Tanaka S
Department of Pediatrics, Nagasaki University School of Medicine.
No To Hattatsu. 1993 Nov;25(6):508-14.
To estimate the primary focus in 17 epileptic children with multifocal spikes, simultaneous averaging of spikes in 16 channels was performed. At first, EEG was recorded on EEG-video monitoring tape. Then, the computer sampled the data every 5 msec through an A-D converter, and stored the corresponding digital values. We used the top of the spike as a trigger point, and averaged 7 to 50 spikes in each lead. The primary focus and areas propagated from it were determined from the latency between the averaged spikes in different leads. We defined multiple foci when morphologically different averaged spikes were independently present in different leads. The averaging method could narrow the areas with spike discharges in 16 of 17 patients, and define a single focus in 6 patients. Furthermore, the single or unilateral foci in averaged data were compatible with the site estimated from lateralizing signs, such as lateral version of head and eyes in 3 of 8 patients. The other 5 patients showed independent bilateral foci, one of whom received focal resection of right anterior frontal lobe which was responsible for ictal symptoms and seizure discharges. Since then, seizures and right frontal epileptic discharges have not been observed but the spikes in left anterior frontal lobe have been left. These findings suggest that averaging of epileptic discharges is useful for determination of primary focus and for differentiation of true multiple foci from secondary propagation.
为评估17例有多灶性棘波的癫痫患儿的主要病灶，对16个通道的棘波进行了同步平均。首先，在脑电图-视频监测磁带上记录脑电图。然后，计算机通过A-D转换器每5毫秒对数据进行采样，并存储相应的数字值。我们将棘波的顶点作为触发点，对每个导联中的7至50个棘波进行平均。根据不同导联中平均棘波之间的潜伏期确定主要病灶及其传播区域。当形态不同的平均棘波独立出现在不同导联时，我们定义为多个病灶。平均法可使17例患者中的16例棘波放电区域变窄，并确定6例患者的单个病灶。此外，平均数据中的单个或单侧病灶与根据如头和眼的侧转等定侧体征估计的部位相符，8例患者中有3例如此。另外5例患者显示独立的双侧病灶，其中1例接受了右侧额前叶病灶切除术，该病灶导致发作症状和癫痫放电。自那以后，未观察到发作和右侧额叶癫痫放电，但左侧额前叶仍有棘波。这些发现表明，癫痫放电的平均法有助于确定主要病灶，并有助于将真正的多灶性与继发性传播区分开来。
