Alteration of functional connectivity in tinnitus brain revealed by resting-state fMRI? A pilot study

We report a case study on possible alterations in resting-state functional connectivity between the auditory network and non-auditory brain regions in tinnitus patients.

Independent component analyses were performed to evaluate coherent spontaneous activity in distributed brain networks. The resting-state functional connectivity scores between the right and left auditory networks were measured. Direct comparison of resting-state connectivity between tinnitus patients and controls was made using a two-sample t-test.

Four patients (three male, one female; mean age 45 ± 3.92 years) with chronic tinnitus lateralized to the left ear, and six age-matched controls (four male, two female; mean age 45 ± 2.76 years) participated in this case study.

The average resting-state functional connectivity (FC) score between the left and right auditory cortical regions was significantly lower in tinnitus patients than in controls (P < 0.05). Direct comparison between patients and controls showed that increased functional connectivity caused by tinnitus occurred predominantly in the left amygdala and in the dorsomedial prefrontal cortex.

Our pilot study suggested that resting state functional magnetic resonance imaging (fMRI) could be useful to investigate possible alterations in resting-state neuronal activity between the auditory and non-auditory networks in tinnitus patients.