Alterations in Event Related Potentials (ERP) Associated with Tinnitus Distress and Attention

Tinnitus related distress corresponds to different degrees of attention paid to the tinnitus. Shifting attention to a signal other than the tinnitus is therefore particularly difficult for patients with high tinnitus related distress. As attention effects on Event Related Potentials (ERP) have been shown this should be reflected in ERP measurements (N100, phase locking). In order to prove this hypothesis single sweep ERP recordings were obtained in 41 tinnitus patients as well as 10 control subjects during a period of time when attention was shifted to a tone (attended) and during a second phase (unattended) when they did not focus attention to the tone. Whereas tinnitus patients with low distress showed a significant reduction in both N100 amplitude and phase locking when comparing the attended and unattended measurement condition a group of patients with high tinnitus related distress did not show such ERP alterations. Using single sweep ERP measurements the results of our study show, that attention in high tinnitus related distress patients is captured by their tinnitus significantly more than in low distress patients. Furthermore our results provide the basis for future neurofeedback based tinnitus therapies aiming at maximizing the ability to shift attention away from the tinnitus. © 2008 The Author(s)

Tinnitus: Distinguishing between Subjectively Perceived Loudness and Tinnitus-Related Distress

OBJECTIVES: Overall success of current tinnitus therapies is low, which may be due to the heterogeneity of tinnitus patients. Therefore, subclassification of tinnitus patients is expected to improve therapeutic allocation, which, in turn, is hoped to improve therapeutic success for the individual patient. The present study aims to define factors that differentially influence subjectively perceived tinnitus loudness and tinnitus-related distress. METHODS: In a questionnaire-based cross-sectional survey, the data of 4705 individuals with tinnitus were analyzed. The self-report questionnaire contained items about subjective tinnitus loudness, type of onset, awareness and localization of the tinnitus, hearing impairment, chronic comorbidities, sleep quality, and psychometrically validated questionnaires addressing tinnitus-related distress, depressivity, anxiety, and somatic symptom severity. In a binary step-wise logistic regression model, we tested the predictive power of these variables on subjective tinnitus loudness and tinnitus-related distress. RESULTS: The present data contribute to the distinction between subjective tinnitus loudness and tinnitus-related distress. Whereas subjective loudness was associated with permanent awareness and binaural localization of the tinnitus, tinnitus-related distress was associated with depressivity, anxiety, and somatic symptom severity. CONCLUSIONS: Subjective tinnitus loudness and the potential presence of severe depressivity, anxiety, and somatic symptom severity should be assessed separately from tinnitus-related distress. If loud tinnitus is the major complaint together with mild or moderate tinnitus-related distress, therapies should focus on auditory perception. If levels of depressivity, anxiety or somatic symptom severity are severe, therapies and further diagnosis should focus on these symptoms at first

Psychoacoustic tinnitus loudness and tinnitus-related distress show different associations with oscillatory brain activity.

BACKGROUND: The phantom auditory perception of subjective tinnitus is associated with aberrant brain activity as evidenced by magneto- and electroencephalographic studies. We tested the hypotheses (1) that psychoacoustically measured tinnitus loudness is related to gamma oscillatory band power, and (2) that tinnitus loudness and tinnitus-related distress are related to distinct brain activity patterns as suggested by the distinction between loudness and distress experienced by tinnitus patients. Furthermore, we explored (3) how hearing impairment, minimum masking level, and (4) psychological comorbidities are related to spontaneous oscillatory brain activity in tinnitus patients. METHODS AND FINDINGS: Resting state oscillatory brain activity recorded electroencephalographically from 46 male tinnitus patients showed a positive correlation between gamma band oscillations and psychoacoustic tinnitus loudness determined with the reconstructed tinnitus sound, but not with the other psychoacoustic loudness measures that were used. Tinnitus-related distress did also correlate with delta band activity, but at electrode positions different from those associated with tinnitus loudness. Furthermore, highly distressed tinnitus patients exhibited a higher level of theta band activity. Moreover, mean hearing loss between 0.125 kHz and 16 kHz was associated with a decrease in gamma activity, whereas minimum masking levels correlated positively with delta band power. In contrast, psychological comorbidities did not express significant correlations with oscillatory brain activity. CONCLUSION: Different clinically relevant tinnitus characteristics show distinctive associations with spontaneous brain oscillatory power. Results support hypothesis (1), but exclusively for the tinnitus loudness derived from matching to the reconstructed tinnitus sound. This suggests to preferably use the reconstructed tinnitus spectrum to determine psychoacoustic tinnitus loudness. Results also support hypothesis (2). Moreover, hearing loss and minimum masking level correlate with oscillatory power in distinctive frequency bands. The lack of an association between psychological comorbidities and oscillatory power may be attributed to the overall low level of mental health problems in the present sample

