Tinnitus distress is associated with enhanced resting-state functional connectivity within the default mode network

Figures & data

Figure 1 No significant differences in auditory thresholds between tinnitus and control groups.

Note: Data are presented as mean±SEM.
Abbreviation: SEM, standard error of the mean.

Table 1 Characteristics of tinnitus patients and healthy controls

	Tinnitus patients (n=40)	Healthy controls (n=41)	p-value
Age (years)	53.6±12.5	49.5±10.5	0.110
Male/female	19/21	16/25	0.441
Education levels (years)	12.5±2.4	12.7±2.9	0.670
Tinnitus duration (months)	41.9±34.5	–	–
THQ score	52.1±15.9	–	–
SDS score	41.8±5.6	40.0±4.6	0.123
SAS score	39.6±6.5	37.0±5.6	0.066
Gray matter	578.8±25.6	577.5±22.7	0.815
White matter	534.6±21.8	526.7±25.6	0.139
Brain parenchyma	1,113.4±32.1	1,104.2±35.4	0.225
Hearing thresholds (left)	15.8±3.5	16.7±2.5	0.093
Hearing thresholds (right)	166±3.4	17.0±2.2	0.592
Hearing thresholds (average)	16.1±3.0	16.8±1.5	0.158
FD value (mm)	0.21±0.06	0.21±0.07	0.952

Note: Data are represented as mean±SD.

Abbreviations: THQ, Tinnitus Handicap Questionnaire; SDS, Self-Rating Depression Scale; SAS, Self-Rating Anxiety Scale; FD, framewise displacement.

Figure 2 Significant FC patterns from the ROIs of the (A) ACC and (B) PCC in whole brain by using one-sample t-test in both chronic tinnitus patients and healthy controls.

Note: Significant thresholds were corrected by using FDR criterion and set at p<0.001.
Abbreviations: FC, functional connectivity; ROI, region of interest; ACC, anterior cingulate cortex; PCC, posterior cingulate cortex; FDR, false discovery rate.

Figure 3 Aberrant FC of the (A) ACC and (B) PCC in tinnitus patients compared with healthy controls.

Note: The threshold was set at a p<0.001 (FDR corrected).
Abbreviations: FC, functional connectivity; ACC, anterior cingulate cortex; PCC, posterior cingulate cortex; FDR, false discovery rate.

Table 2 Abnormal functional connectivity of ACC and PCC in bilateral tinnitus patients compared with healthy controls

Brain region	BA	MNI coordinates x, y, z (mm)	T score	Voxels
ACC
L precuneus	7	−17, −64, 46	3.4215	80
PCC
R medial prefrontal cortex	10	15, 60, 24	3.4359	62

Note: The threshold was set at a p<0.001 (FDR corrected).

Abbreviations: ACC, anterior cingulate cortex; PCC, posterior cingulate cortex; BA, Brodmann’s area; MNI, Montreal Neurological Institute; L, left; R, right; FDR, false discovery rate.

Figure 4 Significant correlations between the enhanced FC and tinnitus characteristics.

Note: (A) Positive correlation between the increased FC of the ACC–left precuneus and the tinnitus duration. (B) Positive correlation between the increased FC of the PCC–right mPFC and the THQ score.
Abbreviations: FC, functional connectivity; ACC, anterior cingulate cortex; PCC, posterior cingulate cortex; mPFC, medial prefrontal cortex; THQ, Tinnitus Handicap Questionnaires.

Table 3 Correlation coefficients between the increased functional connectivity of ACC and PCC and different tinnitus characteristics

Brain region	Tinnitus duration	THQ	SDS	SAS
ACC–left precuneus	r=0.455, p=0.007*	r=0.078, p=0.661	r=−0.082, p=0.690	r=−0.336, p=0.094
PCC–right mPFC	r=−0.115, p=0.518	r=0.381, p=0.026*	r=−0.028, p=0.891	r=0.296, p=0.142

Notes: Partial correlations were controlled for age, sex, education, GM volume, and mean hearing thresholds.

* p<0.05.

Abbreviations: ACC, anterior cingulate cortex; PCC, posterior cingulate cortex; mPFC, medial prefrontal cortex; THQ, Tinnitus Handicap Questionnaires; SDS, Self-Rating Depression Scale; SAS, Self-Rating Anxiety Scale.