Transcranial Direct Current Stimulation and its Impact on Attention Networks in Tinnitus Patients

Document Type : Original Article

Authors

1 Department of Cognitive Neuroscience, Faculty of Psychology and Educational Sciences, University of Tabriz, Tabriz, Iran

2 Department of Psychology, Faculty of Psychology and Educational Sciences, Tabriz University, Tabriz, Iran

3 Department of Audiology, University of Social welfare and Rehabilitation Science, Tehran, Iran & Pediatric Neurorehabilitation Research center, University of Social welfare and Rehabilitation Science, Tehran, Iran

10.30483/rijm.2024.254509.1313

Abstract

Background: Tinnitus is a prevalent condition often leading to disruptions in attentional functions. The effect of transcranial direct current stimulation (tDCS) on cortical attention networks has yielded inconsistent findings.
 
Objectives: This study aimed to examine the influence of tDCS on patients suffering from tinnitus on the efficacy of alerting, orienting, and conflict, as gauged by the Attention Network Test (ANT).
 
Materials and Methods: 30 tinnitus patients with chronic bothersome tinnitus longer than 6 months with moderate and high severities were placed into two separate groups at random. The control group (n=15) underwent sham tDCS, while the treatment group (n=15) received active tDCS, with the anodal electrode placed over the left dorsolateral prefrontal cortex (DLPFC) and the cathodal electrode over the right DLPFC. The ANT and the Electroencephalography (EEG) recording were used before and after interventions. The differences were analyzed using the MANCOVA test.
 
Results: There was a significant difference (P<0.01) between the control and tDCS groups only in terms of the mean post-test scores of conflict. However, no significant difference was observed in the means of alerting and orienting. This suggests that tDCS primarily influenced the conflict index, leading to its enhancement. EEG recording indicated a variety of significant changes in various frequency bands in different channel locations. Theta and high beta showed no significant difference in any channel, and most changes happened in the form of an increase in high alpha after tDCS. Absolute Power in theta and high beta frequency ranges showed no significant difference in any channel, and most changes in Absolute Power happened as an increase in high alpha frequency after tDCS.
 
Conclusion: tDCS potentially improves the attentional network in patients afflicted with tinnitus. More research is required to draw definitive conclusions, especially since only conflict demonstrated significance in the ANT test.

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