To search for any morphological variation contributing to aetiopathogenesis and the diagnosis of benign paroxysmal positional vertigo, we measured the sizes of the semicircular canals in patients with and without benign paroxysmal positional vertigo using multidetector computed tomography.

Cranial bone computed tomography images of 30 benign paroxysmal positional vertigo patients and 30 control patients were acquired with a 128-slice computed tomography scanner and a transverse plane with a thickness of 0.67 mm. The inner diameter, height and width of the canals were measured.

The width of the anterior semicircular canals, and the width and height of the posterior semicircular canals of the affected ears in benign paroxysmal positional vertigo patients (n = 30) were significantly greater than in the control patients (n = 90; p = 0.001, p = 0.023, p = 0.003, respectively).

In benign paroxysmal positional vertigo patients, the posterior and anterior semicircular canals are longer than those in people without benign paroxysmal positional vertigo. These morphological changes may contribute to elucidating the aetiopathogenesis and be used as a radiological sign for diagnosis of benign paroxysmal positional vertigo disease.

To outline the clinical picture of bilateral posterior canal benign paroxysmal positional vertigo.

A total of 573 patients with posterior canal benign paroxysmal positional vertigo were classified as having unilateral, or true or pseudo bilateral, posterior canal benign paroxysmal positional vertigo, and were treated with the Epley manoeuvre. Statistical significance was set at p < 0.05.

Of the patients, 483 had unilateral and 90 (15.7 per cent) had bilateral presentation. Of the latter, 72 patients had pseudo bilateral posterior canal benign paroxysmal positional vertigo. Comparisons of site of involvement, male to female ratio and the incidence of associated problems in unilateral, and true and pseudo bilateral posterior canal benign paroxysmal positional vertigo did not reveal any statistically significant differences (p = 0.828, p = 0.200, p = 0.142). Comparisons of the number of manoeuvres required to provide symptom relief and the rate of recurrence were significant (p < 0.05).

Identification of true and pseudo bilateral posterior canal benign paroxysmal positional vertigo is important given the differences in aetiology and treatment outcome. Treatment of patients with true bilateral posterior canal benign paroxysmal positional vertigo requires several therapeutic manoeuvre attempts, and patients should be warned about recurrence.

This study aimed to evaluate the quality-of-life outcomes following transmastoid plugging of semicircular canal dehiscence in a newly established service in a UK hospital.

Quality-of-life outcomes were measured using the Glasgow benefit Inventory score in three patients who underwent transmastoid plugging for superior semicircular canal dehiscence between September 2019 and March 2020. Patients also completed pre- and post-operative symptomatic questionnaires and vestibular-evoked myogenic potential testing.

All three patients reported an improvement in overall quality-of-life outcomes with a mean overall Glasgow Benefit Inventory score of +37 (range, +22.2–66.6). There were no immediate post-operative complications and hearing was preserved in all patients.

This study reported an initial successful experience with transmastoid plugging of superior semicircular canal dehiscence. In all patients, improvement in quality-of-life measures and symptoms was reported.

Superior semi-circular canal dehiscence syndrome is a disorder characterised by auditory and vestibular symptoms that can significantly impact quality of life, and yet it has no disease-specific quality of life instrument.

Thirty-six patients who underwent transmastoid superior semicircular canal resurfacing and plugging were included from an initial cohort of 60 surgically managed patients. A sub-cohort of 19 consecutive patients completed validated symptom and quality of life questionnaires before and after surgery. Of the 36 patients, 31 participated in a telephone semi-structured interview post-operatively.

Following surgery, there was a statistically significant improvement in autophony index score (p = 0.02), symptom severity score (p < 0.001) and sound hypersensitivity (p = 0.01). Thematic analysis of telephone interviews suggested three main symptom themes: auditory hypersensitivity, dysequilibrium, headache and concentration difficulties. Dysequilibrium was found to persist post-operatively.

Surgery improves overall symptoms and quality of life. However, important symptom themes may be overlooked using the outcome measures that are currently available. A unified disease-specific outcome measure is urgently required to better understand the impact of symptoms and measure treatment effects.

To determine the short- and long-term outcomes of triple semicircular canal occlusion as a potential alternative for patients with intractable Ménière's disease.

A retrospective case series was performed in university settings, enrolling patients with intractable Ménière's disease with previous maximum treatment, who underwent transmastoid, triple semicircular canal occlusion. The study documented: pre- and post-operative Dizziness Handicap Inventory scores at six weeks and one year post-treatment, pure tone audiometry, and surgical aspects.

Two female patients, aged 42 and 65 years, underwent unilateral three-semicircular-canal occlusion. Their respective Dizziness Handicap Inventory scores improved from 88 to 68 and 54 to 30 at six weeks post-operatively, with scores of 66 and 0 at one year post-treatment. The one patient with pre-existing functional hearing maintained her hearing threshold post-operatively.

