Thorsten Zehlicke

Tonic contractions of the tensor tympani muscle: a key to some non-specific middle ear symptoms? Hypothesis and data from temporal bone experiments.

Conclusions. The results of this study show that in clinical practice it will not be easy to diagnose tonic contractions of the tensor tympani muscle and only a combination of findings will be helpful. Based on these experimental results a clinical study will be started which should clarify the diagnostic relevance of indicators of tonic tensor muscle contractions. Objectives. There are indications from the literature and from personal experience that tonic contractions of the tensor tympani muscle may play a role in some ear symptoms, such as fullness, certain cases of tinnitus, slight hearing loss or Ménières disease-like findings. In order to prove this theory we looked for indicators, either visual or functional, to help clinically diagnose the functional state of the muscle, particularly its tonic contraction. Material and methods. Experiments simulating tensor contractions were carried out on temporal bone specimens. Traction was applied either to the isolated muscle, to its tendon or to the malleus neck. Effects were observed either visually via an endoscope or by impedance audiometry using multiple-frequency tympanometry. Results. During simulated tensor traction the aspect of the tympanic membrane changed slightly, i.e. there was some inward movement of the umbo. However, such effects were only identifiable during the pulling action or by directly comparing the “contracted” and “relaxed” states. Tympanometry revealed a decrease in the peak amplitudes and a shift in the middle ear resonance towards higher frequencies during contractions.

Electromyographical recording of the electrically elicited stapedius reflex via a bipolar hook electrode.

Objective: To prove the feasibility of recording stapedius reflexes by bipolar electromyography intra-operatively during cochlea implant via a bipolar hook needle electrode. Study Design: Prospective study. Setting: Tertiary referral center. Patients: Adults receiving a MED-EL cochlear implant. Intervention: Diagnostic. Main Outcome Measures: Stapedius reflex responses can be recorded by electromyography. Results: A double hook electrode could be inserted into the muscle tissue via the natural opening of the pyramid process along with the stapedius tendon. In 7 out of 10 patients supplied with MED-EL CIs (PULSARCI100 or SONATATI100), electrically elicited stapedius reflex potentials were recorded after eliminating stimulation artifacts caused by electromagnetic fields during electical stimulation by low pass filtering. Conclusion: Intraoperative stapedius reflex recording by bipolar electromyography via a hook electrode is feasible. Further research will show whether these signals may be used for establishing a self-adjusting speech processor.

Detection of tympanic membrane movement using film patch with integrated strain gauge, assessed by optical coherence tomography: experimental study

OBJECTIVE We report an ex vivo and in vivo experimental study of a device designed to measure tympanic membrane movement under normal and pathological conditions, assessed using optical coherence tomography. MATERIALS AND METHODS We designed two types of flexible, round film patch with integrated strain gauge, to be attached to the tympanic membrane in order to measure tympanic membrane movement. Tympanic membrane attachment was assessed using optical coherence tomography. The devices were tested experimentally using an ex vivo model with varying middle-ear pressure. RESULTS Optical coherence tomography reliably assessed attachment of the film patch to the tympanic membrane, before and after middle-ear pressure changes. Strain gauge voltage changes were directly proportional to middle-ear pressure recordings, for low pressure changes. Tympanic membrane perforations smaller than 2 mm could be sealed off with the film patch. CONCLUSION Attachment of the film patch with integrated strain gauge to the tympanic membrane was not ideal. Nevertheless, the strain gauge was able to precisely detect small pressure changes within the middle ear, in this experimental model.

Transient facial palsy in two cases of benign, very rare middle ear tumors (carcinoid tumor and myxoma).

Objective:Presentation of the clinical features of 2 very rare middle ear tumors in which the guiding symptom was facial palsy. Material and Methods:Illustrative case reports about a myxoma and a carcinoid tumor of the middle ear associated with peripheral facial palsy. Results:The facial palsy was transient in either case, and its pathomechanism is open for discussion. In both cases, the initial symptoms were typical for an inflammatory process. Moreover, both tumor entities are typically found in organs other than the ear; if located in the middle ear, those neoplasms grow rather superficially. In those cases, a surgical exposure of the middle ear is indicated. Conclusion:The etiopathology of an acute peripheral facial palsy is often hard to identify. If the facial weakness starts together with symptoms suggesting an inflammatory process, the differential diagnosis may be focused first on diseases like herpes zoster oticus and a severe course of acute purulent otitis media. We report the cases of 2 rare middle ear tumors causing facial palsy. Treatment of choice should be complete surgical excision.

