaluating other factors such as piston size. A retrospective case series from April 2006 to November 2021. A single tertiary care hospital in Montreal, QC, Canada. Patients with suspected otosclerosis and no prior stapes surgery. Cold steel primary stapedectomy. In primary analysis, change in pure tone thresholds, pure tone average (PTA), and complication rates were obtained. Secondary analysis measures included rates of relevant CT findings and change in PTA with piston size. A total of 302 cases were included in the analysis. The average change in air conduction PTA was a decrease of 27 dB, with 91% (276/302) having over 10 dB of improvement. The air-bone gap was closed to within 10 dB in 82% (248/302) of cases and within 20 dB in 96% (290/302) of cases. Overclosure occurred in 19% of cases, while only 4% resulted in worsened PTA bone conduction thresholds. In secondary analysis, 74% of CT scans demonstrated radiologic otosclerosis. Other findings included suspected superior semicircular canal dehiscence in 1.8%. Cold steel stapedectomy was demonstrated to be a safe and effective technique, with audiometric results comparable to laser and drill studies in recent literature. It should be considered as a cost-effective and global health accessible alternative. Additionally, CT scans can provide valuable information in the pre-operative workup.

Narrowing of Low-Frequency Air-Bone Gap and Its Association with Symptom Resolution Following Superior Canal Dehiscence Repair.

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. Cohort study. Tertiary Care Center. 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. 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% CI1-30) increase in auditory, and 23-point (β 95% CI2-45) increase in vestibular SRS, respectively. However, LABG narrowing was not significantly associated with the rates of auditory and vestibular OSI at all frequencies assessed. 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.

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

Superior semicircular canal dehiscence (SSCD), an osseous defect overlying the SSC, is associated with aconstellation 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. Included patients were prospectively recruited to undergo atemporal 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. In the study 31patients were evaluated, for atotal of 60individual temporal bones (2were 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 afalse 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). 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.

Delayed Diagnoses in Patients With Dizziness in the US Commonwealth of Virginia and the Tidewater Region.

In a region of approximately 1.7 million people (Tidewater, coastal Virginia), identify secondary diagnoses in persons with dizziness. This cross-sectional study utilizing TriNetX included individuals in the region of interest diagnosed with dizziness between 2010 and 2020. Subsequent diagnoses of vestibular disease or medical conditions possibly associated with dizziness in the same subjects were catalogued. During the study period, 31,670 subjects were identified with diagnoses of dizziness as a symptom; 18,390 subjects were subsequently given a dizziness-related nonvestibular diagnosis, and 930 were given a subsequent vestibular disease diagnosis. The proportion of subjects diagnosed with vestibular disease (3%) after the dizziness diagnosis is far below expected norms (25%-34%) in the general population. There were greater proportions of delayed diagnoses of labyrinth dysfunction (odds ratio [OR], 4.8; P < 0.0001), superior semicircular canal dehiscence (OR, 3.1; P = 0.0023), otolith disease (OR, 3.1; P = 0.0023), among others, and a decreased proportion of delayed diagnosis of benign paroxysmal positional vertigo (OR, 0.56; P < 0.0001). The discrepancy between expected and observed prevalence in our region indicates that vestibular disease is likely underdiagnosed.

SURG-45. THE EFFECT OF STAPEDECTOMY IN POSTOPERATIVE OUTCOME OF SUPERIOR SEMICIRCULAR CANAL DEHISCENCE: A CASE SERIES OF 349 REPAIRS

