Role of transcutaneous electrical nerve stimulation in alleviation of tinnitus in normal hearing subjects.

Background: Subjective tinnitus is characterized by perception of sound in the absence of any external or internal acoustic stimuli. Many approaches have been developed over the years to treat tinnitus (medical and nonmedical). However, no consensus has been reached on the optimal therapeutic approach. Electrical nerve stimulation targeting peripheral auditory pathways presents a promising area of investigation for the treatment of tinnitus. Non-invasive transcutaneous vagal nerve stimulation of the auricular branch of the vagus nerve has been introduced and studied but its success rate varies and conflicting results have been reported. In this study we aim to assess the role of transcutaneous electrical nerve stimulation in alleviation of tinnitus in normal hearing subjects and to study the different factors that may affect the degree of alleviation of tinnitus.

Methods: The study group consisted of 64 subjects (38 male and 26 female). The age ranged between 20 and 60 years. All of them suffering from subjective tinnitus. Assessment of tinnitus loudness analyzed by Visual Analogue Scale (VAS) which was applied before and directly after TENS stimulation.

Results: There is a statistically significant difference in tinnitus loudness before and after TEN stimulation as assessed by VAS. 45 out of 64 (70.31%) patients had improvement after TENS, from them nine patients had a complete reduction of tinnitus. There is no statistically significant relation between the studied variables and the degree of tinnitus reduction.

Conclusion: ta-VNS is an effective treatment of subjective tinnitus but we could not assess for how long this residual inhibition persists due to lack of long term follow up. However, it is difficult to decide who might benefit from ta-VNS, patients with unilateral tinnitus on right ear and those with whistling sound have more reduction in tinnitus loudness than others.