Analysis of the Prevalence and Associated Risk Factors of Tinnitus in Adults

BackgroundTinnitus is a common condition in adults; however, the pathophysiology of tinnitus remains unclear, and no large population-based study has assessed the associated risk factors. The aim of this study was to analyze the prevalence and associated risk factors of tinnitus.MethodsWe conducted a cross-sectional study using data from the Korea National Health and Nutrition Examination Survey, with 19,290 participants ranging in age from 20 to 98 years old, between 2009 and 2012. We investigated the prevalence of tinnitus using a questionnaire and analyzed various possible factors associated with tinnitus using simple and multiple logistic regression analysis with complex sampling.ResultsThe prevalence of tinnitus was 20.7%, and the rates of tinnitus associated with no discomfort, moderate annoyance, and severe annoyance were 69.2%, 27.9%, and 3.0%, respectively. The prevalence of tinnitus and the rates of annoying tinnitus increased with age. The adjusted odds ratio (AOR) of tinnitus was higher for females, those with a smoking history, those reporting less sleep (≤ 6 h), those with more stress, those in smaller households, those with a history of hyperlipidemia osteoarthritis, rheumatoid arthritis, asthma, depression, thyroid disease, an abnormal tympanic membrane, unilateral hearing loss, bilateral hearing loss, noise exposure from earphones, noise exposure at the workplace, noise exposure outside the workplace, and brief noise exposure. Additionally, unemployed individuals and soldiers had higher AORs for tinnitus. The AOR of annoying tinnitus increased with age, stress, history of hyperlipidemia, unilateral hearing loss, and bilateral hearing loss.ConclusionsTinnitus is very common in the general population and is associated with gender, smoking, stress, sleep, hearing loss, hyperlipidemia, osteoarthritis, rheumatoid arthritis, asthma, depression, and thyroid disease history.     

Association of Hearing Loss and Tinnitus with Health-Related Quality of Life: The Korea National Health and Nutrition Examination Survey

Background

Hearing loss and tinnitus are global public health concerns. There have been some studies suggesting a relationship between hearing loss and tinnitus and impaired health-related quality of life (HRQoL), but there have been no large cross-sectional epidemiologic studies of a representative sample of the entire country population investigating this possible association.

Objective

The aim of this study was to investigate the relationship between hearing loss and tinnitus and HRQoL in South Korea using data from the Korea National Health and Nutrition Examination Surveys during 2010–2012.

Methods

Cross-sectional data of 11,266 adults who completed the Korea National Health and Nutrition Examination Surveys were analyzed. Subjects were divided into four groups as follows: normal hearing without tinnitus, normal hearing with tinnitus, hearing loss without tinnitus, and hearing loss with tinnitus.

Results

Among the population that was ≥19 years of age, the prevalence of unilateral hearing loss was 9.69% and that of tinnitus in the prior 12 months was 32.76%. The hearing loss with tinnitus group had the highest percentage of subjects who responded “some or extreme problems” in all five dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) of HRQoL. After adjustment for age, gender, body mass index, smoking status, alcohol intake, regular exercise, house income, education level, diabetes, hypertension, and stress level, the HRQoL odds ratios (OR) were 1.47 (95% confidence interval [CI], 1.07–2.02) for mobility, 1.59 (95% CI, 1.07–2.37) for usual activity, and 1.84 (95% CI, 1.25–2.70) for anxiety/depression in the hearing loss with tinnitus group, compared with the normal hearing without tinnitus group. The ORs for the normal hearing with tinnitus group compared with the hearing loss without tinnitus group was increased in all five dimensions of HRQoL after adjustment for confounders.

Conclusion

Hearing loss with tinnitus has a considerable impact on HRQoL in the Korean population. In our study, the hearing loss without tinnitus group showed better a HRQoL than the normal hearing with tinnitus group.     

Epidemiology of Noise-Induced Tinnitus and the Attitudes and Beliefs towards Noise and Hearing Protection in Adolescents

Background and objectives

Previous research showed an increase of noise-induced symptoms in adolescents. Permanent tinnitus as a consequence of loud music exposure is usually considered as noise-induced damage. The objective was to perform an epidemiological study in order to obtain prevalence data of permanent noise-induced tinnitus as well as temporary tinnitus following noise exposure in a young population. In addition the attitudes and beliefs towards noise and hearing protection were evaluated in order to explain the use/non-use of hearing protection in a young population.

