Murray Nicholas W G, Kneebone Anthony C, Graham Petra L, Wong Chong H, Savage Greg, Gillinder Lisa, Fong Michael W K
School of Psychological Sciences, Macquarie University, Sydney, Australia.
Westmead Comprehensive Epilepsy Centre, The University of Sydney, Sydney, Australia.
Front Netw Physiol. 2024 Jul 24;4:1424004. doi: 10.3389/fnetp.2024.1424004. eCollection 2024.
Neuropsychological assessment forms an integral part of the presurgical evaluation for patients with medically refractory focal epilepsy. Our understanding of cognitive impairment in epilepsy is based on seminal lesional studies that have demonstrated important structure-function relationships within the brain. However, a growing body of literature demonstrating heterogeneity in the cognitive profiles of patients with focal epilepsy (e.g., temporal lobe epilepsy; TLE) has led researchers to speculate that cognition may be impacted by regions outside the seizure onset zone, such as those involved in the interictal or "irritative" network.
Neuropsychological data from 48 patients who underwent stereoelectroencephalography (SEEG) monitoring between 2012 and 2023 were reviewed. Patients were categorized based on the site of seizure onset, as well as their irritative network, to determine the impact of wider network activity on cognition. Neuropsychological data were compared with normative standards (i.e., z = 0), and between groups.
There were very few distinguishing cognitive features between patients when categorized based purely on the seizure onset zone (i.e., frontal lobe vs. temporal lobe epilepsy). In contrast, patients with localized irritative networks (i.e., frontal temporal interictal epileptiform discharges [IEDs]) demonstrated more circumscribed profiles of impairment compared with those demonstrating wider irritative networks (i.e., frontotemporal IEDs). Furthermore, the directionality of propagation within the irritative network was found to influence the manifestations of cognitive impairment.
The findings suggest that neuropsychological assessment is sensitive to network activity beyond the site of seizure onset. As such, an overly focal interpretation may not accurately reflect the distribution of the underlying pathology. This has important implications for presurgical work-up in epilepsy, as well as subsequent surgical outcomes.
神经心理学评估是药物难治性局灶性癫痫患者术前评估的一个组成部分。我们对癫痫认知障碍的理解基于开创性的病灶研究，这些研究已经证明了大脑中重要的结构 - 功能关系。然而，越来越多的文献表明局灶性癫痫患者（如颞叶癫痫；TLE）的认知特征存在异质性，这使得研究人员推测认知可能受到癫痫发作起始区以外区域的影响，例如那些参与发作间期或“刺激性”网络的区域。
回顾了2012年至2023年间接受立体定向脑电图（SEEG）监测的48例患者的神经心理学数据。根据癫痫发作起始部位以及他们的刺激性网络对患者进行分类，以确定更广泛的网络活动对认知的影响。将神经心理学数据与正常标准（即z = 0）以及组间数据进行比较。
单纯根据癫痫发作起始区（即额叶癫痫与颞叶癫痫）对患者进行分类时，区分认知特征的情况很少。相比之下，与那些具有更广泛刺激性网络（即额颞叶发作间期癫痫样放电[IEDs]）的患者相比，具有局限性刺激性网络（即额颞叶IEDs）的患者表现出更局限的损伤特征。此外，发现刺激性网络内的传播方向会影响认知障碍的表现。
研究结果表明，神经心理学评估对癫痫发作起始区以外的网络活动敏感。因此，过于局限的解释可能无法准确反映潜在病理的分布。这对癫痫的术前检查以及后续手术结果具有重要意义。
