Auditory brainstem response audiometry in tinnitus patients

BackgroundTinnitus is hypothesized to be an auditory phantom phenomenon resulting from spontaneous neuronal activity somewhere along the auditory pathway. The neural abnormalities underlying tinnitus are largely unknown.ObjectivesThis study aims to study brainstem function in tinnitus patients using auditory brainstem response audiometry.MethodsThis study included 80 subjects classified into two main groups: Group I (GI): consists of 20 normal hearing subjects without tinnitus. Group II (GII): consisted of 60 normal hearing adults complaining of tinnitus. This group is further divided into three subgroups according to tinnitus laterality: GIIa (20 subjects with bilateral tinnitus), GIIb (20 subjects with right ear tinnitus and GIIc (20 subjects with left ear tinnitus). Both groups were submitted to full audiological history taking, otological examination, basic audiologic evaluation and Auditory brainstem response audiometry (ABR) which was recorded in both groups followed by calculation of the absolute latencies of wave I, III and V, interpeak latencies as well as the interaural latency difference of wave V.ResultsGenerally, there was no significant difference between both groups, however, some tinnitus patients showed abnormal prolonged absolute latencies, interpeak latencies and increased interaural latency difference of wave V. There was some asymmetry in results between different study subgroups.ConclusionsResults of ABR are variable in tinnitus patients. Some cases have normal results while others showed prolonged absolute or interpeak latencies or increased ILD-V difference.