Bedeutung von Stress: Seine Rolle im auditorischen System und bei der Tinnitusentstehung

[Stress and suffering from tinnitus-a psychosomatic approach]

The development and processing of tinnitus is often associated with stress. There are many publications on this subject that have investigated possible connections between stress perception and tinnitus symptoms using different concepts and different test inventories. In this review, we present the development of Selye's concept of stress using the transactional stress model of Lazarus and its transfer to patients suffering from tinnitus. The literature evaluating the influence of stress on tinnitus symptoms with partly very different concepts is critically reviewed. For example, it is suggested that psychosocial stress has the same likelihood of contributing to tinnitus as noise in the workplace. However, what is striking in previous studies is that "stress" as an influencing variable could not be clearly verified with suitable psychometric test procedures or that no significant differences-to very different comparison groups-could be shown. Finally, a possible therapeutic approach to stress management is outlined.

Chronic stress induced loudness hyperacusis, sound avoidance and auditory cortex hyperactivity

Hyperacusis, a debilitating loudness intolerance disorder, has been linked to chronic stress and adrenal insufficiency. To investigate the role of chronic stress, rats were chronically treated with corticosterone (CORT) stress hormone. Chronic CORT produced behavioral evidence of loudness hyperacusis, sound avoidance hyperacusis, and abnormal temporal integration of loudness. CORT treatment did not disrupt cochlear or brainstem function as reflected by normal distortion product otoacoustic emissions, compound action potentials, acoustic startle reflexex, and auditory brainstem responses. In contrast, the evoked response from the auditory cortex was enhanced up to three fold after CORT treatment. This hyperactivity was associated with a significant increase in glucocorticoid receptors in auditory cortex layers II/III and VI. Basal serum CORT levels remained normal after chronic CORT stress whereas reactive serum CORT levels evoked by acute restraint stress were blunted (reduced) after chronic CORT stress; similar changes were observed after chronic, intense noise stress. Taken together, our results show for the first time that chronic stress can induce hyperacusis and sound avoidance. A model is proposed in which chronic stress creates a subclinical state of adrenal insufficiency that establishes the necessary conditions for inducing hyperacusis.

Linking Affective and Hearing Sciences-Affective Audiology

A growing number of health-related sciences, including audiology, have increasingly recognized the importance of affective phenomena. However, in audiology, affective phenomena are mostly studied as a consequence of hearing status. This review first addresses anatomical and functional bidirectional connections between auditory and affective systems that support a reciprocal affect-hearing relationship. We then postulate, by focusing on four practical examples (hearing public campaigns, hearing intervention uptake, thorough hearing evaluation, and tinnitus), that some important challenges in audiology are likely affect-related and that potential solutions could be developed by inspiration from affective science advances. We continue by introducing useful resources from affective science that could help audiology professionals learn about the wide range of affective constructs and integrate them into hearing research and clinical practice in structured and applicable ways. Six important considerations for good quality affective audiology research are summarized. We conclude that it is worthwhile and feasible to explore the explanatory power of emotions, feelings, motivations, attitudes, moods, and other affective processes in depth when trying to understand and predict how people with hearing difficulties perceive, react, and adapt to their environment.

Clinical Findings That Differentiate Co-Occurrence of Hyperacusis and Tinnitus from Tinnitus Alone

PURPOSE

We aimed to assess the characteristics of patients with concurrent tinnitus and hyperacusis, determine the best audiological criteria for predicting hyperacusis, and confirm whether objective evidence of changes in the brain exists.

MATERIALS AND METHODS

The medical records of patients with tinnitus who visited the hospital between March 2020 and December 2021 were reviewed. Data on accompanying hyperacusis, audiological profiles, and questionnaires including the Tinnitus Handicap Inventory (THI), Beck Depression Inventory, and numerical rating scale were analyzed. Resting-state quantitative electroencephalography (qEEG) using power spectral density (PSD) and event-related spectral perturbation (ERSP) were performed to objectively quantify changes in the brain.

