Department of Medicine (Austin Health), University of Melbourne, Heidelberg, Victoria, Australia.
Department of Neurology, Austin Health, Heidelberg, Victoria, Australia.
Epilepsia. 2020 Oct;61(10):2214-2223. doi: 10.1111/epi.16657. Epub 2020 Sep 18.
We aimed to assess the roles of the cortex and thalamus (centromedian nucleus [CM]) during epileptic activity in Lennox-Gastaut syndrome (LGS) patients undergoing deep brain stimulation (DBS) surgery as part of the ESTEL (Electrical Stimulation of the Thalamus for Epilepsy of Lennox-Gastaut Phenotype) trial.
Twelve LGS patients (mean age = 26.8 years) underwent bilateral CM-DBS implantation. Intraoperatively, simultaneous electroencephalogram (EEG) was recorded (range = 10-34 minutes) from scalp electrodes and bilateral thalamic DBS electrodes. Temporal onsets of epileptic discharges (generalized paroxysmal fast activity [GPFA] and slow spike-and-wave [SSW]) were manually marked on recordings from scalp (ie, "cortex") and thalamus (ie, CM-DBS electrodes). Phase transfer entropy (PTE) analysis quantified the degree of information transfer from cortex to thalamus within different frequency bands around GPFA events.
GPFA was captured in eight of 12 patients (total event number across patients = 168, cumulative duration = 358 seconds). Eighty-six percent of GPFA events were seen in both scalp and thalamic recordings. In most events (83%), onset occurred first at scalp, with thalamic onset lagging by a median of 98 milliseconds (interquartile range = 78.5 milliseconds). Results for SSW were more variable and seen in 11 of 12 patients; 25.4% of discharges were noted in both scalp and thalamus. Of these, 74.5% occurred first at scalp, with a median lag of 75 milliseconds (interquartile range = 228 milliseconds). One to 0.5 seconds and 0.5-0 seconds before GPFA onset, PTE analysis showed significant energy transfer from scalp to thalamus in the delta (1-3 Hz) frequency band. For alpha (8-12 Hz) and beta (13-30 Hz) frequencies, PTE was greatest 1-0.5 seconds before GPFA onset.
Epileptic activity is detectable in CM of thalamus, confirming that this nucleus participates in the epileptic network of LGS. Temporal onset of GPFA mostly occurs earlier at the scalp than in the thalamus. This supports our prior EEG-functional magnetic resonance imaging results and provides further evidence for a cortically driven process underlying GPFA in LGS.
作为 ESTEL（Lennox-Gastaut 表型癫痫的丘脑电刺激）试验的一部分，我们旨在评估皮层和丘脑（中央核[CM]）在接受深部脑刺激（DBS）手术的 Lennox-Gastaut 综合征（LGS）患者癫痫活动中的作用。
12 名 LGS 患者（平均年龄=26.8 岁）接受双侧 CM-DBS 植入。术中同时记录头皮电极和双侧丘脑 DBS 电极的脑电图（EEG）（范围=10-34 分钟）。癫痫发作（广义阵发性快活动[GPFA]和慢棘慢波[SSW]）的时间起始通过头皮（即“皮层”）和丘脑（即 CM-DBS 电极）记录上的手动标记进行标记。相位转移熵（PTE）分析量化了 GPFA 事件周围不同频带中从皮层到丘脑的信息传递程度。
12 名患者中有 8 名（患者总事件数=168，累积持续时间=358 秒）捕捉到 GPFA。86%的 GPFA 事件在头皮和丘脑记录中均可见。在大多数事件（83%）中，起始首先发生在头皮，丘脑起始滞后中位数为 98 毫秒（四分位距=78.5 毫秒）。SSW 的结果更为多变，在 12 名患者中有 11 名可见；25.4%的放电在头皮和丘脑均有记录。在这些患者中，74.5%的放电首先出现在头皮，中位滞后 75 毫秒（四分位距=228 毫秒）。在 GPFA 发作前 1 到 0.5 秒和 0.5-0 秒，PTE 分析显示在 delta（1-3 Hz）频带中，能量从头皮向丘脑转移。对于 alpha（8-12 Hz）和 beta（13-30 Hz）频率，PTE 在 GPFA 发作前 1-0.5 秒最大。
在丘脑的 CM 中可检测到癫痫活动，证实该核参与了 LGS 的癫痫网络。GPFA 的时间起始大多较早出现在头皮而不是丘脑。这支持我们之前的 EEG-功能磁共振成像结果，并为 LGS 中 GPFA 下存在皮质驱动过程提供了进一步证据。
