Objective

Functional deficits induced by nerve injuries can be restored by achieving effective reinnervation of the denervated targets and functional reorganization of the central nervous system after nerve reconstruction. In this study, we investigated the effect and extent of cortical functional reorganization related to the ability of transferred hypoglossal neurons to restore facial function in facial paralysis patients after a surgical bridge of neurorrhaphy ectopically between the ipsilateral hypoglossal nerve and injured facial nerve.

Methods

We treated 23 patients (35.4 ± 10.3 years, 10 males) and followed them up for 2.9 ± 0.61 years. We used motor-task-related functional magnetic resonance imaging to map activation change at multiple time points before and after neurorrhaphy; 20 normal subjects were included as control.

Results

All patients regained facial function to some extent after neurorrhaphy. Enhanced activation in motor-related cortices gradually returned to normal levels and was positively correlated with regained facial function. The related cortical functional areas included the left middle temporal gyrus, left inferior frontal gyrus, insula, bilateral motor cortex and the supplementary motor area extending to the paracingulate involved in intensive eye closing, as well as the left superior temporal gyrus, right putamen and the bilateral motor cortex involved in lip pursing. Intriguingly, significant correlations were found between the pre-surgery activation while intensive eye closing in bilateral motor cortex and recovery of facial nerve function induced by the neurorrhaphy treatment.

Conclusion

This is the first study mapping activation change in motor cortices at multiple time points before and after repair of the facial nerve. The cortex functional reorganization found may suggest potential treatment targets in the central nervous system for adjuvant therapies such as repetitive transcranial magnetic stimulation to further improve functional recovery.

中文翻译：

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面部舌下神经缝合术治疗面瘫后的中枢功能重组与恢复

客观的

神经损伤引起的功能缺陷可以通过在神经重建后实现去神经支配目标的有效神经再支配和中枢神经系统的功能重组来恢复。在这项研究中，我们研究了在同侧舌下神经和受伤面神经之间进行异位神经缝合手术桥接后，与转移的舌下神经元恢复面部功能的能力相关的皮层功能重组的影响和程度。

方法

我们治疗了 23 名患者（35.4 ± 10.3 岁，10 名男性）并随访了 2.9 ± 0.61 年。我们使用与运动任务相关的功能磁共振成像来绘制神经修复术前后多个时间点的激活变化；包括 20 名正常受试者作为对照。

结果

所有患者在神经修补术后均有一定程度的面部功能恢复。运动相关皮质的增强激活逐渐恢复到正常水平，并与恢复的面部功能呈正相关。相关皮层功能区包括左侧颞中回、左侧额下回、脑岛、双侧运动皮层和延伸至参与密集闭眼的副扣带回的辅助运动区，以及左侧颞上回、右侧壳核和双侧运动皮层参与噘嘴。有趣的是，在双侧运动皮层密集闭眼时的术前激活与神经缝合术治疗引起的面神经功能恢复之间存在显着相关性。

结论

这是第一项绘制面神经修复前后多个时间点运动皮层激活变化的研究。发现的皮层功能重组可能表明中枢神经系统的潜在治疗靶点用于辅助治疗，例如重复经颅磁刺激，以进一步改善功能恢复。