Tinnitus-Related Distress and the Personality Characteristic Resilience

It has been suggested that personality traits may be prognostic for the severity of suffering from tinnitus. Resilience as measured with the Wagnild and Young resilience scale represents a positive personality characteristic that promotes adaptation to adverse life conditions including chronic health conditions. Aim of the study was to explore the relation between resilience and tinnitus severity. In a cross-sectional study with a self-report questionnaire, information on tinnitus-related distress and subjective tinnitus loudness was recorded together with the personality characteristic resilience and emotional health, a measure generated from depression, anxiety, and somatic symptom severity scales. Data from 4705 individuals with tinnitus indicate that tinnitus-related distress and to a lesser extent the experienced loudness of the tinnitus show an inverse correlation with resilience. A mediation analysis revealed that the relationship between resilience and tinnitus-related distress is mediated by emotional health. This indirect effect indicates that high resilience is associated with better emotional health or less depression, anxiety, and somatic symptom severity, which in turn is associated with a less distressing tinnitus. Validity of resilience as a predictor for tinnitus-related distress is supported but needs to be explored further in longitudinal studies including acute tinnitus patients

Partial correlation of band power averaged over all electrodes with audiological parameters for the subgroup with pure tone tinnitus.

<p>Correlation coefficients (Spearman's ) and corresponding significance levels () for tinnitus loudness (TL), minimum masking level (MML), mean hearing loss (MHL) with oscillatory band power in the delta to gamma range are reported. MHL: mean hearing loss averaged for left and right ears and for the frequencies between 0.125 kHz and 16 kHz; TL: tinnitus loudness measures (see section “Psychoacoustic measurements” and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053180#pone-0053180-t002" target="_blank">Table 2</a>); MML: minimum masking level with white noise; : minimum masking level with white noise above mean hearing threshold. Significant correlations () are indicated by bold letters. Correlations which remained significant after FDR correction (FDR 0.05) are denoted by at the corresponding -value.</p

Averaged audiograms of the patient and control groups.

<p>Hearing ability was determined between 0.125 kHz and 16 kHz. Group means are shown. Tinnitus patients exhibit more pronounced hearing loss than controls above 2 kHz. Note that the controls as a group exhibit noticeable hearing impairment above 10 kHz.</p

Correlation of band power averaged over all electrodes with audiological and psychological parameters of the patient group.

<p>Correlation coefficients (Spearman's ) and corresponding significance levels () between tinnitus characteristics, minimum masking level (MML), mean hearing loss (MHL), tinnitus-related distress (TinDis), psychometric testing scores and oscillatory band power in the delta to gamma range are reported for the whole tinnitus group. MHL: mean hearing loss averaged for left and right ears between 0.125 kHz and 16 kHz; TL: tinnitus loudness measures (see section “Psychoacoustic measurements” and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053180#pone-0053180-t002" target="_blank">Table 2</a>); MML: minimum masking level with white noise; : minimum masking level with white noise above mean hearing threshold; TinDur: tinnitus duration in years; TinDis: tinnitus-related distress; DEP: depression subscale of the SCL-90-R; SOM: somatization subscale of the SCL-90-R; ANX: anxiety subscale of the SCL-90-R. Significant correlations () are indicated by bold letters. Correlations which remained significant after FDR correction (FDR 0.05) are denoted by at the corresponding -value.</p

Correlation strength between tinnitus loudness and oscillatory band power for the subgroup with unilateral pure tone tinnitus.

<p>Group averages are shown. Electrode positions of left and right hemisphere were interchanged for right-sided tinnitus. Left ear in the plots is the tinnitus ear. Power spectra were interpolated with a resolution of 40 points per 1 Hz. Tinnitus loudness was determined by matching the contribution of each frequency component and the loudness of such a reconstructed tinnitus spectrum to the perceived tinnitus. Correlations with oscillatory band power were controlled for age, global psychological distress (GPD), and mean hearing loss (MHL) between 0.125 kHz and 16 kHz. Note that correlation strength for tinnitus loudness and delta band power is highest at the fronto-central electrodes contralateral to the tinnitus ear (A), whereas it is highest at the contralateral fronto-temporal electrodes for tinnitus loudness and gamma band power (B). Correlation strengths did not remain significant after FDR correction (FDR 0.05).</p