Joost van Dinther

A superior semicircular canal dehiscence syndrome multicenter study: is there an association between size and symptoms?

Objective: The aim of this investigation was to determine if there is any association between the size of the canal dehiscences and the symptoms and signs of patients presenting with the superior semicircular canal dehiscence syndrome. Study Design: Prospective multicenter study. Setting: Tertiary referral center. Patients: Twenty-seven patients, 14 females and 13 males, aged 25 to 83 years, coming from Switzerland, France, Belgium, or Italy, with dehiscence of the superior semicircular canal diagnosed by high-resolution computed tomographic scans of the temporal bone. Interventions: Audiologic tests, a battery of vestibular tests (Tullio phenomenon, Hennebert sign, Valsalva maneuver), vestibular evoked myogenic potentials (VEMPs), and high-resolution computed tomographic scans of the temporal bone. Main Outcome Measures: Association between the symptoms/signs and the size of the superior canal dehiscence. Results: Clinically patients could be divided into three different groups: Superior canal dehiscences (≥2.5 mm) presented predominantly with cochleovestibular symptoms and/or signs (sensitivity, 91.7%; specificity, 70%), whereas smaller ones showed either cochlear or vestibular dysfunction. Patients with larger dehiscences were significantly more associated with vestibulocochlear symptoms/signs, lower VEMP thresholds, and objective vestibular findings (e.g., Tullio phenomenon) than subjects with smaller bony defects. No significant association between the size of the dehiscence and the audiogram pattern or individual findings could be found. The location of the dehiscence seemed to have no influence on the clinical manifestation and findings. Conclusion: Patients with larger superior canal dehiscences show significantly more vestibulocochlear symptoms/signs, lower VEMP thresholds, and objective vestibular findings compared with smaller ones. Smaller dehiscences mainly present with either cochlear or vestibular dysfunction.

Skin reactions following BAHA surgery using the skin flap dermatome technique

The objectives of the study were to determine the incidence of skin reactions and complications associated with bone-anchored hearing aid (BAHA) implantation. The study is a retrospective case review done in a tertiary referral center. One hundred thirty-eight consecutive patients between 1998 and 2008 underwent implantation of a BAHA and were regularly seen for follow-up. Indications included conductive or mixed hearing loss where a hearing aid cannot be used and since 2000 also had contralateral single-sided perceptive hearing loss. BAHA implantation was done by creating a pedicled flap using the skin flap dermatome technique. Postoperative incidence of skin reactions and complications were measured. Significant postoperative complications requiring revision surgery occurred 37 times in 30 patients. Normal skin healing was seen in 52 patients (63.4%), while abnormal skin healing occurred in 30 patients (36.6%). This study showed that skin problems occur more often than expected. Because of the skin problems with the skin flap technique, the authors have switched to the linear incision technique, hoping to decrease the incidence of skin problems.

A splice-site mutation and overexpression of MYO6 cause a similar phenotype in two families with autosomal dominant hearing loss

Hearing loss is the most common sensory disorder, affecting 1 in 650 newborns. Linkage analysis revealed linkage to locus DFNA22 in two Belgian families 1 and 2 with autosomal dominant sensorineural hearing loss. As MYO6 has previously been reported as responsible for the hearing loss at loci DFNA22 and DFNB37, respectively, DNA sequencing of the coding region and the promoter of MYO6 was performed but this analysis did not reveal any mutations. However, only in patients of family 2, an insertion of 108 bp was identified in the mRNA of the gene. The inserted fragment was part of intron 23 and sequencing of this intron revealed a new splice-site mutation c.IVS23+2321T>G, segregating with the hearing loss in the family. The mutation causes a frameshift and a premature termination codon, but real-time PCR revealed that only 15–20% of the mRNA is degraded by nonsense-mediated decay, while the other part may give rise to an aberrant protein. In family 1, a quantitative real-time PCR experiment revealed a 1.5–1.8-fold overexpression of MYO6 in patients compared to controls. The possible presence of a gene duplication could be excluded by real-time PCR on genomic level. Most likely, the overexpression is caused by a mutation in an unidentified regulatory region of the gene. This study indicates that the inner ear hair cells are sensitive to changes in expression levels of MYO6.

Transmastoid repair of superior semicircular canal dehiscence.

