Archer John S, Warren Aaron E L, Stagnitti Monique R, Masterton Richard A J, Abbott David F, Jackson Graeme D
Department of Medicine, The University of Melbourne, Melbourne, Victoria, Australia; The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia; Austin Health, Melbourne, Victoria, Australia.
Epilepsia. 2014 Aug;55(8):1245-54. doi: 10.1111/epi.12682. Epub 2014 Jun 5.
Lennox-Gastaut syndrome (LGS) is a severe epilepsy phenotype with characteristic electroclinical features despite diverse etiologies. We previously found common cerebral networks involved during slow spike-and-wave (SSW) and generalized paroxysmal fast activity (PFA), characteristic interictal discharges. Some patients have a Lennox-Gastaut-like phenotype and cortical lesions. We wished to explore the interaction between cerebral networks and lesions in this group.
3 Tesla electroencephalography-functional magnetic resonance imaging (EEG-fMRI) on six subjects with Lennox-Gastaut phenotype and a structural lesion. Timings of SSW and PFA events were used in an event-related fMRI analysis, and to estimate the time course of the hemodynamic response from key regions.
(1) PFA-robust fMRI signal increases were observed in frontal and parietal association cortical areas, thalamus, and pons, with simultaneous increases in both "attention" and resting-state (default mode) networks, a highly unusual pattern. (2) SSW showed mixed increased and decreased fMRI activity, with preevent increases in association cortex and thalamus, and then prominent postevent reduction. There was decreased fMRI activity in primary cortical areas. (3) Lesion-variable fMRI increases were observed during PFA and SSW discharges. Three subjects who proceeded to lesionectomy are >1 year seizure-free.
We conceptualize Lennox-Gastaut phenotype as a being a network epilepsy, where key cerebral networks become autonomously unstable. Epileptiform activity in Lennox-Gastaut phenotype, and by implication in LGS, appears to be amplified and expressed through association cortical areas, possibly because the attention and default-mode networks are widely interconnected, fundamental brain networks. Seizure freedom in the subjects who proceeded to lesionectomy suggests that cortical lesions are able to establish and maintain this abnormal unstable network behavior. LGS may be considered a secondary network epilepsy because the unifying epileptic manifestations of the disorder, including PFA and SSW, reflect network dysfunction, rather than the specific initiating process.
Lennox-Gastaut综合征（LGS）是一种严重的癫痫表型，尽管病因多样，但具有特征性的电临床特征。我们之前发现，在慢棘波-慢波（SSW）和广泛性阵发性快活动（PFA）（特征性的发作间期放电）期间，存在共同的脑网络参与。一些患者具有Lennox-Gastaut样表型和皮质病变。我们希望探究该组中脑网络与病变之间的相互作用。
对6名具有Lennox-Gastaut表型和结构性病变的受试者进行3特斯拉脑电图-功能磁共振成像（EEG-fMRI）检查。在事件相关功能磁共振成像分析中使用SSW和PFA事件的时间，并估计关键区域血流动力学反应的时间进程。
（1）在额叶和顶叶联合皮质区域、丘脑和脑桥观察到PFA-稳健的功能磁共振成像信号增加，同时“注意力”和静息状态（默认模式）网络均增加，这是一种非常不寻常的模式。（2）SSW显示功能磁共振成像活动有增加和减少的混合情况，发作前联合皮质和丘脑增加，然后发作后显著减少。初级皮质区域的功能磁共振成像活动减少。（3）在PFA和SSW放电期间观察到病变可变的功能磁共振成像增加。进行病变切除术的3名受试者已无癫痫发作超过1年。
我们将Lennox-Gastaut表型概念化为一种网络性癫痫，其中关键脑网络变得自主不稳定。Lennox-Gastaut表型中的癫痫样活动，以及由此推断的LGS中的癫痫样活动，似乎通过联合皮质区域被放大和表达，可能是因为注意力和默认模式网络是广泛互连的基础脑网络。进行病变切除术的受试者无癫痫发作表明皮质病变能够建立并维持这种异常的不稳定网络行为。LGS可被视为继发性网络性癫痫，因为该疾病的统一癫痫表现，包括PFA和SSW，反映的是网络功能障碍，而非特定的起始过程。
