Polysomnographic and quantitative electroencephalographic correlates of subjective sleep complaints in chronic tinnitus

Exploding Head Syndrome among Patients Seeking Help for Tinnitus and/or Hyperacusis at an Audiology Department in the UK: A Preliminary Study

BACKGROUND

 Exploding head syndrome (EHS) is characterized by hearing a sudden loud noise or experiencing a sense of explosion in head during the transition of sleep-wake or wake-sleep. The experience of EHS shares similarities with tinnitus, where an individual perceives a sound without any external sound source. To the authors' knowledge, the possible relationship between EHS and tinnitus has not been explored.

PURPOSE

 Preliminary assessment of prevalence of EHS and its related factors among patients seeking help for tinnitus and/or hyperacusis.

RESEARCH DESIGN

 Retrospective cross-sectional study.

STUDY SAMPLE

 A total of 148 consecutive patients who sought help for tinnitus and/or hyperacusis at an audiology clinic in the United Kingdom.

DATA COLLECTION AND ANALYSIS

 The data regarding demographics, medical history, audiological measures, and self-report questionnaires were collected retrospectively from the patients' records. Audiological measures comprised of pure-tone audiometry and uncomfortable loudness levels. The self-report questionnaires which were administered as a part of standard care comprised of the Tinnitus Handicap Inventory, numeric rating scale of tinnitus loudness, annoyance, and effect on life, hyperacusis questionnaire, Insomnia Severity Index, Generalized Anxiety Disorder scale 7, and Patient Health Questionnaire (PHQ-9). To establish presence of EHS, participants were asked "Do you ever hear a sudden, loud noise, or feel a sense of explosion in your head at night?"

RESULTS

 EHS was reported by 8.1% of patients with tinnitus and/or hyperacusis (12 out of 148). The patients with and without EHS were compared, but no significant relationships were found, between the presence of EHS and age, gender, tinnitus/hyperacusis distress, symptoms of anxiety or depression, sleep difficulties, or audiological measures.

CONCLUSION

 The prevalence of EHS in a tinnitus and hyperacusis population is similar to that in the general population. While there does not seem to be any association with sleep or mental factors, this might be due to the limited variability in our clinical sample (i.e., most patients exhibited high level of distress regardless of EHS). Replication of the results in a larger sample with more variety of symptom severity is warranted.

Exploring the interplay of depression, sleep quality, and hearing in tinnitus-related handicap: insights from polysomnography and pure-tone audiometry

BACKGROUND

Tinnitus affects approximately 740 million adults globally, involving hearing, emotion, and sleep systems. However, studies using polysomnography and pure-tone audiometry (PTA) are limited. We aimed to assess the correlation between tinnitus and hearing, sleep quality, characteristics, and depression using polysomnography and PTA.

METHODS

In this cross-sectional study, we divided participants into tinnitus and non-tinnitus groups. We included 100 outpatients (65 with tinnitus, 35 without) from a medical center in Taiwan, who underwent polysomnography and completed rating scales including the Patient Health Questionnaire-9 (PHQ-9), Chinese version of the Pittsburgh Sleep Quality Index (PSQI), and Chinese-Mandarin version of the Tinnitus Handicap Inventory (THI-CM). We analyzed correlations, conducted group comparisons, assessed factors related to THI-CM scores, constructed ROC curves to predict depression in the tinnitus group, and performed multinomial and logistic regression to explore associations.

RESULTS

Descriptive statistics identified a cohort with mean age 53.9 ± 12.80 years, 63% exhibited PHQ-9 scores ≥ 10, and 66% had Apnea-Hypopnea Index (AHI) > 5. The ratio of rapid eye movement and deep sleep to stage 1 + 2 sleep was relatively low and non-significant. Likewise, leg movements was higher in the tinnitus group but not statistically significant. In the tinnitus group, 63.08% had depression, and 81.54% had AHI > 5. Univariate logistic regression linked tinnitus to AHI > 5 (Odds ratio (OR) 2.67, p = 0.026) and male sex (OR 2.49, p = 0.034). A moderate positive correlation was found between the THI-CM score and PHQ-9 score (rs = 0.50, p < 0.001). Further adjustment for obstructive sleep apnea showed associations between PHQ-9 (total score) or depression and THI-CM Grade 3-5 (OR = 1.28; OR = 8.68). Single- and multifactor regression analyses highlighted significant associations of PSQI scores > 13 (OR 7.06, p = 0.018) and THI-CM scores > 47 (OR 7.43, p = 0.002) with depression.

CONCLUSIONS

Our study recruited tinnitus participants with slight or mild hearing loss and mild tinnitus handicap. Depression was identified as a predominant factor in tinnitus-related handicap. The mild tinnitus handicap in tinnitus participants may explain the lack of significant differences in depression, sleep quality, and polysomnographic sleep characteristics between tinnitus and non-tinnitus groups. Further extensive and prospective studies are needed to elucidate the complex links among depression, sleep, and tinnitus.

The association of subjective and objective sleep measures with chronic tinnitus

STUDY OBJECTIVES

Poor sleep is a prevalent complaint in the population with chronic tinnitus, but the relationship between the two is not well-characterized. The objective of this study was to understand how subjective and objective measures of sleep compare in patients with or without chronic tinnitus.

METHODS

This prospective cohort study included consecutive adult patients who presented to a sleep laboratory between January 19, 2017, and January 10, 2020. All patients underwent an in-laboratory nocturnal polysomnogram and filled out questionnaires including the Pittsburgh Sleep Quality Index (PSQI), Tinnitus Screener, and Tinnitus Handicap Inventory, among others.

RESULTS

The study included 1,968 participants, out of which 284 (14.4%) reported chronic tinnitus. Patients with chronic tinnitus were younger (51.6 years vs 54.1 years; P < .05) and more likely female (16.4% vs 11.7%; P < .005). They demonstrated worse subjective sleep quality (PSQI: 11.3 vs 9.5; P < .0005) and increased sleepiness (Epworth Sleepiness Scale: 9.8 vs 8.6; P < .005). In the objective sleep parameters only the total sleep time was increased in chronic tinnitus (311.5 vs 294.5 minutes; P < .05) and total arousals were decreased (41.7 vs 47; P < .005). Sleep stage N3 was higher in those with chronic tinnitus (14.9% vs 13.0%; P < .05). In multivariable analyses, as PSQI increases the odds of chronic tinnitus increases. This effect was modified by age: In those younger than 55 years of age, the odds of the presence of chronic tinnitus was 1.10 (95% confidence interval, 1.03, 1.17) times higher as PSQI increased.

CONCLUSIONS

Chronic tinnitus is associated with significant changes in qualitative sleep (higher PSQI) but no major differences in quantitative sleep measures were observed.

CITATION

Weingarten JA, Islam A, Dubrovsky B, Gharanei M, Coelho DH. The association of subjective and objective sleep measures with chronic tinnitus. J Clin Sleep Med. 2024;20(3):399-405.

