Qiao Yufei, Yang Jiayan, Zhu Min, Liu Qiaoyu, Long Yuanshun, Ke Hepeng, Cai Chang, Shang Yingying
Department of Otorhinolaryngology, Peking Union Medical College Hospital, Beijing, People's Republic of China.
These authors contributed equally to this work.
Ear Hear. 2025;46(5):1210-1221. doi: 10.1097/AUD.0000000000001658. Epub 2025 Mar 11.
Auditory deprivation results in functional enhancement of the remaining intact visual modality, and the underlying mechanisms include cross-modal recruitment of additional resources from the auditory cortex and compensatory reorganization of the visual network in bilateral deafness. However, how resources are allocated between hearing and vision has not been determined in patients with partial auditory deprivation. This study aimed to investigate the relationship between functional plasticity of the visual and auditory pathways in patients with congenital single-sided deafness (SSD), a typical partial deprivation condition.
The cross-sectional cohort was comprised of 25 patients with congenital SSD (mean age ± SD = 31.6 ± 5.2 years, 13 males) and 25 normal hearing (NH) controls (mean age ± SD = 30.9 ± 7.5 years, 13 males). Both visual-evoked potentials (VEPs) and auditory-evoked potentials (AEPs) were assessed for all participants. For assessment of AEPs, auditory stimuli were presented unilaterally through the hearing ear in the SSD group, while the auditory stimuli were presented unilaterally (left and right) and bilaterally in the NH group. Event-related potential analyses focused on the differences in latency and amplitude of VEPs and AEPs between groups. Dipole source analyses of VEPs and AEPs were implemented to measure the dipole strengths and latencies of the bilateral primary visual and auditory cortex and comparisons were made both within and between groups.
For VEPs, SSD patients exhibited a greater amplitude and a shorter latency than NH controls. For dipole source analysis of VEPs, no interhemispheric asymmetry or between-group difference was observed. For AEPs, the amplitude of SSD patients was greater than that of NH controls under the monaural condition but did not exceed that evoked by binaural stimuli in NH controls. For dipole source analysis of AEPs, interhemispheric strength asymmetry was observed in NH controls in response to monaural stimuli but was less clear in SSD subjects. Considering the side of deafness, interhemispheric strength asymmetry was hardly observed in left SSD (LSSD) patients, and was also weakened in right SSD (RSSD) patients. The interhemispheric difference index of dipole strength in LSSD patients was significantly lower than that in NH controls in response to right monaural stimuli. Furthermore, the dipole strength of the ipsilateral hemisphere in both LSSD and RSSD patients was greater than that in NH controls in response to monaural stimuli.
Neural activity and efficiency in the early stage of cortical visual processing in SSD patients were enhanced. The monaural responses of the auditory pathway have lost the typical contralateral organization, becoming more symmetric due to the increased ipsilateral pathways. These findings suggest concurrent compensation for auditory and visual processing in SSD patients.
听觉剥夺会导致剩余完好视觉模态的功能增强，其潜在机制包括从听觉皮层跨模态募集额外资源以及双侧耳聋时视觉网络的代偿性重组。然而，在部分听觉剥夺患者中，听觉和视觉之间的资源分配方式尚未确定。本研究旨在调查先天性单侧耳聋（SSD）患者（一种典型的部分剥夺情况）视觉和听觉通路功能可塑性之间的关系。
横断面队列包括25例先天性SSD患者（平均年龄±标准差=31.6±5.2岁，13例男性）和25名听力正常（NH）对照者（平均年龄±标准差=30.9±7.5岁，13例男性）。对所有参与者进行视觉诱发电位（VEP）和听觉诱发电位（AEP）评估。对于AEP评估，SSD组通过听力正常的耳朵单侧呈现听觉刺激，而NH组单侧（左和右）和双侧呈现听觉刺激。事件相关电位分析聚焦于两组之间VEP和AEP潜伏期和波幅的差异。对VEP和AEP进行偶极子源分析，以测量双侧初级视觉和听觉皮层的偶极子强度和潜伏期，并在组内和组间进行比较。
对于VEP，SSD患者比NH对照者表现出更大的波幅和更短的潜伏期。对于VEP的偶极子源分析，未观察到半球间不对称或组间差异。对于AEP，SSD患者在单耳条件下的波幅大于NH对照者，但不超过NH对照者双耳刺激诱发的波幅。对于AEP的偶极子源分析，NH对照者在单耳刺激时观察到半球间强度不对称，但在SSD受试者中不太明显。考虑耳聋侧，左侧SSD（LSSD）患者几乎未观察到半球间强度不对称，右侧SSD（RSSD）患者的半球间强度不对称也减弱。LSSD患者在右侧单耳刺激时偶极子强度的半球间差异指数显著低于NH对照者。此外，LSSD和RSSD患者在单耳刺激时同侧半球的偶极子强度均大于NH对照者。
SSD患者皮层视觉处理早期的神经活动和效率增强。听觉通路的单耳反应失去了典型的对侧组织，由于同侧通路增加而变得更加对称。这些发现表明SSD患者同时存在听觉和视觉处理的代偿。
