Cochlear implantation in patients with inner ear schwannomas: a systematic review and meta-analysis of audiological outcomes.

PURPOSE: In patients with inner ear schwannomas (IES), reports on hearing rehabilitation with cochlear implants (CI) have increased over the past decade, most of which are case reports or small case series. The aim of this study is to systematically review the reported hearing results with CI in patients with IES considering the different audiologic outcome measures used in different countries. METHODS: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline, a search of published literature was conducted. We included patients with IES (primary or with secondary extension from the internal auditory canal (IAC) to the inner ear, sporadic or NF2 related) undergoing cochlear implantation with or without tumour removal. The audiological results were divided into the categories "monosyllables", "disyllables", "multisyllabic words or numbers", and "sentences". RESULTS: Predefined audiological outcome measures were available from 110 patients and 111 ears in 27 reports. The mean recognition scores for monosyllabic words with CI were 55% (SD: 24), for bisyllabic words 61% (SD: 36), for multisyllabic words and numbers 87% (SD: 25), and 71% (SD: 30) for sentences. Results from for multisyllabic words and numbers in general showed a tendency towards a ceiling effect. Possible risk factors for performance below average were higher complexity tumours (inner ear plus IAC/CPA), NF2, CI without tumour removal ("CI through tumour"), and sequential cochlear implantation after tumour removal (staged surgery). CONCLUSION: Hearing loss in patients with inner ear schwannomas can be successfully rehabilitated with CI with above average speech performance in most cases. Cochlear implantation thus represents a valuable option for hearing rehabilitation also in patients with IES while at the same time maintaining the possibility of MRI follow-up. Further studies should investigate possible risk factors for poor performance. Audiological tests and outcome parameters should be reported in detail and ideally be harmonized to allow better comparison between languages.

Zig-zag structures in silver dichromate precipitate.

Precipitation patterns are commonly concentric rings forming in a Petri dish or parallel bands appearing in a test tube (Liesegang phenomenon). The rings frequently consist of a number of convex segments that are separated from each other by spaces devoid of precipitate resulting in small gaps (dislocations). Along these gaps, the so-called zig-zag structures can form, which connect one side of a gap with its opposite side. We observe that the occurrence of zig-zags requires a minimum thickness of the reactive layer (≥ 0.8 mm). This fact together with microscopic evidence indicates their three-dimensional character. One finds that at the very beginning of the precipitation reaction a curling process starts in the corresponding contour lines. These observations suggest structures of a helicoid with the axis perpendicular to the plane of the reaction-diffusion front to pass through the layer. Zig-zags are not parallel to the reaction plane, i.e., they are not formed periodically, but evolve continuously as a rotating spiral wave. Thus, their topology is closely related to helices in a test tube.

Individual computer-assisted 3D planning for placement of auricular prosthesis anchors in combination with an implantable transcutaneous bone conduction hearing device in patients with aural atresia.

BACKGROUND: The simultaneous implantation of the Bonebridge (MED-EL, Innsbruck, Austria), a semi-implantable active transcutaneous bone conduction hearing device and anchors for auricular prostheses can be challenging as both implants contain magnets and compete for the narrow space in the designated implantation area. MATERIAL AND METHODS: A preoperative planning tool (virtual surgery) was used with individual 3D computer models of the skull and implants for finding optimal implant positions for both the floating mass transducer (FMT) and the anchors for the auricular prosthesis. The interaction between the magnetic prosthesis anchors and the FMT was measured by means of static magnetic forces. A retrospective data analysis was conducted to evaluate the surgical and audiological outcome. RESULTS: Between 2014 and 2021, a 3D planning of a simultaneous implantation of the Bonebridge with auricular prosthesis anchors was conducted on 6 ears of 5 patients (3 males, 2 females; age range 17-56 years). The individual preoperative planning was considered very useful for the optimal placement of bone anchors in combination with the Bonebridge. Audiological data showed a clear benefit for hearing 3 months and > 11 months after implantation. No adverse interactions between the magnetic prosthesis anchors and the FMT were observed. In two patients, revision surgery was carried out due to skin inflammation or wound healing problems. No long-term complications were observed 3-5 years after surgery. CONCLUSION: Preoperative 3D planning represents a clear benefit for the simultaneous audiological and esthetic rehabilitation using the Bonebridge and anchors for auricular prostheses.