Genetic architecture distinguishes tinnitus from hearing loss

Tinnitus is a heritable, highly prevalent auditory disorder treated by multiple medical specialties. Previous GWAS indicated high genetic correlations between tinnitus and hearing loss, with little indication of differentiating signals. We present a GWAS meta-analysis, triple previous sample sizes, and expand to non-European ancestries. GWAS in 596,905 Million Veteran Program subjects identified 39 tinnitus loci, and identified genes related to neuronal synapses and cochlear structural support. Applying state-of-the-art analytic tools, we confirm a large number of shared variants, but also a distinct genetic architecture of tinnitus, with higher polygenicity and large proportion of variants not shared with hearing difficulty. Tissue-expression analysis for tinnitus infers broad enrichment across most brain tissues, in contrast to hearing difficulty. Finally, tinnitus is not only correlated with hearing loss, but also with a spectrum of psychiatric disorders, providing potential new avenues for treatment. This study establishes tinnitus as a distinct disorder separate from hearing difficulties.

[Sleep disorders in patients with chronic tinnitus]

Tinnitus has a lifetime prevalence of 25% in Germany. A common comorbidity in chronic cases are sleep disorders. The aims of this study were to detect sleep disorders and to identify possible associations with tinnitus parameters.Fifty patients with chronic tinnitus were recruited. The patients underwent audiometry, polysomnography, and completed standardised questionnaires on tinnitus and sleep behaviour.Data were available in 30 men and 9 women (age 50.2 ± 11 y, BMI 28.8 ± 4.4 kg/m²). The median duration of tinnitus was 36 (9; 120) months with a severity score of 2.00 (1.00; 3.00). The mean Tinnitus Questionnaire (TF) score was 43.6 ± 17.1, the Epworth Sleepiness Scale (ESS) score was 8.41 ± 4.27, the Pittsburgh Sleep Quality Index (PSQI) score was 9.21 ± 4.32, and the Screening Scale for Chronic Stress (SSCS) score was 58.13 ± 9.58.Sleep diagnoses included 18 cases of insomnia, 4 cases of RLS, and 11 cases of OSA. Patients with sleep comorbidities showed higher tinnitus severity, PSQI scores, and body weight compared to those without sleep disorders.Worse sleep quality was associated with higher tinnitus severity (p=0.038) and more disruptive tinnitus (p=0.03). Patients with subjectively highly disruptive tinnitus reported higher chronic stress scores. Tinnitus duration was correlated with OSA-severity (p=0.026).More than two-thirds of tinnitus patients showed sleep disorders as comorbidity. A sleep screening appears useful in cases of increased tinnitus severity. Whether CPAP therapy is helpful in reducing tinnitus symptoms could not be conclusively determined but deserves further attention.

Effect of sound therapy on whole scalp oscillatory brain activity and distress in chronic tinnitus patients

Introduction

Sound therapy is a common tinnitus treatment, where the tinnitus percept is either fully or partially masked by an external sound. Some tinnitus patients experience a decrease in tinnitus related distress after the use of sound therapy. Differences in the neural response to sound therapy may form a basis for classifying tinnitus patients.

Methods

In this study, the long-term (2 months) effects of sound therapy on the oscillatory brain activity and tinnitus related distress were investigated in chronic tinnitus patients. Baseline oscillatory activity in the group of tinnitus participants was also compared to a matched control group.

Results

No differences were found in the oscillatory activity when comparing the tinnitus group to the control group. Differences were found for the frequency range between 27.5 and 41.5 Hz corresponding to high beta and gamma power when comparing the tinnitus group before and after the use of sound therapy. Furthermore, a reduction of the tinnitus-related distress was found after the long-term use of sound therapy. However, there was no correlation between the changes in the oscillatory activity and the reductions of the tinnitus-related distress.

Discussion

Overall, the lack of correlation between the changes in tinnitus-related distress and changes in power activity hampers the interpretability of the findings and undermines the utility of using oscillatory activity as a biomarker for the effect of sound therapy treatment.

REM Sleep Impairment May Underlie Sleep-Driven Modulations of Tinnitus in Sleep Intermittent Tinnitus Subjects: A Controlled Study

(1) Background: Poor sleep and fragmented sleep are associated with several chronic conditions. Tinnitus is an auditory symptom that often negatively combines with poor sleep and has been associated with sleep impairment and sleep apnea. The relationship between tinnitus psychoacoustic characteristics and sleep is still poorly explored, notably for a particular subgroup of patients, for whom the perceived loudness of their tinnitus is highly modulated by sleep. (2) Methods: For this observational prospective study, 30 subjects with tinnitus were recruited, including 15 "sleep intermittent tinnitus" subjects, who had reported significant modulations of tinnitus loudness related to night sleep and naps, and a control group of 15 subjects displaying constant non-sleep-modulated tinnitus. The control group had matching age, gender, self-reported hearing loss grade and tinnitus impact on quality of life with the study group. All patients underwent a polysomnography (PSG) assessment for one complete night and then were asked to fill in a case report form, as well as a report of tinnitus loudness before and after the PSG. (3) Results: "Sleep Intermittent tinnitus" subjects had less Stage 3 sleep (p < 0.01), less Rapid-Eye Movement (REM) Sleep (p < 0.05) and more Stage 2 sleep (p < 0.05) in proportion and duration than subjects from the control group. In addition, in the "sleep Intermittent tinnitus" sample, a correlation was found between REM sleep duration and tinnitus overnight modulation (p < 0.05), as well as tinnitus impact on quality of life (p < 0.05). These correlations were not present in the control group. (4) Conclusions: This study suggests that among the tinnitus population, patients displaying sleep-modulated tinnitus have deteriorated sleep quality. Furthermore, REM sleep characteristics may play a role in overnight tinnitus modulation. Potential pathophysiological explanations accounting for this observation are hypothesized and discussed.

Effect of Tinnitus on Sleep Quality and Insomnia

Introduction  Tinnitus is a conscious perception of a sound resulting from abnormal activity within the nervous system. A relevant percentage of tinnitus patients report symptoms severe enough to significantly affect quality of life, including sleep disorders. Objective  To analyze the sleep quality, insomnia, daytime sleepiness, and risk of obstructive sleep apnea (OSA) in participants with tinnitus. Methods  The sample comprised 18 adults and older adults aged between 18 and 85 years old (mean age = 58.7 ± 17.5 years old), females and males, with complaint of continuous tinnitus for > 1 month. The instruments used were the Tinnitus Handicap Inventory (THI) questionnaire, the Insomnia Severity Index, the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale, and the STOP-Bang questionnaire. Results  By means of the THI questionnaire, the tinnitus severity degree reported by most participants was mild (27.8%) and moderate (27.8%), having a positive (r = 0.582) and significant (0.011) correlation to sleep quality, measured by means of the Pittsburgh questionnaire. There was a positive correlation between the Insomnia Severity Index and tinnitus handicap (r = 0.499; p  = 0.035). A total of 72.2% of the participants self-assessed their sleep quality as poor, in addition to moderate insomnia (27.8%), although there is low risk of OSA (66.7%), without complaints of excessive daytime sleepiness (72.2%). Conclusion  Subjects with tinnitus complaint self-rated their sleep quality as poor. Moreover, the higher the reported tinnitus handicap, the greater the symptoms of insomnia. There was no influence of tinnitus in relation to daytime sleepiness and no relationship between the severity of tinnitus and the risk of OSA.

