N30 and the effect of explorative finger movements:: a model of the contribution of the motor cortex to early somatosensory potentials
N30 and the effect of explorative finger movements:: a model of the contribution of the motor cortex to early somatosensory potentials
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DOI：
10.1016/s1388-2457(99)00092-9
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发表时间：
1999-09-01
影响因子：
4.7
通讯作者：
Silny, J
中科院分区：
文献类型：
--
作者：
Waberski, TD;Buchner, H;Silny, J
目的：正中神经体感诱发电位（SEP）中N30电位的来源以前曾被归因于中枢前起源（运动皮质或补充运动区，SMA）或位于中枢后的发生器（体感皮质）。这种归因是由病变研究的结果，在病理条件下的潜在行为，和偶极子源定位内的球形体积conductor models.Methods：本研究应用偶极子源定位和电流密度重建内的个人逼真形状的头部模型正中神经SEP在探索手指运动。与刺激手运动相关的SEP显示N20振幅轻微降低，额叶N30和顶叶P27振幅明显降低，在25 ms左右表现出残留的额叶负波，脑干P14保持不变。不同SEP的映射（非刺激手的运动减去刺激手的运动）显示了刺激后30 ms左右最大的双极场模式。在10名正常受试者中的8名中，N30和gN30（减法数据）源都位于中央前回内，比位于中央后的N20更靠中间。两个科目，相反，在这个时间范围内，而后中央本地化的来源。皮质SEP源的模型介绍，解释数据与以前描述的偶极子定位的结果，并从病变的研究和看到在motor diseases.Conclusions的改变：结果提供了证据的前中央N30发电机，主要是切向定向，位于运动皮层内，而没有来源被检测到其他地方。有人建议，在30毫秒的时间范围内探索手指运动的“门控”效应的机制主要出现在运动皮层。(C)1999爱思唯尔科学爱尔兰有限公司保留所有权利。
Objectives: The source of the N30 potential in the median nerve somatosensory evoked potentials (SEP) has been previously attributed to a pre-central origin (motor cortex or the supplementary motor area, SMA) or a post-central located generator (somatosensory cortex). This attribution was made from results of lesion studies, the behavior of the potential under pathological conditions, and dipole source localization within spherical volume conductor models.Methods: The present study applied dipole source localization and current density reconstruction within individual realistically shaped head models to median nerve SEPs obtained during explorative finger movements.Results: The SEPs associated with movement of the stimulated hand showed a minor reduction of the N20 amplitude and a markedly reduced amplitude for the frontal N30 and parietal P27, exhibiting a residual frontal negativity around 25 ms, The brain-stem P14 remained unchanged. Mapping of the different SEPs (movement of the non-stimulated hand minus movement of the stimulated hand) showed a bipolar field pattern with a maximum around 30 ms post-stimulus. In eight out of ten normal subjects, both the N30 and the gN30 (subtraction data) sources resided within the pre-central gyrus, more medially than the post-centrally located N20. Two subjects, in contrast, showed rather post-centrally localized sources in this time range. A model of the cortical SEP sources is introduced, explaining the data with respect to previously described findings of dipole localization, and from lesion studies and the alterations seen in motor diseases.Conclusions: The results provide evidence for a pre-central N30 generator, predominantly tangentially oriented, located within the motor cortex, while no sources were detected elsewhere. It is suggested that the mechanisms underlying the 'gating' effect during explorative finger movements in the 30 ms time range predominantly arise in the motor cortex. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.