RESULTS

A total of 194 patients were analyzed. Among them, 51 (26.3%) reported combined subjective hyperacusis with tinnitus. However, the proportions widely varied from 7.4% to 68.4% based on three audiological criteria for assessment. A higher score on the THI questionnaire was independently associated with the co-occurrence of tinnitus and hyperacusis. Fair agreement was observed between subjective hyperacusis and the audiological criterion based on a loudness discomfort level (LDL) of ≤90 dB at two or more frequencies for the diagnosis of hyperacusis. An increased beta-PSD and decreased levels of gamma-PSD, all-ERSP, and delta-ERSP were observed in patients with hyperacusis (p<0.05).

CONCLUSION

Patients with co-occurring tinnitus and hyperacusis had more severe tinnitus distress. An LDL of ≤90 dB at two or more frequencies may be applicable to predict accompanying hyperacusis in subjects with tinnitus, and qEEG also provides more objective information.

Reduction of Somatic Tinnitus Severity is Mediated by Improvement of Temporomandibular Disorders

BACKGROUND

Successful orofacial treatment can reduce tinnitus severity in patients with somatic tinnitus (ST). However, it is still unclear to what extent the degree of reduction in temporomandibular disorders (TMD) actually contributes to the decrease in tinnitus severity after orofacial treatment. Therefore, the aim of this study was to analyze the mediating effect of reduction in TMD pain on the improvement of tinnitus severity after multidisciplinary orofacial treatment.

METHODS

A total of 80 patients with moderate to severe ST attributed to the temporomandibular region, were recruited from a tertiary tinnitus clinic. At baseline, patients were randomly assigned to the orofacial treatment group or to the control group. Both groups received a minimum of information and advice regarding their tinnitus complaints. The orofacial treatment group received orofacial physical therapy complemented with occlusal splints when needed, while the control group received no other treatment. A mediation analysis was performed according to the steps described by Baron and Kenny and the proportion of the mediating effect was calculated for the potential mediator: "change in TMD pain," measured by a one-point decrease in TMD pain screener score.

RESULTS

Our analysis showed that 35% of the observed decrease in tinnitus severity can be attributed to a reduction in TMD pain. A significant total effect of orofacial treatment compared with control on the change in tinnitus functional index (TFI) score was found (B = 0.253 p = 0.025 Cl for B = 1.265-18.576). Orofacial treatment was also significantly related to the change in TMD pain (Exp (B) = 2.800, p = 0.034 Cl for Exp B 1.081-7.251). Additionally, the change in TMD pain screener score was significantly related to the change in TFI score (B = -0.273 p = 0.016 Cl for B = -19.875 to -2.119).

CONCLUSION

Reduction of TMD pain is a mediating factor in the decrease of tinnitus severity after multidisciplinary orofacial treatment.

PRACTICAL IMPLICATIONS

Orofacial treatment can be used to decrease tinnitus severity in patients with TMD related somatic tinnitus.

Cerebral Cortical Activity During Academic Stress Amongst Undergraduate Medical Students at Kampala International University (Uganda)

BACKGROUND

Stress among medical students is related to their academic lifespan; however, information on brain health among medical students from developing countries continues to be scarce. The objective of this study was to establish perceived academic stress levels, assess the ability to cope with stress, and investigate its effects on the visual reaction time (VRT), audio reaction time (ART), and tactile reaction time (TRT) in the somatosensory cortex among medical students of Uganda.

METHODS

This was a cross-sectional study conducted among preclinical (n = 88) and clinical (n = 96) undergraduate medical students at Kampala International University Western Campus. A standard Perceived Stress Scale (PSS) was used to categorize stress into low, moderate, and severe while the ability to cope with stress was categorized into below average, average, above average, and superior stresscoper (SS). Data on reaction time were acquired through VRT, ART, and TRT using the catch-a-ruler experiment, and this was analyzed using SPSS version 20.

RESULTS

This study shows that preclinical students are more stressed than clinical students (PSS prevalence for low stress = preclinical; clinical: 40, 60%). Moderate stress was 48.4 and 51.6% while high perceived stress was 75 and 25% among preclinical and clinical students. Among male and female students in preclinical years, higher TRT and VRT were found in clinical students showing that stress affects the tactile and visual cortical areas in the brain, although the VRT scores were only significantly (P = 0.0123) poor in male students than female students in biomedical sciences. Also, highly stressed individuals had higher TRT and ART and low VRT. SS had high VRT and ART and low TRT in preclinical students, demonstrating the importance of the visual cortex in stress plasticity. Multiple regression showed a close relationship between PSS, ability to cope with stress, age, and educational level (P < 0.05), demonstrating the importance of social and psychological support, especially in the biomedical sciences.

