Effects of sound therapy on resting‐state functional brain networks in patients with tinnitus: A graph‐theoretical‐based study

Abstract

Background Tinnitus is considered to be triggered by aberrant neural activity in the brain. Sound therapy is regarded as a reasonable management option for tinnitus treatment and has been applied in the clinical setting for decades. Hypothesis We hypothesized that sound therapy, a commonly used tinnitus treatment method, would alter the functional connectivity (FC) of brain regions in tinnitus models. Study Type Longitudinal. Population Resting‐state functional MRI data were collected from 27 tinnitus patients before and after 12 weeks of sound therapy. Twenty‐seven age‐ and sex‐matched healthy controls were also longitudinally scanned at the 12‐week timepoint. Field Strength 3.0T MRI system and echo planar imaging (EPI) sequence, 3D brain volume imaging (BRAVO) sequence. Assessment Functional connectivity strength (FCS), a graph‐theoretical‐based analytic method, was applied to analyze the FC features in the whole brain. Statistical Tests Student's t‐test and chi‐square test were used for analyses between two groups. A two‐way analysis of covariance (ANCOVA) followed by post‐hoc analyses was performed to determine differences of FC. Results The interaction effect between the two groups and two scans on FCS was observed in the bilateral thalami and left anterior cingulate cortex (ACC). The fitted FCS values in the bilateral thalami were significantly higher in tinnitus patients at baseline and decreased to a relatively normal range after sound therapy compared with healthy controls. Conversely, the fitted FCS values in the left ACC were within the normal range, but increased after treatment (1.08 ± 0.29, P < 0.02); however, there was no change in the control group. Importantly, significant correlations were observed between the FCS changes in the right thalamus (P = 0.028), the FC of the right thalamus‐right inferior frontal gyrus (P = 0.015), and symptomatic improvement. Data Conclusion Sound therapy may modulate the brain network by altering the gating function of the thalamus as well as enhancing the tinnitus‐canceling system. Level of Evidence: 2 Technical Efficacy Stage: 4 J. Magn. Reson. Imaging 2019;50:1731–1741.

Neuroanatomical Alterations in Patients With Tinnitus Before and After Sound Therapy: A Voxel-Based Morphometry Study

“…Our results showed GM volume changes in the bilateral thalami, which also illustrated the importance of the thalamus in tinnitus treatment. Previous research by our team has also found that the thalamus is a very important brain area and it plays a critical role in the perception of tinnitus (Han et al, 2019b). It is also a brain relay area that regulates sensory information flow to and from the auditory cortex (Rauschecker et al, 2010;Leaver et al, 2011).…”

“…Although these changes may not be as significant as functional changes, the results also reflect the efficacy of sound therapy to a certain extent. One reason may be that many previous studies have focused more on functional changes, including local abnormal activities and abnormal activities of the network, than on structural changes (Han et al, 2019b). A recent study using two resting-state functional connectivity (RSFC) approaches to better understand functional network disturbances associated with tinnitus also found that there were many changes in brain function level in tinnitus patients (Leaver et al, 2016).…”

“…Narrow band noise sound therapy is a commonly used treatment for tinnitus ( Henry et al, 2002 ). Previous studies have demonstrated functional changes in the brain ( Han et al, 2019a , b ). However, we only found a few related reports on the morphological changes before and after sound therapy with an average treatment time of 1 week ( Krick et al, 2015 , 2017 ).…”

Neuroanatomical Alterations in Patients With Tinnitus Before and After Sound Therapy: A Combined VBM and SCN Study

“…In recent years, narrow band noise sound therapy has been one of the commonly used methods for the treatment of tinnitus (38). Our previous studies have demonstrated functional changes in the brain with this sound therapy (8,39). However, we only found a few related reports on the morphological changes before and after sound therapy (37,40).…”

“…In this study, the 24-week treatment group showed high levels of auditory-related GM volume, but the tinnitus baseline group showed less auditoryrelated GM volume, which suggests that the associations between networks de ned as being within the auditory-related network architecture were generally stronger in the 24-week treatment group. Previous studies have mentioned functional issues but performed fewer structural analyses (39,57). There are structural changes in tinnitus patients, and these structural changes will affect structure after treatment (27); therefore, it is necessary to pay more attention to the structural changes associated with tinnitus patients.…”