ABSTRACT

Objectives

The present study aimed to compare the effectiveness of different provocation tests used for the study of the ‘susceptibility to seizure’ by quantitative electroencephalography (EEG) analysis.

Methods

Eight subjects with a history of a seizure-like disturbed consciousness participated in this preliminary study. A routine EEG was carried out with photic stimulation (eyes closed and after eyes open) at the beginning of the investigation. Some days later, a sleep-deprived EEG was recorded with the same protocol. Selected epochs (in eyes closed condition) after the stimulations were analysed with Point(wise) Correlation Dimension (PD2i) and Synchronization Likelihood (SL) methods. The results were compared to those obtained by similar analysis of the resting state (control) epochs with Wilcoxon Signed Rank Test (p ≤ 0.05).

Results

In our study, significantly lower grand mean PD2i and higher delta SL values were found in sleep-deprived state after stimulation with eyes closed compared to the control. Our results indicated a lower-dimensional, hypersynchronous state of the brain as a consequence of these combined provocations.

Discussion

This may correspond to a possible ’preictal’ state of the brain. Accordingly, it is suggested that photic stimulation together with sleep deprivation seems to be more effective in provocation – especially when the stimulation was made with eyes closed.

摘要

目标

本研究旨在通过定量脑电图 (EEG) 分析比较用于研究“癫痫易感性”的不同激发试验的有效性。

方法

八名有癫痫样意识障碍病史的受试者参与了这项初步研究。在调查开始时，用光刺激（闭眼和睁眼后）进行常规脑电图。几天后，用相同的方案记录了睡眠剥夺的脑电图。用点（明智）相关维度（PD2i）和同步似然（SL）方法分析刺激后的选定时期（在闭眼条件下）。将结果与使用 Wilcoxon 符号秩检验 (p ≤ 0.05) 对静止状态（对照）时期进行类似分析获得的结果进行比较。

结果

在我们的研究中，与对照组相比，在闭眼刺激后睡眠剥夺状态下发现显着降低的总平均 PD2i 和更高的 delta SL 值。我们的结果表明，由于这些联合挑衅，大脑出现了低维、超同步状态。

讨论

这可能对应于大脑可能的“发作前”状态。因此，有人认为光刺激与睡眠剥夺似乎在激发方面更有效——尤其是在闭眼进行刺激时。