[Individual computer-assisted 3D planning for placement of auricular prosthesis anchors in combination with an implantable transcutaneous bone conduction hearing device in patients with aural atresia. German version]. / Individuelle computergestützte 3D-Planung zur Platzierung von Epithesenankern in Kombination mit einem implantierbaren transkutanen Knochenleitungshörgerät bei Patienten mit Ohrfehlbildungen.

BACKGROUND: The simultaneous implantation of the Bonebridge (MED-EL, Innsbruck, Austria), a semi-implantable active transcutaneous bone conduction hearing device and anchors for auricular prostheses can be challenging as both implants contain magnets and compete for the narrow space in the designated implantation area. MATERIAL AND METHODS: A preoperative planning tool (virtual surgery) was used with individual 3D computer models of the skull and implants for finding optimal implant positions for both the floating mass transducer (FMT) and the anchors for the auricular prosthesis. The interaction between the magnetic prosthesis anchors and the FMT was measured by means of static magnetic forces. A retrospective data analysis was conducted to evaluate the surgical and audiological outcome. RESULTS: Between 2014 and 2021 a 3D planning of a simultaneous implantation of the Bonebridge with auricular prosthesis anchors was conducted on 6 ears of 5 patients (3 males, 2 females; age range 17-56 years). The individual preoperative planning was considered very useful for the optimal placement of bone anchors in combination with the Bonebridge. Audiological data showed a clear benefit for hearing 3 months and > 11 months after implantation. No adverse interactions between the magnetic prosthesis anchors and the FMT were observed. In two patients, revision surgery was carried out due to skin inflammation or wound healing problems. No long-term complications were observed 3-5 years after surgery. CONCLUSION: Preoperative 3D planning represents a clear benefit for the simultaneous audiological and esthetic rehabilitation using the Bonebridge and anchors for auricular prostheses.

Clinical and functional results after implantation of the bonebridge, a semi-implantable, active transcutaneous bone conduction device, in children and adults.

PURPOSE: Aim of the study was to evaluate the surgical, clinical and audiological outcome of 32 implantations of the Bonebridge, a semi-implantable transcutaneous active bone conduction implant. METHODS: In a retrospective cohort study, we analyzed data for 32 implantations in 31 patients (one bilateral case; seven age < 16 years) with conductive or mixed hearing loss, malformations, after multiple ear surgery, or with single-sided deafness as contralateral routing of signal (CROS). RESULTS: Four implantations were done as CROS. Five cases were simultaneously planned with ear prosthesis anchors, and 23 implantations (72%) were planned through three-dimensional (3D) "virtual surgery." In all 3D-planned cases, the implant could be placed as expected. For implant-related complications, rates were 12.5% for minor and 3.1% for major complications. Implantation significantly improved mean sound field thresholds from a preoperative 60 dB HL (SD 12) to 33 dB HL (SD 6) at 3 postoperative months and 34 dB HL (SD 6) at > 11 postoperative months (p < 0.0001). Word recognition score in quiet at 65 dB SPL improved from 11% (SD 20) preoperatively to 74% (SD 19) at 3 months and 83% (SD 15) at > 11 months (p < 0.0001). The speech reception threshold in noise improved from - 1.01 dB unaided to - 2.69 dB best-aided (p = 0.0018). CONCLUSION: We found a clinically relevant audiological benefit with Bonebridge. To overcome anatomical challenges, we recommend preoperative 3D planning in small and hypoplastic mastoids, children, ear malformation, and simultaneous implantation of ear prosthesis anchors and after multiple ear surgery.

Speech perception and hearing effort using a new active middle ear implant audio processor.

PURPOSE: The Vibrant Soundbridge (VSB) was introduced in 1996, and the fourth generation of the audio processor recently released. This clinical study evaluates the audiological performance and subjective satisfaction of the new SAMBA 2 audio processor compared to its predecessor, SAMBA. METHOD: Fifteen VSB users tested both audio processors for approximately 3 weeks. Air conduction and bone conduction thresholds and unaided and aided sound field thresholds were measured with both devices. Speech performance in quiet (Freiburg monosyllables) and noise (OLSA) was evaluated as well as subjective listening effort (ACALES) and questionnaire outcomes (SSQ12 and APSQ). In addition, data from 16 subjects with normal hearing were gathered on sound field tests and ACALES. RESULTS: Both audio processors showed substantial improvement compared to the unaided condition. The SAMBA and SAMBA 2 had comparable performance in sound filed thresholds, while the SAMBA 2 was significantly better in speech in quiet, speech in noise, reduced listening effort, and improved subjective satisfaction compared with the SAMBA. CONCLUSION: The SAMBA 2 audio processor, compared to its predecessor SAMBA, offers improved performance throughout the parameters investigated in this study. Patients with a VSB implant would benefit from an upgrade to SAMBA 2.