Cognitive–behavioral factors in tinnitus-related insomnia

Background

A significant proportion of individuals with distressing tinnitus also report insomnia. Limited, but emerging, evidence suggests that tinnitus-related insomnia cannot be explained only by the presence of tinnitus and that sleep-related cognitive–behavioral processes may play a key role in exacerbating tinnitus-related insomnia.

Objectives

This study aimed to assess whether sleep-related cognitions and behaviors believed to maintain insomnia disorder are present in individuals with tinnitus-related insomnia.

Methods

This between-groups study recruited 180 participants online for four groups: tinnitus-related insomnia (N = 49), insomnia disorder without tinnitus (N = 34), tinnitus sufferers who are good sleepers (N = 38), and controls (N = 59). They completed questionnaires assessing insomnia severity, sleep-related cognitions and behaviors, sleep quality, anxiety, and depression. People with tinnitus completed a measure of tinnitus severity and rated the loudness of their tinnitus on a subjective measure.

Results

Linear regression demonstrated that group significantly predicted sleep related thoughts and behaviors, and sleep quality. Pairwise comparisons showed that the tinnitus-related insomnia group had significantly greater insomnia-related thoughts and behaviors and significantly worse sleep quality than tinnitus-good sleepers. No differences were seen between the tinnitus-related insomnia and the insomnia groups. The tinnitus-related insomnia group had significantly higher depression, anxiety, and tinnitus distress than tinnitus-good sleepers.

Conclusion

Findings suggest that tinnitus-related insomnia may be maintained by cognitive–behavioral processes similar to those found in insomnia disorder. Such processes are more important than tinnitus severity when understanding sleep disturbance. People with tinnitus-related insomnia may benefit from treatments such as cognitive–behavioral therapy for insomnia.

Tinnitus and treatment-resistant depression

Tinnitus, a frequent disorder, is the conscious perception of a sound in the absence of a corresponding external acoustic sound source in the sense of a phantom sound. Although the majority of people who perceive a tinnitus sound can cope with it and are only minimaly impaired in their quality of lfe, 2-3% of the population perceive tinnitus as a major problem. Recently it has been proposed that the two groups should be differentiated by distict terms: "Tinnitus" describes the auditory or sensory component, whereas "Tinnitus Disorder" reflects the auditory component and the associated suffering. There is overwhelming evidence that a high tinnitus burden is associated with the increased occurrence of comorbidities, including depression. Since no causal therapeutic options are available for patients with tinnitus at the present time, the identification and adequate treatment of relevant comorbidities is of great importance for the reduction of tinnitus distress. This chapter deals with the relationship between tinnitus and depression. The neuronal mechanisms underlying tinnitus will first be discussed. There will also be an overview about depression and treatment resistant depression (TRD). A comprehensive review about the state-of-the-art evidences of the relationship between tinnitus and TRD will then be provided.

Objective multidisciplinary measurements of sleep disturbance and autonomic dysfunction as risk factors for chronic subjective tinnitus

PURPOSE

This observational study assessed sleep disturbance and autonomic dysfunction as risk factors for chronic subjective tinnitus through polysomnography (PSG) and autonomic function tests.

METHODS

Adult patients with chronic subjective tinnitus who visited the department of otolaryngology in our hospitals (n = 40), along with controls without tinnitus (n = 80), were recruited. Individuals with an average hearing threshold level (HL) exceeding 25 dB HL and a known diagnosis of insomnia were excluded. Objective assessments comprised pure-tone audiometry, PSG, and autonomic function tests (e.g., the cold pressor test).

RESULTS

Patients with prolonged sleep latency, lower sleep efficiency, and sympathetic hyperactivity had significantly higher risks of developing tinnitus. No interaction effect between poor sleep quality and sympathetic hyperactivity on tinnitus was detected.

CONCLUSION

This is the first study to administer PSG and autonomic function tests to patients with chronic subjective tinnitus. Poor sleep quality and autonomic dysfunction were implicated as risk factors for tinnitus. PSG and the autonomic function tests helped identify tinnitus-related comorbidities and inform tinnitus treatment. Sleep disturbance and autonomic dysfunction did not exert an interaction effect on tinnitus. Further studies with a larger sample size and the inclusion of patients with more severe tinnitus are warranted.

The Relationship Between Sleep Traits and Tinnitus in UK Biobank: A Population-Based Cohort Study

OBJECTIVES

Understanding the association between sleep traits and tinnitus could help prevent and provide appropriate interventions against tinnitus. Therefore, this study aimed to assess the relationship between different sleep patterns and tinnitus.

DESIGN

A cross-sectional analysis using baseline data (2006-2010, n = 168,064) by logistic regressions was conducted to evaluate the association between sleep traits (including the overall health sleep score and five sleep behaviors) and the occurrence (yes/no), frequency (constant/transient), and severity (upsetting/not upsetting) of tinnitus. Further, a prospective analysis of participants without tinnitus at baseline (n = 9581) was performed, who had been followed-up for 7 years (2012-2019), to assess the association between new-onset tinnitus and sleep characteristics. Moreover, a subgroup analysis was also carried out to estimate the differences in sex by dividing the participants into male and female groups. A sensitivity analysis was also conducted by excluding ear-related diseases to avoid their confounding effects on tinnitus (n = 102,159).

RESULTS

In the cross-sectional analysis, participants with "current tinnitus" (OR: 1.13, 95% CI: 1.04-1.22, p = 0.004) had a higher risk of having a poor overall healthy sleep score and unhealthy sleep behaviors such as short sleep durations (OR: 1.09, 95% CI: 1.04-1.14, p < 0.001), late chronotypes (OR: 1.09, 95% CI: 1.05-1.13, p < 0.001), and sleeplessness (OR: 1.16, 95% CI: 1.11-1.22, p < 0.001) than those participants who "did not have current tinnitus." However, this trend was not obvious between "constant tinnitus" and "transient tinnitus." When considering the severity of tinnitus, the risk of "upsetting tinnitus" was obviously higher if participants had lower overall healthy sleep scores (OR: 1.31, 95% CI: 1.13-1.53, p < 0.001). Additionally, short sleep duration (OR: 1.22, 95% CI: 1.12-1.33, p < 0.001), late chronotypes (OR: 1.13, 95% CI: 1.04-1.22, p = 0.003), and sleeplessness (OR: 1.43, 95% CI: 1.29-1.59, p < 0.001) showed positive correlations with "upsetting tinnitus." In the prospective analysis, sleeplessness presented a consistently significant association with "upsetting tinnitus" (RR: 2.28, p = 0.001). Consistent results were observed in the sex subgroup analysis, where a much more pronounced trend was identified in females compared with the males. The results of the sensitivity analysis were consistent with those of the cross-sectional and prospective analyses.

