Ikeda A, Terada K, Mikuni N, Burgess R C, Comair Y, Taki W, Hamano T, Kimura J, Lüders H O, Shibasaki H
Department of Brain Pathophysiology, Kyoto University School of Medicine, Japan.
Epilepsia. 1996 Jul;37(7):662-74. doi: 10.1111/j.1528-1157.1996.tb00631.x.
Invasive ictal EEG recording is often necessary to delineate epileptogenic areas in patients with intractable partial epilepsy, but even intracranial ictal recordings often reveal ill-defined onset zones in neocortical epilepsy. We studied the physiologic significance of ictal direct current (DC) potentials recorded intracranially in human epilepsy.
We made intracranial ictal EEG recordings in three patients with intractable partial seizures arising from frontal, lateral temporal, and parietal neocortical areas by using closely spaced subdural electrodes (platinum in two patients and stainless steel in one patient) with both standard (1.5 Hz) and open (0.016 Hz) low-frequency filter (LFF) settings.
The initial ictal pattern was localized to two to nine subdural electrodes and characterized by very low voltage and high-frequency rhythmic activity ("electrodecremental pattern"). A slow-rising negative potential (DC potential) was seen in a slightly more restricted area (two to six electrodes) and occurred 1-10 s before the initial ictal EEG discharges in two patients.
These results agree with those of previous studies of ictal DC shifts in animals and suggest that ictal DC shifts may be helpful in delineating the epileptogenic area more precisely in human epilepsy.
对于难治性部分性癫痫患者，常需进行有创发作期脑电图记录以明确致痫区，但即使是颅内发作期记录，在新皮质癫痫中也常显示起始区不明确。我们研究了人类癫痫患者颅内记录到的发作期直流（DC）电位的生理意义。
我们使用间隔紧密的硬膜下电极（两名患者使用铂电极，一名患者使用不锈钢电极），在标准（1.5 Hz）和开放（0.016 Hz）低频滤波器（LFF）设置下，对三名分别起源于额叶、颞叶外侧和顶叶新皮质区域的难治性部分性发作患者进行颅内发作期脑电图记录。
最初的发作期模式局限于两到九个硬膜下电极，其特征为极低电压和高频节律性活动（“电极递减模式”）。在稍受限的区域（两到六个电极）可见缓慢上升的负电位（DC电位），两名患者中该电位在最初的发作期脑电图放电前1 - 10秒出现。
这些结果与先前动物发作期直流偏移的研究结果一致，提示发作期直流偏移可能有助于更精确地界定人类癫痫的致痫区。