[Development and evaluation of a deep learning algorithm for German word recognition from lip movements]. / Entwicklung und Evaluation eines Deep-Learning-Algorithmus für die Worterkennung aus Lippenbewegungen für die deutsche Sprache.

BACKGROUND: When reading lips, many people benefit from additional visual information from the lip movements of the speaker, which is, however, very error prone. Algorithms for lip reading with artificial intelligence based on artificial neural networks significantly improve word recognition but are not available for the German language. MATERIALS AND METHODS: A total of 1806 videoclips with only one German-speaking person each were selected, split into word segments, and assigned to word classes using speech-recognition software. In 38,391 video segments with 32 speakers, 18 polysyllabic, visually distinguishable words were used to train and validate a neural network. The 3D Convolutional Neural Network and Gated Recurrent Units models and a combination of both models (GRUConv) were compared, as were different image sections and color spaces of the videos. The accuracy was determined in 5000 training epochs. RESULTS: Comparison of the color spaces did not reveal any relevant different correct classification rates in the range from 69% to 72%. With a cut to the lips, a significantly higher accuracy of 70% was achieved than when cut to the entire speaker's face (34%). With the GRUConv model, the maximum accuracies were 87% with known speakers and 63% in the validation with unknown speakers. CONCLUSION: The neural network for lip reading, which was first developed for the German language, shows a very high level of accuracy, comparable to English-language algorithms. It works with unknown speakers as well and can be generalized with more word classes.

[Macroscopic and microscopic changes of the vestibulocochlear nerve after Gamma Knife treatment]. / Makroskopische und mikroskopische Veränderungen des N. vestibulocochlearis nach Gamma-Knife-Therapie.

We report on a case in which macroscopic and microscopic changes of the vestibulocochlear nerve could be observed after radiosurgery of an intrameatal vestibular schwannoma. This case shows for the first time a morphological correlate for undesirable effects after radiosurgical treatment of a vestibular schwannoma and indicates that despite a certain distance to the actual tumor, degenerative changes in neural structures can be expected.

Efficacy and safety of systemic, high-dose glucocorticoid therapy for idiopathic sudden sensorineural hearing loss : Study protocol for a three-armed, randomized, triple-blind, multicenter trial (HODOKORT).

BACKGROUND: Systemic glucocorticosteroids ("steroids") are widely used worldwide as a standard of care for primary therapy of idiopathic sudden sensorineural hearing loss (ISSHL). The German ISSHL guideline recommends high-dose steroids without evidence from randomized controlled trials (RCTs) and refers solely to retrospective cohort studies. This RCT aims to assess the efficacy (improvement in hearing) and safety (especially systemic side effects) of high-dose steroids versus standard of care (standard dose systemic steroids) for the treatment of unilateral ISSHL, when given as a primary therapy. METHODS: The study is designed as a multicenter (approximately 40 centers), randomized, triple-blind, three-armed, parallel group, clinical trial with 312 adult patients. The interventions consist of 5 days of 250 mg/day intravenous prednisolone (intervention 1) + oral placebo, or 5 days of 40 mg/day oral dexamethasone (intervention 2) + intravenous placebo. The control intervention consists of 60 mg oral prednisolone for 5 days followed by five tapering doses + intravenous placebo. The primary efficacy endpoint is the change in hearing threshold in the three most affected contiguous frequencies between 0.25 and 8 kHz 1 month after ISSHL. Secondary endpoints include further measures of hearing improvement including speech audiometry, tinnitus, quality of life, blood pressure, and altered glucose tolerance. DISCUSSION: There is an unmet medical need for an effective medical therapy of ISSHL. Although sensorineural hearing impairment can be partially compensated by hearing aids or cochlear implants (CI), generic hearing is better than using hearing aids or CIs. Since adverse effects of a short course of high-dose systemic corticosteroids have not been documented with good evidence, the trial will improve knowledge on possible side effects in the different treatment arms with a focus on hyperglycemia and hypertension. TRIAL REGISTRATION: EudraCT (European Union Drug Regulating Authorities Clinical Trials Database) Nr. 2015-002602-36; Sponsor code: KKSH-127.