Experimental studies on a new highly porous hydroxyapatite matrix for obliterating open mastoid cavities.

Objective In an initial preliminary study, the applicability of a new high-porosity hydroxyapatite (HA) ceramic for obliterating large open mastoid cavities was proven and tested in an animal model (bulla of guinea pig). Study Design Experimental study. Methods NanoBone, a highly porous matrix consisting of 76% hydroxyl apatite and 24% silicone dioxide fabricated in a sol-gel technique, was administered unilaterally into the opened bullae of 30 guinea pigs. In each animal, the opposite bulla was filled with Bio-Oss, a bone substitute consisting of a portion of mineral bovine bone. Histologic evaluations were performed 1, 2, 3, 4, 5, and 12 weeks after the implantation. Results After an initial phase in which the ceramic granules were surrounded by inflammatory cells (1-2 wk), there were increasing signs of vascularization. Osteoneogenesis and-at the same time-resorption of the HA ceramic were observed after the third week. No major difference in comparison to the bovine bone material could be found. Discussion Our results confirm the favorable qualities of the new ceramic reported in association with current maxillofacial literature. Conventional HA granules used for mastoid obliteration to date often showed problems with prolonged inflammatory reactions and, finally, extrusions. In contrast to those ceramics, the new material seems to induce more osteoneogenesis and undergoes early resorption probably due to its high porosity. Overall, it is similar to the bovine bone substance tested on the opposite ear in each animal. Further clinical studies may reveal whether NanoBone can be an adequate material for obliterating open mastoid cavities in patients.

Multicenter Clinical Trial of Vibroplasty Couplers to Treat Mixed/Conductive Hearing Loss: First Results

Objective: To evaluate the safety and effectiveness of round window (RW), oval window (OW), CliP and Bell couplers for use with an active middle ear implant. Methods: This is a multicenter, long-term, prospective trial with consecutive enrollment, involving 6 university hospitals in Germany. Bone conduction, air conduction, implant-aided warble-tone thresholds and Freiburger monosyllable word recognition scores were compared with unaided preimplantation results in 28 moderate-to-profound hearing-impaired patients after 12 months of follow-up. All patients had previously undergone failed reconstruction surgeries (up to 5 or more). In a subset of patients, additional speech tests at 12 months postoperatively were used to compare the aided with the unaided condition after implantation with the processor switched off. An established quality-of-life questionnaire for hearing aids was used to determine patient satisfaction. Results: Postoperative bone conduction remained stable. Mean functional gain for all couplers was 37 dB HL (RW = 42 dB, OW = 35 dB, Bell = 38 dB, CliP = 27 dB). The mean postoperative Freiburger monosyllable score was 71% at 65 dB SPL. The postimplantation mean SRT50 (speech reception in quiet for 50% understanding of words in sentences) improved on average by 23 dB over unaided testing and signal-to-noise ratios also improved in all patients. The International Outcome Inventory for Hearing Aids (IOI-HA)quality-of-life questionnaire was scored very positively by all patients. Conclusion: A significant improvement was seen with all couplers, and patients were satisfied with the device at 12 months postoperatively. These results demonstrate that an active implant is an advantage in achieving good hearing benefit in patients with prior failed reconstruction surgery.

Optotensometry – Developement of an optic method for measuring tubal function by tympanic membrane movement in a middle ear model

Learning Objectives: Facial nerve management in the surgery Internal carotid artery management in the surgery Intracranial vascular bypass As for the most challenging surgery of the lateral skull base, glomus jugular tumor resection is now safely controlled and managed. In this study we focused on the the strategies of facial nerve and internal carotid artery management during glomus jugular tumor surgery, especially for the C and D stage tumor in which the internal carotid artery was severely involved and could not be easily seperated. Furthermore we tried the extra-intracranial vascular bypass when the internal carotid artery could not be saved in the surgery, by which the mortality and intracranial complications were greatly reduced.