CONCLUSIONS

Different types of sleep disturbance may be associated with the occurrence and severity of tinnitus; therefore, precise interventions for different types of sleep disturbance, particularly sleeplessness, may help in the prevention and treatment of tinnitus.

The Cross-Sectional Association Between Tinnitus and Actigraphy-Estimated Sleep in a Population-Based Cohort of Middle-Aged and Elderly Persons

OBJECTIVES

Tinnitus is a common and burdensome disease, often accompanied by complaints of poor sleep. However, associations of tinnitus with objective estimates of sleep remain unclear, particularly in the general population. We assessed these associations in a population-based cohort of middle-aged and elderly persons.

DESIGN

This study included 1456 participants (mean age: 65.0 ± 7.1 years, 52% women) from the population-based Rotterdam Study. Tinnitus was self-reported and in those who reported tinnitus daily, symptom severity was assessed with the Tinnitus Handicap Inventory. We used actigraphy to estimate sleep and 24-hour activity rhythms objectively and sleep diaries to assess self-reported sleep. We estimated the difference in sleep and 24-hour activity rhythms first between those with and those without tinnitus and secondly with tinnitus severity.

RESULTS

Tinnitus, reported by 341 (23%) participants, and tinnitus severity, assessed in 194 participants with daily tinnitus, were not associated with actigraphy-estimated sleep or 24-hour activity rhythms, but were associated with a longer self-reported sleep onset latency (adjusted difference tinnitus = 2.36, 95% confidence interval [CI] = 0.95-3.78, adjusted difference tinnitus severity = 0.27, 95% CI = 0.013-0.54). After stratification for hearing loss, tinnitus was associated with longer self-reported sleep onset latency (adjusted difference = 2.26, 95% CI = 0.98-3.53) and less stable 24-hour activity rhythms (adjusted difference = -0.02, 95% CI = -0.04 to -0.00) in those with hearing loss. In those without hearing loss, tinnitus was associated with more stable rhythms (adjusted difference = 0.03, 95% CI = 0.01-0.05).

CONCLUSIONS

Having tinnitus is associated with a longer self-reported sleep onset latency, but not with objective estimates of sleep, suggesting that the subjective experience of sleep may be particularly disturbed in those with tinnitus. In addition, hearing loss may modify the association of tinnitus and 24-hour activity rhythms.

Sleep apnea plays a more important role on sleep N3 stage than chronic tinnitus in adults

Sleep apnea is negatively associated with N3 sleep in children. However, the association between tinnitus and sleep N3 stage was still inconclusive. We aimed to clarify the relationship between sleep apnea, chronic tinnitus, and sleep N3 stage in adults. Clinical and overnight polysomnography data of 2847 adults were collected retrospectively. Univariate and multivariate linear regression was used to test the impacts of sleep apnea indices and chronic tinnitus on the percentage of sleep N3 stage in all adults. Univariate linear regression analysis showed that sleep apnea indices, chronic tinnitus, age, sex, hypertension, diabetes mellitus, dyslipidemia, subjective insomnia, sleep efficiency, and rapid eye movement sleep were significantly associated with sleep N3 stage. However, multivariate linear regression showed that apnea-hyponea index, but not chronic tinnitus, has a significant negative association with the percentage of sleep N3 stage. Sleep apnea plays a more important role on sleep N3 stage than chronic tinnitus in adults.

The Interrelationship of Tinnitus and Hearing Loss Secondary to Age, Noise Exposure, and Traumatic Brain Injury

OBJECTIVE

Tinnitus has been the No. 1 disability at the Veteran Administration for the last 15 years, yet its interaction with hearing loss secondary to etiologies such as age, noise trauma, and traumatic brain injuries remains poorly characterized. Our objective was to analyze hearing loss and tinnitus, including audiogram data, of the Million Veteran Program within the context of military exposures in an aging population.

DESIGN

Health records, questionnaires, audiograms, and military data were aggregated for 758,005 Veteran participants in the Million Veteran Program 2011 to 2020, with relative risks (RR) calculated for ancestries, sex, hearing loss and military exposures such as combat, blast, and military era served. A multivariate model with significant demographic measures and exposures was then analyzed. Next, audiogram data stratified by sex were compared for those with and without tinnitus by two methods: first, mean thresholds at standard frequencies were compared to thresholds adjusted per ISO 7029:2000E age and sex formulae. Second, levels for those ≤40 years of age were compared with those 41 and older. Finally, a proportional hazards model was examined to ascertain the timing between the onset of tinnitus and hearing loss, calculated separately for electronic health record diagnoses (ICD) and self-report.

RESULTS

Tinnitus was either self-reported, diagnosed, or both in 37.5% (95% CI, 37.4 to 37.6), mean age 61.5 (95% CI, 61.4 to 61.5), range 18 to 112 years. Those with hearing loss were 4.15 times (95% CI, 4.12 to 4.15) as likely to have tinnitus. Americans of African descent were less likely to manifest tinnitus (RR 0.61, 95% CI, 0.60 to 0.61), as were women (RR 0.65, 95% CI, 0.64 to 0.65). A multivariate model indicated a higher RR of 1.73 for traumatic brain injury (95% CI, 1.71 to 1.73) and daily combat noise exposure (1.17, 95% CI, 1.14 to 1.17) than age (0.998, 95% CI, 0.997 to 0.998). Subjects ≤40 years of age had small but significantly elevated hearing thresholds through all standard frequencies compared to Veterans without tinnitus, and the effect of tinnitus on hearing thresholds diminished with age. In the hazard model, those >40 with new onset of tinnitus were at risk for hearing loss sooner and with greater incidence than those who were younger. The rate of hearing loss following tinnitus approached 100%. In contrast, only approximately 50% of those who self-reported hearing loss initially were at risk for later hearing loss, in contrast to ICD comparison, where those with ICD of hearing loss were more likely to sustain an ICD of tinnitus subsequently.

CONCLUSIONS

Evidence suggests that the occurrence of tinnitus in the military is more closely related to environmental exposures than to aging. The finding that tinnitus affects hearing frequencies across the audiogram spectrum suggests an acoustic injury independent of tonotopicity. Particularly for males >40, tinnitus may be a harbinger of audiologic damage predictive of later hearing loss.

Tinnitus: at a crossroad between phantom perception and sleep

Sensory disconnection from the environment is a hallmark of sleep and is crucial for sleep maintenance. It remains unclear, however, whether internally generated percepts—phantom percepts—may overcome such disconnection and, in turn, how sleep and its effect on sensory processing and brain plasticity may affect the function of the specific neural networks underlying such phenomena. A major hurdle in addressing this relationship is the methodological difficulty to study sensory phantoms, due to their subjective nature and lack of control over the parameters or neural activity underlying that percept. Here, we explore the most prevalent phantom percept, subjective tinnitus—or tinnitus for short—as a model to investigate this. Tinnitus is the permanent perception of a sound with no identifiable corresponding acoustic source. This review offers a novel perspective on the functional interaction between brain activity across the sleep–wake cycle and tinnitus. We discuss characteristic features of brain activity during tinnitus in the awake and the sleeping brain and explore its effect on sleep functions and homeostasis. We ask whether local changes in cortical activity in tinnitus may overcome sensory disconnection and prevent the occurrence of global restorative sleep and, in turn, how accumulating sleep pressure may temporarily alleviate the persistence of a phantom sound. Beyond an acute interaction between sleep and neural activity, we discuss how the effects of sleep on brain plasticity may contribute to aberrant neural circuit activity and promote tinnitus consolidation. Tinnitus represents a unique window into understanding the role of sleep in sensory processing. Clarification of the underlying relationship may offer novel insights into therapeutic interventions in tinnitus management.

