Invasive electrical stimulation techniques as potential therapeutic interventions to alleviate tinnitus symptoms.

Recent efforts have focused on non-invasive electrical stimulation techniques as potential therapeutic interventions to alleviate tinnitus symptoms. This review synthesizes findings from various studies to present the current state-of-the-art approaches utilizing non-invasive electrical stimulation for the treatment of chronic tinnitus.

Transcranial Direct Current Stimulation (tDCS) and Transcranial Magnetic Stimulation (TMS) are two of the most widely studied non-invasive electrical stimulation techniques. tDCS involves the application of a weak electrical current through the scalp, which modulates neuronal activity in targeted brain areas. Several studies indicate that tDCS can provide symptomatic relief for tinnitus patients. For instance, recent research noted that tDCS had a favorable impact on tinnitus severity and was associated with improvements in auditory cortex activity, further confirming its potential as a therapeutic option for chronic tinnitus (Han et al., 2024; , Santos et al., 2018; , Langguth, 2020). TMS has similarly been shown to disrupt pathological neural synchrony associated with tinnitus; repetitive TMS (rTMS) protocols targeting relevant cortical areas have demonstrated efficacy in alleviating symptoms in chronic tinnitus patients (Lan et al., 2022; , Heiland et al., 2024).

Another promising approach is the combination of different stimulation techniques, such as transcutaneous vagus nerve stimulation paired with notched music therapy. This method aims to enhance the effects of electrical stimulation by simultaneously delivering auditory stimulation that is spectrally notched, excluding the frequency of the patient's tinnitus. Evidence suggests that this combined therapy can lead to significant reductions in tinnitus loudness and may enhance auditory cortical activity (Shim et al., 2015). Additionally, a recent systematic review highlighted the potential benefits of bimodal stimulation combining auditory and somatosensory inputs, indicating that such combined approaches may yield superior outcomes compared to single-modality stimulation (Heiland et al., 2024).

Further studies have demonstrated electrical stimulation's ability to induce changes in brain wave patterns, particularly an increase in alpha band activity in the auditory cortex, which is associated with tinnitus relief (Müller et al., 2013). Additionally, non-invasive stimulation techniques have been employed to explore individualized treatment protocols that adapt stimulation sites and parameters based on response patterns in tinnitus patients. Research on dose-response relationships in transcranial stimulation has shown that optimized stimulation protocols can yield better outcomes in symptom management (Shekhawat & Vanneste, 2018).

Overall, the implementation of non-invasive electric stimulation presents a promising avenue for the treatment of chronic tinnitus. While there is encouraging evidence for several techniques, ongoing research is vital to fully understand their mechanisms of action and to develop optimized treatment protocols tailored to individual patient profiles. As the evidence base continues to grow, the goal remains clear: to provide effective and accessible treatment options for those affected by tinnitus.

References:

Han, S., Lee, J., Choi, Y., Hong, S., Kim, J., & Kim, S. (2024). Consecutive dual-session transcranial direct current stimulation in chronic subjective severe to catastrophic tinnitus with normal hearing. Journal of Personalized Medicine, 14(6), 577. https://doi.org/10.3390/jpm14060577

Heiland, L., Owen, J., Nguyen, S., Labadie, R., Lambert, P., & Meyer, T. (2024). Neuromodulation for treatment of tinnitus: a systematic review and meta‐analysis. Otolaryngology, 170(5), 1234-1245. https://doi.org/10.1002/ohn.671

Lan, L., Liu, Y., Wu, Y., Xu, Z., Xǔ, J., Song, J., … & Cai, Y. (2022). Specific brain network predictors of interventions with different mechanisms for tinnitus patients. Ebiomedicine, 76, 103862. https://doi.org/10.1016/j.ebiom.2022.103862

Langguth, B. (2020). Non-invasive neuromodulation for tinnitus. Journal of Audiology & Otology, 24(3), 113-118. https://doi.org/10.7874/jao.2020.00052

Müller, N., Lorenz, I., Langguth, B., & Weisz, N. (2013). Rtms induced tinnitus relief is related to an increase in auditory cortical alpha activity. Plos One, 8(2), e55557. https://doi.org/10.1371/journal.pone.0055557

Santos, A., Santos, A., Santos, H., & Silva, A. (2018). The use of tdcs as a therapeutic option for tinnitus: a systematic review. Brazilian Journal of Otorhinolaryngology, 84(5), 653-659. https://doi.org/10.1016/j.bjorl.2018.02.003

Shekhawat, G. and Vanneste, S. (2018). Optimization of transcranial direct current stimulation of dorsolateral prefrontal cortex for tinnitus: a non-linear dose-response effect. Scientific Reports, 8(1). https://doi.org/10.1038/s41598-018-26665-1

Shim, H., Kwak, M., An, Y., Kim, D., Kim, Y., & Kim, H. (2015). Feasibility and safety of transcutaneous vagus nerve stimulation paired with notched music therapy for the treatment of chronic tinnitus. Journal of Audiology & Otology, 19(3), 159-167. https://doi.org/10.7874/jao.2015.19.3.159