Functional connectivity in human cortical motor system:: a cortico-cortical evoked potential study
Functional connectivity in human cortical motor system:: a cortico-cortical evoked potential study
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DOI：
10.1093/brain/awl257
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发表时间：
2007-01-01
期刊：
影响因子：
14.5
通讯作者：
Luders, Hans O.
中科院分区：
文献类型：
--
作者：
Matsumoto, Riki;Nair, Dileep R.;Luders, Hans O.
为了了解运动系统的复杂功能组织，了解各个运动区域之间的解剖和功能连接是至关重要的。在临床上，这些皮质-皮质连接的知识是很重要的，以了解癫痫放电的快速蔓延，通过网络潜在的发作运动表现。然而，在人类中，神经元在体内连接的知识是有限的。我们最近报道了一种新的方法，“皮质-皮质诱发电位（CCEP）”，通过硬膜下电极刺激大脑的一部分，并记录皮层诱发电位，通过神经元投射从皮层的远侧区域发出，来电跟踪皮质-皮质连接。我们应用CCEP方法研究了外侧运动皮层[LMCx;感觉运动（SM）和外侧运动前区]和内侧运动皮层[MMCx;补充运动区（SMA），前SMA和足SM]之间的体内皮质-皮质连接。7例顽固性部分性癫痫患者进行了研究。这些患者长期植入硬膜下电极，覆盖部分外侧和内侧额叶区域。作为常规术前评价的一部分，通过硬膜下电极的电刺激进行全面皮质标测，并通过MRI配准确定硬膜下电极的精确定位。向MMCx（7名患者）和LMCx（4名患者）提供单脉冲电刺激，并通过分别对LMCx和MMCx的皮质电图取平均值来记录与刺激时间锁定的CCEP。当刺激MMCx并从LMCx记录时观察到短潜伏期CCEP（平均潜伏期：21.6 ms，范围：9-47 ms），当刺激LMCx并从MMCx记录时观察到短潜伏期CCEP（平均潜伏期：29.4 ms，范围：11-57 ms）。在这些刺激位点的位置和CCEP响应沿着的rostrocaudal轴方面，回归分析揭示了一致的刺激位点和最大CCEP刺激MMCx和LMCx之间的相关性。在功能上，刺激MMCx中的阳性运动区在LMCx中的躯体位置同源区域引起CCEP（71%）。刺激LMCx后，在MMCx（82%）中观察到相同的结果。在通过刺激MMCx和LMCx研究双向连接的四名受试者中，在大多数连接中观察到互惠性（78-94%）。总之，本研究证明了人类运动皮质-皮质网络连接（i）LMCx和MMCx的解剖学同源区域，沿着吻尾侧认知运动梯度;和（ii）LMCx和MMCx中的躯体位置同源区域，以相互的方式。
In order to understand the complex functional organization of the motor system, it is essential to know the anatomical and functional connectivity among individual motor areas. Clinically, knowledge of these cortico-cortical connections is important to understand the rapid spread of epileptic discharges through the network underlying ictal motor manifestation. In humans, however, knowledge of neuronal in vivo connectivity has been limited. We recently reported a new method, 'cortico-cortical evoked potential (CCEP)', to electrically track the cortico-cortical connections by stimulating a part of the brain through subdural electrodes and recording the cortical evoked potentials that emanate from a distant region of the cortex via neuronal projections. We applied the CCEP methodology to investigate in vivo cortico-cortical connections between the lateral motor cortex [LMCx; sensorimotor (SM) and lateral premotor areas] and the medial motor cortex [MMCx; supplementary motor area proper (SMA), pre-SMA and foot SM]. Seven patients with intractable partial epilepsy were studied. These patients had chronic implantation of subdural electrodes covering part of the lateral and medial frontal areas. As a part of the routine pre-surgical evaluation, comprehensive cortical mapping was performed by electrical stimulation of the subdural electrodes, and the precise localization of the subdural electrodes was defined by MRI co-registration. Single-pulse electrical stimuli were delivered to MMCx (7 patients) and LMCx (4), and CCEPs time-locked to the stimuli were recorded by averaging electrocorticograms from LMCx and MMCx, respectively. Short-latency CCEPs were observed when stimulating MMCx and recording from LMCx (mean latency: 21.6 ms, range: 9-47 ms) and vice versa when stimulating LMCx and recording from MMCx (mean latency: 29.4 ms, range: 11-57 ms). In terms of the location of these stimulus sites and CCEP responses along the rostrocaudal axis, regression analysis revealed a consistent correlation between the sites of stimulation and maximum CCEP for stimulation of both MMCx and LMCx. Functionally, stimulation of the positive motor areas in MMCx elicited CCEPs at the somatotopically homologous regions in LMCx (71%). The same findings were observed in MMCx (82%) upon stimulation of LMCx. In four subjects in whom bi-directional connectivity was investigated by stimulating both MMCx and LMCx, reciprocality was observed in the majority of connections (78-94%). In conclusion, the present study demonstrated a human motor cortico-cortical network connecting (i) anatomically homologous areas of LMCx and MMCx along the rostrocaudal cognitive-motor gradient; and (ii) somatotopically homologous regions in LMCx and MMCx in a reciprocal manner.