Risk factors of decompensated tinnitus and the interaction effect of anxiety and poor sleep on decompensated tinnitus: a multicenter study

BACKGROUND

Decompensated tinnitus substantially degrades quality of life. Anxiety and poor sleep are comorbidities in decompensated tinnitus.

OBJECTIVE

This multicenter study was designed to investigate the risk factors of decompensated tinnitus and to analyze the interaction effect of anxiety and poor sleep on decompensated tinnitus by conducting a multicenter study.

MATERIAL AND METHODS

We retrospectively analyzed patients with subjective chronic tinnitus who presented to five Chinese hospitals in China from September 2019 to November 2020. Demographic characteristics, pure tone audiometry, tinnitus-related tests, psychometric and sleep questionnaires were applied.

RESULTS

A total of 338 patients were included, and 99 (29.3%) patients were in the decompensated group. Poor sleep and anxiety were possible risk factors of decompensated tinnitus by a forced-entry binary logistic analysis. Sleep disturbances and anxiety had an additive interaction that accounted for 87% of the decompensated tinnitus cases in our study population (RERI = 10.96, S = 18.22, AP = 0.87).

CONCLUSIONS AND SIGNIFICANCE

Anxiety and sleep disturbances are possible risk factors of decompensated tinnitus. The combination of poor sleep and anxiety exerts a greater impact on tinnitus severity than either risk factor alone.

Prevalence of sleep impairment in patients with tinnitus: a systematic review and single-arm meta-analysis

PURPOSE

This study aimed to comprehensively review the literature and synthesize relevant data to examine the pooled prevalence of poor sleep quality (sleep impairment) and assess overall sleep quality in patients with tinnitus.

METHODS

This meta-analysis systematically searched both English (PubMed, Embase, and Web of Science) and Chinese (Wanfang Data Chinese database, Veep Chinese Database, and Chinese National Knowledge Infrastructure) databases. Data extraction and quality assessment were independently performed by two authors. The pooled prevalence of sleep impairment and poor sleep quality was calculated via a random-effects model. Sub-group and sensitivity analyses were performed to explore the source of heterogeneity.

RESULTS

A total of seven studies were included with a total sample of 3041 tinnitus participants. The pooled prevalence of sleep impairment was 53.5% (95% confidence interval: 40.2-66.8%) and the I2 was 97.8% (Q = 7.90, p = 0.000). There were significant differences in the prevalence of poor sleep quality between males and females (39.1% vs. 44.6%, P = 0.034), between different PSQI cut-off values ≥ 7 and > 5 (53.1% vs. 53.8%, P = 0.000), and between sample sizes > 200 and ≤ 200 (54.0% vs. 52.7%, P = 0.000). In non-Asia area, the prevalence (56.6%, 95% CI: 42.6-70.5%) was lower than that in Asia areas (34.5%, 95% CI: 25.7-43.3%).

CONCLUSION

Sleep impairment is common among patients with tinnitus. Development of interventions for conditions associated with poor sleep quality should be recommended to offer a safe and efficacious solution for this population.

Effects of Dinner Timing on Sleep Stage Distribution and EEG Power Spectrum in Healthy Volunteers

PURPOSE

Eating time and sleep habits are important modifiable behaviors that affect metabolic health, but the relationship between food intake and sleep remains incompletely understood. Observational data suggest that late food intake is associated with impaired sleep quality. We examined the effect of routine dinner (RD, 5 hours before bedtime) vs late dinner (LD, 1 hour before bedtime) on sleep architecture in healthy volunteers.

PARTICIPANTS AND METHODS

This was a post hoc analysis of a randomized crossover study of RD vs LD with a fixed sleep opportunity in a laboratory setting. On each of the two visits, 20 healthy adult volunteers (10 women) received an isocaloric meal followed by overnight polysomnography. Sleep architecture over the course of the night was assessed using visual sleep staging and EEG spectral power analysis and was compared between RD and LD. We modeled the proportions of spectral power in alpha, beta, delta, and theta bands as functions of dinner timing, time of night, and their interaction with mixed-effect spline regression.

RESULTS

Conventional sleep stages were similar between the 2 visits. LD caused a 2.5% initial increase in delta power and a reciprocal 2.7% decrease in combined alpha and beta power (p<0.0001). These effects diminished as sleep continued with a reversal of these patterns in the latter part of the night.

CONCLUSION

Contrary to the existing literature, shifting dinner timing from 5 hours before sleep to 1 hour before sleep in healthy volunteers did not result in significant adverse changes in overnight sleep architecture. In fact, LD was associated with deeper sleep in the beginning of the night and lighter sleep in the latter part of the night in healthy volunteers. This novel manifestation of postprandial hypersomnia may have therapeutic potential in patients with sleep disorders.

Blast-induced tinnitus: Animal models

Blast-induced tinnitus is a prevalent problem among military personnel and veterans, as blast-related trauma damages the vulnerable microstructures within the cochlea, impacts auditory and non-auditory brain structures, and causes tinnitus and other disorders. Thus far, there is no effective treatment of blast-induced tinnitus due to an incomplete understanding of its underlying mechanisms, necessitating development of reliable animal models. This article focuses on recent animal studies using behavioral, electrophysiological, imaging, and pharmacological tools. The mechanisms underlying blast-induced tinnitus are largely similar to those underlying noise-induced tinnitus: increased spontaneous firing rates, bursting, and neurosynchrony, Mn++ accumulation, and elevated excitatory synaptic transmission. The differences mainly lie in the data variability and time course. Noise trauma-induced tinnitus mainly originates from direct peripheral deafferentation at the cochlea, and its etiology subsequently develops along the ascending auditory pathways. Blast trauma-induced tinnitus, on the other hand, results from simultaneous impact on both the peripheral and central auditory systems, and the resultant maladaptive neuroplasticity may also be related to the additional traumatic brain injury. Consequently, the neural correlates of blast-induced tinnitus have different time courses and less uniform manifestations of its neural correlates.

The sound-sensitive tinnitus index: Psychometric properties of a scale to assess the impact of tinnitus exacerbated by sound

CONTEXT

Although studies of tinnitus exacerbated by sound exposure have indicated increased treatment challenges and intensified mental health and quality of life concerns, there is a lack of valid screening measures to differentiate or assess diagnostic factors and areas of impact unique to this specific symptom manifestation.

AIMS

The purpose of this study was to design a self-rated measurement tool that can accurately assess the subjective impact of tinnitus negatively modulated by external sound.

