Thomas Somers

Consensus statements on the BAHA system: where do we stand at present?

After more than 25 years of clinical experience, the BAHA (bone-anchored hearing aid) system is a well-established treatment for hearing-impaired patients with conductive or mixed hearing loss. Owing to its success, the use of the BAHA system has spread and the indications for application have gradually become broader. New indications, as well as clinical applications, were discussed during scientific roundtable meetings in 2004 by experts in the field, and the outcomes of these discussions are presented in the form of statements. The issues that were discussed concerned BAHA surgery, the fitting range of the BAHA system, the BAHA system compared to conventional devices, bilateral application, the BAHA system in children, the BAHA system in patients with single-sided deafness, and, finally, the BAHA system in patients with unilateral conductive hearing loss.

Outcome of cochlear implantation at different ages from 0 to 6 years.

Objective To evaluate the outcome of cochlear implantation in young children in relation to the age at implantation. Study Design A retrospective longitudinal and cross-sectional analysis of pediatric cochlear implant patients. Patients All children with congenital deafness who underwent implantation before the age of 6 years (n = 48 for the longitudinal analysis and n = 70 for the cross-sectional analysis) Interventions All children received a multichannel cochlear implant. Main Outcome Measures Categories of Auditory Performance (CAP) score and integration into the mainstream school system. Results For all children, the CAP score increased after implantation. Implantation beyond the age of 4 years hardly ever resulted in normal CAP scores or in integration into the mainstream primary school (20 to 30% of cases). Implantation between the age of 2 and 4 years always resulted in normal CAP scores after 3 years with a 66% probability of integration into the primary school. Implantation before the age of 2 years always resulted in immediate normalization of the CAP scores, with a 90% probability of integration into the mainstream kindergarten, well before entrance into the primary school. Conclusion All children with congenital deafness who underwent implantation before the age of 6 years appeared to benefit from the implant. However, these data add evidence to the importance of early implantation (before the age of 2 years). Intervention before the age of 4 years seemed to be critical to avoid irreversible auditory performance losses, and intervention before the age of 2 years seemed to be critical to achieve optimal results.

The value of diffusion-weighted MR imaging in the diagnosis of primary acquired and residual cholesteatoma : a surgical verified study of 100 patients

Our goal was to determine the value of echo-planar diffusion-weighted MR imaging in detecting the presence of primary acquired and residual cholesteatoma. One hundred patients were evaluated by preoperative magnetic resonance (MR) imaging with diffusion-weighted MR imaging. The patient population consisted of a first group of 55 patients evaluated in order to detect the presence of a primary acquired cholesteatoma. In the second group, 45 patients were evaluated for the presence of a residual cholesteatoma 8–18 months after cholesteatoma surgery, prior to second-look surgery. Surgical findings were compared with preoperative findings on diffusion-weighted imaging (DWI). The sensitivity, specificity, positive and negative predictive values of both groups was assessed. In the group of primary surgery patients, hyperintense signal compatible with cholesteatoma was found in 89% of cases with a sensitivity, specificity, positive and negative predictive value for DWI of 81, 100, 100 and 40%, respectively. In the group of second-look surgery patients, only one of seven surgically verified residual cases was correctly diagnosed using DWI, with a sensitivity, specificity, positive and negative predictive values of 12.5, 100, 100 and 72%, respectively. These results confirm the value of DWI in detecting primary cholesteatoma, but show the poor capability of DWI in detecting small residual cholesteatoma.

Detection of postoperative residual cholesteatoma with non-echo-planar diffusion-weighted magnetic resonance imaging.

Objective: The aim of this study was to analyze the role of non-echo-planar imaging (non-EPI)-based diffusion-weighted (DW) magnetic resonance imaging (MRI) for the detection of residual cholesteatoma after canal wall-up mastoidectomy before eventual second-look surgery. Study Design: Prospective and blinded study. Setting: Tertiary referral center. Patients: The study group included the surgical, clinical, and imaging follow-up of 32 consecutive patients after primary cholesteatoma surgery. Interventions: All patients were investigated with MRI, including late postgadolinium T1-weighted sequence and non-EPI-DW sequence, 10 to 18 months after first-stage cholesteatoma surgery by experienced surgeons using a canal wall-up mastoidectomy. The non-EPI-DW images were evaluated for the presence of a high-signal intensity lesion consistent with residual cholesteatoma. Imaging findings were correlated with findings from second-stage surgery in 19 patients, clinical follow-up examination in 11 patients, and, in 2 patients, clinical and MRI follow-up examination. Results: Non-EPI-DW sequences depicted 9 of 10 residual cholesteatomas. The only lesion missed was a 2-mm cholesteatoma in an examination degraded by motion artifacts in a child. All other diagnosed cholesteatomas measured between 2 and 6 mm. Sensitivity, specificity, positive predictive value, and negative predictive value were 90, 100, 100, and 96%, respectively. Conclusion: Except for motion artifact-degraded examinations, non-EPI-DW MRI is able to detect even very small residual cholesteatoma after first-stage surgery by showing a high-signal intensity lesion. It has the capability of selecting patients for second-look surgery, avoiding unnecessary second-look surgery.

