Ikeda A, Taki W, Kunieda T, Terada K, Mikuni N, Nagamine T, Yazawa S, Ohara S, Hori T, Kaji R, Kimura J, Shibasaki H
Department of Brain Pathophysiology, Kyoto University School of Medicine, Japan.
Brain. 1999 May;122 ( Pt 5):827-38. doi: 10.1093/brain/122.5.827.
In order to clarify further the characteristics of ictal direct current (DC) shifts in human epilepsy, we investigated them by subdural and scalp recording in six and three patients, respectively, both having mainly neocortical lobe epilepsy (five with frontal lobe epilepsy, two with parietal lobe epilepsy and two with temporal lobe epilepsy). By using subdural electrodes made of platinum, ictal DC shifts were observed in 85% of all the recorded seizures (89 seizures) among the six patients, and they were localized to just one or two electrodes at which the conventional initial ictal EEG change was also observed. They were closely accompanied by the electrodecremental pattern in all patients except for one in whom 1 Hz rhythmic activity was superimposed on clear negative slow shifts. Seizure control after resection of the cortex, including the area showing DC shifts, was favourable irrespective of histological diagnosis. Scalp-recorded ictal slow shifts were observed in 23% of all the recorded seizures (60 seizures) among the three patients. They were, like the subdurally recorded ones, mainly surface-negative in polarity, closely related to the electrodecremental pattern and consistent in their location. It seems that scalp-recorded DC shifts were detected particularly when seizures were clinically intense, while no slow shifts were observed in small seizures. It is concluded that at least subdurally recorded ictal slow shifts are clinically useful before epilepsy surgery to delineate more specifically an epileptogenic area as well as to further confirm the conventional initial ictal EEG change, and that scalp-recorded ictal slow shifts also have high specificity although their low sensitivity is to be taken into account.
为了进一步阐明人类癫痫发作期直流电（DC）变化的特征，我们分别对6例和3例主要为新皮质叶癫痫（5例额叶癫痫、2例顶叶癫痫和2例颞叶癫痫）患者进行了硬膜下和头皮记录来研究这些变化。通过使用铂制成的硬膜下电极，在6例患者记录的所有发作（89次发作）中，85%观察到发作期DC变化，且这些变化仅局限于一两个电极，在这些电极上也观察到了传统的发作起始期脑电图变化。除1例患者外，所有患者的发作期DC变化均紧密伴随电极减量模式，该例患者在明显的负向慢波变化上叠加有1Hz节律性活动。切除包括显示DC变化区域在内的皮质后，癫痫控制情况良好，与组织学诊断无关。在3例患者记录的所有发作（60次发作）中，23%观察到头皮记录的发作期慢波变化。与硬膜下记录的变化一样，它们主要为表面负极性，与电极减量模式密切相关且位置一致。似乎在临床发作强烈时尤其能检测到头皮记录的DC变化，而在小发作中未观察到慢波变化。结论是，至少硬膜下记录的发作期慢波变化在癫痫手术前在临床上有助于更精确地界定致痫区以及进一步确认传统的发作起始期脑电图变化，并且头皮记录的发作期慢波变化也具有高特异性，尽管其低敏感性也应予以考虑。