Triple semicircular canal occlusion is a safe, hearing-preserving, extracranial alternative technique that can control rotatory vertigo in patients with intractable Ménière's disease, when other measures have failed.

This study aimed to evaluate serum otolin-1 levels in patients with benign paroxysmal positional vertigo and to compare these levels with healthy individuals.

This was a case-control study. After obtaining institutional ethical committee clearance, the serum level of otolin-1 was calculated in adult individuals (18–75 years old) who were divided into group 1 (patients presenting with benign paroxysmal positional vertigo) and group 2 (healthy patients without benign paroxysmal positional vertigo as the control group). Data analysis was carried out to compare the serum levels in the cases and controls. A p-value less than 0.05 was considered significant.

A total of 70 age-matched individuals (cases, n = 40; controls, n = 30) were included in the study. The mean serum level of otolin-1 was 636.8 pg/ml (range, 259–981 pg/ml) in the group of patients with benign paroxysmal positional vertigo and 236.2 pg/ml (range, 189–370 pg/ml) in the control group. The difference was statistically significant (p = 0.0000).

The serum levels of otolin-1 in patients with benign paroxysmal positional vertigo are significantly higher compared with individuals without benign paroxysmal positional vertigo.

This study aimed to evaluate the association between cochlear nerve canal dimensions and semicircular canal abnormalities and to determine the distribution of bony labyrinth anomalies in patients with cochlear nerve canal stenosis.

This was a retrospective study in which high-resolution computed tomography images of paediatric patients with severe-to-profound sensorineural hearing loss were reviewed. A cochlear nerve canal diameter of 1.5 mm or less in the axial plane was classified as stenotic. Semicircular canals and other bony labyrinth morphology and abnormality were evaluated.

Cochlear nerve canal stenosis was detected in 65 out of 265 ears (24 per cent). Of the 65 ears, 17 ears had abnormal semicircular canals (26 per cent). Significant correlation was demonstrated between cochlear nerve canal stenosis and semicircular canal abnormalities (p < 0.01). Incomplete partition type II was the most common accompanying abnormality of cochlear nerve canal stenosis (15 out of 65, 23 per cent).

Cochlear nerve canal stenosis is statistically associated with semicircular canal abnormalities. Whenever a cochlear nerve canal stenosis is present in a patient with sensorineural hearing loss, the semicircular canal should be scrutinised for presence of abnormalities.

Transmastoid occlusion of the posterior or superior semicircular canal is an effective and safe management option in patients with refractory benign paroxysmal positional vertigo or symptomatic superior semicircular canal dehiscence. A method of quantifying successful canal occlusion surgery is described.

This paper presents representative patients with intractable benign paroxysmal positional vertigo or symptomatic superior semicircular canal dehiscence, who underwent transmastoid occlusion of the posterior or superior semicircular canal respectively. Vestibular function was assessed pre- and post-operatively. The video head impulse test was included as a measure of semicircular canal and vestibulo-ocular reflex functions.

Post-operative video head impulse testing showed reduced vestibulo-ocular reflex gain in occluded canals. Gain remained normal in the non-operated canals. Post-operative audiometry demonstrated no change in hearing in the benign paroxysmal positional vertigo patient and slight hearing improvement in the superior semicircular canal dehiscence syndrome patient.

Transmastoid occlusion of the posterior or superior semicircular canal is effective and safe for treating troublesome benign paroxysmal positional vertigo or symptomatic superior semicircular canal dehiscence. Post-operative video head impulse testing demonstrating a reduction in vestibulo-ocular reflex gain can reliably confirm successful occlusion of the canal and is a useful adjunct in post-operative evaluation.

To characterise subjective symptoms in patients undergoing surgical repair of superior semicircular canal dehiscence.

Questionnaires assessing symptom severity and impact on function and quality of life were administered to patients before superior semicircular canal dehiscence surgery, between June 2011 and March 2016. Questionnaire sections included general quality of life, internal amplified sounds, dizziness and tinnitus, with scores of 0–100 points.

Twenty-three patients completed the questionnaire before surgery. Section scores (mean±standard deviation) were: 38.2 ± 25.2 for general quality of life, 52.5 ± 23.9 for internal amplified sounds, 35.1 ± 28.8 for dizziness, 33.3 ± 30.7 for tinnitus, and 39.8 ± 22.2 for the composite score. Cronbach's α statistic averaged 0.93 (range, 0.84–0.97) across section scores, and 0.83 for the composite score.

The Gopen–Yang Superior Semicircular Canal Dehiscence Questionnaire provides a holistic, patient-centred characterisation of superior semicircular canal dehiscence symptoms. Internal consistency analysis validated the questionnaire and provided a quantitative framework for further optimisation in the clinical setting.