SETTINGS AND DESIGN

Based on review of established models of tinnitus and hyperacusis measurement and a two-part pilot study, the 20-item Sound-Sensitive Tinnitus Index (SSTI) was developed and administered in online survey format to 277 individuals worldwide.

METHODS AND MATERIAL

Cronbach's alpha was used to estimate reliability properties, and dimensional factor analysis was performed. To establish validity, statistical correlations of the SSTI were estimated with valid measures of related constructs including tinnitus, hyperacusis, depression, anxiety, and quality of life.

RESULTS

Statistical analysis yielded high levels of internal consistency reliability, and convergent validity was demonstrated through significant correlations with all established measures of related constructs. Initial factor analysis indicated two components split between overall functional impact and coping factors, while rotated factor analyses revealed four distinct scale dimensions, labeled: functional challenges, relational and communication challenges, coping factors, and prevention and hearing protection.

CONCLUSIONS

As a valid and reliable measure, the SSTI fills an important gap as a clinical and research tool that can differentiate and assess severity and treatment progress in manifestations of combined tinnitus and auditory sensitivity symptoms.

Cognitive behavioural therapy for tinnitus-related insomnia: evaluating a new treatment approach

OBJECTIVE

Insomnia frequently occurs alongside distressing tinnitus, and greater tinnitus severity is associated with more sleep disturbance. Insomnia and tinnitus probably share common underlying processes and sleep studies show striking similarities between primary and tinnitus-related insomnia. This is the first study to evaluate outcomes following insomnia-specific Cognitive Behavioural Therapy (CBTi) for tinnitus-related insomnia in a "real world" clinic.

DESIGN

Treatment was six-sessions of group-based CBTi. Measures of insomnia, sleep diaries, tinnitus distress, psychological distress, anxiety and depression were completed pre-intervention, post-intervention and at six-weeks follow up.

STUDY SAMPLE

Participants were 24 adults with chronic, distressing tinnitus and associated sleep disturbance. Twenty-two completed treatment.

RESULTS

CBTi was associated with significant improvements from pre-intervention to post-intervention maintained at follow up in insomnia, sleep-diary measures, tinnitus distress, psychological distress, anxiety and depression, largely maintained at follow-up. Reliable improvements were reported in insomnia (by 67% of patients), tinnitus distress (by 50% of patients) and psychological distress (by 38% of patients) post-intervention.

CONCLUSIONS

The results suggest that CBTi is associated with reduced insomnia and distress for patients reporting chronic and distressing tinnitus with related insomnia. Further research into CBTi for this population, using utilising robust, randomised controlled designs, is warranted.

Sensory neurologic disorders: Tinnitus

Tinnitus is the sensation of hearing a sound with no external auditory stimulus present. It is a public health issue correlated with multiple comorbidities and precipitating factors such as noise exposure, military service, and traumatic brain injury, migraine, insomnia, small vessel disease, smoking history, stress exposure, anxiety, depression, and socioeconomic status. Clinical experience and a recent literature review point at tinnitus as a neuropsychiatric condition involving both auditory and nonauditory cortical areas of the brain and affecting brain-auditory circuitry. In fact, brain-ear connections have been highlighted in different models. Forward management of this disorder should take this body of research into consideration as tinnitus remains a challenging condition to evaluate and treat with current management protocols still symptomatic at best. With a better understanding of the etiologic factors and comorbidities of tinnitus, additional research trials and new therapeutic approaches could see the light to tackle this public health disability bringing hope to patients and doctors.

Blast-Induced Tinnitus and Elevated Central Auditory and Limbic Activity in Rats: A Manganese-Enhanced MRI and Behavioral Study

Blast-induced tinitus is the number one service-connected disability that currently affects military personnel and veterans. To elucidate its underlying mechanisms, we subjected 13 Sprague Dawley adult rats to unilateral 14 psi blast exposure to induce tinnitus and measured auditory and limbic brain activity using manganese-enhanced MRI (MEMRI). Tinnitus was evaluated with a gap detection acoustic startle reflex paradigm, while hearing status was assessed with prepulse inhibition (PPI) and auditory brainstem responses (ABRs). Both anxiety and cognitive functioning were assessed using elevated plus maze and Morris water maze, respectively. Five weeks after blast exposure, 8 of the 13 blasted rats exhibited chronic tinnitus. While acoustic PPI remained intact and ABR thresholds recovered, the ABR wave P1-N1 amplitude reduction persisted in all blast-exposed rats. No differences in spatial cognition were observed, but blasted rats as a whole exhibited increased anxiety. MEMRI data revealed a bilateral increase in activity along the auditory pathway and in certain limbic regions of rats with tinnitus compared to age-matched controls. Taken together, our data suggest that while blast-induced tinnitus may play a role in auditory and limbic hyperactivity, the non-auditory effects of blast and potential traumatic brain injury may also exert an effect.

Polysomnography Applied to Patients with Tinnitus: A Review

Introduction  Tinnitus has been defined as an “auditory phantom perception,” meaning that tinnitus results from an abnormal activity within the nervous system, in the absence of any internal or external acoustic stimulation. About 10 to 15% of the adult population is affected by tinnitus, and a relevant percentage of tinnitus sufferers experience symptoms severe enough to significantly affect quality of life, including sleep disturbances, work impairment, and, in some cases, psychiatric distress. The self-rated complaints about tinnitus focus on emotional distress, auditory perceptual difficulties, and sleep disturbances.

Objectives  To evaluate the works that show sleep disorders in patients with tinnitus, and sleep disorders assessed by polysomnography.

Data Synthesis  We found four studies with polysomnography to assess sleep disorders in patients with tinnitus. The first study evaluated 80 patients who were military personnel without major psychiatric disturbances, and their tinnitus was associated with noise-induced permanent hearing. The second study was a prospective, case-control, nonrandomized study of 18 patients affected by chronic tinnitus who were compared with a homogeneous control group consisting of 15 healthy subjects. The last work evaluated questionnaires mailed to patients before their initial appointment at the Oregon Health Sciences University Tinnitus Clinic between 1994 and 1997. These questionnaires requested information pertaining to insomnia, tinnitus severity, and loudness. Follow-up questionnaires were mailed to 350 patients 1 to 4 years (mean 5 ± 2.3 years) after their initial appointment at the clinic.

Conclusion  There are few studies with polysomnography for the evaluation of patients with sleep disorders caused by tinnitus. This shows the need for more studies on this subject.

Risk of tinnitus in patients with sleep apnea: A nationwide, population-based, case-control study

OBJECTIVE

To investigate the risk of tinnitus in patients with sleep disturbance or sleep apnea.

STUDY DESIGN

Case control study.

METHODS

We identified 21,798 middle-aged and elderly patients with otolaryngologist-diagnosed tinnitus between January 1, 2000, and December 31, 2012, from the Longitudinal Health Insurance Database 2000 of the Taiwan National Health Insurance Research Database. A total of 108,990 controls were also identified from the same database based on frequency-matching on 10-year age interval, sex, and year of index date of the cases. Diagnoses of sleep disturbance (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] codes 780.50, 780.52, 307.4) and sleep apnea (ICD-9-CM codes 780.51, 780.53, 780.57) in the cases and controls prior to the index date were assessed. The risks of tinnitus in patients with sleep disturbance and sleep apnea were separately evaluated with multivariate logistic regression analyses.

