Halász Péter, Kelemen Anna, Clemens Béla, Saracz Judit, Rosdy Beáta, Rásonyi György, Szücs Anna
National Institute of Psychiatry and Neurology, Neurological Department, Budapest.
Ideggyogy Sz. 2005 Jan 20;58(1-2):21-31.
In this work the authors provide evidences for a unifying concept of the syndromes of benign focal childhood epilepsies, Landau-Kleffner syndrome, and electrical status epilepticus in sleep treating them as a spectrum of disorders with a common transient, age dependent, non lesional, genetically based epileptogenic abnormality, the nature of which is still not known. The electro-clinical features of these syndromes are congruent with the different degree involvement of the perisylvian cognitive network and with the involvement of the thalamo-cortical associative system of variable degree. These epilepsies are characterized by the abundance of regional epileptiform discharges in sharp contrast with the rare and in several cases lacking seizures. The nature and severity of interictal cognitive symptoms are closely related to localization within the network and amount of epileptic interictal discharges. Spike-wave discharges are attributed to an alternation of overexcitation (spikes) and overinhibition (waves). The recurrent overinhibition represented by the wave of the discharges may interfere with the continuous depolarization of the cells of a large population of neurons, which is a requirement of the overt seizures. The overinhibition also interfere with cognitive processes which are correlated with the continuous presence of the fast (gamma) activity, binding the required cortical areas. Hence the recurrent inhibition works against the existence of the binding fast frequency activity. This is the assumed reason for the co-existence of the relative lack of overt seizures and in the same time for the frequently observed epileptogenic cognitive deficit symptoms ("cognitive epilepsies"). The time course of these syndromes overlaps with important developmental milestones. The frequent epileptic discharges alters the evolution of the perisylvian network developing late after early childhood and is very vulnerable for any interference in this imprinting time for speech and other cognitive functions. This spectrum of disorders represents a type of age linked, mild to severe 'epileptic encephalopathy' limited to the perisylvian network, where the cognitive impairment is caused by epileptic discharges interfering with cognitive development.
在这项研究中，作者为儿童良性局灶性癫痫、Landau-Kleffner综合征和睡眠中癫痫性电持续状态的综合征统一概念提供了证据，将它们视为一系列具有共同的短暂性、年龄依赖性、非病灶性、基于遗传的致痫异常的疾病，其本质尚不清楚。这些综合征的电临床特征与颞叶周围认知网络的不同程度受累以及不同程度的丘脑-皮质联合系统受累相一致。这些癫痫的特征是大量的局灶性癫痫样放电，这与罕见且在某些情况下缺乏发作形成鲜明对比。发作间期认知症状的性质和严重程度与网络内的定位以及癫痫发作间期放电的数量密切相关。棘波放电归因于过度兴奋（棘波）和过度抑制（慢波）的交替。放电慢波所代表的反复过度抑制可能会干扰大量神经元细胞的持续去极化，而这是明显发作所必需的。过度抑制还会干扰与快速（γ）活动的持续存在相关的认知过程，而快速（γ）活动是连接所需皮质区域所必需的。因此，反复抑制不利于快速频率活动连接的存在。这是相对缺乏明显发作同时又频繁出现致痫性认知缺陷症状（“认知性癫痫”）的假定原因。这些综合征的病程与重要的发育里程碑重叠。频繁的癫痫放电会改变幼儿期后期发育的颞叶周围网络的发育，并且在这个语言和其他认知功能的印记期极易受到任何干扰。这种疾病谱代表了一种与年龄相关的、轻度至重度的“癫痫性脑病”，局限于颞叶周围网络，其中认知障碍是由干扰认知发育的癫痫放电引起的。
