Department of Clinical Neurophysiology and Epilepsies, Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom.
Epilepsia. 2012 May;53(5):840-9. doi: 10.1111/j.1528-1167.2012.03424.x. Epub 2012 Feb 23.
To better understand the nature of the focal spike-wave discharges (FSWDs) and focally led generalized spike-wave discharges (GSWDs) in typical childhood absence epilepsy (CAE) and by implication their nosologic and taxonomic significance.
Twenty-four abnormal video-electroencephalography (EEG) studies from 13 consecutive children with CAE and good response to appropriate antiepileptic drugs (AEDs) were analyzed. We studied the association between the topography of absence onset and the ictal automatisms, and the topographic correlation between FSWDs and GSWDs and their respective behavior during hyperventilation and the different states of phasic and nonphasic non-rapid eye movement (NREM) sleep. GSWDs were considered as of "focal" onset if a lead-in could be visibly recognized at a paper speed of 60 mm/s, and were classified by their topography.
(1) Multifocal absences occurred in 10 children; anterior onset was noted in 81 absences (73.6%) from 12 children and posterior in 18 (16.4%) from 7 children; there was no association between topography of absence onset and ictal automatisms; (2) FSWDs occurred in 85% of children and were multifocal in 73% of them; 85% of FSWDs were anterior and 14% posterior; (3) there was good topographic association between FSWDs and the leading spike of GSWDs of "focal" onset in all children with FSWDs; (4) both FSWDs and GSWDs increased during hyperventilation; (5) FSWDs occurred mainly during noncyclical NREM sleep and during periods of reduced vigilance of cyclical NREM sleep, whereas GSWDs occurred during the periods of enhanced vigilance of NREM sleep; GSWDs occurred significantly more frequently than FSWDs at the transition from reduced to enhanced vigilance of NREM sleep.
Our findings suggest that in CAE focal EEG paroxysms reflect a system of multifocal nonlocalizing electrically unstable cortical areas that under the facilitatory influence of exogenous or endogenous factors like sleep instability can foster a corticothalamic response of sufficient strength to generate 3-Hz GSWDs that are conditionally sustainable and potentially ictal. FSWDs can be viewed as incomplete forms of the GSWDs; together they define the EEG identity of idiopathic "generalized" epileptogenesis.
更好地了解典型儿童失神癫痫（CAE）中局灶性棘波放电（FSWDs）和局灶性引导的泛化棘波放电（GSWDs）的性质，并暗示其分类学和分类学意义。
对 13 例连续 CAE 患儿的 24 例异常视频-脑电图（EEG）研究和对适当抗癫痫药物（AED）反应良好的患儿进行了分析。我们研究了失神发作起始的拓扑结构与发作性自动症之间的关系，以及 FSWD 和 GSWD 的拓扑相关性，以及它们在过度通气和不同相和非相非快速眼动（NREM）睡眠状态下的行为。如果在 60mm/s 的纸速下可以明显识别出导联，则将 GSWD 视为“局灶性”起始，并按其拓扑结构进行分类。
（1）10 例患儿出现多灶性失神；12 例患儿中有 81 例（73.6%）起始于前侧，7 例患儿中有 18 例（16.4%）起始于后侧；失神发作起始的拓扑结构与发作性自动症之间无相关性；（2）85%的患儿出现 FSWD，其中 73%为多灶性；85%的 FSWD 在前侧，14%在后侧；（3）在所有有 FSWD 的患儿中，FSWD 与“局灶性”起始的 GSWD 的主导棘波之间存在良好的拓扑关联；（4）在过度通气期间，FSWD 和 GSWD 均增加；（5）FSWD 主要发生在非周期性 NREM 睡眠期间和周期性 NREM 睡眠警觉性降低期间，而 GSWD 发生在 NREM 睡眠警觉性增强期间；在从 NREM 睡眠警觉性降低到增强的转变过程中，GSWD 比 FSWD 更频繁地发生。
我们的发现表明，在 CAE 中，局灶性 EEG 发作反映了一个多灶性非局部化电不稳定皮质区域的系统，在外源性或内源性因素（如睡眠不稳定）的促进作用下，可以产生足够强度的皮质丘脑反应，从而产生条件可持续性和潜在的发作性 3Hz GSWD。FSWD 可以被视为 GSWD 的不完全形式；它们共同定义了特发性“全身性”癫痫发生的 EEG 特征。
