Altered intra- and interregional synchronization in resting-state cerebral networks associated with chronic tinnitus.
OBJECTIVE
Subjective tinnitus is hypothesized to arise from aberrant neural activity; however, its neural bases are poorly understood. To identify aberrant neural networks involved in chronic tinnitus, we compared the resting-state functional magnetic resonance imaging (fMRI) patterns of tinnitus patients and healthy controls.


METHODS
Resting-state fMRI measurements were obtained from a group of chronic tinnitus patients (n = 29) with normal hearing and well-matched healthy controls (n = 30). Regional homogeneity (ReHo) analysis and functional connectivity analysis were used to identify abnormal brain activity; these abnormalities were compared to tinnitus distress.


RESULTS
Relative to healthy controls, tinnitus patients had significant greater ReHo values in several brain regions including the bilateral anterior insula (AI), left inferior frontal gyrus, and right supramarginal gyrus. Furthermore, the left AI showed enhanced functional connectivity with the left middle frontal gyrus (MFG), while the right AI had enhanced functional connectivity with the right MFG; these measures were positively correlated with Tinnitus Handicap Questionnaires (r = 0.459, P = 0.012 and r = 0.479, P = 0.009, resp.).


CONCLUSIONS
Chronic tinnitus patients showed abnormal intra- and interregional synchronization in several resting-state cerebral networks; these abnormalities were correlated with clinical tinnitus distress. These results suggest that tinnitus distress is exacerbated by attention networks that focus on internally generated phantom sounds.
Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing 210009, China ; Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA.
Yu-Chen
YC
Chen
Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing 210009, China.
Jian
J
Zhang
Department of Physiology, Southeast University, Nanjing 210009, China ; Medical School, Southeast University, Nanjing 210009, China.
Xiao-Wei
XW
Li
Medical School, Southeast University, Nanjing 210009, China ; Center for Functional Neuroimaging, University of Pennsylvania, Philadelphia, PA 19104, USA.
Wenqing
W
Xia
Department of Otolaryngology, Zhongda Hospital, Medical School, Southeast University, Nanjing 210009, China.
Xu
X
Feng
Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing 210009, China.
Cheng
C
Qian
Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing 210009, China.
Xiang-Yu
XY
Yang
Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing 210009, China.
Chun-Qiang
CQ
Lu
Department of Physiology, Southeast University, Nanjing 210009, China ; School of Human Communication Disorders, Dalhousie University, Halifax, NS, Canada B3J 1Y6.
Jian
J
Wang
Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA.
Richard
R
Salvi
Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing 210009, China.
Gao-Jun
GJ
Teng
D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology*; D002908:Chronic Disease; D003344:Cortical Synchronization; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D014012:Tinnitus / Q000503:physiopathology*