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Zusammenfassung Zielsetzung Der plötzliche Herztod gehört europaweit zu den führenden Todesursachen, doch trotz intensiver Bemühungen ist die Laienreanimationsquote in Deutschland seit Jahren niedrig. In dieser Studie wurden der diesbezügliche Wissensstand sowie die Fortbildungsbereitschaft der Bevölkerung am Beispiel Berlin erhoben. Methodik Die Studienteilnehmer wurden zufällig ausgewählt. Eingeschlossen wurden 120 Personen im Alter von 40 bis 70 Jahren. Das Wissen über Reanimation wurde mittels eines Fragebogens mit 24 Items erhoben. Zusätzlicher Bestandteil des Fragebogens waren drei Videos mit unterschiedlichen Situationen die Laienreanimation betreffend. Diese mussten von den Teilnehmern mithilfe von 6 Antwortmöglichkeiten bearbeitet werden. Ein Item diente darüber hinaus zur Erhebung der Fortbildungsbereitschaft zu diesem Thema. Um etwaige Unterschiede aufzuzeigen, wurden eine Gruppe mit Erste-Hilfe-Kurs im zurückliegenden Jahr und eine Gruppe mit Erste-Hilfe-Kurs vor längerer Zeit getrennt betrachtet. Ergebnisse Von den Teilnehmern schlossen 74 % (n = 89) die Erhebung vollständig ab. Davon hatten 11 % (n = 10) innerhalb des letzten Jahres an einem Erste-Hilfe-Kurs teilgenommen. In dieser Gruppe trauten sich 90 % (n = 9) der Teilnehmer zu, einen Herz-Kreislauf-Stillstand erkennen und versorgen zu können, dem gegenüber stehen 20 % (n = 16) in der Vergleichsgruppe mit Erste-Hilfe-Kurs vor längerer Zeit. Einen automatisierten externen Defibrillator anzuwenden, trauten sich 50 % (n = 5) bzw. 11 % (n = 9) der Teilnehmer zu. 92 % (n = 82) aller Teilnehmer bestätigten die Bereitschaft zu einer regelmäßigen Erste-Hilfe-Fortbildung. Schlussfolgerung Die Gruppe mit kürzlichem Erste-Hilfe-Kurs schneidet im Wissen zu Reanimation, Erkennen und Behandeln von Notfallsituationen besser ab als die Vergleichsgruppe. Um die herausgestellten Kenntnislücken zu schließen, sollte ein neuer Ansatz gefunden werden. Ein bundesweites, jährlich zu absolvierendes Kursprogramm für alle Erwachsenen in Deutschland könnte diese Lücke schnell und nachhaltig füllen.

BACKGROUND Background: In cases of terrorism, disasters or mass casualty incidents, far-reaching life-and-death decisions about prioritizing patients are currently made using triage algorithms that focus solely on the patient's current health status rather than their prognosis, thus leaving a fatal gap of patients who are under- or overtriaged. In this proof-of-concept study, we demonstrate a novel approach for triage that no longer classifies patients into triage categories but ranks their urgency according to the anticipated survival time without intervention. Using this approach, we aimed to improve prioritization of casualties by respecting individual injury patterns and vital signs, survival likelihoods and availability of rescue resources. OBJECTIVE Objective: The objective of this proof-of-concept study was to demonstrate a novel approach for triage that no longer classifies patients into triage categories but ranks their urgency according to the anticipated survival time without intervention. Using this approach, we aimed to improve prioritization of casualties by respecting individual injury patterns and vital signs, survival likelihoods and availability of rescue resources. METHODS Methods: A mathematical model was designed that allows dynamic simulation of the time course of a patient’s vital parameters depending on individual baseline vital signs and injury severity. The two variables are integrated by the well-established Revised Trauma Score (RTS) and New Injury Severity Score (NISS). An artificial patient database of unique trauma patients (n = 82,277) was generated and used for analysis of the time course modeling and triage classification. In addition, we applied a sophisticated, state-of-the-art clustering method using Gower Distance to visualize patient cohorts at risk for mistriage. RESULTS Results: The proposed triage model ranks patients according to their anticipated temporal course. Regarding the identification of patients at risk for mistriage, the model outperforms Simple Triage And Rapid Treatment (START)’s triage algorithm, but also exclusive stratification by RTS or NISS. Multidimensional analysis separated patients with similar patterns of injuries and vital parameters into clusters with different triage classifications. In this large-scale analysis, our algorithm confirmed the previously mentioned conclusions during simulation and descriptive analysis, and underlined the significance of this novel approach to triage. CONCLUSIONS Conclusions: The findings in this study suggest the feasibility and relevance of our model, which is unique in terms of its ranking system, prognosis outline and time course anticipation. The proposed triage ranking algorithm could offer an innovative triage method with a wide range of applications in prehospital, disaster and emergency medicine, as well as simulation and research. CLINICALTRIAL not needed

