Background

Vagal nerve stimulation (VNS) is widely used as an auxiliary treatment for patients with intractable epilepsy. Up to now, the therapeutic mechanisms remain elusive, and no surgical prediction criteria has been proposed.

Methods

In this study, the resting-state functional magnetic resonance imaging (rs-fMRI) was chosen to explore aberrant intrinsic brain activity and functional connections in 14 epilepsy patients with VNS stimulators between March 2019 and April 2019. Seven patients who ≥ 50 % seizure reduction was defined as responders, and seven non-responders. All patients had got rs-fMRI scan before and after operation. The hippocampal - thalamic connections (hippocampal and thalamus as regions of interest) were detected to evaluate the diversity in all 14 patients and seven responders with stimulation at 0, 0.5, 1.0, and 1.5 mA. The hippocampal-thalamic connections before operation were also examined between responders and non-responders.

Results

The preoperative left hippocampal - left thalamic connections and left hippocampal - right thalamic connections in responders were lower than those in non-responders (p < 0.05). While, there was no significant difference in hippocampal - thalamic connections in all epilepsy patients or responders with different current intensities (p > 0.05).

Conclusions

VNS may be more suitable for patients with lower left hippocampal - left thalamic connections and/or left hippocampal - right thalamic connections. The current intensity ≤ 1.5 mA and stimulation time ≤ 3 months may not cause significant changes in hippocampal-thalamic functional connectivity.

中文翻译：

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迷走神经刺激对癫痫患者海马-丘脑功能连接的影响。

背景

迷走神经刺激（VNS）被广泛用作顽固性癫痫患者的辅助治疗。到目前为止，治疗机制仍然难以捉摸，也没有提出手术预测标准。

方法

在本研究中，2019 年 3 月至 2019 年 4 月期间，14 名使用 VNS 刺激器的癫痫患者选择静息状态功能磁共振成像 (rs-fMRI) 来探索异常的内在大脑活动和功能连接。 7 名癫痫发作减少 ≥ 50 % 的患者被定义为响应者和七名无响应者。所有患者术前术后均行rs-fMRI扫描。检测海马 - 丘脑连接（海马和丘脑作为感兴趣区域）以评估所有 14 名患者和 7 名响应者的多样性，刺激电流为 0、0.5、1.0 和 1.5 mA。还检查了反应者和非反应者之间的手术前海马 - 丘脑连接。

结果

有反应者术前左海马-左丘脑连接和左海马-右丘脑连接低于无反应者（p < 0.05）。同时，所有癫痫患者或不同电流强度的反应者的海马 - 丘脑连接没有显着差异（p > 0.05）。

结论

VNS 可能更适合左下海马 - 左丘脑连接和/或左海马 - 右丘脑连接的患者。电流强度 ≤ 1.5 mA 和刺激时间 ≤ 3 个月可能不会引起海马-丘脑功能连接的显着变化。