Direct current stimulation of the ear in tinnitus treatment: a double-blind placebo-controlled study

Abstract

The objectives of the study are assessment of the influence of direct current electrical stimulations of the ear in tinnitus treatment, comparison of the results with placebo group and evaluation of hearing after electrical stimulations. The study comprised 120 tinnitus and sensorineural hearing loss patients (n = 184 tinnitus ears). In group one (n = 119 tinnitus ears) the authors applied a non-invasive hydrotransmissive electrical stimulation (15) of the ear, in group two (n = 65 tinnitus ears)—placebo electrical stimulation. Direct rectangular, positive polarization current was used. The frequency of stimulation was adjusted according to tinnitus frequency. In group two, the authors used similar procedure, but no current was delivered through the active electrode. Evaluation of tinnitus and hearing was conducted. In groups one and two, directly after the treatment, the number of ears with permanent tinnitus decreased considerably. In group one in 40 ears (33.6 %) tinnitus disappeared; in group two, tinnitus disappeared in four ears (6.1 %). After 30 days, statistically significant changes were observed in group one (p < 0.05), which were comparable with results returned 90 days later (p > 0.05). Changes in group two (after 30 and 90 days) were not significant (p > 0.05). The authors recognized audiometric improvement of hearing (in pure tone audiometry). The application of direct current electrical stimulation of the hearing organ, with current frequencies similar to tinnitus frequencies (selective electrical stimulation), was an efficient method in severe tinnitus treatment. We did not observe a harmful effect of direct current on hearing organ.

Electrical Stimulation of the Ear, Head, Cranial Nerve, or Cortex for the Treatment of Tinnitus: A Scoping Review

“…In addition self-reported and audiometric improvement of hearing was noted in both groups, in 34% and 26% of ears, respectively. This study was followed by a double-blind placebo-controlled study in 120 patients using the same method of electrical stimulation of the ear [ 37 ]. The placebo involved application of the electrode to the ear canal without any current.…”

Input–Output Functions in Human Heads Obtained With Cochlear Implant and Transcranial Electric Stimulation

“…To date, non-invasive deep brain stimulation has not been achieved in humans. However, remote activation of the auditory nerve through tES has been shown to produce auditory sensations 26,52 , suppress the loudness of tinnitus 25,26,52,53 , and reduce the annoyance of the tinnitus 53 . Optimizing stimulation parameters with the methods introduced here, could aid the development of viable treatment or therapy options for a wide variety of neurological disorders.…”

Evidence and evidence gaps in tinnitus therapy

“…However, the follow-up showed results that were less favorable but the improvement of the group of electro-stimulation was significant. The changes were assessed by means of a self-designed questionnaire encompassing 20 items [77]. …”