BACKGROUND Virtual reality (VR)–based simulation is being increasingly used to train medical students in emergency medicine. However, because the usefulness of VR may depend on various factors, the best practices for implementing this technology in the medical school curriculum are yet to be determined. OBJECTIVE The overall objective of our study was to assess the perceptions of a large cohort of students toward VR-based training and to identify the associations between these attitudes and individual factors, such as gender and age. METHODS The authors implemented a voluntary, VR-based teaching session in the emergency medicine course at the Medical Faculty in Tübingen, Germany. Fourth-year medical students were invited to participate on a voluntary basis. Afterward, we asked the students about their perceptions, collected data on individual factors, and assessed the test scores achieved by them in the VR-based assessment scenarios. We used ordinal regression analysis and linear mixed-effects analysis to detect the impact of individual factors on the questionnaire answers. RESULTS A total of 129 students participated in our study (mean age 24.7, SD 2.9 years; n=51, 39.8% male; n=77, 60.2% female). No student had previously used VR for learning, and only 4.7% (n=6) of the students had prior experience with VR. Most of the students agreed that VR can convey complex issues quickly (n=117, 91%), that VR is a useful addition to mannequin-based courses (n=114, 88%) or could even replace them (n=93, 72%), and that VR simulations should also be used for examinations (n=103, 80%). However, female students showed significantly less agreement with these statements. Most students perceived the VR scenario as realistic (n=69, 53%) and intuitive (n=62, 48%), with a relatively lower agreement for the latter among female respondents. We found high agreement among all participants (n=88, 69%) for immersion but strong disagreement (n=69, 54%) for empathy with the virtual patient. Only 3% (n=4) of the students felt confident regarding the medical content. Responses for the linguistic aspects of the scenario were largely mixed; however, most of the students were confident with the English language (not native) scenarios and disagreed that the scenario should be offered in their native language (female students agreed more strongly than male students). Most of the students would not have felt confident with the scenarios in a real-world context (n=69, 53%). Although physical symptoms during VR sessions were reported by 16% (n=21) of the respondents, this did not lead to the termination of the simulation. The regression analysis revealed that the final test scores were not influenced by gender, age, or prior experience in emergency medicine or with virtual reality. CONCLUSIONS In this study, we observed a strong positive attitude in medical students toward VR-based teaching and assessment. However, this positivity was comparatively lower among female students, potentially indicating that gender differences need to be addressed when VR is implemented in the curriculum. Interestingly, gender, age, or prior experience did not influence the final test scores. Furthermore, confidence regarding the medical content was low, which suggests that the students may need further training in emergency medicine.