CONCLUSION

Preclinical students suffer more from stress and are poorer SS than clinical students. This strongly impairs their cortical regions in the brain, thus affecting their academic productivity.

Neurobiology of Stress-Induced Tinnitus

Emotional stress has accompanied humans since the dawn of time and has played an essential role not only in positive selection and adaptation to an ever-changing environment, but also in the acceleration or even initiation of many illnesses. The three main somatic mechanisms induced by stress are the hypothalamus-pituitary-adrenal axis (HPA axis), the sympathetic-adreno-medullar (SAM) axis, and the immune axis. In this chapter, the stress-induced mechanisms that can affect cochlear physiology are presented and discussed in the context of tinnitus generation and auditory neurobiology. It is concluded that all of the presented mechanisms need to be further investigated. It is advised that clinical practitioners ask patients about stressful events or chronic stress preceding the tinnitus onset and measure the vital signs. Finally, taking into account that tinnitus itself acts as a stressor, the implementation of anti-stress therapies for tinnitus treatment is recommended.

Effects of stress on the auditory system: an approach to study a common origin for mood disorders and dementia

The concept of stress is a fundamental piece to understand how organisms can adapt to the demands produced by a continuously changing environment. However, modern lifestyle subjects humans to high levels of negative stress or distress, which increases the prevalence of mental illnesses. Definitely, stress has become the pandemic of the 21st century, a fact that demands a great intellectual effort from scientists to understand the neurobiology of stress. This review proposes an innovative point of view to understand that mood disorders and dementia have a common etiology in a stressful environment. We propose that distress produces sensory deprivation, and this interferes with the connection between the brain and the environment in which the subject lives. The auditory system can serve as an example to understand this idea. In this sense, distress impairs the auditory system and induces hearing loss or presbycusis at an early age; this can increase the cognitive load in stressed people, which can stimulate the development of dementia in them. On the other hand, distress impairs the auditory system and increases the excitability of the amygdala, a limbic structure involved in the emotional processing of sounds. A consequence of these alterations could be the increase in the persistence of auditory fear memory, which could increase the development of mood disorders. Finally, it is important to emphasize that stress is an evolutionary issue that is necessary to understand the mental health of humans in these modern times. This article is a contribution to this discussion and will provide insights into the origin of stress-related neuropsychiatric disorders.

Interaction of tinnitus suppression and hearing ability after cochlear implantation

OBJECTIVES

To study the postoperative impact of cochlear implants (CIs) on tinnitus, as well as the impact of tinnitus on speech recognition with CI switched on.

METHODS

Fifty-two postlingual deafened CI recipients (21 males and 31 females) were assessed using an established Tinnitus Characteristics Questionnaire and Tinnitus Handicap Inventory (THI) before and after cochlear implantation. The tinnitus loudness was investigated when CI was switched on and off in CI recipients with persistent tinnitus. The relation between tinnitus loudness and recipients' satisfaction of cochlear implantation was analyzed by the visual analogue scale (VAS) score.

RESULTS

With CI 'OFF', 42 CI recipients experienced tinnitus postimplant ipsilaterally and 44 contralaterally. Tinnitus was totally suppressed ipsilateral to the CI with CI 'ON' in 42.9%, partially suppressed in 42.9%, unchanged in 11.9% and aggravated in 2.4%. Tinnitus was totally suppressed contralaterally with CI 'ON' in 31.8% of CI recipients, partially suppressed in 47.7%, unchanged in 20.5%. Pearson correlation analysis showed that tinnitus loudness and the results of cochlear implant patients satisfaction was negatively correlated (r = .674, p < .001).

CONCLUSION

The study suggests six-month CI activation can be effective for suppressing tinnitus. The tinnitus loudness may affect patients' satisfaction with the use of CI.

The Relevance of Interoception in Chronic Tinnitus: Analyzing Interoceptive Sensibility and Accuracy

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.

