Clinical Neurophysiology Division, Department of Neurology, Boston, MA, USA.
Clin Neurophysiol. 2010 May;121(5):784-92. doi: 10.1016/j.clinph.2010.01.002. Epub 2010 Feb 8.
To investigate the effects of EEG suppression and anesthetics on variability of electrical stimulus thresholds during functional cortical motor mapping, and the possible influences of age, lesion location and pathology.
Multivariate regression analysis was performed to study these relationships in 60 cases of successful mapping using the monopolar multipulse train technique.
An increase in the length of EEG "flats" by 1s produced an increase in stimulus threshold by 1.08 mA (p=0.0004). Administration of TIVA (total intravenous anesthesia) or inhalational agents produced an additional increase in threshold by 1.27 mA (p=0.38) or 4.84 mA (p=0.04) respectively, when compared to awake patients.
Depth of cortical suppression impacts the stimulus thresholds. The effect of TIVA on thresholds is mediated by its effect on cortical excitability. The effects of inhalational agents on thresholds involve their influence on excitability at other levels of the neuraxis.
The study represents an important step towards building a predictive model for stimulus thresholds. It also improves our understanding of the relationships of anesthetics, EEG burst suppression pattern and age with cortical excitability.
研究脑电图抑制和麻醉对功能皮质运动映射过程中电刺激阈值变异性的影响，以及年龄、病变部位和病变病理的可能影响。
采用单极多脉冲技术对 60 例成功映射病例进行多元回归分析，研究这些关系。
脑电图“平坦”长度增加 1s，刺激阈值增加 1.08mA（p=0.0004）。与清醒患者相比，使用 TIVA（全静脉麻醉）或吸入性药物分别使阈值增加 1.27mA（p=0.38）或 4.84mA（p=0.04）。
皮质抑制的深度影响刺激阈值。TIVA 对阈值的影响是通过其对皮质兴奋性的影响介导的。吸入性药物对阈值的影响涉及它们对神经轴其他水平兴奋性的影响。
该研究是朝着建立刺激阈值预测模型迈出的重要一步。它还提高了我们对麻醉、脑电图爆发抑制模式和年龄与皮质兴奋性关系的理解。
