Epidural magnetic stimulation of the motor cortex using an implantable coil

IF 7.6 1区医学 Q1 CLINICAL NEUROLOGY

Brain Stimulation Pub Date : 2024-09-01 DOI:10.1016/j.brs.2024.10.001

Kyeong Jae Lee , Jae-Won Jang , June Sic Kim , Sohee Kim

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引用次数: 0

Abstract

Background

Magnetic stimulation, represented by transcranial magnetic stimulation (TMS), is used to treat neurological diseases. Various strategies have been explored to improve the spatial resolution of magnetic stimulation. While reducing the coil size is the most impactful approach for increasing the spatial resolution, it decreases the stimulation intensity and increases heat generation.

Objective

We aim to demonstrate the feasibility of magnetic stimulation using an epidurally implanted millimeter-sized coil and that it does not damage the cortical tissue via heating even when a repetitive stimulation protocol is used.

Methods

A coil with dimensions of 3.5 × 3.5 × 2.6 mm³ was epidurally implanted on the left motor cortex of rat, corresponding to the right hindlimb. Before and after epidural magnetic stimulation using a quadripulse stimulation (QPS) protocol, changes in the amplitude of motor evoked potentials (MEPs) elicited by a TMS coil were compared.

Results

The experimental group showed an average increase of 88 % in MEP amplitude in the right hindlimb after QPS, whereas the MEP amplitude in the left hindlimb increased by 18 % on average. The control group showed no significant change in MEP amplitude after QPS in either hindlimb. The temperature changes at the coil surface remained <2 °C during repetitive stimulation, meeting the thermal safety limit for implantable medical devices.

Conclusion

These results demonstrate the feasibility of epidural magnetic stimulation using an implantable coil to induce neuromodulation effects. This novel method is expected to be a promising alternative for focal magnetic stimulation with an improved spatial resolution and lowered stimulus current than previous magnetic stimulation methods.

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使用植入式线圈对运动皮层进行硬膜外磁刺激

背景：以经颅磁刺激为代表的磁刺激被用于治疗神经系统疾病。人们探索了各种策略来提高磁刺激的空间分辨率。虽然缩小线圈尺寸是提高空间分辨率的最有效方法，但它会降低刺激强度并增加发热量：我们旨在证明使用硬膜外植入毫米级线圈进行磁刺激的可行性，并证明即使使用重复刺激方案，也不会因发热而损害皮质组织：方法：将一个尺寸为 3.5 × 3.5 × 2.6 mm3 的线圈经硬膜外植入大鼠左侧运动皮层（相当于右后肢）。在使用四脉冲刺激（QPS）方案进行硬膜外磁刺激前后，比较了经颅磁刺激（TMS）线圈诱发的运动诱发电位（MEPs）振幅的变化：实验组在 QPS 后右侧后肢的运动诱发电位振幅平均增加了 88%，而左侧后肢的运动诱发电位振幅平均增加了 18%。对照组的任一后肢在 QPS 后 MEP 振幅均无明显变化。线圈表面的温度变化仍为结论：这些结果证明了使用植入式线圈进行硬膜外磁刺激以诱导神经调节效应的可行性。与以前的磁刺激方法相比，这种新方法具有更高的空间分辨率和更低的刺激电流，有望成为局灶磁刺激的替代方法。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Brain Stimulation 医学-临床神经学

CiteScore

13.10

自引率

9.10%

发文量

256

审稿时长

72 days

期刊介绍： Brain Stimulation publishes on the entire field of brain stimulation, including noninvasive and invasive techniques and technologies that alter brain function through the use of electrical, magnetic, radiowave, or focally targeted pharmacologic stimulation. Brain Stimulation aims to be the premier journal for publication of original research in the field of neuromodulation. The journal includes: a) Original articles; b) Short Communications; c) Invited and original reviews; d) Technology and methodological perspectives (reviews of new devices, description of new methods, etc.); and e) Letters to the Editor. Special issues of the journal will be considered based on scientific merit.