Three years later: report on the state of well-being of patients with chronic tinnitus who underwent modified tinnitus retraining therapy

Successful management of patients with chronic tinnitus is an important health issue. One of the tinnitus management strategies used at our Tinnitus Center is a combination of tinnitus retraining therapy (TRT) with physiotherapy and psychological management [called modified TRT (MTRT)]. We have used this type of management for over a decade and have described the protocol in detail elsewhere. In the present study, we wanted to determine the effect of MTRT on the well-being of tinnitus patients 3 years after treatment onset. One hundred and thirty patients with chronic tinnitus were assessed using psychometric instruments immediately before 7-day MTRT, immediately after the therapy and 3 years later. Patients with very severe tinnitus-related distress associated with major depression and a risk of suicide were excluded from this study. MTRT resulted in a sustained reduction of tinnitus-related distress. Moreover, the quality of life of patients had increased, as assessed by a separate questionnaire. The effect of MTRT was influenced by the degree of tinnitus-related distress and by the patients' age, the latter being gender dependent. Hearing loss and tinnitus duration had only a minor influence on the therapeutic effect. Taken together, we report a positive change in the state of well-being of patients with chronic tinnitus measurable with various psychometric instruments 3 years after the onset of MTRT.

Seasonal trends in tinnitus symptomatology: evidence from Internet search engine query data

The primary aim of this study was to test the hypothesis that the symptom of tinnitus demonstrates a seasonal pattern with worsening in the winter relative to the summer using Internet search engine query data. Normalized search volume for the term 'tinnitus' from January 2004 through December 2013 was retrieved from Google Trends. Seasonal effects were evaluated using cosinor regression models. Primary countries of interest were the United States and Australia. Secondary exploratory analyses were also performed using data from Germany, the United Kingdom, Canada, Sweden, and Switzerland. Significant seasonal effects for 'tinnitus' search queries were found in the United States and Australia (p < 0.00001 for both countries), with peaks in the winter and troughs in the summer. Secondary analyses demonstrated similarly significant seasonal effects for Germany (p < 0.00001), Canada (p < 0.00001), and Sweden (p = 0.0008), again with increased search volume in the winter relative to the summer. Our findings indicate that there are significant seasonal trends for Internet search queries for tinnitus, with a zenith in winter months. Further research is indicated to determine the biological mechanisms underlying these findings, as they may provide insights into the pathophysiology of this common and debilitating medical symptom.

Tinnitus: clinical experience of the psychosomatic connection

BACKGROUND

The connection between psychopathology and tinnitus is complex and not adequately studied. The aim of this study is to investigate the relationship between tinnitus and psychiatric comorbidities from different points of view: categorical, dimensional, temperamental, and perceived stress level.

METHODS

Two hundred and thirty-nine patients affected by tinnitus were recruited between January and October 2012. Patients underwent a preliminary battery of tests including the Tinnitus Handicap Inventory (THI), Symptom Check List (SCL90-R), Temperament and Character Inventory (TCI), and Stress-Related Vulnerability Scale (VRS), and eventually a full psychiatric evaluation.

RESULTS

One hundred and fourteen patients (48% of the total sample) presented psychiatric comorbidity. Among these, a higher prevalence of depression, somatization, obsession, and anxiety was found. More than 41% of patients affected by decompensated tinnitus reported a family history of psychiatric disorders. Significant positive correlations between the psychopathological screening tools (SCL90-R and VRS) and THI were found. Patients affected by comorbid psychiatric disorder showed specific temperamental and characterial predispositions.

CONCLUSION

Psychiatric comorbidity in subjects affected by tinnitus is frequent. Stress can be considered as a factor leading to damage and dysfunction of the auditory apparatus. The vulnerability to neurotic disorders and the lack of coping capabilities can play a critical role in the clinical history of patients affected by severe tinnitus.

Otology versus Otosociology

Otology concerns the biological study of ear alterations and diseases, solely. So, the diagnosis of audiovestibular diseases tends to be idiopathic or is based on theoretical concepts such as idiopathic sudden deafness, Ménière disease, benign paroxysmal positional vertigo, tinnitus, hyperacusis, or idiopathic facial paralysis. The treatment for these pathologies is symptomatic. Otosociology takes the aetiology and pathogenesis of the ear and situates them within the social and cultural environment of the patient. Then, audiovestibular disease is based on evidence, and the treatment options seek to solve the causes and consequences produced. Otosociology should be considered as a new discipline. Otosociology came into being since otology does not provide definitive solutions for the audiovestibular alterations produced from the point of view of the ear, whereas otosociology finds these solutions within the social/cultural environment of the patient. Where otology emphasises the diseases of the ear, otosociology deals with social manifestations. Where otology deals with idiopathic diseases, otosociology deals with causes and pathogeny produced by interactions in the social and cultural surroundings of the patient. Where otology offers symptomatic treatment, otosociology offers treatment of causes and consequences. Otosociology can fill significant voids in audiovestibular processes from the perspective of the patient's social environment.