Methods

A questionnaire was completed by 3892 high school students (mean age: 16.64 years old, SD: 1.29 years). The prevalence of temporary and permanent tinnitus was assessed. In addition the ‘Youth Attitudes to Noise Scale’ and the ‘Beliefs About Hearing Protection and Hearing Loss’ were used in order to assess the attitudes and beliefs towards noise and hearing protection respectively.

Results

The prevalence of temporary noise-induced tinnitus and permanent tinnitus in high school students was respectively 74.9% and 18.3%. An increasing prevalence of temporary tinnitus with age was present. Most students had a ‘neutral attitude’ towards loud music and the use of hearing protection was minimal (4.7%). The limited use of hearing protection is explained by a logistic regression analysis showing the relations between certain parameters and the use of hearing protection.

Conclusions

Despite the very high prevalence of tinnitus in such a young population, the rate of hearing protection use and the knowledge about the risks of loud music is extremely low. Future preventive campaigns should focus more on tinnitus as a warning signal for noise-induced damage and emphasize that also temporary symptoms can result in permanent noise-induced damage.     

Olfactory Bulbectomy Leads to the Development of Epilepsy in Mice

There is a clear link between epilepsy and depression. Clinical data demonstrate a 30–35% lifetime prevalence of depression in patients with epilepsy, and patients diagnosed with depression have a three to sevenfold higher risk of developing epilepsy. Traditional epilepsy models partially replicate the clinical observations, with the demonstration of depressive traits in epileptic animals. Studies assessing pro-epileptogenic changes in models of depression, however, are more limited. Here, we examined whether a traditional rodent depression model—bilateral olfactory bulbectomy—predisposes the animals towards the development of epilepsy. Past studies have demonstrated increased neuronal excitability after bulbectomy, but continuous seizure monitoring had not been conducted. For the present study, we monitored control and bulbectomized animals by video-EEG 24/7 for approximately two weeks following the surgery to determine whether they develop spontaneous seizures. All seven bulbectomized mice exhibited seizures during the monitoring period. Seizures began about one week after surgery, and occurred in clusters with severity increasing over the monitoring period. These results suggest that olfactory bulbectomy could be a useful model of TBI-induced epilepsy, with advantages of relatively rapid seizure onset and a high number of individuals developing the disease. The model may also be useful for investigating the mechanisms underlying the bidirectional relationship between epilepsy and depression.     

The Disability Rate of 5-Year Post-Stroke and Its Correlation Factors: A National Survey in China

Few studies on long-term functional outcome have been conducted in post-stroke patients in China. The objective of this study was to conduct a nationwide survey in China to investigate the 5-year prevalence of post-stroke disability and its correlation factors. A total of 893 patients with ischemic stroke were included. Demographic, clinical and neuro-imaging information were collected with standardized instruments that assessed stroke severity, depression, cognitive impairment, stroke recurrence and physical disability. Disability was assessed with the modified Ranking Score (mRS), of which a cutoff score ≥2 indicates disability. Statistical analysis included chi-square tests, two independent samples t-tests, Mann-Whitney U test and multiple logistic regression analysis. The frequency of disability in this study population was 45%. Multivariate analyses revealed that older age, lower education level, previous history of stroke, stroke severity at admission, depression, cognitive impairment at 3 months, and stroke recurrence within 5 years follow up were all significantly associated with post-stroke disability. The disability rate in 5-year post-stroke was high in Chinese patients. Treatment of depression, secondary prevention of stroke and rehabilitation may benefit disabled patients with stroke in China.     