[Objective Audiological Test Procedures: Indications and Differential Diagnostics]. / Objektive audiologische Messverfahren: Indikationen und Differenzialdiagnostik.

Diagnostics of hearing loss comprises subjective and objective methods and is successfully applied since many decades. This article introduces into the methods of impedance audiometry, otoacoustic emissions, auditory evoked potentials and electrically evoked potentials and describes the respective methodologies. Using an exemplary case, in this article we guide through all stages of objective audiological diagnostics and introduce the scientific and technical background, the application and evaluation of the findings of the objective test procedures. An application pathway for objective audiometric diagnostic tools is also described, including newborn hearing screening, differential diagnostics of hearing loss, auditory neuropathy, sudden sensorineural hearing loss, vestibular schwannoma and pediatrics patients. Finally, the application to patients with active middle-ear implants and cochlear implants is described.

Hearing rehabilitation after subtotal cochleoectomy using a new, perimodiolar malleable cochlear implant electrode array: a preliminary report.

PURPOSE: We here report about the first surgical experience and audiological outcome using a new, perimodiolar malleable cochlear implant electrode array for hearing rehabilitation after subtotal cochleoectomy for intralabyrinthine schwannoma (ILS). METHOD: Based on a cochlear implant with MRI compatibility of the magnet in the receiver coil up to 3 T, a cochlear implant electrode array was developed that is malleable and can be placed perimodiolar after tumor removal from the cochlea via subtotal cochleoectomy. Malleability was reached by incorporating a nitinol wire into the silicone of the electrode array lateral to the electrode contacts. The custom-made device was implanted in four patients with intracochlear, intravestibulocochlear or transmodiolar schwannomas. Outcome was assessed by evaluating the feasibility of the surgical procedure and by measuring sound field thresholds and word recognition scores. RESULTS: After complete or partial tumor removal via subtotal cochleoectomy with or without labyrinthectomy, the new, perimodiolar malleable electrode array could successfully be implanted in all four patients. Six months after surgery, the averaged sound field thresholds to pulsed narrowband noise in the four patients were 36, 28, 41, and 35 dB HL, and the word recognitions scores for monosyllables at 65 dB SPL were 65, 80, 70, and 25% (one patient non-German speaking). CONCLUSION: The surgical evaluation demonstrated the feasibility of cochlear implantation with the new, perimodiolar malleable electrode array after subtotal cochleoectomy. The audiological results were comparable to those achieved with another commercially available type of perimodiolar electrode array from a different manufacturer applied in patients with ILS.

A retrospective European multicenter analysis of the functional outcomes after active middle ear implant surgery using the third generation vibroplasty couplers.

PURPOSE: To evaluate the safety and performance of three novel vibroplasty couplers that allow attachment of the floating mass transducer of a transcutaneous active middle ear implant (AMEI) to the round window (RW) membrane, the long process (LP), or the incus body and the short process (SP) of the incus. METHODS: Retrospective multicenter cohort study of 25 AMEI users with sensorineural or mixed hearing loss that were among the first implanted with an AMEI vibrating ossicular prosthesis in combination with the third generation of vibroplasty couplers between 2014 and 2016. Main Outcome Measures were bone-conduction pure-tone and vibroplasty thresholds, postoperative aided sound field thresholds and postoperative aided word recognition score (WRS). RESULTS: Bone conduction threshold changes of more than 10 dB in 4PTABC were observed in two subjects. A mean improvement of 57.8% in speech recognition was observed with a mean WRS at 65 dB SPL improving from 14.8% (SD 21.9%) preoperatively to a mean aided score of 72.6% (SD 18.6%). Sound field thresholds improved from an average 4PTASF of 64.1 dB HL (SD 9.8 dB HL) to 37.0 dB HL (SD 8.9 dB HL), resulting in a mean functional gain of 27.1 dB. There was no significant difference in WRS or functional gain between the coupler types. CONCLUSION: Initial experience shows that all three third generation vibroplasty couplers represent safe and efficient attachment options for the FMT allowing the surgeon to choose the coupling type based on the present pathology.

Intraoperative quantification of floating mass transducer coupling quality in active middle ear implants: a multicenter study.

