Jonas Jae-Hyun Park

Autosomal recessive postlingual hearing loss (DFNB8): compound heterozygosity for two novel TMPRSS3 mutations in German siblings

Mutations in the transmembrane protease, serine 3 (TMPRSS3) gene, encoding a transmembrane serine protease, cause autosomal recessive deafness childhood (DFNB8) or congenital onset (DFNB10). TMPRSS3 mutations have been mainly identified in patients from Asian and Mediterranean countries and seem to be a rare finding in the Northern European population so far. The identification of two novel pathogenic TMPRSS3 mutations (c.646C→T − R216C; c.916G→A − A306T) is described in four affected siblings of German origin with postlingual hearing loss, treated by bilateral cochlear implantation with good results. Although TMPRSS3 mutations are supposed to be a rare cause of autosomal recessive hearing loss, in families with postlingual disease onset TMPRSS3 is the most favourable candidate gene after exclusion of GJB2 mutations.

Meniere's disease and middle ear pressure – vestibular function after transtympanic tube placement

Conclusion: Selected patients with Menieres disease (MD) show an improvement of disability from vertigo after transtympanic ventilation tube insertion, although an effect on vestibular function is not seen if ipsilateral middle ear pressure lower than –50 daPa is used as a selection criterion. Objectives: Transtympanic ventilation tube insertion as a treatment option for MD has been reported but its results have been controversial. So far, no investigations on vestibular function in patients with MD after tube insertion have been carried out. Subjects and methods: Twenty-two patients with unilateral MD who were intractable to medical treatment and who had an ipsilateral middle ear pressure lower than –50 daPa received a transtympanic ventilation tube. Vestibular evoked myogenic potentials (VEMPs) and sinusoidal harmonic acceleration (SHA) testing were recorded pre- and postoperatively and were compared. Results: Most patients (68.2%) reported an improvement of vertigo. Before surgery 63.6% of patients did not show VEMPs, whereas vestibulo-collic reflexes were measured in 36.4% of all cases compared with 68.2% of patients without and 31.8% with recorded VEMPs after surgery. No statistically different findings in gain and phase lag of SHA testing were seen postoperatively compared to preoperative findings.

Using a high-definition stereoscopic video system to teach microscopic surgery

Introduction: While there is an increasing demand for minimally invasive operative techniques in Ear, Nose and Throat surgery, these operations are difficult to learn for junior doctors and demanding to supervise for experienced surgeons. The motivation for this study was to integrate high-definition (HD) stereoscopic video monitoring in microscopic surgery in order to facilitate teaching interaction between senior and junior surgeon. Material and methods: We attached a 1280x1024 HD stereo camera (TrueVisionSystemsTM Inc., Santa Barbara, CA, USA) to an operating microscope (Zeiss ProMagis, Zeiss Co., Oberkochen, Germany), whose images were processed online by a PC workstation consisting of a dual Intel® Xeon® CPU (Intel Co., Santa Clara, CA). The live image was displayed by two LCD projectors @ 1280x768 pixels on a 1,25m rear-projection screen by polarized filters. While the junior surgeon performed the surgical procedure based on the displayed stereoscopic image, all other participants (senior surgeon, nurse and medical students) shared the same stereoscopic image from the screen. Results: With the basic setup being performed only once on the day before surgery, fine adjustments required about 10 minutes extra during the operation schedule, which fitted into the time interval between patients and thus did not prolong operation times. As all relevant features of the operative field were demonstrated on one large screen, four major effects were obtained: A) Stereoscopy facilitated orientation for the junior surgeon as well as for medical students. B) The stereoscopic image served as an unequivocal guide for the senior surgeon to demonstrate the next surgical steps to the junior colleague. C) The theatre nurse shared the same image, anticipating the next instruments which were needed. D) Medical students instantly share the information given by all staff and the image, thus avoiding the need for an extra teaching session. Conclusion: High definition stereoscopy bears the potential to compress the learning curve for undergraduate as well as postgraduate medical professionals in minimally invasive surgery. Further studies will focus on the long term effect for operative training as well as on post-processing of HD stereoscopy video content for off-line interactive medical education.

