Resting state connectivity biomarkers of seizure freedom after epilepsy surgery

IF 3.4 2区医学 Q2 NEUROIMAGING

Neuroimage-Clinical Pub Date : 2024-01-01 DOI:10.1016/j.nicl.2024.103673

Eva Martinez-Lizana, Armin Brandt, Matthias Dümpelmann, Andreas Schulze-Bonhage

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引用次数: 0

Abstract

Alterations in brain networks may cause the lowering of the seizure threshold and hypersynchronization that underlie the recurrence of unprovoked seizures in epilepsy. The aim of this work is to estimate functional network characteristics, which may help predicting outcome of epilepsy surgery.

Twenty patients were studied (11 females, 9 males, mean age 33 years) with scalp-recorded HD-EEG in resting state (eyes closed, no interictal discharges) before intracranial evaluation, which allowed the precise determination of the epileptogenic zone. Dipole source time courses in the brain were estimated using Weighted Minimum Norm Estimate based on HD-EEG signals. Information inflow and outflow of atlas-based brain regions were computed using partial directed connectivity. A set of graph measures for pairwise connections in standard EEG frequency bands was calculated.

After epilepsy surgery 10 patients were seizure-free (Engel 1a) and 10 patients continued suffering from seizures (Engel outcome worse than 1a). Inflow of the regions containing the epileptogenic zone in the beta and delta frequency bands was significantly lower in patients who achieved seizure-freedom after surgery, compared with patients who continued to have seizures (p = 0.012, and p = 0.026, respectively). Average path length in the beta frequency band was significantly higher in patients who achieved seizure freedom (p = 0.012). In the delta frequency band, local efficiency and clustering coefficient were significantly higher in patients who achieved seizure freedom (0.033, 0.046).

In patients who achieved seizure freedom after surgery, the preoperative analysis of the epileptic network exhibited stronger separation of the region containing the seizure onset zone, with less inflow of information. In contrast, shorter paths within the epileptic network may facilitate hypersynchronous neuronal activity and thus the recurrence of seizures in non-seizure free patients. This study supports the hypothesis that epileptic network properties might help to define suitable candidates for epilepsy surgery.

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癫痫手术后癫痫发作自由度的静息状态连接生物标志物

大脑网络的改变可能会导致癫痫发作阈值降低和超同步化，而这正是癫痫无诱因发作复发的基础。研究人员对 20 名患者（11 名女性，9 名男性，平均年龄 33 岁）进行了颅内评估前的静息状态（闭眼，无发作间期放电）头皮记录 HD-EEG，从而精确确定了致痫区。利用基于 HD-EEG 信号的加权最小规范估计法估算大脑中偶极子源的时间进程。利用部分定向连接计算了基于图谱的脑区信息流入和流出。在癫痫手术后，10 名患者无癫痫发作（Engel 1a），10 名患者仍有癫痫发作（Engel 结果差于 1a）。与癫痫继续发作的患者相比，术后癫痫不再发作的患者在 beta 和 delta 频段中包含致痫区的区域的入流明显较低（分别为 p = 0.012 和 p = 0.026）。在获得癫痫发作自由的患者中，β 频段的平均路径长度明显更高（p = 0.012）。在德尔塔频段，获得癫痫发作自由的患者的局部效率和聚类系数明显更高（0.033、0.046）。在术后获得癫痫发作自由的患者中，癫痫网络的术前分析显示包含癫痫发作起始区的区域分离更强，信息流入更少。相反，癫痫网络内较短的路径可能会促进神经元的超同步活动，从而导致未摆脱癫痫发作的患者癫痫复发。这项研究支持这样的假设，即癫痫网络特性可能有助于确定癫痫手术的合适人选。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Neuroimage-Clinical NEUROIMAGING-

CiteScore

7.50

自引率

4.80%

发文量

368

审稿时长

52 days

期刊介绍： NeuroImage: Clinical, a journal of diseases, disorders and syndromes involving the Nervous System, provides a vehicle for communicating important advances in the study of abnormal structure-function relationships of the human nervous system based on imaging. The focus of NeuroImage: Clinical is on defining changes to the brain associated with primary neurologic and psychiatric diseases and disorders of the nervous system as well as behavioral syndromes and developmental conditions. The main criterion for judging papers is the extent of scientific advancement in the understanding of the pathophysiologic mechanisms of diseases and disorders, in identification of functional models that link clinical signs and symptoms with brain function and in the creation of image based tools applicable to a broad range of clinical needs including diagnosis, monitoring and tracking of illness, predicting therapeutic response and development of new treatments. Papers dealing with structure and function in animal models will also be considered if they reveal mechanisms that can be readily translated to human conditions.