The prevalence of urinary incontinence

Urinary incontinence is a significant health problem with considerable social and economic impact. It is important to distinguish between prevalence and incidence with regard to incontinence, and prevalence-the probability of having incontinence within a defined population at a defined point in time-is the more important when considering its impact and the utilization of healthcare resources. There are large variations in the severity and impact of incontinence, and its severity, frequency, and predictability all need to be considered when evaluating its effects on patients, The degree of bother is particularly significant when determining who will need treatment. Incontinence may be a result of bladder dysfunction, sphincter dysfunction, or a combination of both, but large-scale studies are not designed to determine the etiology. In young women, the prevalence of incontinence is usually low, but prevalence peaks around menopause, with a steady rise there-after into later life. Although the prevalence of stress and mixed (stress and urge) incontinence is higher than urge incontinence, the latter is more likely to require treatment. In women, moderate and severe bother have a prevalence ranging from about 3% to 17%. Severe incontinence has a low prevalence in young women, but rapidly increases at ages 70 through 80. In men, the prevalence of incontinence is much lower than in women, about 3% to 11% overall, with urge incontinence accounting for 40% to 80% of all male patients. Stress incontinence accounts for less than 10% of cases and is attributable to prostate surgery, trauma, or neurological injury. Incontinence in men also increases with age, but severe incontinence in 70- to 80-year-old men is about half of that in women. The most effective therapy for incontinence will rely on targeting the correct populations to be treated, which depends on how data is collected on prevalence and severity.     

Interactive effects of environmental stress and inbreeding on reproductive traits in a wild bird population

1. Conservation biologists are concerned about the interactive effects of environmental stress and inbreeding because such interactions could affect the dynamics and extinction risk of small and isolated populations, but few studies have tested for these interactions in nature. 2. We used data from the long-term population study of song sparrows Melospiza melodia on Mandarte Island to examine the joint effects of inbreeding and environmental stress on four fitness traits that are known to be affected by the inbreeding level of adult birds: hatching success, laying date, male mating success and fledgling survival. 3. We found that inbreeding depression interacted with environmental stress to reduce hatching success in the nests of inbred females during periods of rain. 4. For laying date, we found equivocal support for an interaction between parental inbreeding and environmental stress. In this case, however, inbred females experienced less inbreeding depression in more stressful, cooler years. 5. For two other traits, we found no evidence that the strength of inbreeding depression varied with environmental stress. First, mated males fathered fewer nests per season if inbred or if the ratio of males to females in the population was high, but inbreeding depression did not depend on sex ratio. Second, fledglings survived poorly during rainy periods and if their father was inbred, but the effects of paternal inbreeding and rain did not interact. 6. Thus, even for a single species, interactions between the inbreeding level and environmental stress may not occur in all traits affected by inbreeding depression, and interactions that do occur will not always act synergistically to further decrease fitness.     

Predictors of response to combined wake and light therapy in treatment-resistant inpatients with depression

ABSTRACT

There is growing evidence for combined chronotherapeutic interventions as adjunctive treatments for major depression. However, as the treatments can be demanding, we need to identify predictors of response. This study aimed to describe predictors of response, remission and deterioration in the short-term phase, as well as predictors of long-term response. The predictors investigated were gender, type of depression, severity of depression, treatment resistance, quetiapine use, general self-efficacy, educational level and positive diurnal variation. Follow-up data from 27 inpatients with moderate-to-severe depression participating in a chronotherapeutic intervention were analysed. As a supplement to standard treatment, they completed 3 wake therapy sessions in the first week, 30 min daily light treatment and sleep-time stabilisation in the entire 9-week study period. Patients had a significant decrease of depressive symptoms during the first 6 days measured by HAM-D6. At Day 6, 41% of the patients responded to the treatment and 19% fulfilled the criteria of remission. Deterioration by the end of wake therapy sessions was however not uncommon. In the short-term phase, mild degree of treatment resistance was associated with remission and low educational level associated with deterioration. Positive diurnal variation (mood best in the evening) was a predictor of both short-term and long-term response to combined wake and light therapy. Furthermore, patients with evening chronotypes (measured with morningness-eveningness score) were more responsive. Our results suggest that targeting the combined chronotherapeutic intervention at patients with positive diurnal variation and evening types is a viable option.     

Does Tinnitus Distress Depend on Age of Onset?

Objectives

Tinnitus is the perception of a sound in the absence of any physical source of it. About 5–15% of the population report hearing such a tinnitus and about 1–2% suffer from their tinnitus leading to anxiety, sleep disorders or depression. It is currently not completely understood why some people feel distressed by their tinnitus, while others don''t. Several studies indicate that the amount of tinnitus distress is associated with many factors including comorbid anxiety, comorbid depression, personality, the psychosocial situation, the amount of the related hearing loss and the loudness of the tinnitus. Furthermore, theoretical considerations suggest an impact of the age at tinnitus onset influencing tinnitus distress.

