Waterstraat Gunnar, Scheuermann Manuel, Curio Gabriel
Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Charité - University Medicine Berlin, Hindenburgdamm 30, 12203 Berlin, Germany.
Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Charité - University Medicine Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; Medizinische Ingenieurswissenschaft, Universität zu Lübeck, Ratzeburger Allee 160, 23563 Lübeck, Germany.
Clin Neurophysiol. 2016 Mar;127(3):1872-8. doi: 10.1016/j.clinph.2015.12.005. Epub 2015 Dec 15.
Somatosensory evoked potentials (SEPs) around 600 Hz ('σ-bursts') are correlates of cortical population spikes. Recently, single-trial σ-bursts were detected in human scalp EEG using 29-channel low-noise recordings in an electromagnetically shielded room. To achieve clinical applicability, this study aimed to establish a protocol using only 8 EEG channels in an unshielded environment and to quantify the variability of σ-bursts.
Median nerve SEPs were recorded in 10 healthy subjects using a custom-built low-noise EEG amplifier. A detection algorithm for single-trial σ-bursts was trained as combination of spatio-temporal filters and a non-linear classifier. The single-trial responses were probed for the presence of significant increases of amplitude and variability.
Single-trial σ-burst detection succeeded with Detection Rates and Positive Predictive Values above 80% in subjects with high SNR. A significant inter-trial variability in the amplitudes of early low-frequency SEPs and σ-bursts could be demonstrated.
Single-trial σ-bursts can be detected on scalp-EEG using only 8 EEG channels in an electromagnetically disturbed environment. The combination of dedicated hardware and detection algorithms allows quantifying and describing their variability.
The variability of population spikes in the human somatosensory cortex can be traced non-invasively in a clinical setting.
600Hz左右的体感诱发电位（SEPs，“σ爆发”）与皮质群体锋电位相关。最近，在电磁屏蔽室内使用29通道低噪声记录在人类头皮脑电图中检测到了单次试验的σ爆发。为了实现临床应用，本研究旨在建立一种在非屏蔽环境中仅使用8个脑电图通道的方案，并对σ爆发的变异性进行量化。
使用定制的低噪声脑电图放大器记录10名健康受试者的正中神经SEP。作为时空滤波器和非线性分类器的组合，训练了一种单次试验σ爆发的检测算法。对单次试验反应进行探测，以确定是否存在幅度和变异性的显著增加。
在高信噪比的受试者中，单次试验σ爆发检测成功，检测率和阳性预测值均高于80%。可以证明早期低频SEP和σ爆发的幅度在试验间存在显著变异性。
在电磁干扰环境中，仅使用8个脑电图通道就可以在头皮脑电图上检测到单次试验的σ爆发。专用硬件和检测算法的结合允许对其变异性进行量化和描述。
在临床环境中，可以通过非侵入性方法追踪人类体感皮质中群体锋电位的变异性。