Artificial patient database generated for the publication in a semi-supervised manner and used for analysis.&nbsp

Introduction: The determination of the tinnitus pitch-match (PM) frequency is not straightforward but an important audiological assessment recommended for clinical and research purposes. We evaluated repetitive recursive matching using an iPod-based matching procedure as a method to estimate a patient’s PM frequency without audiometric equipment. Methods: One hundred and seventeen patients with chronic tonal tinnitus (uni- and bilateral tinnitus) measured their tinnitus in 10 sessions using a self-administered automated iPod-based procedure comprising a recursive 2 interval forced-choice test. Results: Mean SD of the PM frequency of all participants across sessions was 0.41 octaves. The internal consistency measured by Cronbach’s α was very high (0.8–>0.95). As an example, 7 PMs obtained excellent internal consistency (α = 0.93). The exclusion of the first and/or second session led to more definite PMs with a decreased SD. Outliers were identified by PMs departing 2 SDs (i.e., 0.94 octaves) from the mean variability (n = 5). Conclusion: Repetitive recursive matching together with recommendations for the exclusion of initial and redundant sessions as well as outlier identification and treatment can enable a reliable estimation of the PM frequency.

In the ongoing Second Decade of Action for Road Safety, road traffic crashes pose a considerable threat especially in low-income countries. Uganda shows a vast burden of non-fatal injuries and resides at the top range of countries with the highest death rates due to unsafe roads. However, little is known about the differences in road traffic associated injuries between urban and rural areas and potential influence factors. Here, we used a cross-sectional study conducted by a retrospective medical record review from trauma cases admitted in 2016 to hospitals in rural and urban areas in Uganda. Injury severity scores were calculated and descriptive analysis was carried out while multivariate logistic regression was applied to assess significant covariates. According to the 1683 medical records reviewed, the mean age of trauma patients in the dataset under investigation was 30.8 years with 74% male. The trauma in-hospital mortality was 4% while prevalence of traumatic injuries is 56.4%. Motorcycle users (49.6%) and pedestrians (33.7%) were identified as the most vulnerable groups in both urban and rural setting while mild injuries of extremities (61.6%) and the head/neck-region (42.0%) were registered most. The frequency of road traffic injuries was homogenous in the urban and rural hospitals investigated in this study, interventions should therefore be intensified ubiquitously. The identification of significant differences in road traffic crash and injury characteristics provides the opportunity for specific programmes to decrease the socio-economic and health burden of unsafe roads. In addition to law enforcement and introduction of a Systems Thinking approach to road safety including infrastructural and educational concepts, the strengthening of trauma care and health resources is recommended.

Background: Disaster medicine is a component of the German medical education since 2003. However, studies have shown some inconsistencies within the implementation of the national curriculum, and limits with the number of students trained over the years. Facing the SARS-CoV-2 pandemic and other disasters, it became much more important to train medical students in disaster medicine on a coordinated basis.Methods: The University Clinic for Anaesthesiology and Intensive Care Medicine in Tübingen, Germany, expanded the existing curriculum of undergraduate disaster medicine training with fundamentals of humanitarian medicine, integrating the experience with distance learning, interactive teaching and simulation sessions. Survey tools were used to assess participants’ previous experiences and interest in the field of disaster medicine, to compare the self-reported degree of knowledge before and after training, and the programme’s quality evaluation. A mandatory pre- and post-test of knowledge was also administered to evaluate learner outcomes. The prospective and cross-sectional study evaluates the pilot course Disaster Medicine and Humanitarian Assistance carried out for third-, fourth- and fifth- year medical students over five semesters during the period between 2018 and 2020.Results: Data was collected from 107 students over five training sessions. Out of a sample of 82 students, the subjective perception of knowledge increased after the course (t [81] = 24.426, p < .001), alongside with the interest in engaging in the field of disaster medicine (t[81 ] = 7.031, p < .001). 102 students entered the mandatory knowledge assessment, with the rate of correct answers passing from 73.27% in the pre-test to 95.23% in the post-test (t [101] = 18.939, p < .001). The 93.46% of the medical students (N = 100) graded the training received with an excellent overall score (1.01 out of 6).Discussion: The study indicates a significant increase in students’ understanding of disaster medicine through the use of both subjective and objective measures, as well as an increase interest in the field of disaster and humanitarian medicine. The educational programme appears to address the deficiencies documented in previous studies, and possible adaptation with virtual reality approaches could expand access to a larger audience.Conclusion: The programme offers an effective and comprehensive tool to address the urgent need of quality education for medical students, suggesting integrated strategies to implement disaster medicine training.