RESULTS

The mean age of the total 130,788 patients was 59.8 years, and 47% of them were males. The risk of tinnitus was higher in patients with sleep disturbance compared to those without the condition (adjusted odds ratio [OR] = 1.13, 95% confidence interval [CI] [95% CI] = 1.11-1.17), and the risk of tinnitus was higher in patients with sleep apnea compared to those without the condition (adjusted OR = 1.36, 95% CI = 1.16-1.60).

CONCLUSION

In this population-based, case-control study, the risk of tinnitus was found to be significantly higher among middle-aged and elderly Taiwanese patients with sleep disturbances, especially with sleep apnea.

LEVEL OF EVIDENCE

3b. Laryngoscope, 127:2171-2175, 2017.

Whole scalp resting state EEG of oscillatory brain activity shows no parametric relationship with psychoacoustic and psychosocial assessment of tinnitus: A repeated measures study

Tinnitus is a perception of sound that can occur in the absence of an external stimulus. A brief review of electroencephalography (EEG) and magnetoencephalography (MEG) literature demonstrates that there is no clear relationship between tinnitus presence and frequency band power in whole scalp or source oscillatory activity. Yet a preconception persists that such a relationship exists and that resting state EEG could be utilised as an outcome measure for clinical trials of tinnitus interventions, e.g. as a neurophysiological marker of therapeutic benefit. To address this issue, we first examined the test-retest correlation of EEG band power measures in tinnitus patients (n = 42). Second we examined the evidence for a parametric relationship between numerous commonly used tinnitus variables (psychoacoustic and psychosocial) and whole scalp EEG power spectra, directly and after applying factor reduction techniques. Test-retest correlation for both EEG band power measures and tinnitus variables were high. Yet we found no relationship between whole scalp EEG band powers and psychoacoustic or psychosocial variables. We conclude from these data that resting state whole scalp EEG should not be used as a biomarker for tinnitus and that greater caution should be exercised in regard to reporting of findings to avoid confirmation bias. The data was collected during a randomised controlled trial registered at ClinicalTrials.gov (Identifier: NCT01541969).

Psychophysiological Associations between Chronic Tinnitus and Sleep: A Cross Validation of Tinnitus and Insomnia Questionnaires

Background. The aim of the present study was to assess the prevalence of insomnia in chronic tinnitus and the association of tinnitus distress and sleep disturbance. Methods. We retrospectively analysed data of 182 patients with chronic tinnitus who completed the Tinnitus Questionnaire (TQ) and the Regensburg Insomnia Scale (RIS). Descriptive comparisons with the validation sample of the RIS including exclusively patients with primary/psychophysiological insomnia, correlation analyses of the RIS with TQ scales, and principal component analyses (PCA) in the tinnitus sample were performed. TQ total score was corrected for the TQ sleep items. Results. Prevalence of insomnia was high in tinnitus patients (76%) and tinnitus distress correlated with sleep disturbance (r = 0.558). TQ sleep subscore correlated with the RIS sum score (r = 0.690). PCA with all TQ and RIS items showed one sleep factor consisting of all RIS and the TQ sleep items. PCA with only TQ sleep and RIS items showed sleep- and tinnitus-specific factors. The sleep factors (only RIS items) were sleep depth and fearful focusing. The TQ sleep items represented tinnitus-related sleep problems. Discussion. Chronic tinnitus and primary insomnia are highly related and might share similar psychological and neurophysiological mechanisms leading to impaired sleep quality.

Has adult sleep duration declined over the last 50+ years?

The common assumption that population sleep duration has declined in the past few decades has not been supported by recent reviews, which have been limited to self-reported data. The aim of this review was to assess whether there has been a reduction in objectively recorded sleep duration over the last 50+ years. The literature was searched for studies published from 1960 to 2013, which assessed objective sleep duration (total sleep time (TST)) in healthy normal-sleeping adults. The search found 168 studies that met inclusion criteria, with 257 data points representing 6052 individuals ages 18-88 y. Data were assessed by comparing the regression lines of age vs. TST in studies conducted between 1960 and 1989 vs. 1990-2013. Weighted regression analyses assessed the association of year of study with age-adjusted TST across all data points. Regression analyses also assessed the association of year of study with TST separately for 10-y age categories (e.g., ages 18-27 y), and separately for polysomnographic and actigraphic data, and for studies involving a fixed sleep schedule and participants' customary sleep schedules. Analyses revealed no significant association of sleep duration with study year. The results are consistent with recent reviews of subjective data, which have challenged the notion of a modern epidemic of insufficient sleep.

A confirmatory factor analytic validation of the Tinnitus Handicap Inventory

OBJECTIVE

Because the postulated three-factor structure of the internationally widely used Tinnitus Handicap Inventory (THI) has not been confirmed yet by a confirmatory factor analytic approach this was the central aim of the current study.

METHODS

From a clinical setting, N=373 patients with chronic tinnitus completed the THI and further questionnaires assessing tinnitus-related and psychological variables. In order to analyze the psychometric properties of the THI, confirmatory factor analysis (CFA) and correlational analyses were conducted.

RESULTS

CFA provided a statistically significant support for a better fit of the data to the hypothesized three-factor structure (RMSEA=.049, WRMR=1.062, CFI=.965, TLI=.961) than to a general factor model (RMSEA=.062, WRMR=1.258, CFI=.942, TLI=.937). The calculation of Cronbach's alpha as indicator of internal consistency revealed satisfactory values (.80-.91) with the exception of the catastrophic subscale (.65). High positive correlations of the THI and its subscales with other measures of tinnitus distress, anxiety, and depression, high negative correlations with tinnitus acceptance, moderate positive correlations with anxiety sensitivity, sleeping difficulties, tinnitus loudness, and small correlations with the Big Five personality dimensions confirmed construct validity.

CONCLUSION

Results show that the THI is a highly reliable and valid measure of tinnitus-related handicap. In contrast to results of previous exploratory analyses the current findings speak for a three-factor in contrast to a unifactorial structure. Future research is needed to replicate this result in different tinnitus populations.

The epworth sleepiness scale in the assessment of sleep disturbance in veterans with tinnitus

Purpose. Tinnitus and sleep disturbance are prevalent in veterans, and a better understanding of their relationship can help with tinnitus treatment. Materials and Methods. Retrospective chart review of 94 veterans seen in audiology clinic between 2010 and 2013 is presented. Results. The mean age was 62 years, and 93 of 94 veterans were males. The majority (96%) had hearing loss. The positive predictive value of the ESS for sleep disorder was 97% and the negative predictive value was 100%. Veterans with a Tinnitus Handicap Inventory (THI) score ≥38 had significantly higher Epworth Sleepiness Scale (ESS) scores compared to those with THI score <38 (P = 0.006). The former had a significantly higher incidence of PTSD, anxiety, and sleep disorder. A subgroup of patients had normal sleep despite rising THI scores. Bilateral tinnitus, vertigo, and anxiety were found to be predictors of sleep disturbance. Conclusions. The ESS can be used as a tool in the initial assessment of sleep disorders in veterans with tinnitus. Higher tinnitus handicap severity is significantly associated with greater sleep disturbance. Optimal management of tinnitus may require concomitant treatment of sleep disorder, PTSD, anxiety, and depression.