Underwater endoscopic ear surgery does not require suction and so protects the inner ear from unexpected aeration that may damage its function in the treatment of labyrinthine fistula. A method of underwater endoscopic ear surgery is proposed for the treatment of superior canal dehiscence.

Underwater endoscopic ear surgery was performed for plugging of the superior semicircular canal through the transmastoid approach. Saline solution was infused into the mastoid cavity through an Endo-Scrub Lens Cleaning Sheath. The tip of the inserted endoscope was filled completely with saline water.

Using this underwater endoscopic view, the canal was clearly dissected to expose the semicircular canal membranous labyrinth and dehiscence area. No particular complication occurred during the surgical procedure.

The underwater endoscopic ear surgery technique for plugging in superior canal dehiscence secures an excellent visual field and protects the inner ear from unexpected aeration.

To determine signs and symptoms for superior canal dehiscence syndrome caused by the superior petrosal sinus.

A review of the English-language literature on PubMed and Embase databases was conducted, in addition to a multi-centre case series report.

The most common symptoms of 17 patients with superior petrosal sinus related superior canal dehiscence syndrome were: hearing loss (53 per cent), aural fullness (47 per cent), pulsatile tinnitus (41 per cent) and pressure-induced vertigo (41 per cent). The diagnosis was made by demonstration of the characteristic bony groove of the superior petrosal sinus and the ‘cookie bite’ out of the superior semicircular canal on computed tomography imaging.

Pulsatile tinnitus, hearing loss, aural fullness and pressure-induced vertigo are the most common symptoms in superior petrosal sinus related superior canal dehiscence syndrome. Compared to superior canal dehiscence syndrome caused by the more common apical location of the dehiscence, pulsatile tinnitus and exercise-induced vertigo are more frequent, while sound-induced vertigo and autophony are less frequent. There is, however, considerable overlap between the two subtypes. The distinction cannot as yet be made on clinical signs and symptoms alone, and requires careful analysis of computed tomography imaging.

To determine if there is gender or laterality predilection in patients with semicircular canal dehiscence syndrome.

A multi-institutional chart review was performed to identify patients diagnosed with semicircular canal dehiscence between 2000 and 2015. A systematic literature search was conducted using PubMed to further identify patients with semicircular canal dehiscence. Age, gender and laterality data were collected. Statistical analysis was performed to evaluate for gender or laterality preponderance.

A total of 682 patients with semicircular canal dehiscence were identified by literature and chart review. Mean age of diagnosis was 49.75 years (standard deviation = 15.33). Semicircular canal dehiscence was associated with a statistically significant female predominance (chi-square = 7.185, p = 0.007); the female-to-male ratio was 1.2 to 1. Left-sided semicircular canal dehiscence was most common, followed by right-sided then bilateral (chi-square = 23.457, p < 0.001).

Semicircular canal dehiscence syndrome is most commonly left-sided and exhibits a female predominance. This may be secondary to morphological cerebral hemisphere asymmetries in both sexes and a predilection of women to seek more medical care than men.

Benign paroxysmal positional vertigo is a common vestibular disorder that negatively affects an individual's health-related quality of life. This study aimed to examine the effectiveness of the Parnes particle repositioning manoeuvre as an intervention for individuals with posterior canal benign paroxysmal positional vertigo.

The de-identified records of 155 individuals treated with the Parnes manoeuvre were examined. Descriptive statistics were calculated, including the frequency and valid per cent of participants whose nystagmus was resolved with the Parnes manoeuvre.

In all, nystagmus was resolved with the Parnes manoeuvre in 145 participants (93.5 per cent). The mean number of manoeuvres needed to resolve the nystagmus was 1.3.

The Parnes manoeuvre proved to be as effective as the Epley canalith repositioning manoeuvre, currently the most common intervention, in treating individuals with posterior canal benign paroxysmal positional vertigo.

This paper reports five cases of aberrant cochlear implant electrode array insertion into the vestibular labyrinth. A review of the literature was conducted in order to clarify reasonable preventive and detection strategies and endorse the routine use of intra-operative plain skull X-ray.

The study entailed a clinical case series and literature review. The setting was a tertiary academic referral centre. The following data were evaluated: pre-operative temporal bone computed tomography, operative reports, intra-operative imaging, neural response telemetry/imaging and post-operative imaging.

There were no consistent pre-operative risk factors found on computed tomography scans and no reliable intra-operative signs of electrode array misdirection. All misdirections in our case series, and those in the literature, were easily detectable on intra-operative plain film X-ray.

These reported cases demonstrate implant misdirection without the surgeon's awareness. Aberrant insertion cannot be anticipated, and neural response telemetry/imaging is not a reliable indicator of misdirection. Routine intra-operative anteroposterior plain X-ray of the head is a reliable indicator of misdirection, and is fast and relatively inexpensive.