Introduction The primary objective of this paper is to evaluate the safety impacts of red-light running camera (RLC) system installation and then deactivation at 48 intersections in Houston, Texas. The second objective is to evaluate the spillover effect at nearby non-treated intersections in Houston after the deactivation. Methods To accomplish study objectives, an Empirical Bayes (EB) before-after analysis was used. Results The results indicate statistically significant collision reductions on all red-light running (RLR) crash types (37 percent) as well as right-angle RLR crashes (47 percent) at the treated intersections after RLC activation. By way of comparison, the RLC deactivation analysis indicated that crashes increased by 20 percent for all RLR crash types and by 23 percent in right-angle RLR crashes at the formerly treated intersections. After deactivation, all severity RLR crashes increased more than expected at nearby non-treated intersections, which indicates the possibility of an adverse spillover effect. However, fatal/injury crashes associated with rear-end decreased after deactivation at both formerly treated and non-treated intersections, although those rear-end crashes account for smaller proportions when compared to all crash types/right-angle crashes. Practical applications Overall, removing RLC treatments results in a negative reaction to the safety benefits that the treatment provides when it is in place and actively working and to the nearby intersections where the treatment has not been implemented. This study helps define the effects that RLCs have on safety at signalized intersections after installation and deactivation.

BackgroundFollowing the recommendations of the World Association for Disaster and Emergency Medicine (WADEM; Madison, Wisconsin USA) to develop standards for training the undergraduates in disaster-relevant fields (2004), a German curriculum was approved in 2006. This paper aims to describe the level of training and interest of medical students nine years later.ProblemThe aim of this study was to assess the self-perception of medical students’ knowledge and interest in disaster medicine nine years after the implementation of a standardized disaster medicine curriculum in German medical schools.MethodsThis prospective, cross-sectional, observational study was conducted with medical students in Germany using a web-based, purpose-designed questionnaire consisting of 27 mandatory and 11 optional questions.ResultsNine hundred ninety-two students from 36 of 37 medical schools in Germany participated. More than one-half of medical students were aware of the field of disaster medicine. One hundred twenty-one students undertook training internally within their university and 307 undertook training externally at other institutions. Only a small content of the curriculum was taught. A difference in self-perception of knowledge between trained and untrained participants was found, despite the level of training being low in both groups. Participants were generally highly motivated to learn disaster medicine in a variety of institutions.ConclusionGerman students are still largely not well educated regarding disaster medicine, despite their high motivation. The curriculum of 2006 was not implemented as originally planned and the number of trained students still remains low as the self-perception of knowledge. Currently, there is no clear and standardized training concept in place. A renewal in the agreement of implementation of the curriculum at medical schools should be targeted in order to follow the recommendation of WADEM.WunderlichRRagazzoniLIngrassiaPLDella CorteFGrundgeigerJBickelmayerJWDomresB. Self-perception of medical students’ knowledge and interest in disaster medicine: nine years after the approval of the curriculum in German universities. Prehosp Disaster Med. 2017;32(4):374–381.

Traffic fatalities present a significant public health issue as one of the leading causes of preventable death in the world. In the United States, approximately one-quarter of all fatal injuries are due to traffic crashes. The frequency of traffic fatalities in the United States varies over time with notable differences by rural versus urban geography, single versus multivehicle crashes, mode type, and demographic characteristics of drivers and passengers. Continued population growth and expanded economic opportunity are likely to increase travel. Reducing the risk associated with that travel is critical to improving health outcomes. There is no one approach that appears likely to solve the traffic crash issue, but increased emphasis on implementing infrastructure improvements, incentivizing safe behaviors and sanctioning, and discouraging high-risk behaviors, including advanced safety technology in vehicles, and adopting a safe system approach, can all make a difference in the quality and longevity of life throughout the world.

