Event-Related Potentials before and after HD tDCS in Tinnitus Patients: Preliminary Results - OMAI 2018- The 10th International Symposium on Objective Measures in Auditory Implants

L. Jacquemin ^1,2 Paul Van de Heyning ^1,2 Griet Mertens ^1,2 J. Moyaert ¹ Annick Gilles ^1,2,3

¹Department of Otorhinolaryngology and Head & Neck Surgery, Antwerp University Hospital, Edegem, Belgium
²Faculty of Medicine, Campus Drie Eiken, Antwerp University, Wilrijk, Belgium
³Dept. of Human and Social Welfare, University College Ghent, Ghent, Belgium

Objective: There is currently a lack of objective measurements to evaluate the effects of therapeutic interventions in tinnitus patients. Previous studies have shown the underlying mechanism of maladaptive plastic changes and altered activity in the auditory and prefrontal cortex in tinnitus patients. Therefore, event-related potentials (ERPs) can provide substantial insight into processes in the brain. The current study explores the value of ERPs in the evaluation of high-definition transcranial direct current stimulation (HD tDCS) in tinnitus patients.
Methods: This study compares ERPs before and after HD tDCS treatment in 22 tinnitus patients. The ERPs are recorded with a traditional oddball paradigm using a 32-channel EEG system. In addition to this objective measurement, the therapy effects are determined by use of questionnaires.
Results: Preliminary results indicate a shortening of the N1, P2, N2 and P3 latencies after HD tDCS. However, the ERPs change is not significant correlated with the change in questionnaires. Finally, P2 and N2 are more salient and show clear peaks after HD tDCS.
Conclusions: The current study uses ERPs as an auditory technology to investigate the sound processing in the brain. The shortening of ERP latencies after HD tDCS can reflect more effective sound processing due to a decreased tinnitus impact. Yet, these changes are not correlated with the subjective tinnitus perception. The more salient and clear P2 and N3 may be explained by much more cells in the auditory cortex which are recruited to analyzing sound and may imply a better synchronization in nerve cells firing.