da Silva Braga Aline Marques, Fujisao Elaine Keiko, Betting Luiz Eduardo
Departamento de Neurologia, Psiquiatria e Psicologia Faculdade de Medicina de Botucatu - UNESP - Univ Estadual Paulista, Brazil.
Departamento de Neurologia, Psiquiatria e Psicologia Faculdade de Medicina de Botucatu - UNESP - Univ Estadual Paulista, Brazil.
Epilepsy Res. 2014 Dec;108(10):1740-7. doi: 10.1016/j.eplepsyres.2014.09.004. Epub 2014 Sep 17.
Experimental evidence from animal models of the absence seizures suggests a focal source for the initiation of generalized spike-and-wave (GSW) discharges. Furthermore, clinical studies indicate that patients diagnosed with idiopathic generalized epilepsy (IGE) exhibit focal electroencephalographic abnormalities, which involve the thalamo-cortical circuitry. This circuitry is a key network that has been implicated in the initiation of generalized discharges, and may contribute to the pathophysiology of GSW discharges. Quantitative electroencephalogram (qEEG) analysis may be able to detect abnormalities associated with the initiation of GSW discharges. The objective of this study was to determine whether interictal GSW discharges exhibit focal characteristics using qEEG analysis. In this study, 75 EEG recordings from 64 patients were analyzed. All EEG recordings analyzed contained at least one GSW discharge. EEG recordings were obtained by a 22-channel recorder with electrodes positioned according to the international 10-20 system of electrode placement. EEG activity was recorded for 20 min including photic stimulation and hyperventilation. The EEG recordings were visually inspected, and the first unequivocally confirmed generalized spike was marked for each discharge. Three methods of source imaging analysis were applied: dipole source imaging (DSI), classical LORETA analysis recursively applied (CLARA), and equivalent dipole of independent components with cluster analysis. A total of 753 GSW discharges were identified and spatiotemporally analyzed. Source evaluation analysis using all three techniques revealed that the frontal lobe was the principal source of GSW discharges (70%), followed by the parietal and occipital lobes (14%), and the basal ganglia (12%). The main anatomical sources of GSW discharges were the anterior cingulate cortex (36%) and the medial frontal gyrus (23%). Source analysis did not reveal a common focal source of GSW discharges. However, there was a predominance of GSW discharges originating from the cingulate gyrus and the frontal lobe.
失神发作动物模型的实验证据表明，全身性棘慢波（GSW）放电起始于局灶性来源。此外，临床研究表明，被诊断为特发性全身性癫痫（IGE）的患者表现出局灶性脑电图异常，涉及丘脑 - 皮质回路。该回路是一个关键网络，与全身性放电的起始有关，可能导致GSW放电的病理生理学改变。定量脑电图（qEEG）分析或许能够检测出与GSW放电起始相关的异常。本研究的目的是使用qEEG分析确定发作间期GSW放电是否具有局灶性特征。在本研究中，分析了来自64名患者的75份脑电图记录。所有分析的脑电图记录均至少包含一次GSW放电。脑电图记录由一台22通道记录仪获取，电极根据国际10 - 20电极放置系统定位。记录脑电图活动20分钟，包括光刺激和过度换气。对脑电图记录进行目视检查，并为每次放电标记首个明确确认的全身性棘波。应用了三种源成像分析方法：偶极子源成像（DSI）、递归应用的经典LORETA分析（CLARA）以及独立成分等效偶极子与聚类分析。共识别出753次GSW放电并进行了时空分析。使用所有三种技术的源评估分析表明，额叶是GSW放电的主要来源（70%），其次是顶叶和枕叶（14%）以及基底神经节（12%）。GSW放电的主要解剖学来源是前扣带回皮质（36%）和额内侧回（23%）。源分析未揭示GSW放电的共同局灶性来源。然而，源自扣带回和额叶的GSW放电占主导。