Methods

Based on a sample of 755 normal hearing tinnitus patients we tested this assumption. All participants answered a questionnaire on the amount of tinnitus distress together with a large variety of clinical and demographic data.

Results

Patients with an earlier onset of tinnitus suffer significantly less than patients with an onset later in life. Furthermore, patients with a later onset of tinnitus describe their course of tinnitus distress as more abrupt and distressing right from the beginning.

Conclusion

We argue that a decline of compensatory brain plasticity in older age accounts for this age-dependent tinnitus decompensation.     

Low blood pressure and depression in older men: a population based study.

OBJECTIVE--To determine if an association exists between low blood pressure and depressive symptoms in older men living in the community. DESIGN--Cross sectional, population based study. SETTING--Town of Rancho Bernardo, California, United States. SUBJECTS--846 men aged 60-89 years. Comparisons between hypotensive, normotensive, and hypertensive groups were limited to 594 men not taking drugs for hypertension. MAIN OUTCOME MEASURES--Mean scores on Beck depression inventory and prevalence of scores > or = 13. RESULTS--Men with diastolic blood pressure < 75 mm Hg had significantly higher depression scores (mean scores 6.35 v 4.96; P < 0.001) and more categorical depression (7.6% v 1.8% with scores > or = 13; P < 0.01) than men with diastolic blood pressure levels between 75 and 85 mm Hg. Men with diastolic blood pressure levels > 85 mm Hg had higher depression scores than men with intermediate blood pressure levels (mean scores 5.85 v 4.96; P < 0.05). Men with diastolic hypotension scored significantly higher on both affective and somatic item subscales of the Beck depression inventory and on individual measures of fatigue, pessimism, sadness, loss of appetite, weight loss, and preoccupation with health. Low diastolic blood pressure was a significant predictor of both mean depression score and prevalence of categorical depression, independent of age and change in weight since the baseline visit. The presence of several chronic diseases was associated with depressed mood and higher blood pressure but not with low blood pressure. CONCLUSION--The association of relatively low diastolic blood pressure with higher depressive symptom scores and rates of categorical depression was independent of age or weight loss. Since fatigue is a prominent symptom of depression, any association of low blood pressure with fatigue could reflect depressive disorders or clinically important depression.     

Anpassungsstörungen im Sinne einer reaktiven Depression

There is an overlap between adjustment disorders and (sub-)threshold depression. Thereby, adjustment disorders correspond with the concept of reactive depression, a concept recently discussed as being worth reintroducing as a subcategory of depression. However, there is a lack of prevalence rates for adjustment disorders in terms of reactive depression. The present study estimates prevalence rates and characteristics of subjects with reactive compared with other types of depression. Data from the German National Health and Examination Survey (GHS) were used. The sample consists of 4181 subjects of the German population. Subthreshold and threshold depression were assessed by means of the M-CIDI, including a question about life events, which were considered as causal for the depressive symptoms. The 4-week prevalence rates of reactive and other subthreshold depression were 0.7% and 0.2%, while the 12-month prevalence rates were 1.7% and 0.5%, respectively. The corresponding threshold rates were 1.9% and 0.7% for the 4-week prevalence rates and were 4.1% and 1.3%, respectively, for the 12-month prevalence rates. With regard to the sociodemographic and medical characteristics of subjects with reactive and other depression, no significant differences were found except for the number of inpatient days (mean: 1.9 vs. 0) and the number of mental disorders (1.5 vs. 0.9). Persons with subthreshold reactive depression reported more often “suicidal ideations” compared with person with other subthreshold depression. The results of the present study emphasize the importance of adjustment disorders in terms of reactive depression. Considering the high clinical relevance of adjustment disorders and the scientific neglect of this category, a revision within the forthcoming classification systems is necessary.     