PURPOSE: Evaluating the effectiveness of intraoperative auditory brainstem responses (ABRs) to stimulation by the Vibrant Soundbridge (VSB) active middle ear implant for quantifying the implant's floating mass transducer (FMT) coupling quality. METHODS: In a diagnostic multicentric study, patients (> 18 years) who received a VSB with different coupling modalities were included. Pre- and postoperative bone conduction thresholds, intraoperative VSB-evoked ABR thresholds (VSB-ABR) using a modified audio processor programmed to preoperative bone conduction thresholds, postoperative vibrogram thresholds, and postoperative VSB-ABR thresholds were measured. Coupling quality was calculated from the difference between the pure tone average at 1000, 2000, and 4000 Hz (3PTA) vibrogram and postoperative 3PTA bone conduction thresholds. RESULTS: Twenty-three patients (13 males, 10 females, mean age 56.6 (± 12.5) years) were included in the study. Intraoperative VSB-ABR response thresholds could be obtained in all except one patient where the threshold was > 30 dB nHL. Postoperatively, an insufficient coupling of 36.7 dB was confirmed in this patient. In a Bland-Altman analysis of the intraoperative VSB-ABRs and coupling quality, the limits of agreement exceeded ± 10 dB, i.e., the maximum allowed difference considered as not clinically important but the variation was within the general precision of auditory brainstem responses to predict behavioral thresholds. Five outliers were identified. In two patients, the postoperative VSB-ABR thresholds were in agreement with the coupling quality, indicating a change of coupling before the postoperative testing. CONCLUSION: The response thresholds recorded in this set-up have the potential to predict the VSB coupling quality and optimize postoperative audiological results.

[Physical audiological principles of implantable hearing systems : About power transmission, coupling and power output]. / Physikalisch-audiologische Grundlagen implantierbarer Hörsysteme : Über Energieübertragung, Ankopplung und Ausgangsleistung.

Implantable hearing systems work because mechanical vibration energy is introduced into the hearing system. The performance of the hearing system is thus essentially determined by physical parameters. Together with the tone and speech audiogram the indications for deciding on a system are based on the efficacy of the respective system and the patient's wishes. Hearing-assisted patients should have a dynamic range of 30-35 dB to adequately understand speech. This should be guaranteed with the respective system also in the medium to long term. In addition, sufficient cochlear reserve performance for implantable hearing systems is critical for success. The expected and achieved audiological success can be the effective gain as a difference of aided hearing threshold to bone conduction threshold and should be preferred to the unreflecting use of gain or functional gain. With good differential diagnostic indications and the inclusion of conventional hearing aids and cochlear implants, optimal hearing solutions can be found for almost all patients.

[Multimodal training concept for temporal bone surgery]. / Multimodales Weiterbildungskonzept Schläfenbeinchirurgie.

BACKGROUND: Surgical training is increasingly supported by the use of simulators. For temporal bone surgery, shown here by means of mastoidectomy, there are other training models besides cadaver specimens, such as artificial temporal bones or computer-based simulators. OBJECTIVES: A structured training concept was created which integrates different training methods of mastoidectomy with regard to effectiveness and current learning theory in education. METHOD: A selective literature research was conducted to compare learning-theoretical findings and the availability and effectiveness of currently existing training models. RESULTS: To acquire surgical skills, a stepwise approach is suggested. Depending on the progress with computer-based simulation, plastic or native temporal bones should be used. To achieve a plateau of the learning curve, approximately 25 semi-autonomous preparations are recommended. Different 'Objective Structured Assessments of Technical Skills' (OSATS) are implemented to assess the learning progress at different levels. DISCUSSION: Simulation-based training is recommended until an adequate learning curve plateau is achieved. This is reasonable for patient safety, based on limited accessibility of human cadaveric temporal bones but also by findings of the learning theory. CONCLUSION: The curriculum integrates different training models of mastoidectomy and OSATS into an overall concept. The training plan has to be continuously adapted to new findings and technical developments.

Vasculitis and the ear: a literature review.

PURPOSE OF REVIEW: Systemic vasculitides as a group of inflammatory disorders of blood vessels may show clinical manifestations in the ear. This article reviews the recent literature about vasculitis of the ear or the cochleovestibular system, focusing on giant-cell arteritis, Takayasu's arteritis, polyarteritis nodosa, Kawasaki disease, microscopic polyangiitis, granulomatosis with polyangiitis (GPA), eosinophilic GPA, systemic lupus erythematosus, Cogan's syndrome and Behçet's disease. RECENT FINDINGS: In patients with vasculitis, hearing impairment is a frequent problem, followed by tinnitus and vertigo. The severity of sensorineural hearing loss can range from mild impairment to deafness. Autoimmune diseases can induce a conductive hearing loss as a result of effusions of the middle ear, the inflammation of the mucosa of the Eustachian tube, or the involvement of the ossicular chain. Vertigo may be caused by the temporary or permanent occlusion of the labyrinthine or the anterior vestibular artery. Middle ear inflammation is frequent in GPA and eosinophilic GPA. SUMMARY: The progressive sensorineural hearing loss in polyarteritis nodosa or Cogan's syndrome patients may be treated by cochlear implantation.

