title: Modulation of Perception or Emotion? A Scoping Review of Tinnitus Neuromodulation Using Transcranial Direct Current Stimulation.
abstract: BACKGROUND
  Tinnitus is the phantom perception of sound and can have negative effect on the quality of life. Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation technique, which can increase or decrease the cortical excitability in the brain region to which it is applied. tDCS has been used for tinnitus research since 2006.
  
  
  OBJECTIVE
  To investigate whether tDCS affects tinnitus perception, related emotion, or both, and the potential implications for tinnitus management.
  
  
  METHODS
  A scoping review was undertaken using the methods proposed by Arksey and O'Malley. After initial consideration of title relevance and reading abstracts, 15 studies were included in this review. The data from these studies were charted to investigate the impact of tDCS on tinnitus perception and emotions.
  
  
  RESULTS
  tDCS results in transient suppression of tinnitus loudness and annoyance; however, it does not lead to long-term impact on tinnitus related emotion. Local stimulation of different sites of stimulation (left temporoparietal area, dorsolateral prefrontal cortex, and auditory cortex) might modulate tinnitus perception (loudness) and emotions differently; however, further research is needed to explore this hypothesis. This review has identified aspects of methodologies that require attention in upcoming tinnitus and tDCS trials to offer better insights.
  
  
  CONCLUSIONS
  tDCS is an effective research tool for transient tinnitus neuromodulation. However, efforts should be invested in designing clinical trials using local and multiple sites of stimulation, optimized parameters, and objective outcome measures before it can be translated in to a clinical tool for tinnitus management.
authors: University of Auckland, Auckland, New Zealand.
authors: Giriraj Singh
authors: GS
authors: Shekhawat
authors: University of Auckland, Auckland, New Zealand.
authors: Cathy M
authors: CM
authors: Stinear
authors: University of Auckland, Auckland, New Zealand Tinnitus Research Initiative, Regensburg, Germany g.searchfield@auckland.ac.nz.
authors: Grant D
authors: GD
authors: Searchfield
mesh_terms: D001307:Auditory Perception / Q000502:physiology*; D002540:Cerebral Cortex / Q000503:physiopathology*; D004644:Emotions / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D014012:Tinnitus / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy*; D065908:Transcranial Direct Current Stimulation; D016896:Treatment Outcome
keywords: brain stimulation; neuromodulation; tinnitus; transcranial direct current stimulation; treatment