Introduction:Crises, wars, and disasters are remarkably increasing across the world. Responders are frequently tackled with an ever-greater number of challenges, and undoubtedly, they are physically and mentally affected during and after their missions, during which posttraumatic stress disorder (PTSD) is considered high-risk. To the authors’ knowledge, no studies have addressed which type of incident has the greatest influence to trigger stress, and consequently, to cause PTSD for the responders after their missions.Methods:A prospective longitudinal study was conducted with 69 participants of the “Safety and Security” course at the Federal Office for Civil Protection and Disaster Aid of the Federal Ministry of Interior Affairs (Berlin, Germany). The course is certified by the Hostile Environment Awareness Training (HEAT) guidelines of Europe’s New Training Initiative for Civilian Crisis Management (ENTRi; Center for International Peace Operations; Berlin, Germany). Four incidents were evaluated: hostage-taking, carjacking, evacuation, and border-crossing. The participants completed the Positive and Negative Affect Schedule (PANAS) before and after each incident. For each incident, the delta of the PANAS scores was calculated. The differences between the described incidents, as well as the differences between novice and experienced responders, were evaluated.Results:The hostage-taking incident had the greatest influence on the participants’ temper, followed by carjacking and evacuation. Ultimately, the border-crossing event had the least effect on the responders. Novices were more affected by hostage-taking than experienced responders; however, no significant difference had been demonstrated between novices and experienced responders for the other evaluated incidents.Conclusion:Different incidents have big psychological impacts on humanitarian responders, in which consequences vary from short-term effects to PTSD. Therefore, humanitarian responders should be selected very carefully. They should also have more specific preparation for their missions. Mental after-care should be obligatory. Further studies are needed to understand and avoid reasons for the development of PTSD or other potential problems of responders.

Tinnitus is a prevalent phenomenon and bothersome for people affected by it. Its occurrence and maintenance have a clear neuroscientific tie and one aspect are differences in the neuronal oscillatory pattern, especially in auditory cortical areas. As studies in this field come to different results, the aim of this study was to analyze a large number of participants to achieve more stable results. Furthermore, we expanded our analysis to two variables of potential influence, namely being a novice to neuroscientific measurements and the exclusion of psychological comorbidities. Oscillatory brain activity of 88 subjects (46 with a chronic tinnitus percept, 42 without) measured in resting state by MEG was investigated. In the analysis based on the whole group, in sensor space increased activity in the delta frequency band was found in tinnitus patients. Analyzing the subgroup of novices, a significant difference in the theta band emerged additionally to the delta band difference (sensor space). Localizing the origin of the activity, we found a difference in theta and gamma band for the auditory regions for the whole group and the same significant difference in the subgroup of novices. However, no differences in oscillatory activity were observed between tinnitus and control groups once subjects with mental health comorbidity were excluded. Against the background of previous studies, the study at hand underlines the fragility of the results in the field of neuronal cortical oscillations in tinnitus. It supports the body of research arguing for low frequency oscillations and gamma band activity as markers associated with tinnitus.

Background: Tinnitus is the perception of sound unrelated to any external source. Diagnostic approaches to assess tinnitus characteristics such as tinnitus pitch are crucial for new attempts of tinnitus therapy. Purpose: The purpose of this study was to develop and evaluate reliable tinnitus pitch-matching procedures. Existing procedures usually require audiometric equipment and are time consuming. However, some patients with tinnitus find it hard to match their tinnitus in one single session. Therefore, we developed an iPod-based application for self-administered tinnitus pitch matching and compared it with a standardized audiometric procedure. Study Sample: A total of 17 patients with chronic tonal tinnitus participated in two sessions including both pitch-matching procedures. Method: In the conventional audiometric test, the investigator adjusted the frequency and loudness of pure tones led by the responses of the patient. For the iPod-based procedure, we used a recursive two-interval forced-choice test that required no interaction with an investigator. Both procedures included loudness matching and testing for octave confusion. Results: The iPod-based procedure resulted in lower pitch matches as compared with the conventional audiometry. Psychometric qualities such as test-retest reliability of both methods were comparable. Participants rated the iPod-based procedure as easier to perform and more comfortable to use. Conclusions: In conclusion, we find that the use of self-administered tinnitus pitch-matching procedures on a mobile device is feasible and easier in practice without any loss of reliability and validity. A major advantage is the possibility of repeated measurements without expensive equipment and experienced staff. Repeated measurements of tinnitus pitch can provide more information about the stability of the tinnitus perception and may improve the ability of participants to match their tinnitus.

