Abstract
It remains unknown whether tinnitus or tinnitus-related hearing loss (HL) could indirectly impair or reshape the white matter (WM) of the human brain. We aim to explore the possible brain WM change in tinnitus patients without HL and further to investigate their associations with clinical variables. Structural and diffusion tensor imaging (DTI) of 20 idiopathic tinnitus patients without HL and 22 healthy controls (HCs) were obtained. Voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analysis were conducted to investigate the differences in WM volume and integrity between patients and HCs, separately. We extracted WM parameters to determine a sensitive imaging index to differentiate the idiopathic tinnitus patients from the HCs in the early stage. Correlations between the clinical variables and WM indices were also performed in patients. Compared with the controls, the tinnitus patients without HL exhibited significant decreased fractional anisotropy (FA) in the body and genu of corpus callosum (CC), left cingulum (LC) and right cingulum (RC), and right superior longitudinal fasciculus (RSLF) and increase in mean diffusivity (MD) in the body of CC in WM. Moreover, the patients also showed decreases in WM axial diffusivity (AD) in LC, left superior longitudinal fasciculus (LSLF), and right interior cerebellar peduncle (ICP) and increases in radial diffusivity (RD) in the body and genu of CC and RSLF (p < 0.05, voxel-level FWE corrected). Furthermore, the increased RD value of the genu of CC is closely associated with the tinnitus handicap inventory (THI) subscale scores. No WMV changes were detected in tinnitus patients. We combined the altered WM integrity index of body and genu of CC and LC and RSLF as an index to differentiate the two groups and reached a sensitivity of 100% and a specificity of 77.3%. Our findings suggest that tinnitus without HL is associated with significant alterations of WM integrity. These changes may be irrespective of the duration and other clinical performance. The combination of diffusion indices of body and genu of CC and LC and RSLF might be used as the potential useful imaging index for the diagnosis of persistent idiopathic tinnitus without HL in the early stage.
Highlights
Tinnitus, as a perception of sound without an external source, is regarded as a problem of the central nervous system (CNS) (Eggermont and Roberts, 2004)
Compared with the healthy control (HC), we found that the tinnitus patients exhibited significant decreases in white matter fractional anisotropy (FA) in the body and genu of the corpus callosum (CC), left cingulum (LC) and right cingulum (RC), right superior longitudinal fasciculus (RSLF), and increase in mean diffusivity (MD) in the body of CC
No significant differences in white matter volume (WMV) were found between the tinnitus and HCs
Summary
As a perception of sound without an external source, is regarded as a problem of the central nervous system (CNS) (Eggermont and Roberts, 2004). There have been a few non-invasive structural studies on brain WM change in tinnitus patients with diverse results (Crippa et al, 2010; Husain et al, 2011; Aldhafeeri et al, 2012; Benson et al, 2014; Seydell-Greenwald et al, 2014; Ryu et al, 2016; Schmidt et al, 2018). Using tract-based spatial statistics (TBSS) analysis, the study conducted by Seydell-Greenwald et al (2014) indicates tinnitus-related FA and mean diffusivity (MD) changes in auditory cortical WM, which were correlated with age and hearing loss. Ryu et al (2016) find that the tinnitus group has higher MD and axial diffusivity (AD) in WM under the auditory cortex and limbic system, and the changed diffusion indices are correlated with patients’ depression. All the studies above prove that tinnitus can result in changes in brain WM integrity, but none of them has made it clear whether the alterations are due to tinnitus or hearing loss (HL)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