Prevalence and correlations with depression, anxiety, and other features in outpatients with chronic obstructive pulmonary disease in China: a cross-sectional case control study

ABSTRACT: BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) often experience depression and anxiety, but little information is available regarding Chinese patients with these conditions. The present study assessed depression and anxiety in Chinese patients with COPD. METHODS: A case--controlled study was designed with 1100 patients with COPD enrolled in the case group and1100 residents without COPD and respiratory symptoms selected as the control group. Anxiety and depression in both groups were evaluated using the Hospital Anxiety and Depression Scale (HADS). The body mass index,degree of airflow obstruction, dyspnea, and exercise capacity (BODE ) index was used to assess COPD severity. Binary logistic regression models were used to test the association between anxiety and depression. RESULTS: The patients with COPD were more likely than controls to experience depression (cases, HADS 10.5 +/- 3.6, prevalence 35.7%; controls, HADS 8.7 +/- 2.7, prevalence 7.2%) and anxiety (cases, HADS 10.4 +/- 3.1, prevalence 18.3%; controls, HADS 8.6 +/- 2.1, prevalence 5.3%). Subjects with anxious and depressive symptoms had poorer health outcomes including a higher BODE index, a shorter 6-minute-walk distance (6MWD), more dyspnea, and a higher St George's respiratory questionnaire (SGRQ) score. The prevalence of anxious and depressive symptoms increased with increasing BODE scores. On the basis of binary logistic regression, the BODE index was significantly correlated with anxiety (OR = 1.47, p < 0.001) and depression (OR = 1.51, p < 0.001). Anxious and depressive symptoms were also associated with several factors including younger age, female sex, higher education level, lower household income and history of smoking. CONCLUSIONS: This study confirmed the high prevalence of anxiety and depression in Chinese outpatients with COPD. Patients with COPD who had anxiety and/or depression had a poorer health-related quality of life.Trial registrationChinese Clinical Trials Registration(ChiCTR-TRC-12001958).     

Prefrontal cortex based sex differences in tinnitus perception: same tinnitus intensity, same tinnitus distress, different mood

Background

Tinnitus refers to auditory phantom sensation. It is estimated that for 2% of the population this auditory phantom percept severely affects the quality of life, due to tinnitus related distress. Although the overall distress levels do not differ between sexes in tinnitus, females are more influenced by distress than males. Typically, pain, sleep, and depression are perceived as significantly more severe by female tinnitus patients. Studies on gender differences in emotional regulation indicate that females with high depressive symptoms show greater attention to emotion, and use less anti-rumination emotional repair strategies than males.

Methodology

The objective of this study was to verify whether the activity and connectivity of the resting brain is different for male and female tinnitus patients using resting-state EEG.

Conclusions

Females had a higher mean score than male tinnitus patients on the BDI–II. Female tinnitus patients differ from male tinnitus patients in the orbitofrontal cortex (OFC) extending to the frontopolar cortex in beta1 and beta2. The OFC is important for emotional processing of sounds. Increased functional alpha connectivity is found between the OFC, insula, subgenual anterior cingulate (sgACC), parahippocampal (PHC) areas and the auditory cortex in females. Our data suggest increased functional connectivity that binds tinnitus-related auditory cortex activity to auditory emotion-related areas via the PHC-sgACC connections resulting in a more depressive state even though the tinnitus intensity and tinnitus-related distress are not different from men. Comparing male tinnitus patients to a control group of males significant differences could be found for beta3 in the posterior cingulate cortex (PCC). The PCC might be related to cognitive and memory-related aspects of the tinnitus percept. Our results propose that sex influences in tinnitus research cannot be ignored and should be taken into account in functional imaging studies related to tinnitus.     

Prevalence of major depression one year after predictive testing for Huntington's disease

Psychiatric hospitalizations, completed suicides, and suicide attempts are rare after predictive testing for Huntington's disease (HD). Case studies have shown that major depression can be a consequence of being tested, although no studies have shown how common this is. The present study evaluated the prevalence of major depression during the first year after disclosure. We conducted retrospective data and chart reviews of 153 persons (50 testing positive, 103 testing negative) evaluated every 3 months for depression. There was no significant baseline difference in the percentage of "positives" and "negatives" who had pre-testing major depressive episodes (14% vs. 12%, respectively). A senior psychiatrist reviewed data from the Schedule for Affective Disorders and Schizophrenia-Change Version, from the Beck Depression Inventory, and from clinical notes for every follow-up contact completed. The 1-year prevalence of major depression among positives was 6.0%, compared to 3.0% among negatives (p = 0.30), and an estimated 3% population prevalence. One-year prevalence of clinically significant depressive symptoms, whether or not major depression was diagnosed, was 20.0% in positives and 12.6% in negatives (p = 0.17). Although not statistically significant, depressive symptoms and major depression occurred more frequently among those who tested positive. Despite some evidence to the contrary, including our own studies, a positive predictive test for HD is not psychologically benign. Clinical testing programs should assess patients for depressive symptoms after testing, and patients with clinically significant complaints should be referred to a mental health professional.     