We describe a multimodal dataset acquired in a controlled experiment on a driving simulator. The set includes data for n=68 volunteers that drove the same highway under four different conditions: No distraction, cognitive distraction, emotional distraction, and sensorimotor distraction. The experiment closed with a special driving session, where all subjects experienced a startle stimulus in the form of unintended acceleration—half of them under a mixed distraction, and the other half in the absence of a distraction. During the experimental drives key response variables and several explanatory variables were continuously recorded. The response variables included speed, acceleration, brake force, steering, and lane position signals, while the explanatory variables included perinasal electrodermal activity (EDA), palm EDA, heart rate, breathing rate, and facial expression signals; biographical and psychometric covariates as well as eye tracking data were also obtained. This dataset enables research into driving behaviors under neatly abstracted distracting stressors, which account for many car crashes. The set can also be used in physiological channel benchmarking and multispectral face recognition. Machine-accessible metadata file describing the reported data (ISA-Tab format)

This paper investigated the characteristics of vehicle longitudinal jerk (change rate of acceleration with respect to time) by using vehicle sensor data from an existing naturalistic driving study. The main objective was to examine whether vehicle jerk contains useful information that could be potentially used to identify aggressive drivers. Initial investigation showed that there are unique characteristics of vehicle jerk in drivers’ gas and brake pedal operations. Thus two jerk-based metrics were examined: (1) driver’s frequency of using large positive jerk when pressing the gas pedal, and (2) driver’s frequency of using large negative jerk when pressing the brake pedal. To validate the performance of the two metrics, drivers were firstly divided into an aggressive group and a normal group using three classification methods (1) traveling at excessive speed (speeding), (2) following too closely to a front vehicle (tailgating), and (3) their association with crashes or near-crashes in the dataset. The results show that those aggressive drivers defined using any of the three methods above were associated with significantly higher values of the two jerk-based metrics. Between the two metrics the frequency of using large negative jerk seems to have better performance in identifying aggressive drivers. A sensitivity analysis shows the findings were largely consistent with varying parameters in the analysis. The potential applications of this work include developing quantitative surrogate safety measures to identify aggressive drivers and aggressive driving, which could be potentially used to, for example, provide real-time or post-ride performance feedback to the drivers, or warn the surrounding drivers or vehicles using the connected vehicle technologies.

Reduced neural processing of a tone is observed when it is presented after a sound whose spectral range closely frames the frequency of the tone. This observation might be explained by the mechanism of lateral inhibition (LI) due to inhibitory interneurons in the auditory system. So far, several characteristics of bottom up influences on LI have been identified, while the influence of top-down processes such as directed attention on LI has not been investigated. Hence, the study at hand aims at investigating the modulatory effects of focused attention on LI in the human auditory cortex. In the magnetoencephalograph, we present two types of masking sounds (white noise vs. withe noise passing through a notch filter centered at a specific frequency), followed by a test tone with a frequency corresponding to the center-frequency of the notch filter. Simultaneously, subjects were presented with visual input on a screen. To modulate the focus of attention, subjects were instructed to concentrate either on the auditory input or the visual stimuli. More specific, on one half of the trials, subjects were instructed to detect small deviations in loudness in the masking sounds while on the other half of the trials subjects were asked to detect target stimuli on the screen. The results revealed a reduction in neural activation due to LI, which was larger during auditory compared to visual focused attention. Attentional modulations of LI were observed in two post-N1m time intervals. These findings underline the robustness of reduced neural activation due to LI in the auditory cortex and point towards the important role of attention on the modulation of this mechanism in more evaluative processing stages.