Abstract INTRODUCTION Superior Semicircular Canal Dehiscence (SSCD) is a pathology of the otic capsule, in which, a “third mobile window” is formed on the osseous labyrinth surrounding the superior semicircular canal. Otosclerosis, another otic capsule pathology, can occur concurrently, therefore obscuring the symptoms seen in patients with SSCD. It is currently unknown whether the surgical procedures to treat otosclerosis such as stapedectomy can affect symptom resolution in patients following SSCD repair. Objective: To examine the association between post-SSCD repair symptom resolution and history of stapedectomy. METHODS A single institution retrospective review was conducted to evaluate post-operative symptom resolution in patients undergoing SSCD repair from 2011-2021. 349 SSCD repairs performed in a cohort of 279 patients were included, and among those were 10 patients with a history of stapedectomy. A p-value &amp;lt; 0.05 was considered statistically significant. RESULTS A total of 349 surgical repairs were analyzed. The patient population was composed of 63% female and 37% male with patient ages’ ranging from 13-84 years. Patients were divided into two different cohorts based on their history of stapedectomy. We compared these cohorts looking at their post-SSCD repair symptom changes and found no statistically significant differences between patients with and without history of stapedectomy. We also compared pre- and post-operative symptoms amongst the 10 patients with a history of stapedectomy and found no statistically significant differences in symptom resolution post-SSCD repair. Post-operative symptoms analyzed included amplification (p = 0.2), aural fullness (p = 0.2), autophony (p = 0.8), disequilibrium/imbalance (p = 0.8), dizziness (p = 0.3), headache (p = 0.7), hearing loss (p = 1), hyperacusis (p = 1), tinnitus (p = 0.4), and vertigo (p = 0.3). CONCLUSIONS With respect to symptom resolution post-SSCD repair, there were no significant differences between patients with and without a history of stapedectomy. Hence, previous stapedectomy surgery should not be considered an adverse condition to SSCD repair, with similar rates of improvement after SSCD surgery.

First-Side and Second-Side Repair of Bilateral Superior Canal Dehiscence.

Bilateral superior canal dehiscence (SCD) may warrant surgeries on both sides. With repairs of unilateral SCD as reference, we investigate the comparativeeffectiveness 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. 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. 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). 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. 3 Laryngoscope, 134:1882-1888, 2024.

Superior semicircular canal dehiscence: a radiological and clinical study.

to assess radiologically the prevalence of SSCD with its clinical presentations and its relationship with age. a prospective cohort study carried out on 200 consecutive patients (400 temporal bones). Radiological evaluation was performed using High Resolution Computed Tomography (HRCT) with measurement of thickness of bone covering superior semicircular canal (SCC), height and diameter of SSC. Two hundred patients (400 temporal bones) were involved. The mean thickness ± SD, the mean diameter ± SD and the mean height ± SD were 1.38 ± 0.80mm, 0.94 ± 0.26mm and 10.91 ± 2.39mm respectively. The prevalence of SSCD and predehiscence were 1% and 14% respectively. The commonest symptom encountered was autophony (48.3%). When the SSC thickness, diameter and height were compared with the age of patients, statistically significant differences were detected. The highest diameter, lowest height and lowest thickness were found in patients aged from 54 to 72 years. Thickness of bony layer covering SSC was found to be the most validated measurement for differentiation between cases with positive and negative symptoms with the highest sensitivity and specificity. The prevalence of SSCD and predehiscence varied among the studies. Autophony is the commonest symptom usually encountered. The condition is acquired rather than congenital. The thickness of bone covering SCC is the most validated measurement in differentiation between cases with positive and negative symptoms.

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

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. 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. 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. 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.

Impaired Vestibulo-Ocular Reflex on Video Head Impulse Test in Superior Canal Dehiscence: "Spontaneous Plugging" or Endolymphatic Flow Dissipation?

Surgical plugging of the superior semicircular canal (SSC) represents an effective procedure to treat disabling symptoms in superior canal dehiscence (SCD), despite resulting in an impaired vestibulo-ocular reflex (VOR) gain for the SSC. On the other hand, SSC hypofunction on video head impulse test (vHIT) represents a common finding in patients with SCD exhibiting sound/pressure-induced vertigo, a low-frequency air-bone gap (ABG), and enhanced vestibular-evoked myogenic potentials (VEMPs). "Spontaneous canal plugging" has been assumed as the underlying process. Nevertheless, missing/mitigated symptoms and/or near-normal instrumental findings would be expected. An endolymphatic flow dissipation has been recently proposed as an alternative pathomechanism for SSC VOR gain reduction in SCD. We aimed to shed light on this debate by comparing instrumental findings from 46 ears of 44 patients with SCD exhibiting SSC hypofunction with post-operative data from 10 ears of 10 patients with SCD who underwent surgical plugging. While no difference in SSC VOR gain values was found between the two groups (p = 0.199), operated ears developed a posterior canal hypofunction (p = 0.002). Moreover, both ABG values (p = 0.012) and cervical/ocular VEMP amplitudes (p < 0.001) were significantly higher and VEMP thresholds were significantly lower (p < 0.001) in ears with SCD compared to operated ears. According to our data, canal VOR gain reduction in SCD should be considered as an additional sign of a third window mechanism, likely due to an endolymphatic flow dissipation.

Superior semicircular canal dehiscence and subsequent closure induces reversible impaired decision-making.