The relationship between jugular bulb position and jugular bulb related inner ear dehiscence: a retrospective analysis

OBJECTIVE High jugular bulb (HJB) can erode inner ear structures creating a jugular bulb related inner ear dehiscence (JBID). The aim of this study was to analyze the relationship between the position of jugular bulb (JB) and JBID using high-resolution computed tomography (HRCT). MATERIAL AND METHODS In this retrospective study HRCT images of 552 ears of 276 patients with hearing loss, otogenic vertigo, tinnitus or idiopathic peripheral facial nerve paralysis were analyzed. HJB type-1 was defined when JB dome reached above the inferior part of the round window, but was below the inferior edge of the internal acoustic meatus (IAM). HJB type-2 was defined when the dome of JB was higher than the inferior edge of IAM. The frequencies and types of HJB were evaluated. JBID for each HJB type was determined. Frequencies of JBID eroding the vestibular aqueduct (VA), the cochlear aqueduct and the posterior semicircular canal were examined. RESULTS HJB type-1 and HJB type-2 were found in 19% (105/552) and in 15.8% (87/552) of studied ears. JBID showed to be in 3.8% (21/552) of all ears. 90.5% (19/21) of JBID revealed eroding of VA. Jugular bulb related cochlear aqueduct dehiscence and jugular bulb related posterior semicircular canal dehiscence were found in one ear each. The frequency of jugular bulb related vestibular aqueduct dehiscence (JBVAD) in patients with HJB reaching above IAM was higher than in patients with HJB lower than IAM. CONCLUSIONS HJB is common, but JBID is rare. JBID prevalently erodes VA. HJB rising above IAM is most at risk to show JBVAD.

Role of neck ultrasound during follow-up care of head and neck squamous cell carcinomas

Abstract Conclusion: No impact of neck ultrasound on the detection rate of neck recurrences of head and neck squamous cell carcinomas (HNSCCs) was seen. The outcome of salvage therapy was not influenced by close neck ultrasound monitoring during follow-up. Tendencies of earlier detection of neck recurrences were noticed. Objectives: Neck ultrasound is more feasible for frequent application than computed tomography, while having comparable sensitivity and specificity in detecting neck metastasis. Before this study the effect of neck ultrasound on salvage therapy of neck recurrences when used in short defined intervals during follow-up was unknown. Methods: A total of 140 patients with primarily surgically treated HNSCC were enrolled in a follow-up program with defined close time intervals. Neck ultrasound was applied during every follow-up visit. Recurrence rate, survival rate, and outcome of salvage therapy were determined. Results: Overall recurrences occurred in 35.0% of patients. Local, regional, and distant recurrences were found in 11.4%, 7.9%, and 15.7%. Hypopharyngeal carcinoma and advanced staged tumor showed highest recurrence rates. In all, 24.5% of all recurrences were treated successfully by salvage therapy. Resection of local, regional, and distant recurrences resulted in 3-year survival rates of 43.8%, 36.4%, and 4.5%. The outcome of secondary therapy worsened with advancing initial primary tumor stage.

Promontory electrical stimulation to elicit vestibular evoked myogenic potentials (VEMPs)

Abstract Conclusion: Vestibular evoked myogenic potentials (VEMPs) provoked electrically at the promontory provide a feasible method to record vestibular responses in awake patients. Objectives: Electrically evoked VEMP testing has been performed by galvanic stimulation at the mastoid so far. The present study examined an electrical stimulation mode close to the otolith organs at the promontory. Methods: Fourteen cochlear implant candidates who were planned for clinical routine promontory stimulation testing (PST) to assess auditory nerve function underwent promontory VEMP testing. After testing the cochlear nerve function during PST promontory cervical VEMPs (p-c-VEMPs) and promontory ocular VEMPs (p-o-VEMPs) were recorded during subsequent transtympanic electrical stimulation at the promontory. Results: Promontory VEMP testing was well tolerated by the patients. Mean latencies for p-c-VEMPs were 10.30 ± 2.23 ms (p1) and 17.86 ± 3.83 ms (n1). Mean latencies for p-o-VEMPs were 7.64 ± 1.24 ms (n1) and 11.2 ± 1.81 ms (p1). The stimulation threshold level was measured at 0.15 ± 0.07 mA for p-c-VEMPs and at 0.19 ± 0.11 mA for p-o-VEMPs. The discomfort level was found to be at 0.78 ± 0.29 mA for p-c-VEMPs and at 0.69 ± 0.25 mA for p-oVEMPs. Mean p1-n1 amplitude in p-c-VEMPs was 124.78 ± 56.55 µV and p-o-VEMPs showed a mean n1-p1 amplitude of 30.94 ± 18.98 µV.

