Kobayashi K, Ohtsuka Y, Oka E, Ohtahara S
Department of Child Neurology, Okayama University Medical School, Japan.
Electroencephalogr Clin Neurophysiol. 1992 Aug;83(2):93-103. doi: 10.1016/0013-4694(92)90022-a.
Estimation of interhemispheric small time differences (TDs) during spike-wave bursts in the EEG by coherence and phase analysis is useful for differentiation between primary bilateral synchrony (PBS) and secondary bilateral synchrony (SBS) in epilepsy. Because the previous method via Fast Fourier Transform needed long bursts for reliable analysis, a method using a 2-dimensional autoregressive model was newly developed to enable estimation of TDs even in 1.2 sec bursts, and applied to 19 epileptic patients with apparently bilaterally synchronous spike-wave bursts. At the onsets of bursts, estimated maximal TDs were 5.8 msec or less and inconsistent in leading hemispheres in 10 patients with a clinical diagnosis of idiopathic, cryptogenic or symptomatic generalized epilepsy indicating PBS, while the maximal TDs were 9.3-41.5 msec and consistent in leading in 7 patients with clinically symptomatic partial epilepsy and also in two with idiopathic and symptomatic generalized epilepsy suggesting SBS. Among 8 patients with bursts which suggested SBS and long enough for evaluation of intra-burst TD variation, TDs tended to disappear in the middle to end parts of the bursts in 5 cases, but not in the other 3, suggesting 2 different pathophysiological mechanisms in SBS.
通过相干性和相位分析估计脑电图中棘波-慢波暴发期间的半球间微小时间差（TDs），对于区分癫痫中的原发性双侧同步（PBS）和继发性双侧同步（SBS）很有用。由于先前通过快速傅里叶变换的方法需要长时间的暴发才能进行可靠分析，因此新开发了一种使用二维自回归模型的方法，即使在1.2秒的暴发中也能估计TDs，并将其应用于19例明显双侧同步棘波-慢波暴发的癫痫患者。在暴发开始时，10例临床诊断为特发性、隐源性或症状性全身性癫痫提示PBS的患者，估计的最大TDs为5.8毫秒或更小，且领先半球不一致，而7例临床症状性部分性癫痫患者以及2例特发性和症状性全身性癫痫提示SBS的患者，最大TDs为9.3 - 41.5毫秒且领先一致。在8例提示SBS且暴发时间足够长以评估暴发内TD变化的患者中，5例患者的TDs在暴发的中晚期倾向于消失，但其他3例则不然，这表明SBS存在两种不同的病理生理机制。