Vestibular loss and dysfunction has been associated with cognitive deficits, decreased spatial navigation, spatial memory, visuospatial ability, attention, executive function, and processing speed among others. 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; however, individuals also experience measurable deficits in basic decision-making, short-term memory, concentration, spatial cognition, and depression. These suggest central mechanisms of impairment are associated with vestibular disorders; therefore, we directly tested this hypothesis using both an auditory and visual decision-making task of varying difficulty levels in our model of SSCD. Adult Mongolian gerbils (n = 33) were trained on one of four versions of a Go-NoGo stimulus presentation rate discrimination task that included standard ("easy") or more difficult ("hard") auditory and visual stimuli. After 10 days of training, preoperative ABR and c+VEMP testing was followed by a surgical fenestration of the left superior semicircular canal. Animals with persistent circling or head tilt were excluded to minimize effects from acute vestibular injury. Testing recommenced at postoperative day 5 and continued through postoperative day 15 at which point final ABR and c+VEMP testing was carried out. Behavioral data (d-primes) were compared between preoperative performance (training day 8-10) and postoperative days 6-8 and 13-15. Behavioral performance was measured during the peak of SSCD induced ABR and c + VEMP impairment and the return towards baseline as the dehiscence began to resurface by osteoneogenesis. There were significant differences in behavioral performance (d-prime) and its behavioral components (Hits, Misses, False Alarms, and Correct Rejections). These changes were highly correlated with persistent deficits in c + VEMPs at the end of training (postoperative day 15). The controls demonstrated additional learning post procedure that was absent in the SSCD group. These results suggest that aberrant asymmetric vestibular output results in decision-making impairments in these discrimination tasks and could be associated with the other cognitive impairments resulting from vestibular dysfunction.

Hearing Results after Transmastoid Superior Semicircular Canal Plugging for Superior Semicircular Canal Dehiscence: A Meta-Analysis.

The transmastoid plugging of a superior semicircular canal is considered a safe and effective technique for the management of superior semicircular canal dehiscence (SSCD). The aim of this meta-analysis is to assess the postoperative hearing outcomes after the transmastoid plugging of the superior semicircular canal. Search method and data sources: A systematic database search was performed on the following databases until 30 January 2023: MEDLINE, Embase, Cochrane Library, Web of Science, CINAHL, ICTRP, and clinicaltrials.gov. A systematic literature review and meta-analysis of the pooled data were conducted. We also included a consecutive case series with SCDS for those who underwent transmastoid plugging treatment at our clinic. We identified 643 citations and examined 358 full abstracts and 88 full manuscripts. A total of 16 studies were eligible for the systematic review and 11 studies for the meta-analysis. Furthermore, 159 ears (152 patients) were included. The postoperative mean air conduction threshold remained unchanged (mean difference, 2.89 dB; 95% CI: -0.05, 5.84 dB, p = 0.58), while the mean bone conduction threshold was significantly worse (mean difference, -3.53 dB; 95% CI, -6.1, -0.95 dB, p = 0.9). The transmastoid plugging technique for superior semicircular canal dehiscence syndrome, although minimally worsening the inner ear threshold, is a safe procedure in terms of hearing preservation and satisfactory symptom relief.

An evidenced-based diagnostic tool for superior semicircular canal dehiscence syndrome

PurposeTo construct a symptoms-based prediction tool to assess the likelihood of superior canal dehiscence (SSCD) on high-resolution CT. Materials and methodsMathematical modeling was employed to predict radiologic evidence of SSCD at a tertiary neurotology referral center. ResultsA total of 168 patients were included, of which 118 had imaging-confirmed SSCD. On univariate analysis significant predictors of SSCD presence were: sound/pressure-induced vertigo (p = 0.006), disequilibrium (p = 0.008), hyperacusis (p = 0.008), and autophony (p = 0.034). Multivariate analysis enabled a 14-point symptom-weighted tool to be developed, wherein a score of ≥6 raised the suspicion of SSCD (≥70% likelihood of being present), R2 = 0.853. ConclusionsThe likelihood of SSCD on CT scan can be determined with a high degree of certainty based on symptoms recorded at presentation. Using the evidenced-based diagnostic tool validated herein, a score ≥6 with any symptom combination justifies ordering a CT scan.

Superior Semicircular Canal Dehiscence: a Potential Cause of Vestibular and Auditory Impairment Following Head Trauma

Superior Semicircular Canal Dehiscence: a Potential Cause of Vestibular and Auditory Impairment Following Head Trauma

MRI features to aid the identification of lateral temporal bone cephaloceles.

