Neuromodulatory effects of dual-site repetitive transcranial magnetic stimulation targeting frontal and temporal cortices in subjective tinnitus: A functional magneti resonance imaging study.

OBJECTIVE

This study investigated the neurofunctional effects of frontotemporal dual-site repetitive transcranial magnetic stimulation (rTMS) in patients with subjective tinnitus (ST).

METHODS

Ninety ST patients were randomly assigned to active (n = 45) or sham (n = 45) with rTMS. Fifty-two healthy subjects served as controls. All underwent resting-state fMRI (rs-fMRI) and clinical assessment (Tinnitus Handicap Inventory, THI) before and after a two-week intervention. Brain metrics included regional homogeneity (ReHo), fractional amplitude of low-frequency fluctuations (fALFF), degree centrality (DC), functional connectivity (FC), and structural covariance networks (SCN).

RESULTS

Active rTMS significantly reduced THI scores (P < 0.001). Rs-fMRI showed decreased ReHo in the right inferior parietal lobule, decreased fALFF in the right superior temporal gyrus (STG), but increased fALFF in the right temporal pole, and reduced DC in the right middle temporal gyrus (MTG) (all P < 0.05). FC weakened between right STG-MTG and right MTG-occipital gyrus (P < 0.05). SCN nodal centrality changed in right STG and left MTG (P < 0.05). No such changes were seen in sham or control groups (all P > 0.05).

CONCLUSION

Frontotemporal dual-site rTMS alleviates tinnitus, likely by modulating activity and connectivity in auditory and cross-modal integration regions, involving the default mode and auditory-visual processing networks.