Carbon M, Wübbeler G, Trahms L, Curio G
Neurophysics Group, Department of Neurology, Klinikum Benjamin Franklin, Freie Universität, Berlin, Germany.
Neurosci Lett. 2000 Jun 30;287(3):227-30. doi: 10.1016/s0304-3940(00)01192-7.
Self-paced hyperventilation (HV) induces slow cerebral magnetic field changes which were monitored and mapped continuously over 15 min using 49-channel DC-coupled ('direct current') magnetoencephalography (DC-MEG) based on a modulation technique. In nine/nine healthy subjects HV caused an increase (range: 1.1-6.2 pT) of the mean global DC-MEG field strength which slowly decayed after HV termination (mean time constant: 2 min). The complex HV-related field patterns were distinctly different from mainly dipolar somatosensory evoked field maps (N20m) in four/four subjects. Thus, current sources in the primary somatosensory cortex need not regularly dominate DC-field changes as had been previously considered. Rather, DC-MEG enabled the monitoring of a widely distributed HV-induced enhanced cortical excitability which may serve as model to study epileptic or post-anoxic cerebral hyperexcitability.
自主呼吸过度换气（HV）会诱发缓慢的脑磁场变化，基于一种调制技术，使用49通道直流耦合（“直流电”）脑磁图（DC-MEG）在15分钟内对这些变化进行连续监测和映射。在9名/9名健康受试者中，HV导致平均全脑DC-MEG场强增加（范围：1.1 - 6.2皮特斯拉），在HV终止后该场强缓慢衰减（平均时间常数：2分钟）。在4名/4名受试者中，与HV相关的复杂场模式与主要为偶极体感诱发电场图（N20m）明显不同。因此，初级体感皮层中的电流源不一定像之前认为的那样经常主导DC场变化。相反，DC-MEG能够监测广泛分布的HV诱导的皮层兴奋性增强，这可以作为研究癫痫或缺氧后脑过度兴奋性的模型。