The neuropsychiatry of tinnitus: a circuit-based approach to the causes and treatments available

Patients presenting with tinnitus commonly have neuropsychiatric symptoms with which physicians need to be familiar. We provide an overview of tinnitus, including its types and pathophysiology. We discuss how recent methods such as transcranial magnetic stimulation, positron emission tomography, MRI, magnetoencephalography and quantitative EEG improve our understanding of the pathophysiology of tinnitus and connect tinnitus to the neuropsychiatric symptoms. We then explain why treatment of the tinnitus patient falls within the purview of neuropsychiatry. Psychiatric problems such as depression, anxiety and personality disorders are discussed. We also discuss how stress, headache, cognitive processing speed and sleep disturbance are associated with tinnitus. Finally, we provide a brief overview of treatment options and discuss the efficacy of various medications, including benzodiazepines, antidepressants, antipsychotics and mood-stabilising agents, and various non-pharmacological treatment options, such as cognitive behavioural therapy, habituation therapy and acupuncture. We also discuss how brain stimulation therapies are being developed for the treatment of tinnitus. In conclusion, a review of the literature demonstrates the varied neuropsychiatric manifestations of tinnitus. Imaging studies help to explain the mechanism of the association. However, more research is needed to elucidate the neurocircuitry underlying the association.

Noise-induced tinnitus using individualized gap detection analysis and its relationship with hyperacusis, anxiety, and spatial cognition

Tinnitus has a complex etiology that involves auditory and non-auditory factors and may be accompanied by hyperacusis, anxiety and cognitive changes. Thus far, investigations of the interrelationship between tinnitus and auditory and non-auditory impairment have yielded conflicting results. To further address this issue, we noise exposed rats and assessed them for tinnitus using a gap detection behavioral paradigm combined with statistically-driven analysis to diagnose tinnitus in individual rats. We also tested rats for hearing detection, responsivity, and loss using prepulse inhibition and auditory brainstem response, and for spatial cognition and anxiety using Morris water maze and elevated plus maze. We found that our tinnitus diagnosis method reliably separated noise-exposed rats into tinnitus⁽⁺⁾ and tinnitus⁽⁻⁾ groups and detected no evidence of tinnitus in tinnitus⁽⁻⁾ and control rats. In addition, the tinnitus⁽⁺⁾ group demonstrated enhanced startle amplitude, indicating hyperacusis-like behavior. Despite these results, neither tinnitus, hyperacusis nor hearing loss yielded any significant effects on spatial learning and memory or anxiety, though a majority of rats with the highest anxiety levels had tinnitus. These findings showed that we were able to develop a clinically relevant tinnitus⁽⁺⁾ group and that our diagnosis method is sound. At the same time, like clinical studies, we found that tinnitus does not always result in cognitive-emotional dysfunction, although tinnitus may predispose subjects to certain impairment like anxiety. Other behavioral assessments may be needed to further define the relationship between tinnitus and anxiety, cognitive deficits, and other impairments.

Gap detection deficits in humans with tinnitus as assessed with the acoustic startle paradigm: does tinnitus fill in the gap?

The measurement of tinnitus in humans relies on subjective measures such as self-report, visual analog scales and questionnaires. Gap detection impairments have been tested in animals in an attempt to objectify the presence of tinnitus. The main purpose of this study was to investigate the gap startle paradigm in human participants with high-frequency tinnitus. Fifteen adults with bilateral high-frequency tinnitus but normal hearing at standard frequencies and seventeen matched controls without tinnitus were tested. The psychoacoustic characteristics of the tinnitus spectrum (pitch and loudness) were assessed using novel participant-directed custom-made methods. The startle task consisted of startle-alone, prepulse inhibition and gap-in-noise condition at low- and high-background noise frequencies. All measurements were retested after several months. Data indicate normal prepulse inhibition but higher reactivity to the startle sounds in the tinnitus group in comparison with controls. Most importantly, the tinnitus group displayed a consistent deficit in gap processing at both low- and high-background noise frequencies. All effects were identified consistently and were reproducible at retest. We propose that the higher reactivity to startle might reflect hyperacusis and that the gap deficit might be an index of abnormal cortical auditory processing in tinnitus.

Cortisol suppression and hearing thresholds in tinnitus after low-dose dexamethasone challenge

BACKGROUND

Tinnitus is a frequent, debilitating hearing disorder associated with severe emotional and psychological suffering. Although a link between stress and tinnitus has been widely recognized, the empirical evidence is scant. Our aims were to test for dysregulation of the stress-related hypothalamus-pituitary adrenal (HPA) axis in tinnitus and to examine ear sensitivity variations with cortisol manipulation.

METHODS

Twenty-one tinnitus participants and 21 controls comparable in age, education, and overall health status but without tinnitus underwent basal cortisol assessments on three non-consecutive days and took 0.5 mg of dexamethasone (DEX) at 23:00 on the first day. Cortisol levels were measured hourly the next morning. Detection and discomfort hearing thresholds were measured before and after dexamethasone suppression test.

RESULTS

Both groups displayed similar basal cortisol levels, but tinnitus participants showed stronger and longer-lasting cortisol suppression after DEX administration. Suppression was unrelated to hearing loss. Discomfort threshold was lower after cortisol suppression in tinnitus ears.

CONCLUSIONS

Our findings suggest heightened glucocorticoid sensitivity in tinnitus in terms of an abnormally strong glucocorticoid receptor (GR)-mediated HPA-axis feedback (despite a normal mineralocorticoid receptor (MR)-mediated tone) and lower tolerance for sound loudness with suppressed cortisol levels. Long-term stress exposure and its deleterious effects therefore constitute an important predisposing factor for, or a significant pathological consequence of, this debilitating hearing disorder.

A review of tinnitus symptoms beyond 'ringing in the ears': a call to action

BACKGROUND

Tinnitus, often referred to as 'ringing in the ears', is highly prevalent. However, patients may also present with a number of other symptoms.

SCOPE

To review the broad range of symptoms of tinnitus, to evaluate their impact on patient quality of life and to explore methods of diagnosis and assessment. An electronic literature search was performed in PubMed between September and December 2010.

FINDINGS

Accumulating evidence suggests that the symptoms of tinnitus are not confined to the characteristic 'ringing in the ears', but instead encompass wide-ranging symptoms that include emotional components such as sleep disturbance, anxiety, depression, irritation, and concentration difficulties.

CONCLUSION

Patients with tinnitus experience a spectrum of distressing symptoms that impact their quality of life and there is a clear need for action. Clinicians need to recognize and diagnose tinnitus that occurs with other wide-ranging symptoms to ensure that these symptoms are identified and patients receive effective treatment.