Prefrontal TMS produces smaller EEG responses than motor-cortex TMS:: implications for rTMS treatment in depression
Prefrontal TMS produces smaller EEG responses than motor-cortex TMS:: implications for rTMS treatment in depression
复制标题
DOI：
10.1007/s00213-005-2197-3
复制
发表时间：
2005-08-01
影响因子：
3.4
通讯作者：
Ilmoniemi, RJ
中科院分区：
文献类型：
--
作者：
Kähkönen, S;Komssi, S;Ilmoniemi, RJ
原理：抑郁症治疗期间前额叶重复经颅磁刺激（rTMS）的刺激强度通常是根据运动阈值（MT）来调整的。有证据表明，经颅磁刺激时，前额叶皮层的反应性低于运动皮层。然而，当使用其他刺激强度时，这种情况是否成立尚不清楚。我们研究了前额叶和运动皮层的tms诱发脑电图（EEG）反应的大小和形状是否存在差异。方法：以4种强度（右小指外展肌MT的60,80,100,120%）向6名受试者的左侧运动和前额叶皮层（通过磁共振图像识别的额叶中回）施加磁脉冲。同时用60个头皮电极记录脑电图。结果：反映皮层整体活动的全局平均场振幅（GMFAs）在前额叶经颅磁刺激后明显小于运动皮层经颅磁刺激后。运动区与前额叶皮质区GMFAs在各时段呈显著正相关（r(s)= 0.84, p < 0.01）。然而，当检查运动和前额叶皮层反应之间的相关性时，仅在80%和100%强度下发现显著的正相关。结论：本研究进一步证明了前额叶和运动皮层对经颅磁刺激有不同的反应性，但MT可用于确定抑郁症前额叶rTMS治疗的刺激强度，至少在运动阈值强度或接近运动阈值强度。
Rationale: The stimulus intensity of prefrontal repetitive transcranial magnetic stimulation (rTMS) during depression treatment is usually determined by adjusting it with respect to the motor threshold (MT). There is some evidence that reactivity of the prefrontal cortex to transcranial magnetic stimulation (TMS) is lower than that of the motor cortex at MT stimulation. However, it is unknown whether this is true when other stimulus intensities are used. We investigated whether the magnitude and shape of the overall TMS-evoked electroencephalographic (EEG) responses differ between prefrontal and motor cortices. Methods: Magnetic pulses to the left motor and prefrontal cortices (the middle frontal gyrus identified from magnetic resonance images) were delivered at four intensities (60, 80, 100, and 120% of MT of the right abductor digiti minimi muscle) for six subjects. Simultaneously, EEG was recorded with 60 scalp electrodes. Results: Global mean-field amplitudes (GMFAs) reflecting overall cortical activity were significantly smaller after prefrontal- than after motor-cortex TMS. A significant positive correlation (r(s)= 0.84, p < 0.01) was found between GMFAs of motor- and prefrontal-cortex TMS across the experiments. However, when correlation between the responses of motor and prefrontal cortices was examined, significant positive correlations were found at 80 and 100% intensities only. Conclusions: This study provides further evidence that the prefrontal and motor cortices have different reactivity to TMS, but the MT may be used for determining the stimulus intensity of prefrontal rTMS treatment in depression, at least at motor threshold intensities or near to it.