Objective/Hypothesis Superior semicircular canal (Sup SC) dehiscence syndrome is a rare condition, causing a variety of auditory and vestibular symptoms. The traditional surgical management is a middle cranial fossa, extradural approach to resurface the Sup SC. Recently, a transmastoid approach for plugging of the Sup SC has been developed. We present further data supporting the use of the transmastoid approach in preference to the middle fossa approach. Design This is a retrospective multi-institutional case series. Method We included 10 patients in this case series from two tertiary otology institutions. Sup SC dehiscence was confirmed by correlation of clinical symptoms with positive audiometric, vestibular evoked myogenic potential, and computed tomography findings. A transmastoid approach was used for plugging of the Sup SC. Either a single fenestration was created at the site of dehiscence or separate fenestrations sited ampullopetal and ampullofugal to the dehiscence. Results All patients who underwent this procedure had good symptom control and hearing preservation postoperatively. Conclusion In patients with adequate temporal bone pneumatization, the transmastoid approach provides a safe and effective alternative to the middle cranial fossa approach. This series has demonstrated excellent symptom control and preservation of hearing with the transmastoid approach.

Genotype-Phenotype Correlation for DFNA22: Characterization of Non-Syndromic, Autosomal Dominant, Progressive Sensorineural Hearing Loss due to MYO6 Mutations

Clinical and audiological examination was done in 2 Belgian families with autosomal dominant sensorineural hearing loss (SNHL) linked to DFNA22. Nineteen subjects in family 1 had mild to moderate SNHL starting in the third decade. The hearing loss was characterized by a flat audiogram affecting all tested frequencies with statistically significant progression. In family 2 eleven subjects were affected with mild to moderate SNHL starting in the second decade. Most of them showed a flat audiogram, but some had mid-frequency hearing loss. Significant progression of thresholds was present at 4 and 8 kHz. For all hitherto known DFNA22 families the audiological and clinical characteristics were correlated with the molecular data. This study describes the phenotype of 2 Belgian families with SNHL linked to DFNA22, both with a pathogenic change in the deafness gene MYO6. The phenotypes of all hitherto reported DFNA22 families with mutations in the MYO6 gene have been studied and compared. It seems that genetic defects that spare the motor domain of the myosin VI protein have a milder phenotype.

Handling an Isolated Malleus Handle Fracture: Current Diagnostic Work-up and Treatment Options.

Background: An isolated malleus handle fracture is rare and presents with vague otological symptoms. Diagnosis depends on careful history taking and otoscopic examination. Different treatment options are available. Reconstruction with hydroxyapatite bone cement is a relatively new technique. Objective: The aim of this article is to review the current diagnostic work-up and treatment options and to demonstrate our method of treatment with hydroxyapatite bone cement. Methods: Three cases, repaired with hydroxyapatite bone cement in a tertiary referral otologic center, were retrospectively analyzed. A review of the literature on diagnosis and treatment procedures was performed. Results: One fracture occurred by withdrawing a finger from the external auditory canal and 2 occurred without clear prior trauma. Our 3 cases were successfully repaired with hydroxyapatite bone cement. Conclusion: Diagnosis of an isolated malleus handle fracture still depends on careful clinical examination. In addition to pure tone audiometry, both low and higher frequency tympanometry may be useful. High resolution computed tomography with reformatting through the malleus handle is the most accurate imaging modality. Reconstruction with hydroxyapatite bone cement is reliable by restoring the original situation with only minimal manipulation and without additional ossicular interruption.