A Second Gene for Otosclerosis, OTSC2, Maps to Chromosome 7q34-36

Otosclerosis due to abnormal bone homeostasis of the otic capsule is a frequent cause of hearing loss in adults. Usually, the hearing loss is conductive, resulting from fixation of the stapedial footplate, which prevents normal ossicular vibration in response to sound. An additional type of sensorineural hearing loss may be caused by otosclerotic damage to the cochlea. The etiology of the disease is unknown, and both environmental and genetic factors have been implicated. Autosomal dominant inheritance with reduced penetrance has been proposed, but large families are extremely rare. To elucidate the pathogenesis of the disease, identification of the responsible genes is essential. In this study, we completed linkage analysis in a Belgian family in which otosclerosis segregates as an autosomal dominant disease. After excluding linkage to a known locus on chromosome 15 (OTSC1), we found linkage on chromosome 7q, with a multipoint LOD score of 3.54. Analysis of key recombinant individuals maps this otosclerosis locus (OTSC2) to a 16-cM interval on chromosome 7q34-36 between markers D7S495 and D7S2426.

Statistical Analysis of Otosclerosis Surgery Performed by Jean Marquet

The early and long-term hearing results of 1,681 primary otosclerosis operations performed by the same surgeon, Jean Marquet, were reviewed retrospectively and analyzed with very strict statistical standards. Significantly better short- and long-term results were achieved with the stapedotomy technique compared to total stapedectomy, mainly at the higher frequencies (4 and 8 kHz) important for speech discrimination. Whatever technique was used to open the footplate (micropick, microdrill, or laser), no statistical audiometric difference could be found. The results were equal whether or not the stapedial tendon was preserved. Perioperative problems like pronounced oozing, difficult anatomic relationships, and accidental perilymph aspiration could affect hearing at higher frequencies. The calibrated hole technique was equally as good as conventional oval window sealing in sealing of the fenestra to prevent fistula. The stapedotomy technique was found the safest, having fewer complications.

A mutation in HOXA2 is responsible for autosomal-recessive microtia in an Iranian family.

Microtia, a congenital deformity manifesting as an abnormally shaped or absent external ear, occurs in one out of 8,000-10,000 births. We ascertained a consanguineous Iranian family segregating with autosomal-recessive bilateral microtia, mixed symmetrical severe to profound hearing impairment, and partial cleft palate. Genome-wide linkage analysis localized the responsible gene to chromosome 7p14.3-p15.3 with a maximum multi-point LOD score of 4.17. In this region, homeobox genes from the HOXA cluster were the most interesting candidates. Subsequent DNA sequence analysis of the HOXA1 and HOXA2 homeobox genes from the candidate region identified an interesting HOXA2 homeodomain variant: a change in a highly conserved amino acid (p.Q186K). The variant was not found in 231 Iranian and 109 Belgian control samples. The critical contribution of HoxA2 for auditory-system development has already been shown in mouse models. We built a homology model to predict the effect of this mutation on the structure and DNA-binding activity of the homeodomain by using the program Modeler 8v2. In the model of the mutant homeodomain, the position of the mutant lysine side chain is consistently farther away from a nearby phosphate group; this altered position results in the loss of a hydrogen bond and affects the DNA-binding activity.

Mastoid and Epitympanic Bony Obliteration in Pediatric Cholesteatoma

Objective: The primary goal of cholesteatoma surgery is complete eradication of the disease. To lower the recurrence rate in the pediatric population in canal wall up techniques and to avoid the disadvantages of canal wall down techniques, the bony obliteration technique with epitympanic and mastoid obliteration has been developed. The objective of this study was to evaluate the long-term surgical outcome and recurrence rate of this technique in children. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: Fifty-two children (<16 yr) were operated on in 90.4% (n = 47) for a primary or recurrent cholesteatoma and in 9.6% (n = 5) for an unstable cavity. Intervention: In all cases, we closed the tympanoattical barrier and the posterior tympanotomy with sculpted cortical bone and then completed obliteration of the epitympanum and mastoid with bone pâté. A reconstruction of the middle ear was performed by means of an allograft tympanic membrane including the malleus handle and a sculpted allograft malleus or incus for columellar reconstruction. Main Outcome Measures: Recurrent rate; residual rate; functional outcome; hygienic status of the ear; long-term safety issues. Results: The mean follow-up time was 49.5 months (range, 12-101.3 mo). Recurrent cholesteatoma occurred in 1.9% (n = 1). Residual cholesteatoma was detected in 15.4% (n = 8) of the cases. Postoperative hearing results revealed a median gain on pure-tone averages of 14.3 dB and a median postoperative air-bone gap of 25.6 dB. Conclusion: The mastoid and epitympanic BOT is an effective technique to lower the recurrence rate of cholesteatoma in the pediatric population. Follow-up by magnetic resonance imaging provides a safe, noninvasive method for postoperative detection of residual cholesteatoma.

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.

Association of Bone Morphogenetic Proteins With Otosclerosis

We studied the role of polymorphisms in 13 candidate genes on the risk of otosclerosis in two large independent case‐control sets. We found significant association in both populations with BMP2 and BMP4, implicating these two genes in the pathogenesis of this disease.