Jacxsens Laura, De Pauw Joke, Cardon Emilie, van der Wal Annemarie, Jacquemin Laure, Gilles Annick, Michiels Sarah, Van Rompaey Vincent, Lammers Marc J W, De Hertogh Willem
Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.
Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp University Hospital (UZA), Edegem, Belgium.
Front Neurol. 2022 Aug 22;13:941876. doi: 10.3389/fneur.2022.941876. eCollection 2022.
Accumulating evidence suggests a role of the brainstem in tinnitus generation and modulation. Several studies in chronic tinnitus patients have reported latency and amplitude changes of the different peaks of the auditory brainstem response, possibly reflecting neural changes or altered activity. The aim of the systematic review was to assess if alterations within the brainstem of chronic tinnitus patients are reflected in short- and middle-latency auditory evoked potentials (AEPs).
A systematic review was performed and reported according to the PRISMA guidelines. Studies evaluating short- and middle-latency AEPs in tinnitus patients and controls were included. Two independent reviewers conducted the study selection, data extraction, and risk of bias assessment. Meta-analysis was performed using a multivariate meta-analytic model.
Twenty-seven cross-sectional studies were included. Multivariate meta-analysis revealed that in tinnitus patients with normal hearing, significantly longer latencies of auditory brainstem response (ABR) waves I (SMD = 0.66 ms, < 0.001), III (SMD = 0.43 ms, < 0.001), and V (SMD = 0.47 ms, < 0.01) are present. The results regarding possible changes in middle-latency responses (MLRs) and frequency-following responses (FFRs) were inconclusive.
The discovered changes in short-latency AEPs reflect alterations at brainstem level in tinnitus patients. More specifically, the prolonged ABR latencies could possibly be explained by high frequency sensorineural hearing loss, or other modulating factors such as cochlear synaptopathy or somatosensory tinnitus generators. The question whether middle-latency AEP changes, representing subcortical level of the auditory pathway, are present in tinnitus still remains unanswered. Future studies should identify and correctly deal with confounding factors, such as age, gender and the presence of somatosensory tinnitus components.
https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021243687, PROSPERO [CRD42021243687].
越来越多的证据表明脑干在耳鸣的产生和调节中起作用。多项针对慢性耳鸣患者的研究报告了听觉脑干反应不同波峰的潜伏期和振幅变化，这可能反映了神经变化或活动改变。本系统评价的目的是评估慢性耳鸣患者脑干内的改变是否反映在短潜伏期和中潜伏期听觉诱发电位（AEP）中。
按照PRISMA指南进行系统评价并报告。纳入评估耳鸣患者和对照组短潜伏期和中潜伏期AEP的研究。两名独立评审员进行研究选择、数据提取和偏倚风险评估。使用多变量荟萃分析模型进行荟萃分析。
纳入27项横断面研究。多变量荟萃分析显示，听力正常的耳鸣患者中，听觉脑干反应（ABR）波I（标准化均数差[SMD]=0.66毫秒，P<0.001）、波III（SMD=0.43毫秒，P<0.001）和波V（SMD=0.47毫秒，P<0.01）的潜伏期显著延长。关于中潜伏期反应（MLR）和频率跟随反应（FFR）可能变化的结果尚无定论。
短潜伏期AEP中发现的变化反映了耳鸣患者脑干水平的改变。更具体地说，ABR潜伏期延长可能由高频感音神经性听力损失或其他调节因素（如耳蜗突触病变或躯体感觉性耳鸣发生器）解释。耳鸣患者是否存在代表听觉通路皮质下水平的中潜伏期AEP变化这一问题仍未得到解答。未来的研究应识别并正确处理混杂因素，如年龄、性别和躯体感觉性耳鸣成分的存在。
https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021243687，PROSPERO[CRD42021243687]