Surgical Management and Hearing Outcome of Traumatic Ossicular Injuries

OBJECTIVE The purpose of this study was to investigate etiological, clinical, and pathological characteristics of traumatic injuries of the middle ear ossicular chain and to evaluate hearing outcome after surgery. MATERIAL AND METHODS Thirty consecutive patients (31 ears) with traumatic ossicular injuries operated on between 2004 and 2015 in two tertiary referral otologic centers were retrospectively analyzed. Traumatic events, clinical features, ossicular lesions, treatment procedures, and audiometric results were evaluated. Air conduction (AC), bone conduction (BC), and air-bone gap (ABG) were analyzed preoperatively and postoperatively. Amsterdam Hearing Evaluation Plots (AHEPs) were used to visualize the individual hearing results. RESULTS The mean age at the moment of trauma was 27.9±17.1 years (range, 2-75 years) and the mean age at surgery was 33.2±16.3 years (range, 5-75 years). In 10 cases (32.3%), the injury occurred by a fall on the head and in 9 (29.0%) by a traffic accident. Isolated luxation of the incus was observed in 8 cases (25.8%). Dislocation of the stapes footplate was seen in 4 cases (12.9%). The postoperative ABG closure to within 10 and 20 dB was 30% and 76.7%, respectively. CONCLUSION Ossicular chain injury by direct or indirect trauma can provoke hearing loss, tinnitus, and vertigo. As injuries are heterogeneous, they require a tailored surgical approach. In this study, the overall hearing outcome after surgical repair was favorable.OBJECTIVE The purpose of this study was to investigate etiological, clinical, and pathological characteristics of traumatic injuries of the middle ear ossicular chain and to evaluate hearing outcome after surgery. MATERIAL AND METHODS Thirty consecutive patients (31 ears) with traumatic ossicular injuries operated on between 2004 and 2015 in two tertiary referral otologic centers were retrospectively analyzed. Traumatic events, clinical features, ossicular lesions, treatment procedures, and audiometric results were evaluated. Air conduction (AC), bone conduction (BC), and air-bone gap (ABG) were analyzed preoperatively and postoperatively. Amsterdam Hearing Evaluation Plots (AHEPs) were used to visualize the individual hearing results. RESULTS The mean age at the moment of trauma was 27.9±17.1 years (range, 2-75 years) and the mean age at surgery was 33.2±16.3 years (range, 5-75 years). In 10 cases (32.3%), the injury occurred by a fall on the head and in 9 (29.0%) by a traffic accident. Isolated luxation of the incus was observed in 8 cases (25.8%). Dislocation of the stapes footplate was seen in 4 cases (12.9%). The postoperative ABG closure to within 10 and 20 dB was 30% and 76.7%, respectively. CONCLUSION Ossicular chain injury by direct or indirect trauma can provoke hearing loss, tinnitus, and vertigo. As injuries are heterogeneous, they require a tailored surgical approach. In this study, the overall hearing outcome after surgical repair was favorable.

Subarcuate supralabyrinthine approach for supralabyrinthine petrosal cholesteatoma.

Congenital cholesteatomas of the petrosal apex account for 1% to 3% of all cholesteatomas and often present an important surgical challenge. This report describes an exceptional case of a “nondestructive” translabyrinthine surgical approach to a large congenital petrosal cholesteatoma that threatened the vestibulum, superior semicircular canal, facial nerve, and internal auditory canal. We applied a nonconventional transmastoid subarcuate supralabyrinthine approach in a 20-year-old patient by accessing the lesion through the center of the superior semicircular arch without damaging the integrity of the canal. This led to a complete removal of the petrosal cholesteatoma with preservation of hearing and vestibular function. Follow-up imaging performed 1 and 2 years after operation by means of non—echo-planar diffusion-weighted imaging did not show residual cholesteatoma. This report describes the first successful use of a subarcuate supralabyrinthine approach through the arches of the superior semicircular canal in a case of petrosal cholesteatoma.

Treatment of traumatic stapediovestibular luxation: case report with the introduction of a new technique and review of literature.

Objective Stapediovestibular luxations are rare lesions that are most commonly caused by direct, penetrating trauma to the external ear canal. In this type of ossicular dislocation, disruption of the annular ligament or footplate fracture may lead to a perilymphatic fistula (PLF) presenting with cochleovestibular symptoms including (progressive) sensorineural hearing loss, tinnitus, and vestibular symptoms. The objective of this article is to define the optimal treatment of stapediovestibular luxations and review the literature on this topic. Patient We present a case of internal stapediovestibular dislocation and pneumolabyrinth after penetrating trauma with predominantly conductive hearing loss and incapacitating vertigo. Intervention Middle ear inspection with removal of the luxated incus, repositioning of the stapes with a “stapedial strut” and closure of the tympanic membrane. Main outcome measures Hearing outcome and vestibular symptoms of this patient are presented, and all comparable cases in the literature are reviewed. Results Complete resolution of the vestibular symptoms and stabilization of the bone conduction thresholds. Conclusion In patients with pneumolabyrinth after middle ear trauma with mild symptoms, we recommend initial conservative treatment with close monitoring of hearing. In patients with severe, persisting, or progressive vestibulocochlear symptoms, exploratory tympanotomy should be performed to check for and treat PLF. Oval window fistula repair is reported to have variable hearing outcomes but offers complete resolution of vestibular symptoms in most cases. The stapedial strut is one of the possible surgical techniques in case of an internally luxated stapes.

Aberrant internal carotid artery presenting as a retrotympanic vascular mass

We report a case of a young woman with an aberrant right internal carotid artery (ICA) presenting as a retrotympanic reddish mass. This variant of the ICA represents the collateral pathway that is formed as a result of an embryological agenesis of the cervical segment of the ICA. The embryonic inferior tympanic artery is recruited to bypass the absent carotid segment. This hypertrophied vessel may be seen otoscopically and wrongfully considered to be a vascular middle ear tumor. Informing the otorhinolaryngologist of this important vascular variant not only obviates biopsy but also helps in careful preoperative planning of eventual middle ear procedures.