Minimal Reporting Standards for Active Middle Ear Hearing Implants.

There is currently no standardized method for reporting audiological, surgical and subjective outcome measures in clinical trials with active middle ear implants (AMEIs). It is often difficult to compare studies due to data incompatibility and to perform meta-analyses across different centres is almost impossible. A committee of ENT and audiological experts from Germany, Austria and Switzerland decided to address this issue by developing new minimal standards for reporting the outcomes of AMEI clinical trials. The consensus presented here aims to provide a recommendation to enable better inter-study comparability.

Perception of Iterated Rippled Noise Periodicity in Cochlear Implant Users.

Pitch perception is more challenging for individuals with cochlear implants (CIs) than normal-hearing subjects because the signal processing by CIs is restricted. Processing and perceiving the periodicity of signals may contribute to pitch perception. Whether individuals with CIs can discern pitch within an iterated rippled noise (IRN) signal is still unclear. In a prospective controlled psychoacoustic study with 34 CI users and 15 normal-hearing control subjects, the difference limen between IRN signals with different numbers of iterations was measured. In 7 CI users and 15 normal-hearing control listeners with single-sided deafness, pitch matching between IRN and harmonic complex tones was measured. The pitch onset response (POR) following signal changes from white noise to IRN was measured electrophysiologically. The CI users could discriminate different numbers of iteration in IRN signals, but worse than normal-hearing listeners. A POR was measured for both normal-hearing subjects and CI users increasing with the pitch salience of the IRN. This indicates that the POR could serve as an objective measure to monitor progress during audioverbal therapy after CI surgery.

Vibrotactile Thresholds on the Mastoid and Forehead Position of Deaf Patients Using Radioear B71 and B81.

OBJECTIVES: The main objective of this study was to measure the vibrotactile thresholds on the mastoid process and forehead positions using patients with bilateral deafness and to compare the results from the two bone conduction vibrators Radioear B71 and B81. DESIGN: There is a possibility that the vibrotactile sensation on the skin makes it difficult to discriminate between sound and vibration. The risk is highest for patients who have bone conduction hearing thresholds in proximity to or worse than their vibrotactile thresholds. All measurements were performed similar to regular bone conduction threshold testing using an audiometer-driven bone conduction vibrator and pulsed warble tones, but the patients were instructed to respond only when feeling vibrations of the bone conduction vibrator instead of when hearing sound. Both the posterior forehead position and the mastoid process position on the temporal bone were tested for comparative reasons. In total, 16 patients participated in the study, 31% females and 69% males of age 29 to 77 years. All subjects were cochlear implant recipients, either uni- or bilaterally implanted. They were selected based on their audiogram data showing unmeasurable unaided hearing. RESULTS: The force level at which the vibrotactile thresholds were reached, increased with frequency from 125 up to 500 Hz, but remained constant for higher frequencies up to 2 kHz. A statistically significant difference was found between the 2 devices at 125 Hz at both the mastoid process and forehead position, where the vibrotactile threshold seem to be more sensitive for B71, possibly due to contribution of distortion components. There was no statistically significant difference in vibrotactile thresholds between the mastoid process and forehead position in absolute values (force level in dB re 1 µN), but in terms of hearing levels (dB HL) there was an average difference of 10 and 9 dB for B71 and B81, respectively. CONCLUSIONS: The results indicate that the vibrotactile thresholds can be confounded with bone conduction hearing thresholds measurements up to 500 Hz when using a standard audiometer and in particular when measuring on the forehead position.

Comparison of intraobserver single-task reliabilities of the Interactive Balance System (IBS) and Vertiguard in asymptomatic subjects.

The intraobserver reliabilities of the Interactive Balance System (IBS) and Vertiguard were compared in 30 asymptomatic volunteers. Relative reliability for all IBS single tasks and parameters in the IBS was excellent (intraclass correlation coefficient, ICC ≥0.75). The ICC values ranged from 0.78 to 0.89. The ICC values of the Vertiguard system ranged from 0 to 0.75. The cumulative measure of injury risk of the Vertiguard system was highly reliable.