In order to better understand tinnitus and distress associated with tinnitus, psychological variables such as emotional and cognitive processing are a central element in theoretical models of this debilitating condition. Interoception, that is, the perception of internal processes, may be such a psychological factor relevant to tinnitus. Against this background, 20 participants suffering from chronic tinnitus and 20 matched healthy controls were tested with questionnaires, assessing interoceptive sensibility, and participated in two tasks, assessing interoceptive accuracy: the Schandry task, a heartbeat estimation assignment, and a skin conductance fluctuations perception task assessing the participants’ ability to perceive phasic increases in sympathetic activation were used. To test stress reactivity, a construct tightly connected to tinnitus onset, we also included a stress induction. No differences between the groups were found for interoceptive accuracy and sensibility. However, the tinnitus group tended to overestimate the occurrence of phasic activation. Loudness of the tinnitus was associated with reduced interoceptive performance under stress. Our results indicate that interoceptive sensibility and accuracy do not play a significant role in tinnitus. However, tinnitus might be associated with a tendency to overestimate physical changes.

Chronic tinnitus seems to be caused by reduced inhibition among frequency selective neurons in the auditory cortex. One possibility to reduce tinnitus perception is to induce inhibition onto over-activated neurons representing the tinnitus frequency via tailor-made notched music (TMNM). Since lateral inhibition is modifiable by spectral energy contrasts, the question arises if the effects of inhibition-induced plasticity can be enhanced by introducing increased spectral energy contrasts (ISEC) in TMNM. Eighteen participants suffering from chronic tonal tinnitus, pseudo randomly assigned to either a classical TMNM or an ISEC-TMNM group, listened to notched music for three hours on three consecutive days. The music was filtered for both groups by introducing a notch filter centered at the individual tinnitus frequency. For the ISEC-TMNM group a frequency bandwidth of 3/8 octaves on each side of the notch was amplified, additionally, by about 20 dB. Before and after each music exposure, participants rated their subjectively perceived tinnitus loudness on a visual analog scale. During the magnetoencephalographic recordings, participants were stimulated with either a reference tone of 500 Hz or a test tone with a carrier frequency representing the individual tinnitus pitch. Perceived tinnitus loudness was significantly reduced after TMNM exposure, though TMNM type did not influence the loudness ratings. Tinnitus related neural activity in the N1m time window and in the so called tinnitus network comprising temporal, parietal and frontal regions was reduced after TMNM exposure. The ISEC-TMNM group revealed even enhanced inhibition-induced plasticity in a temporal and a frontal cortical area. Overall, inhibition of tinnitus related neural activity could be strengthened in people affected with tinnitus by increasing spectral energy contrast in TMNM, confirming the concepts of inhibition-induced plasticity via TMNM and spectral energy contrasts.

Objective Notch-filtered music has been shown to induce frequency-specific inhibition. Here, we investigated which cortical structures are affected by tailor-made notched music (TMNM) in tinnitus patients and how this inhibition-induced plasticity develops over time. Methods Nine subjects suffering from chronic tonal tinnitus listened to music passing through a notch-filter centered at the patient’s individual tinnitus frequency (TMNM) for three hours on three consecutive days. Before and after each listening session, a tone at the tinnitus frequency and a control tone of 500 Hz were presented in the magnetoencephalograph. Subjective tinnitus loudness was measured via visual analog scales. Results TMNM exposure reduced subjective tinnitus loudness and neural activity evoked by the tinnitus tone in temporal, parietal and frontal regions within the N1m time interval. Reduction of temporal and frontal activation correlated significantly with tinnitus loudness decline. Reduction of tinnitus related neural activity persisted and accumulated over three days. Conclusions Inhibition-induced plasticity occurs in a cortical network, known to be crucial for tinnitus perception. This cortical reorganization evolves fast and accumulates across sessions. Significance This study extends previous work on inhibition-induced plasticity, as it demonstrates the involvement of parietal and frontal areas and discovers a cumulative effect of cortical reorganization in tinnitus patients.

