Rostro-caudal TMS mapping of immediate transcranial evoked potentials reveals a pericentral crescendo-decrescendo pattern

IF 4.5 2区医学 Q1 NEUROIMAGING

NeuroImage Pub Date : 2025-09-06 DOI:10.1016/j.neuroimage.2025.121446

Marten Nuyts , Mikkel Malling Beck , Agata Banach , Axel Thielscher , Raf Meesen , Leo Tomasevic , Hartwig Roman Siebner , Lasse Christiansen

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引用次数: 0

Abstract

Background

We recently demonstrated that single-pulse TMS of the primary sensorimotor hand area (SM1_HAND) elicits an immediate transcranial evoked potential (iTEP). This iTEP response appears within 2–8 ms post-TMS, featuring high-frequency peaks superimposed on a slow positive wave. Here, we used a linear TMS-EEG mapping approach to characterize the rostro-caudal iTEP expression and compared it to that of motor-evoked potentials (MEPs).

Methods

In 15 healthy young volunteers (9 females), we identified the iTEP hotspot in left SM1_HAND. We applied single biphasic TMS pulses at an intensity of 110 % of resting motor threshold over six cortical sites along a rostro-caudal axis (2 cm rostral to 3 cm caudal to the SM1_HAND hotspot). We analyzed site-specific iTEP and MEP responses.

Results

iTEP magnitude decreased rostrally and caudally from the SM1_HAND hotspot. MEPs exhibited a similar rostro-caudal crescendo-decrescendo pattern. While iTEP and MEP response profiles were similar, normalized iTEP amplitudes decayed less rapidly at the first postcentral site.

Discussion

These findings support the idea that pericentral iTEPs reflect a direct response signature of the pericentral cortex, possibly involving a synchronized TMS-induced excitation of cortical pyramidal tract neurons. Similar but non-identical rostro-caudal patterns suggest that iTEPs and MEPs may arise from overlapping but distinct neuronal populations.

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直接经颅诱发电位的经颅磁刺激图显示一个中央周围渐强-渐弱模式

我们最近证明了单脉冲经颅磁刺激对初级感觉运动手区（SM1HAND）可引起立即经颅诱发电位（iTEP）。这种iTEP反应出现在经颅磁刺激后的2-8 ms内，其特征是高频峰叠加在慢正波上。在这里，我们使用线性TMS-EEG映射方法来表征iTEP的背尾表达，并将其与运动诱发电位（MEPs）进行比较。方法在15名健康青年志愿者（9名女性）中，我们确定了左SM1HAND的iTEP热点。我们在沿背尾轴（SM1HAND热点的背侧2厘米至尾侧3厘米）的6个皮质部位施加单双相TMS脉冲，强度为静息运动阈值的110%。我们分析了特定地点的iTEP和MEP响应。结果在SM1HAND热点处，侧侧和侧侧sitep强度均减小。MEPs表现出类似的直立-尾端渐强-渐弱模式。虽然iTEP和MEP的响应曲线相似，但标准化iTEP振幅在第一个中心后位点的衰减速度较慢。这些发现支持了这样一种观点，即中央周围iTEPs反映了中央周围皮层的直接反应特征，可能涉及tms诱导的皮质锥体束神经元的同步兴奋。类似但不相同的背尾模式表明itep和mep可能来自重叠但不同的神经元群。

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

NeuroImage 医学-核医学

CiteScore

11.30

自引率

10.50%

发文量

809

审稿时长

63 days

期刊介绍： NeuroImage, a Journal of Brain Function provides a vehicle for communicating important advances in acquiring, analyzing, and modelling neuroimaging data and in applying these techniques to the study of structure-function and brain-behavior relationships. Though the emphasis is on the macroscopic level of human brain organization, meso-and microscopic neuroimaging across all species will be considered if informative for understanding the aforementioned relationships.