To evaluate ancillary MRI features which may aid the identification of lateral temporal bone cephaloceles (LTBCs). A retrospective cohort study analysed patients with MRI evidence of surgically confirmed spontaneous LTBCs as defined by intracranial contents traversing the tegmen tympani or mastoideum. Cases were identified from radiology and surgical databases. Two observers analysed three-dimensional T 2W temporal bone and whole brain imaging according to a priori criteria by consensus, with emphasis on the relationship of any adjacent cerebrospinal fluid (CSF) cleft to the defect. The contents, location, and clinical features of the LTBCs were recorded. Eighteen patients (11 female, 7 male; mean age 59.3 years, age range 42-86 years) with 20 surgically confirmed spontaneous LTBCs (2 bilateral;16 unilateral) were evaluated. A temporal lobe sulcus or other CSF cleft extending to or traversing the defect was identified in 19/20 (95%) cases. Isointense CSF tympanomastoid signal was present in 41.2% cases, whilst superior semi-circular canal dehiscence was found in 40% of cephaloceles. At least two MRI features of idiopathic intracranial hypertension were seen in 38.9% patients. Cephaloceles were most commonly centred on the tegmen tympani (55%). Meningoencephaloceles were present in 95% cases. A temporal lobe sulcus or CSF cleft extending to or traversing the defect may aid the identification of LTBCs. Isointense CSF tympanomastoid signal, superior semi-circular canal dehiscence and MRI features of idiopathic intracranial hypertension are only present in under half of LTBCs. The study details novel ancillary MRI features of LTBCs which may aid their identification.

Managing cholesteatomas with labyrinthine fistula.

A retrospective study (2011 to 2018) was conducted to evaluate the management of cholesteatomas with labyrinthine fistulae (LFs), clinical characteristics and postoperative hearing outcomes in a hospital. Demographic data of patients with primary middle ear mastoidectomies for cholesteatoma were extracted. Preoperative high-resolution computed tomography (HRCT) temporal bone and intraoperative findings, and hearing levels preoperatively and postoperatively were evaluated. Of the middle ear cholesteatomas, 15.6% (n = 14) of ears were complicated by LF. HRCT scans showed 92.9% sensitivity and 94.7% specificity in the identification of LFs. Intraoperative findings of LFs include stapes erosion (78.6%), malleus erosion (78.6%), incus erosion (92.9%), dehiscence of tegmen tympani (28.6%) and tympanic facial canal (64.3%). Compared to the non-LF group, the LF group showed significantly higher incidence of stapes erosion (P < 0.001), tegmen tympani dehiscence (P = 0.016) and semicircular canal dehiscence (P < 0.001). Matrix was removed completely in 85.7% (n = 12) and was left behind in 14.3% (n = 2) of ears. Also, 21.5% (n = 3) had preoperative dead ears. Postoperative hearing results had a mean follow-up time of 2.1 (standard deviation 1.5, range 0.14-4.84) years. In the matrix removal group (n = 9), 77.9% had unchanged hearing levels, 11.1% showed improvement and 11.1% showed decrease in hearing levels. The matrix preservation group (n = 2) had deteriorated hearing levels. Preservation of hearing in LFs is possible with cautious matrix removal. Despite matrix preservation to preserve hearing in large LFs, our patients' hearing deteriorated postoperatively. Longer follow-up of hearing with matrix preservation may show poorer hearing outcomes.

Low-Lying Tegmen and Surgical Outcomes Following the Middle Cranial Fossa Repair of Superior Canal Dehiscence.

To compare treatment response from the middle cranial fossa repair of superior canal dehiscence (SCD) between cases with and cases without low-lying tegmen (LLT). Cohort study. Single tertiary care institution. Two investigators independently reviewed preoperative high-resolution temporal bone computed tomography images and classified the ipsilateral tegmen as either "low-lying" or "control." Patients completed a symptom questionnaire and underwent audiometric testing pre- and post-operatively. Multivariable regression models assessed for symptomatic resolution and audiometric improvement following surgery with tegmen status as the primary predictor. Models controlled for patient age, sex, bilateral SCD disease, dehiscence location, prior ear surgery status, surgery duration, and follow-up duration. Among a total of 410 cases included, we identified 121 (29.5%) LLT cases. Accounting for all control measures, patients with LLT were significantly less likely to experience overall symptom improvement (adjusted odds ratio: 0.32, 95% confidence interval [CI]: 0.18-0.57, p < .001) and reported a significantly lower proportion of preoperative symptoms that resolved following surgery (adjusted β: -25.6%, 95% CI: -37.0% to -14.3%, p < .001). However, audiometric outcomes following surgery did not differ significantly between patients with and patients without LLT. This is the first investigation on the relationship between LLT and surgical outcomes following the middle fossa repair of SCD. Patients with LLT reported less favorable symptomatic response but exhibited a similar degree of audiometric improvement.