We investigated the modulation of lateral inhibition in the human auditory cortex by means of magnetoencephalography (MEG). In the first experiment, five acoustic masking stimuli (MS), consisting of noise passing through a digital notch filter which was centered at 1 kHz, were presented. The spectral energy contrasts of four MS were modified systematically by either amplifying or attenuating the edge-frequency bands around the notch (EFB) by 30 dB. Additionally, the width of EFB amplification/attenuation was varied (3/8 or 7/8 octave on each side of the notch). N1m and auditory steady state responses (ASSR), evoked by a test stimulus with a carrier frequency of 1 kHz, were evaluated. A consistent dependence of N1m responses upon the preceding MS was observed. The minimal N1m source strength was found in the narrowest amplified EFB condition, representing pronounced lateral inhibition of neurons with characteristic frequencies corresponding to the center frequency of the notch (NOTCH CF) in secondary auditory cortical areas. We tested in a second experiment whether an even narrower bandwidth of EFB amplification would result in further enhanced lateral inhibition of the NOTCH CF. Here three MS were presented, two of which were modified by amplifying 1/8 or 1/24 octave EFB width around the notch. We found that N1m responses were again significantly smaller in both amplified EFB conditions as compared to the NFN condition. To our knowledge, this is the first study demonstrating that the energy and width of the EFB around the notch modulate lateral inhibition in human secondary auditory cortical areas. Because it is assumed that chronic tinnitus is caused by a lack of lateral inhibition, these new insights could be used as a tool for further improvement of tinnitus treatments focusing on the lateral inhibition of neurons corresponding to the tinnitus frequency, such as the tailor-made notched music training.

Tinnitus is a result of hyper-activity/hyper-synchrony of auditory neurons coding the tinnitus frequency, which has developed due to synchronous mass activity owing to the lack of inhibition. We assume that removal of exactly these frequencies from a complex auditory stimulus will cause the brain to reorganize around tonotopic regions coding the tinnitus frequency through inhibition-induced plasticity. Based on this assumption, a novel treatment for tonal tinnitus - tailor-made notched music training (TMNMT) - has been introduced and was tested in this clinical trial. A randomized controlled trial in parallel group design was performed in a double-blinded manner. We included 100 participants with chronic, tonal tinnitus who listened to tailor-made notched music for two hours a day for three consecutive months. Our primary outcome measures were the Tinnitus Handicap Questionnaire and Visual Analog Scales measuring perceived tinnitus loudness, awareness, distress and handicap. Participants rated their tinnitus before and after the training as well as one month after cessation of the training. While no effect was found for the primary outcome measures, tinnitus distress, as measured by the Tinnitus Questionnaire, a secondary outcome measure, developed differently in the two groups. The treatment group showed higher distress scores while the placebo group revealed lower distress scores after the training. However, this effect did not reach significance in post-hoc analysis and disappeared at follow-up measurements. At follow-up, tinnitus loudness in the treatment group was significantly reduced as compared to the control group. Post hoc analysis, accounting for low reliability scores in the Visual Analog Scales, showed a significant reduction of the overall Visual Analog Scale mean score in the treatment group even at the post measurement. This is the first study on TMNMT that was planned and conducted following the CONSORT statement standards for clinical trials. The current work is one more step towards a final evaluation of TMNMT. Already after three months the effect of training with tailor-made notched music is observable in the most direct rating of tinnitus perception – the tinnitus loudness, while more global measures of tinnitus distress do not show relevant changes. Current Controlled Trials ISRCTN04840953 ; Trial registration date: 17.07.2013