Auditory-somatosensory bimodal stimulation desynchronizes brain circuitry to reduce tinnitus in guinea pigs and humans.

Summary

This foundational work established the bimodal stimulation approach. In a guinea pig model of noise-induced tinnitus, DCN fusiform cells showed elevated spontaneous activity and cross-unit synchrony. Twenty minutes/day of LTD-inducing bimodal (but not unimodal) stimulation reduced tinnitus correlates after 25 days. The same protocol was then applied to 20 humans in a double-blind, sham-controlled crossover study, reducing tinnitus loudness and intrusiveness.

Key findings

• DCN fusiform cells in tinnitus animals show increased spontaneous firing and cross-unit synchrony.
• Bimodal stimulation timed to induce LTD reduced physiological and behavioral tinnitus in guinea pigs.
• Unimodal auditory stimulation alone produced no benefit; the somatosensory pairing is essential.
• First-in-human crossover study reduced tinnitus loudness and intrusiveness.