Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran.
Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran; Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.
Braz J Otorhinolaryngol. 2022 Nov-Dec;88 Suppl 3(Suppl 3):S130-S138. doi: 10.1016/j.bjorl.2022.09.005. Epub 2022 Oct 12.
Tinnitus can result from auditory system reorganization due to neural activity dysfunctions. Auditory stimulation can cause temporary or persistent tinnitus alleviation by altering the neural generators. The present study investigated the changes in Late-Latency Auditory Evoked Potentials (LLAEPs) after tinnitus suppression using auditory stimulation with short-term Residual Inhibition (RI) and long-term Tinnitus Masker (TM).
The study included 40 participates with equal numbers in the Tinnitus Group (TG), including the chronic tinnitus subjects, and the Control Group (CG), including matched volunteers. The participants had normal hearing in conventional audiometry. All the participants underwent LLAEP recording pre-intervention and after a one-minute auditory stimulation (RI), as well as a pre-intervention Dichotic Digit Test (DDT) as a behavioral assessment of the selective attention. Moreover, TG underwent a 3-month course of TM, a third LLAEP recording post-TM, a second DDT post-TM, and the Tinnitus Handicap Inventory (THI) before and after the TM.
In the baseline LLAEP recording, the TG had significantly later N1, P3a, and P3b latencies, as well as significantly lower P3a and P3b amplitudes. The second LLAEP recording showed a significant intragroup increase in P3a amplitude and a significant decrease in P3a latency in the TG, while no significant intragroup difference was observed in the CG. In the third LLAEP recording performed on TG, the P3a amplitude and latency had significant changes compared to the second recording, while the N1 latency was significantly decreased. Moreover, the DDT and THI scores had significant improvement after the TM in TG.
The present study showed the neurophysiological changes after short-term (RI) and long-term (TM) auditory stimulations in tinnitus subjects. The LLAEP changes suggest that these interventions lead to tinnitus suppression through common mechanisms. The electrophysiological observation was also confirmed using behavioral assessments.
This study type is a "comparative study" with the level of evidence "3".
耳鸣可源于听觉系统因神经活动功能障碍而发生重组。听觉刺激可通过改变神经发生源暂时或长期缓解耳鸣。本研究采用短时间残余抑制（RI）和长时间耳鸣掩蔽（TM）的听觉刺激，观察耳鸣抑制后晚期听觉诱发电位（LLAEPs）的变化。
研究纳入 40 名参与者，其中耳鸣组（TG）和对照组（CG）各 20 名。TG 包括慢性耳鸣患者，CG 包括匹配的志愿者。所有参与者的常规听力学检查均正常。所有参与者在干预前进行 LLAEP 记录，然后进行一分钟听觉刺激（RI），并在干预前进行双耳分听数字测试（DDT）作为选择性注意的行为评估。此外，TG 接受了为期 3 个月的 TM 治疗，在 TM 后进行第三次 LLAEP 记录、第二次 DDT 记录和 TM 前后的耳鸣残疾量表（THI）评估。
在基线 LLAEP 记录中，TG 的 N1、P3a 和 P3b 潜伏期明显延迟，P3a 和 P3b 振幅明显降低。第二次 LLAEP 记录显示 TG 组 P3a 振幅明显增加，P3a 潜伏期明显缩短，而 CG 组无明显组内差异。在 TG 的第三次 LLAEP 记录中，与第二次记录相比，P3a 振幅和潜伏期均有显著变化，而 N1 潜伏期明显缩短。此外，TM 后 TG 的 DDT 和 THI 评分显著改善。
本研究显示了短期（RI）和长期（TM）听觉刺激后耳鸣患者的神经生理变化。LLAEPs 的变化表明这些干预措施通过共同的机制导致耳鸣抑制。电生理观察也得到了行为评估的证实。
本研究类型为“比较研究”，证据水平为“3”。