Disentangling depression and distress networks in the tinnitus brain

Tinnitus is the continuous perception of an internal auditory stimulus. This permanent sound often affects a person's emotional state inducing distress and depressive feelings changes in 6-25% of the affected population. Distress and depression are two distinct emotional states. Whereas distress describes a transient aversive state, interfering with a person's ability to adequately adapt to stressors, depressive feelings should rather be considered as a more constant emotional state. Based on previous observations in chronic pain, posttraumatic stress disorder and depression, we assume that both states are related to separate neural circuits. We used the Dutch version of the Tinnitus Questionnaire to assess the global index of distress together with the Beck Depression Inventory to evaluate the depressive symptoms accompanying tinnitus. Furthermore sLORETA analysis was performed to correlate current density distribution with distress and depression scores, revealing a lateralization effect of depression versus distress. Distress is mainly correlated with alpha 2, beta 1 and beta 2 activity of the right frontopolar cortex and orbitofrontal cortex in combination with beta 2 activation of the anterior cingulate cortex. In contrast, the more permanent depressive alterations induced by tinnitus are associated with activity of alpha 2 activity in the left frontopolar and orbitofrontal cortex. These specific neural circuits are embedded in a greater neural network, with the parahippocampal region functioning as a crucial linkage between both tinnitus related pathways.     

Self-Administered Domiciliary tDCS Treatment for Tinnitus: A Double-Blind Sham-Controlled Study

Transcranial direct current stimulation (tDCS) has shown potential for providing tinnitus relief, although positive effects have usually been observed only during a short time period after treatment. In recent studies the focus has turned from one-session experiments towards multi-session treatment studies investigating long-term outcomes with double-blinded and sham-controlled study designs. Traditionally, tDCS has been administered in a clinical setting by a healthcare professional but in studies involving multiple treatment sessions, often a trade-off has to be made between sample size and the amount of labor needed to run the trial. Also, as the number of required visits to the clinic increases, the dropout rate is likely to rise proportionally.The aim of the current study was to find out if tDCS treatment for tinnitus could be patient-administered in a domiciliary setting and whether the results would be comparable to those from in-hospital treatment studies. Forty-three patients with chronic (> 6 months) tinnitus were involved in the study, and data on 35 out of these patients were included in final analysis. Patients received 20 minutes of left temporal area anodal (LTA) or bifrontal tDCS stimulation (2 mA) or sham stimulation (0.3 mA) for ten consecutive days. An overall reduction in the main outcome measure, Tinnitus Handicap Inventory (THI), was found (mean change −5.0 points, p < 0.05), but there was no significant difference between active and sham treatment outcomes. Patients found the tDCS treatment easy to administer and they all tolerated it well. In conclusion, self-administered domiciliary tDCS treatment for tinnitus was found safe and feasible and gave outcome results similar to recent randomized controlled long-term treatment trials. The results suggest better overall treatment response—as measured by THI—with domiciliary treatment than with in-hospital treatment, but this advantage is not related to the tDCS variant. The study protocol demonstrated in the current study is not restricted to tinnitus only.     

Étude de divers aspects de la prise en charge des acouphènes pour un sourd unilatéral avec le stimulateur électrique implantable extracochléaire Tinnelec RW®

Study of some aspects of the tinnitus treatment for unilateral deaf with an extracochlear electrical stimulation device. In France, there are about 6000 cases of sudden hearing loss, all of them bring with tinnitus. At present, the treatment of chronic tinnitus is based on the natural development or the facilitation of habituation. For the tinnitus, which resist to the habituation, the principle of the treatments consists in facilitating the habituation process. In a sound therapy the use of a sound generator, with a hearing aid if necessary, is proposed in order to facilitate habituation. But, in case of unilateral deafness acoustical habituation is not possible and tinnitus may cause a depression. Electrical stimulation offers a new therapeutic perspective, which overcomes the main problems to habituation. This approach is very promising that's why it seems essential to study some aspects. The project tries to answer to four questions: How do we have to stimulate electrically for a maximal efficiency? how can we fit the electric stimulation for maximal efficiency? When is it necessary to set up the stimulation? Can we intend to apply this technique to subjects having hearing residues? Recent experimental studies have proposed Tinnelec^® stimulator of the MXM Company as a therapeutic solution for the difficult tinnitus treatment in-patient with unilateral deafness. Many points will be examined through a clinical study and an animal study.     

