Electrophysiological differences in sensorineural hearing loss patients with and without problem-tinnitus

Abstract

EnAbstract Objects Problem-tinnitus refers to tinnitus that is sufficiently severe to produce a major disruption in the patient’s life; tinnitus of such severity involves a number of regions of the auditory system and other brain systems may also play an essential role. Auditory brainstem responses (ABR) and event-related potentials (ERP) were recorded from sensorineural hearing loss (SNHL) patients with problem-tinnitus and were then compared with responses from normal hearing and hearing loss tinnitus-free patients. Aim To study whether differences exist in ABR and/or ERP parameters in SNHL patients with and without problem-tinnitus when matched as closely as possible for hearing loss, age, and sex to investigate the mechanism responsible for tinnitus. Materials and Methods Ninety participants were included in this study. They were divided into two groups: the study group included 66 participants with bilateral symmetrical SNHL that did not exceed a moderate degree. The study group was divided into two subgroups: 36 patients had problem-tinnitus and 30 patients were tinnitus-free (SNHL, age, and sex matched). Participants in each of these subgroups were compared with each other and were also compared with 24 healthy individuals in the control group (age and sex matched with the study group). All participants were subjected to a basic audiological evaluation and electrophysiological tests (ABR and ERP). Results This work had shown a higher prevalence of ABR abnormalities in tinnitus patients in comparison with either the control group or the SNHL tinnitus-free group. Statistically significant differences were found in III–V and I–V interpeak latencies and in the VI amplitude ratio in problem-tinnitus female patients compared with tinnitus-free female patients. Meanwhile, in problem tinnitus male patients when compared with tinnitus-free male patients at III–V interpeak latencies and at VI amplitude ratio. As regards the results of ERP in this work, an increase in latency and amplitude reduction were found. Statistically significant differences were observed regarding both the mean latency values of waves N1, P2, and P300 and the amplitude mean values of P2 and P300 when we compared the problem-tinnitus subgroup with either the tinnitus-free subgroup or the control group (both female and male patients. Conclusion A variety of ABR and ERP components are altered in tinnitus patients; this would indicate impairment in both the central auditory pathway and central auditory processing. Thus, it is suggested that this form of ABR, ERP testing could be considered as an objective measure to complement behavioral, audiologic, and other physiologic methods of assessing tinnitus, rather than a single definitive tinnitus measure in an attempt to supplement and thereby extend knowledge of the nature and origins of tinnitus. Furthermore, these results provide the basis for future neurofeedback-based tinnitus therapies aiming at maximizing the ability to shift attention away from the tinnitus.