Auditory evoked potential p300 characteristics in adults with and without idiopathic bilateral tinnitus

Background and Aim: Based on neurophysio-logical measurements, auditory and non-audi-tory pathways are involved in tinnitus. People who experience tinnitus may suffer from several problems such as attention disorder. The auditory evoked potential P300 is an endogenous response and depends on cognitive processes like attention. The purpose of this study was to compare the auditory P300 characteristics (amp-litude and latency) in adults with and without tinnitus. Methods: Participants were 20 adults with idio-pathic bilateral tinnitus with mean duration of 8.4 ± 4.73 months, and 20 healthy adults. The P300 was recorded using oddball paradigm con-sisted of two standard (1000 Hz) and target stimuli (2000 Hz). To reduce eye blink during recording, all participants was instructed to look at and fixate on a dot sign located in front of them. The tinnitus handicap inventory (THI) was completed and pitch matching (PM) and loudness matching (LM) were measured in tinn-itus group. Results: P300 amplitude was lower at both Fz and Cz electrode placements in tinnitus patients compared to the normal group, but it was not statistically significant (p = 0.57). Tinnitus patients had delayed latency at Fz and Cz, but this difference was not significant either psychometric and psychoacoustic assessment had no statistically significant correlation with P300 amplitude and latency. Conclusion: It seems that P300 characteristics are not different between adults with and without idiopathic bilateral tinnitus, may be due to using low sample size.