Department of Pediatrics, The University of Chicago, Chicago, Illinois 60637-1470, USA.
J Clin Neurophysiol. 2010 Dec;27(6):458-64. doi: 10.1097/WNP.0b013e3181fdf8e5.
Epileptiform activity in the EEG is frequently characterized by rhythmic, correlated patterns or synchronized bursts. Long-range temporal correlations (LRTC) are described by power law scaling of the autocorrelation function and have been observed in scalp and intracranial EEG recordings. Synchronous large-amplitude bursts (also called neuronal avalanches) have been observed in local field potentials both in vitro and in vivo. This article explores the presence of neuronal avalanches in scalp and intracranial EEG in the context of LRTC. Results indicate that both scalp and intracranial EEG show LRTC, with larger scaling exponents in scalp recordings than intracranial. A subset of analyzed recordings also show avalanche behavior, indicating that avalanches may be associated with LRTC. Artificial test signals reveal a linear relationship between the scaling exponent measured by detrended fluctuation analysis and the exponent of the avalanche size distribution. Analysis and evaluation of simulated data reveal that preprocessing of EEG (squaring the signal or applying a filter) affect the ability of detrended fluctuation analysis to reliably measure LRTC.
脑电图中的癫痫样活动通常表现为有节律、相关的模式或同步爆发。长程时间相关性（LRTC）通过自相关函数的幂律标度来描述，并且已经在头皮和颅内脑电图记录中观察到。在体外和体内的局部场电位中也观察到同步的大振幅爆发（也称为神经元瀑流）。本文探讨了在 LRTC 背景下头皮和颅内 EEG 中神经元瀑流的存在。结果表明，头皮和颅内 EEG 都表现出 LRTC，头皮记录的标度指数大于颅内记录。分析的记录中有一部分也表现出瀑流行为，表明瀑流可能与 LRTC 相关。人工测试信号表明，去趋势波动分析测量的标度指数与瀑流大小分布的指数之间存在线性关系。对模拟数据的分析和评估表明，脑电图的预处理（对信号平方或应用滤波器）会影响去趋势波动分析可靠测量 LRTC 的能力。