Sensitive males: inbreeding depression in an endangered bird

Attempts to conserve threatened species by establishing new populations via reintroduction are controversial. Theory predicts that genetic bottlenecks result in increased mating between relatives and inbreeding depression. However, few studies of wild sourced reintroductions have carefully examined these genetic consequences. Our study assesses inbreeding and inbreeding depression in a free-living reintroduced population of an endangered New Zealand bird, the hihi (Notiomystis cincta). Using molecular sexing and marker-based inbreeding coefficients estimated from 19 autosomal microsatellite loci, we show that (i) inbreeding depresses offspring survival, (ii) male embryos are more inbred on average than female embryos, (iii) the effect of inbreeding depression is male-biased and (iv) this population has a substantial genetic load. Male susceptibility to inbreeding during embryo and nestling development may be due to size dimorphism, resulting in faster growth rates and more stressful development for male embryos and nestlings compared with females. This work highlights the effects of inbreeding at early life-history stages and the repercussions for the long-term population viability of threatened species.     

rTMS Induced Tinnitus Relief Is Related to an Increase in Auditory Cortical Alpha Activity

Chronic tinnitus, the continuous perception of a phantom sound, is a highly prevalent audiological symptom. A promising approach for the treatment of tinnitus is repetitive transcranial magnetic stimulation (rTMS) as this directly affects tinnitus-related brain activity. Several studies indeed show tinnitus relief after rTMS, however effects are moderate and vary strongly across patients. This may be due to a lack of knowledge regarding how rTMS affects oscillatory activity in tinnitus sufferers and which modulations are associated with tinnitus relief. In the present study we examined the effects of five different stimulation protocols (including sham) by measuring tinnitus loudness and tinnitus-related brain activity with Magnetoencephalography before and after rTMS. Changes in oscillatory activity were analysed for the stimulated auditory cortex as well as for the entire brain regarding certain frequency bands of interest (delta, theta, alpha, gamma). In line with the literature the effects of rTMS on tinnitus loudness varied strongly across patients. This variability was also reflected in the rTMS effects on oscillatory activity. Importantly, strong reductions in tinnitus loudness were associated with increases in alpha power in the stimulated auditory cortex, while an unspecific decrease in gamma and alpha power, particularly in left frontal regions, was linked to an increase in tinnitus loudness. The identification of alpha power increase as main correlate for tinnitus reduction sheds further light on the pathophysiology of tinnitus. This will hopefully stimulate the development of more effective therapy approaches.     

Long-Term Tinnitus Suppression with Linear Octave Frequency Transposition Hearing Aids

Over the last three years of hearing aid dispensing, it was observed that among 74 subjects fitted with a linear octave frequency transposition (LOFT) hearing aid, 60 reported partial or complete tinnitus suppression during day and night, an effect still lasting after several months or years of daily use. We report in more details on 38 subjects from whom we obtained quantified measures of tinnitus suppression through visual analog scaling and several additional psychoacoustic and audiometric measures. The long-term suppression seems independent of subject age, and of duration and subjective localization of tinnitus. A small but significant correlation was found with audiogram losses but not with high frequency loss slope. Long-term tinnitus suppression was observed for different etiologies, but with a low success rate for sudden deafness. It should be noted that a majority of subjects (23) had a history of noise exposure. Tinnitus suppression started after a few days of LOFT hearing aid use and reached a maximum after a few weeks of daily use. For nine subjects different amounts of frequency shifting were tried and found more or less successful for long-term tinnitus suppression, no correlation was found with tinnitus pitch. When the use of the LOFT hearing aid was stopped tinnitus reappeared within a day, and after re-using the LOFT aid it disappeared again within a day. For about one third of the 38 subjects a classical amplification or a non linear frequency compression aid was also tried, and no such tinnitus suppression was observed. Besides improvements in audiometric sensitivity to high frequencies and in speech discrimination scores, LOFT can be considered as a remarkable opportunity to suppress tinnitus over a long time scale. From a pathophysiological viewpoint these observations seem to fit with a possible re-attribution of activity to previously deprived cerebral areas corresponding to high frequency coding.