Why should multiple dehiscences of the otic capsule be considered before surgically treating patients with superior semicircular canal dehiscence? A radiological monocentric review and a case series.

This review aims to draw attention to the multiple ipsilateral otic capsule dehiscences (OCDs), which may cause therapeutic failure in operated patients. A series of six severely disabled patients with symptoms and signs consistent with a superior semicircular canal dehiscence (SSCD) diagnosis, confirmed by a high-resolution CT scan, is presented here. Five of the patients underwent surgery, and in four of the cases, the postoperative results were poor and/or disappointing. The ethical principles underlying modern medicine encourage medical staff to learn from past experience even when the results are modest despite the accuracy of the treatment applied to a patient. Consequently, we reviewed the radiological records of symptomatic and asymptomatic patients diagnosed or referred to our center for confirmation over the past 5 years to determine the incidence of multiple OCD in this population. Multiple localizations of suspected OCD in the ipsilateral ear did not appear to be rare and were found in 29 of 157 patients (18.47%) in our retrospective review using high-resolution thin-sliced CT scans. The decision to perform surgery for a documented symptomatic superior SSCD should be made with caution only after ruling out concomitant lesser-known variants of OCD in the ipsilateral ear.

Literature study: Superior semicircular canal syndrome (SSCS)

Superior Semicircular Canal Syndrome (SSCS) or Superior Canal Dehiscence Syndrome is a rare abnormality in the medical field in the form of balance disturbance or vertigo caused by loud noises or changes in pressure causing rupture of the roof of the superior semicircular canal. SSCS was first described by Lloyd Minor in 1998 after more than 70 years since Tullio and Hennebert discovered the Tullio phenomenon, a condition in which vertigo or nystagmus is triggered by loud noises, and the Hennebert phenomenon, a condition in which vertigo or nystagmus, is triggered by changes in pressure. The exact prevalence of superior semicircular canal syndrome is not known until now. Estimates of prevalence varied from 0.5–2% of cases in temporal bone studies, to 3–9% of cases in studies performed with CT scans. Cases of SSCS are more common in males than females. Clinical symptoms that appear in SSCS are caused by dehiscence so that patients will complain of autophonia, which the sound produced by their body sounds louder, hyperacusis, tinnitus, vertigo which is triggered by loud noises, and nystagmus. A Careful history, an examination of hearing and balance function, also high-resolution CT scan are needed to establish the diagnose of SSCS. Management can be done conservatively. If the complaints are severe, then operative options can be considered.

MDCT of Dehiscent or Thin Bone Coverage over the Superior Semicircular Canal: Assessment of Prevalence by Age and Contralateral Canal Bone Thickness

Objective: Superior semicircular canal dehiscence (SSCD) describes the presence of a defect in the superior bone coverage of the membranous SSC. The etiology of the defect is not known and its reported CT prevalence is variable. This study primarily aimed to report MDCT prevalences of SSCD and thin bone coverage over SSC among different age groups. A secondary aim was to assess for any association between SSCD and the thickness of contralateral bone coverage over SSC.&#x0D; Materials and Methods: Temporal bone MDCTs were retrospectively evaluated for SSCD and the thickness bone coverage over SSC. The prevalences of SSCD and thin bone coverage over SSC among different age groups, and the thickness of bone over SCC in SSCD and non-SSCD subjects were analyzed.&#x0D; Results: 509 subjects were included in the study. Age-adjusted models did not demonstrate a significant association between the age groups and the prevalence of SSCD (p=0.63) or between the age groups and the prevalence of thin bone coverage over SSC (p=0,81). Unilateral SSC roof thickness of ≤ 0.5 mm was significantly associated with increased prevalence of contralateral SSCD (p=0.05 and p=0.04). In subjects without radiological evidence of SSCD, right-or left-sided thin bone coverage over SSC was significantly associated with contralateral thin bone coverage (p