Teaching microsurgery to undergraduate medical students by means of high-definition stereo video microscopy: the Aachen skills lab experience

Introduction: The master plan for innovative medical education established at RWTH Aachen Medical Faculty helped to set up an inter-disciplinary, interactive teaching environment for undergraduate medical students during their clinical course. This study presents our first experience with teaching microsurgery to medical students by means of highdefinition stereo video monitoring. Material and methods: A plastic model created for ear inspection with a handheld otoscope was modified with an exchangeable membrane resembling an eardrum plus a model of the human cochlea. We attached a 1280×1024 HD stereo camera to an operating microscope, whose images were processed online by a PC workstation. The live image was displayed by two LCD projectors @ 1280×720 pixels on a 1,25m rear-projection screen by polarized filters. Each medical student was asked to perform standard otosurgical procedures (paracentesis and insertion of grommets; insertion of a cochlear implant electrode) being guided by the HD stereoscopic video image. Results: Students quickly adopted this method of training, as all attendants shared the same high-definition stereoscopic image. The learning process of coordinating hand movement with visual feedback was regarded being challenging as well as instructive by all students. Watching the same image facilitated valuable feedback from the audience for each student performing his tasks. All students noted that this course made them feel more confident in their manual skills and that they would consider a career in a microsurgical specialty. Conclusion: High definition stereoscopy provides an easy access to microsurgical techniques for undergraduate medical students. This access not only bears the potential to compress the learning curve for junior doctors during their clinical training but also helps to attract medical students to a career in a microsurgical specialty.

Long-term middle ear pressure measurements in inner ear disorders

Abstract Conclusion: Repetitive portable tympanometry is a feasible method to examine long-term middle ear pressure profile. This method might be suitable for detecting patients with Menieres disease whose middle ear pressure shows intermittently pathological values. Objectives: Contradictory study results regarding middle ear pressure in patients with Menieres disease might be due to solitary tympanometric measurements. Pathological pressure conditions in patients with pressure regulation disorders might be missed by a single examination. The aim of the study was to examine the pressure profile of patients with Menieres disease by long-term measurements. Methods: Patients with Menieres disease (n = 33), patients with sudden hearing loss (n = 20), and healthy subjects (n = 30) were examined. Patients carried out long-term middle ear pressure measurements with the portable tympanometer Otoflex 100. Examinations were carried out during daily activities at defined time intervals. Results: Significant negative middle ear pressure were seen in patients with Menieres disease compared with patients with sudden hearing loss and healthy subjects (p < 0.01). Average middle ear pressure in patients with Menieres disease was –43 daPa, in patients with sudden hearing loss it was 2 daPa, and in healthy subjects it was 4 daPa. Patients with Menieres disease showed a large variability of pressure values ranging from strongly pathological to normal values during long-term measurements.

Use of Stereoscopic Video Monitoring for Surgical Teaching

Objectives: To evaluate the usefulness for online computer-based stereoscopic video monitoring for teaching junior surgeons To define which operative procedures in otorhinolaryngology benefit most form surgical teaching using stereoscopic monitors. Methods: This clinical study was conducted from January 2008 until January 2010. 95 operative procedures (12 cochlear implantations, 3 stapedotomies, 28 tympanoplasties, 17 endonasal sinus surgeries and 35 endolaryngeal procedures) were conducted under stereoscopic video monitoring in addition to (55) or replacing binoculars (40). In 78 procedures, junior surgeons were supervised performing surgical procedures in a step-by step approach. We measured setup and operation times plus the time saved by instructing the junior surgeon on the screen compared to swapping roles between junior and senior surgeon. Results: Initially setup times for the system varied between 12 and 17 minutes before each procedure. The main factor was identified as adjustment of outputs for left and right image on the screen. With the use of adjustment-free monitors, this interval was significantly reduced to 4-5 minutes (p<0,01). Procedures that replace binoculars by on-line stereoscopic monitoring benefit most from this technology as junior and senior surgeon share the same depth information on the stereo monitor. Under these conditions operative times were reduced by 3 to 7 minutes. Conclusion: The additional information given by stereoscopic video processing in real time outweighs the extra effort for handling and maintenance depending on the ease of system setup. Thus, further integration with existing the general workflow is necessary to enhance acceptance in high turnover of operative procedures.

Impact of endolymphatic mastoid shunt surgery on saccule and lateral semicircular canal function

Endolymphatic mastoid shunt surgery (EMSS) is widely performed in patients with medically intractable Meniere’s disease. Although many patients report an improvement of symptoms after surgery, the mechanisms which are responsible for the relief of complaints are not known. To date, only few studies exist which studied the influence of EMSS on vestibular function. The present study examines the effect of EMSS on saccule function by measuring vestibular evoked myogenic potentials and the effect on lateral semicircular canal function by sinusoidal harmonic acceleration (SHA) testing. No changes in vestibulo-collic reflexes were found after surgery compared to before surgery. SHA testing resulted in comparable phase lag and gain pre- and postoperatively. Although central compensation is clinically evident no effect in specific vestibular diagnostic testing is seen. Modulations of canal–otolith interaction might suggest a change of symptoms. The only method so far to evaluate the success of EMSS is the patient’s subjective assessment.