Transient reduction of tinnitus intensity is marked by concomitant reductions of delta band power-0

<p><b>Copyright information:</b></p><p>Taken from "Transient reduction of tinnitus intensity is marked by concomitant reductions of delta band power"</p><p>http://www.biomedcentral.com/1741-7007/6/4</p><p>BMC Biology 2008;6():4-4.</p><p>Published online 16 Jan 2008</p><p>PMCID:PMC2254377.</p><p></p>for every subject pre- and post-stimulation. One line represents one subject. The thick grey lines indicate the mean tinnitus loudness over all subjects. CO and RI conditions are shown separately. Please note that due to a decrease in tinnitus loudness over the course of the experiment, in some subjects the mean pre-tinnitus loudness is not 10 for every subject

Transient reduction of tinnitus intensity is marked by concomitant reductions of delta band power-1

<p><b>Copyright information:</b></p><p>Taken from "Transient reduction of tinnitus intensity is marked by concomitant reductions of delta band power"</p><p>http://www.biomedcentral.com/1741-7007/6/4</p><p>BMC Biology 2008;6():4-4.</p><p>Published online 16 Jan 2008</p><p>PMCID:PMC2254377.</p><p></p>arately. Each line represents a single subject. The thick grey lines indicate the mean delta band activities over all subjects

Transient reduction of tinnitus intensity is marked by concomitant reductions of delta band power-2

<p><b>Copyright information:</b></p><p>Taken from "Transient reduction of tinnitus intensity is marked by concomitant reductions of delta band power"</p><p>http://www.biomedcentral.com/1741-7007/6/4</p><p>BMC Biology 2008;6():4-4.</p><p>Published online 16 Jan 2008</p><p>PMCID:PMC2254377.</p><p></p>for every subject pre- and post-stimulation. One line represents one subject. The thick grey lines indicate the mean tinnitus loudness over all subjects. CO and RI conditions are shown separately. Please note that due to a decrease in tinnitus loudness over the course of the experiment, in some subjects the mean pre-tinnitus loudness is not 10 for every subject

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

<div><p>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.</p> </div

Changes in oscillatory activity in non-auditory brain areas for the most effective stimulation protocols.

<p>Shown are the changes in oscillatory activity in non-auditory brain areas after application of the rTMS protocols that were most effective in enhancing tinnitus loudness. The upper panel displays brain regions with power modulations in the alpha band, while the lower panel illustrates the areas exhibiting modulations in gamma power. Displayed are comparisons from pre to post rTMS and are quantified in t-values. Gamma power was significantly (p<.01; corrected) reduced in a left prefrontal, a left precentral and a left parieto-temporo-occipital region. Alpha power was reduced (p<.01; corrected) in a left superior frontal area.</p

Consistent changes in tinnitus loudness after the four active TMS protocols compared to sham.

<p>The upper panel displays tinnitus loudness modulations that were measured with a matched-intensity approach (TIM), while the lower panel illustrates tinnitus loudness modulations that were quantified with a visual analogue scale (VAS). Sham effects are visualised in the right panel. Shown are the 95% confidence intervals. The small bars display the median. The asterisk indicates significant modulations, while the cross points to marginally significant modulations. According to the TIM, tinnitus loudness was reduced after 1-Hz rTMS. A trend pointing to a tinnitus reduction was revealed after 1-Hz rTMS and cTBS, while tinnitus loudness was marginally enhanced after IAF rTMS.</p

Modulation of auditory alpha power in the individual patients.

<p>Depicted are modulations of auditory alpha power in the individual patients and for the four active TMS protocols (black bars) and sham (grey bars). Shown are the 95% confidence intervals (uncorrected). The small bars display the median. The asterisks indicate significant modulations from pre to post TMS. The orange boxes point to significant modulations against sham stimulation. TMS modulates alpha activity significantly already in individual patients: 1 Hz rTMS (4 of 10, against Sham: 2 of 10), cTBS (10 of 10, against sham 5 of 10), IAF rTMS (4 of 10, against sham 4 of 10), iTBS (2 of 10, against Sham 3 of 10), however, not consistently into the same direction (increase vs decrease of alpha power).</p

Experimental design.

<p>Patients underwent five sessions with five different rTMS protocols (including Sham). In each session, tinnitus loudness and oscillatory brain activity were measured before and after rTMS. The right upper panel illustrates the different stimulation protocols.</p

Changes in tinnitus loudness after application of the stimulation protocol that enhanced tinnitus loudness.

<p>The upper panel displays tinnitus loudness modulations that were measured with the tinnitus intensity matching procedure (TIM), while the lower panel illustrates tinnitus loudness modulations that were quantified using a visual analogue scale (VAS). The 95% confidence intervals are shown on the left side. The small bars display the median. The asterisks indicate significant modulations. As expected tinnitus loudness was significantly reduced after application of the individually selected protocol that worsened tinnitus. The distribution of these protocols is displayed on the right side. Note that, as the ambiguous cases (when selecting the most effective protocol with VAS) were included for this illustration, the summed frequency of occurrence can be higher than the total number of patients.</p

Consistent changes in oscillatory activity after the four active TMS protocols compared to sham.

<p>The upper panel displays alpha power modulations, while the lower panel illustrates modulations of high gamma power at the stimulated auditory cortex. The stimulated region and region of interest are displayed on the right side. Shown are the 95% confidence intervals. The small bars display the median while the asterisks indicate that the modulations were significant. Alpha power was significantly reduced after IAF rTMS and iTBS, while gamma power was significantly decreased by 1-Hz rTMS and iTBS (uncorrected).</p