Combining transcranial direct current stimulation and tailor-made notched music training to decrease tinnitus-related distress--a pilot study

PLoS One. 2014 Feb 25;9(2):e89904. doi: 10.1371/journal.pone.0089904. eCollection 2014.

Abstract

The central auditory system has a crucial role in tinnitus generation and maintenance. Curative treatments for tinnitus do not yet exist. However, recent attempts in the therapeutic application of both acoustic stimulation/training procedures and electric/magnetic brain stimulation techniques have yielded promising results. Here, for the first time we combined tailor-made notched music training (TMNMT) with transcranial direct current stimulation (tDCS) in an effort to modulate TMNMT efficacy in the treatment of 32 patients with tonal tinnitus and without severe hearing loss. TMNMT is characterized by regular listening to so-called notched music, which is generated by digitally removing the frequency band of one octave width centered at the individual tinnitus frequency. TMNMT was applied for 10 subsequent days (2.5 hours of daily treatment). During the initial 5 days of treatment and the initial 30 minutes of TMNMT sessions, tDCS (current strength: 2 mA; anodal (N = 10) vs. cathodal (N = 11) vs. sham (N = 11) groups) was applied simultaneously. The active electrode was placed on the head surface over left auditory cortex; the reference electrode was put over right supra-orbital cortex. To evaluate treatment outcome, tinnitus-related distress and perceived tinnitus loudness were assessed using standardized tinnitus questionnaires and a visual analogue scale. The results showed a significant treatment effect reflected in the Tinnitus Handicap Questionnaire that was largest after 5 days of treatment. This effect remained significant at the end of follow-up 31 days after treatment cessation. Crucially, tDCS did not significantly modulate treatment efficacy--it did not make a difference whether anodal, cathodal, or sham tDCS was applied. Possible explanations for the findings and functional modifications of the experimental design for future studies (e.g. the selection of control conditions) are discussed.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Analysis of Variance
  • Humans
  • Music Therapy / methods*
  • Precision Medicine / methods*
  • Surveys and Questionnaires
  • Tinnitus / pathology
  • Tinnitus / therapy*
  • Transcranial Direct Current Stimulation / methods*
  • Treatment Outcome

Grants and funding

This work was supported by the “Interdisziplinäre Zentrum für Klinische Forschung Münster” (CRA05) and the „Japan Society for the Promotion of Science for Young Scientists” (23689070). We acknowledge support by the “Deutsche Forschungsgemeinschaft” and the “Open Access Publication Fund of the University of Münster”. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.