This study was conducted to investigate the angles and orientation of semicircular canals, and the coplanarity of functional canal pairs.

Fluid signals in semicircular canals were reconstructed with three-dimensional reconstruction software using 20 temporal bone magnetic resonance images of normal subjects. The angles between each pair of semicircular canals were measured.

The mean angles between the anterior and horizontal semicircular canal plane, the horizontal and posterior semicircular canal plane, and the anterior and posterior semicircular canal plane were 83.7°, 82.5° and 88.4°, respectively. Pairs of contralateral synergistic canal planes were formed 15.1° between the right and left horizontal semicircular canal planes, 21.2° between the right anterior and left posterior semicircular canal, and 21.7° between the left anterior and right posterior semicircular canal.

Each semicircular canal makes an almost right angle with other canals, but synergistically acting functional canal pairs of both ears do not lie in exactly the same plane.

This study aimed to review the current advances in superior semicircular canal dehiscence syndrome and to ascertain its aetiology, whether dehiscence size correlates with symptoms, signs and investigation results, the best investigations, and its surgical management.

A literature search using the key words ‘superior semicircular canal dehiscence’ was performed using the Allied and Complementary Medicine Database and the Embase, Health Management Information Consortium, Medline, PsycINFO, British Nursing Index, Cinahl and Health Business Elite databases for the period January 2009 to May 2014. Systematic reviews, meta-analyses, randomised controlled trials, prospective and retrospective case series, case reports, and observational studies were included.

Of the 205 papers identified, 35 were considered relevant.

The aetiology of superior semicircular canal dehiscence syndrome is unclear. Dehiscence size significantly affects the air–bone gap and ocular vestibular evoked myogenic potential thresholds. Computed tomography evaluation has a high false positive rate. The middle cranial fossa approach is the surgical standard for treating this syndrome; however, the transmastoid approach is gaining popularity.

To describe a case of bilateral superior and posterior semicircular canal dehiscences, and the use of a unilateral transmastoid approach to address both right-sided defects simultaneously.

In a patient with right-sided hyperacusis, bilateral dehiscence of both the superior and the posterior semicircular canals was identified, located adjacent to the common crus, together with a right-sided, anterosuperiorly positioned sigmoid sinus and a high-riding jugular bulb. Results for audiography and cervical vestibular evoked myogenic potential testing were consistent with right-sided semicircular canal dehiscence. At surgery, a right-sided transmastoid approach provided access to plug both defects simultaneously, following posterior mobilisation of the sigmoid sinus. The patient's hyperacusis was completely resolved, with a 10–30 dB improvement in his right ear air conduction hearing, without decrement in bone conduction.

In properly selected patients, a transmastoid approach can be used to effectively manage superior semicircular canal dehiscence and posterior semicircular canal dehiscence simultaneously. Pre-operative computed tomography is recommended to evaluate the dehiscence sites and to identify complicating vascular anatomy.

Conductive hyperacusis in superior semicircular canal dehiscence syndrome occurs due to the presence of a ‘third window’ created by the dehiscence. Reversible blocking of the round window can, in theory, cause a reduction in the compression-related volume displacement, and thereby minimise symptoms of conductive hyperacusis. This study describes a technique of permeatal blocking of the round window.

The tympanomeatal flap is elevated and the round window niche is identified. The round window membrane is subsequently identified and occluded with bone wax, muscle and fascia, in three separate layers. Finally, the tympanomeatal flap is reflected, and an ear wick is inserted.

Two patients who underwent the procedure reported a reduction in symptoms. Importantly, no Tullio phenomenon was reported post-operation.

Blocking of the round window can be used to control symptoms of superior semicircular canal dehiscence syndrome in patients who present solely with symptoms of conductive hyperacusis. This technique provides an alternative to resurfacing techniques. The procedure is simple to perform, reversible and can be undertaken as day-case surgery.

We report a rare case of posterior semicircular canal dehiscence caused by a jugular diverticulum, and we describe its surgical treatment using a dehiscence resurfacing manoeuvre.

The clinical findings, surgical procedure and outcomes are presented.

A 66-year-old man presented with disequilibrium, sound-induced vertigo, a reduced ocular vestibular evoked myogenic potential threshold, and pressure-induced vertical and torsional nystagmus. Computed tomography revealed a right posterior semicircular canal dehiscence caused by a diverticulum of the jugular bulb. The defect in the posterior semicircular canal was localised and resurfaced with bone paté, temporalis muscle fascia and conchal cartilage, under direct visualisation. Post-operatively, the patient's symptoms disappeared and his ocular vestibular evoked myogenic potential threshold normalised.

This case illustrates that posterior semicircular canal dehiscence can be surgically managed by resurfacing the defect site via a transmastoid approach.