NESA neuromodulation protocol for tinnitus associated with cochlear synaptopathy: stimulation sequence and electrode placement

This figure illustrates the stimulation sequence and electrode placement used in an exploratory protocol of non-invasive neuromodulation (NESA) in tinnitus associated with cochlear synaptopathy. The protocol consists of 20 sessions structured in 15-minute stimulation blocks combining different device programs (P1, P2, P5, P7, P7H and P8). Program progression was designed to progressively engage neural regulatory mechanisms potentially involved in auditory processing and autonomic nervous system modulation. Electrode placement configurations included combinations involving C7–Fpz, C7–sternum–Fpz and C2–C3–Fpz depending on treatment phase. The sequence reflects a structured progression of stimulation conditions across sessions. The protocol is based on the hypothesis that tinnitus in individuals with normal audiometric thresholds may be associated with cochlear synaptopathy, characterized by reduced neural output from the auditory nerve despite preserved outer hair cell function. In this context, neuromodulation may influence auditory perception through modulation of neural excitability and autonomic balance. This figure provides a reproducible methodological reference for future studies exploring the interaction between peripheral auditory function, neural synchrony and autonomic nervous system regulation in tinnitus.