Auditory evoked potential P300 characteristics in adults with and without idiopathic bilateral tinnitus

Abstract

Background and Aim: Based on neurophysio­logical measurements, auditory and non-audi­tory 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 (amp­litude and latency) in adults with and without tinnitus.

Methods: Participants were 20 adults with idio­pathic bilateral tinnitus with mean duration of 8.4 ± 4.73 months, and 20 healthy adults. The P300 was recorded using oddball paradigm con­sisted 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 tinn­itus 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.

Keywords: Tinnitus; auditory evoked potential P300; attention