Zumsteg Dominik, Lozano Andres M, Wennberg Richard A
Krembil Neuroscience Centre, Toronto Western Hospital, University of Toronto, 399 Bathurst Street, Toronto, Ont., Canada M5T 2S8.
Clin Neurophysiol. 2006 Jul;117(7):1602-9. doi: 10.1016/j.clinph.2006.04.008. Epub 2006 Jun 8.
We investigated the relation between anterior thalamic stimulation and the morphology of the evoked cerebral responses (CRs) using intracerebral depth electrodes in patients with intractable epilepsy undergoing deep brain stimulation (DBS) of the thalamus.
Monopolar cathodic and bipolar stimuli were delivered at a rate of 2 or 1 Hz to the anterior nucleus (AN) and the dorsomedian nucleus (DM) of two patients using the programmable stimulation device (Medtronic ITREL II) or a GRASS stimulation device (S12). CRs were recorded from depth or DBS electrodes, situated bilaterally in mesial temporal (hippocampus, both patients), lateral temporal (one patient), orbitofrontal (Brodmann area 11, one patient) and anterior thalamic sites (one patient).
The distribution and morphology of the CRs depended primarily on the site of stimulation within the anterior thalamic region. Overall, monopolar cathodic and bipolar stimulation of the AN elicited CRs mainly in ipsilateral mesial temporal cortical areas, whereas stimulation of the DM evoked high-amplitude CRs predominantly in ipsilateral orbitofrontal areas. The amplitude of the CR was positively related to the strength of the stimulus and generally higher with monopolar than with bipolar stimulation. The differences between CRs elicited during wakefulness or slow wave sleep were minimal.
The distribution of the CRs corresponded with the intracerebral pathways of the involved structures and the findings are in good accordance with those of our previous study investigating the sources of CRs using statistical non-parametric mapping of low resolution electromagnetic tomography (LORETA) values.
Our findings indicate a certain degree of point-to-point specificity within the thalamocortical circuitry, which may make optimal localization of DBS electrodes important in patients with epilepsy.
我们使用脑深部电极，对接受丘脑深部脑刺激（DBS）治疗的难治性癫痫患者，研究丘脑前核刺激与诱发脑反应（CRs）形态之间的关系。
使用可编程刺激装置（美敦力ITREL II）或GRASS刺激装置（S12），以2或1 Hz的频率，对两名患者的前核（AN）和背内侧核（DM）进行单极阴极和双极刺激。从双侧位于内侧颞叶（海马，两名患者）、外侧颞叶（一名患者）、眶额部（布罗德曼区11，一名患者）和丘脑前部位（一名患者）的深部或DBS电极记录CRs。
CRs的分布和形态主要取决于丘脑前区的刺激部位。总体而言，对AN进行单极阴极和双极刺激主要在同侧内侧颞叶皮质区域诱发CRs，而对DM的刺激则主要在同侧眶额部区域诱发高振幅CRs。CR的振幅与刺激强度呈正相关，单极刺激时通常比双极刺激时更高。清醒或慢波睡眠期间诱发的CRs之间差异最小。
CRs的分布与所涉及结构的脑内通路相对应，这些发现与我们之前使用低分辨率电磁断层扫描（LORETA）值的统计非参数映射研究CRs来源的研究结果高度一致。
我们的研究结果表明丘脑皮质回路内存在一定程度的点对点特异性，这可能使DBS电极的最佳定位对癫痫患者很重要。
