Sofack Ghislain, Raouafi Kotaiba, Heinrich Sven P, Aschendorff Antje, Wesarg Thomas, Arndt Susan, Sandmann Pascale, Speck Iva
Department of Otorhinolaryngology-Head and Neck Surgery, Medical Center - University of Freiburg, Freiburg, Germany.
Department of Nuclear Medicine, Medical Center - University of Freiburg, Freiburg, Germany.
Front Neurosci. 2025 Sep 5;19:1618134. doi: 10.3389/fnins.2025.1618134. eCollection 2025.
The neural mechanisms underlying somatosensory processing in individuals with acquired single-sided deafness (SSD) and potential central neuronal cross-modal reorganization remain largely unexplored. This study investigates the impact of SSD on somatosensory perception and attentional processing.
Electrophysiological responses using EEG, and behavioral measures (discrimination thresholds, hit rates and reaction times) were assessed in adults with acquired SSD and normal-hearing (NH) controls for vibrotactile stimulation at two distinct frequencies. Differences in cortical somatosensory evoked potentials between adults with acquired SSD and normal-hearing (NH) controls, focusing on peak amplitudes and peak times of key event-related potential components (P50, N70, P100, N140, and P3b) and their cortical generators were assessed.
While both groups exhibited comparable behavioral performance, significant differences emerged in electrophysiological responses. Individuals with SSD showed increased P3b amplitude (albeit non-significant) and significantly delayed P3b peak times, indicating that individuals with acquired SSD exhibit alterations in attentional mechanisms associated with somatosensory perception. In addition, source localization analysis of the P50 component using standardized low-resolution brain electromagnetic tomography (sLORETA) revealed group differences in cortical activation patterns, with SSD individual showing additional recruitment of auditory-related areas, including the superior temporal gyrus, the middle temporal gyrus and the insula. This further supports the notion of compensatory neuroplasticity in auditory pathways following severe to profound unilateral hearing loss.
Our results indicate that SSD is associated with neural reorganization in somatosensory and auditory pathways. The observed modifications in both early and late somatosensory responses, coupled with alterations in source activity, suggest that individuals with SSD engage alternative neural mechanisms when processing vibrotactile stimuli, differing from the typical patterns observed in NH individuals. Understanding these changes prior to cochlear implantation will facilitate the development of personalized auditory rehabilitation strategies following cochlear implantation.
获得性单侧耳聋（SSD）个体体感处理的神经机制以及潜在的中枢神经元跨模态重组在很大程度上仍未得到充分探索。本研究调查了SSD对体感知觉和注意力处理的影响。
对获得性SSD的成年人和听力正常（NH）的对照组进行了两种不同频率的振动触觉刺激，评估了使用脑电图的电生理反应以及行为指标（辨别阈值、命中率和反应时间）。评估了获得性SSD的成年人与听力正常（NH）的对照组之间皮质体感诱发电位的差异，重点关注关键事件相关电位成分（P50、N70、P100、N140和P3b）的峰值幅度和峰值时间及其皮质发生器。
虽然两组表现出相当的行为表现，但电生理反应出现了显著差异。SSD个体的P3b幅度增加（尽管不显著）且P3b峰值时间显著延迟，这表明获得性SSD个体在与体感知觉相关的注意力机制方面存在改变。此外，使用标准化低分辨率脑电磁断层扫描（sLORETA）对P50成分进行的源定位分析揭示了两组在皮质激活模式上的差异，SSD个体显示出额外激活了与听觉相关的区域，包括颞上回、颞中回和脑岛。这进一步支持了严重至极重度单侧听力损失后听觉通路中代偿性神经可塑性的观点。
我们的结果表明，SSD与体感和听觉通路中的神经重组有关。在早期和晚期体感反应中观察到的变化，以及源活动的改变，表明SSD个体在处理振动触觉刺激时采用了不同的神经机制，与NH个体中观察到的典型模式不同。在人工耳蜗植入前了解这些变化将有助于制定人工耳蜗植入后的个性化听觉康复策略。
