Increased Resting-State Cerebellar-Cerebral Functional Connectivity Underlying Chronic Tinnitus.

Yuan Feng,Han Lv,Xindao Yin,Huiyou Chen,Yu-Chen Chen,Fan Bo,Jin-Jing Xu,Wenqing Xia,Cun-Nan Mao

doi:10.3389/fnagi.2018.00059

Abstract

Purpose: Chronic subjective tinnitus may arise from aberrant functional coupling between the cerebellum and the cerebral cortex. To explore this hypothesis, we used resting-state functional magnetic resonance imaging (fMRI) to illuminate the functional connectivity network of the cerebellar regions in chronic tinnitus patients and controls.Methods: Resting-state fMRI scans were obtained from 28 chronic tinnitus patients and 29 healthy controls (well matched for age, sex and education) in this study. Cerebellar-cerebral functional connectivity was characterized using a seed-based whole-brain correlation method. The resulting cerebellar functional connectivity measures were correlated with each clinical tinnitus characteristic.Results: Chronic tinnitus patients demonstrated increased functional connectivity between the cerebellum and several cerebral regions, including the superior temporal gyrus (STG), parahippocampal gyrus (PHG), inferior occipital gyrus (IOG), and precentral gyrus. The enhanced functional connectivity between the left cerebellar Lobule VIIb and the right STG was positively correlated with the Tinnitus Handicap Questionnaires (THQ) score (r = 0.577, p = 0.004). Furthermore, the increased functional connectivity between the cerebellar vermis and the right STG was also associated with the THQ score (r = 0.432, p = 0.039).Conclusions: Chronic tinnitus patients have greater cerebellar functional connectivity to certain cerebral brain regions which is associated with specific tinnitus characteristics. Resting-state cerebellar-cerebral functional connectivity disturbances may play a pivotal role in neuropathological features of tinnitus.

Highlights

Tinnitus is defined as a phantom auditory perception, such as ringing, roaring, or buzzing in ears without any external sounds (Jastreboff, 1990; Lockwood et al, 2002; Wegger et al, 2017)
Increased cerebellar functional connectivity in chronic tinnitus patients was shown in Figure 2 and Table 2
Chronic tinnitus patients showed significantly increased connectivity between the seed region in left Crus I and left parahippocampal gyrus (PHG); increased connectivity was observed between the right Crus I and right inferior occipital gyrus (IOG)

Summary

Introduction

Tinnitus is defined as a phantom auditory perception, such as ringing, roaring, or buzzing in ears without any external sounds (Jastreboff, 1990; Lockwood et al, 2002; Wegger et al, 2017). Tinnitus may be derived from aberrant neural activity in the central auditory pathway or in the acoustic center other than the cochlea, as shown in previous electrophysiological and neuroimaging studies (Lockwood et al, 1998; Kaltenbach et al, 2005). It has been demonstrated that tinnitus involves aberrant neural activity in auditory regions and non-auditory structures such as the prefrontal cortex, parahippocampal gyrus (PHG), amygdala, and cerebellum, which have been confirmed to be important in the development or progression of tinnitus (Rauschecker et al, 2010; Leaver et al, 2011; Langguth et al, 2013; Chen et al, 2015a, 2017a,b,c; Brozoski et al, 2017)

Methods

Results

Conclusion