[Possible molecular mechanisms of spontaneous remission in sudden idiopathic hearing loss]

According to current knowledge, it must be assumed that temporary idiopathic hearing loss and its spontaneous remission are based on mechanical and/or pathological alterations in the inner ear. The causal mechanisms might be based on inter-individual variations. Induced by dose-dependent activators, temporary as well as permanent damage might occur. Sudden hearing loss may be initiated by an increase in the local nitric oxide (NO) concentration. Spontaneous remission, i.e. functional restoration, can be explained by a local decrease in the NO concentration. In this context, regulatory systems such as the gap-junction system, blood vessels or synapses might be affected. In addition, alterations in the hormone level of estrogen and mineralocorticoids, as well as cellular glutathione and vitamin levels, might lead to temporary alterations in the inner ear. Recent experimental findings indicate a role for the shuttle protein Survivin in the spontaneous remission of sudden hearing loss.

Oxidative stress, redox homeostasis and cellular stress response in Ménière's disease: role of vitagenes

Ménière's disease (MD) is characterized by the triad of fluctuating hearing loss, episodic vertigo and tinnitus, and by endolymphatic hydrops found on post-mortem examination. Increasing evidence suggests that oxidative stress is involved in the development of endolymphatic hydrops and that cellular damage and apoptotic cell death might contribute to the sensorineural hearing loss found in later stages of MD. While excess reactive oxygen species (ROS) are toxic, regulated ROS, however, play an important role in cellular signaling. The ability of a cell to counteract stressful conditions, known as cellular stress response, requires the activation of pro-survival pathways and the production of molecules with anti-oxidant, anti-apoptotic or pro-apoptotic activities. Among the cellular pathways conferring protection against oxidative stress, a key role is played by vitagenes, which include heat shock proteins (Hsps) as well as the thioredoxin/thioredoxin reductase system. In this study we tested the hypothesis that in MD patients measurable increases in markers of cellular stress response and oxidative stress in peripheral blood are present. This study also explores the hypothesis that changes in the redox status of glutathione, the major endogenous antioxidant, associated with abnormal expression and activity of carbonic anhydrase can contribute to increase oxidative stress and to disruption of systemic redox homeostasis which can be associated to possible alterations on vulnerable neurons such as spiral ganglion neurons and consequent cellular degeneration. We therefore evaluated systemic oxidative stress and cellular stress response in patients suffering from Meniere's disease (MD) and in age-matched healthy subjects. Systemic oxidative stress was estimated by measuring protein oxidation, such as protein carbonyls (PC) and 4-hydroxynonenal (HNE) in lymphocytes of MD patients, as well as ultraweak luminescence (UCL) as end-stable products of lipid oxidation in MD plasma and lymphocytes, as compared to age-matched controls, whereas heat shock proteins Hsp70 and thioredoxin (Trx) expression were measured in lymphocytes to evaluate the systemic cellular stress response. Increased levels of PC (P < 0.01) and HNE (P < 0.05) have been found in lymphocytes from MD patients with respect to control group. This was paralleled by a significant induction of Hsp70, and a decreased expression of Trx (P < 0.01), whereas a significant decrease in both plasma and lymphocyte ratio reduced glutathione GSH) vs. oxidized glutathione (GSSG) (P < 0.05) were also observed. In conclusion, patients affected by MD are under condition of systemic oxidative stress and the induction of vitagenes Hsp70 is a maintained response in counteracting the intracellular pro-oxidant status generated by decreased content of GSH as well as expression of Trx. The search for novel and more potent inducers of vitagenes will facilitate the development of pharmacological strategies to increase the intrinsic capacity of vulnerable ganglion cells to maximize antidegenerative mechanisms, such as stress response and thus cytoprotection.