University of Wisconsin-Madison, Department of Neurology, United States; William S. Middleton Veterans Administration Hospital, Madison, WI, United States.
University of Wisconsin-Madison, Department of Neurology, United States.
Epilepsy Behav. 2021 Apr;117:107841. doi: 10.1016/j.yebeh.2021.107841. Epub 2021 Feb 18.
Temporal lobe epilepsy (TLE) has been conceptualized as focal disease with a discrete neurobiological focus and can respond well to targeted resection or ablation. In contrast, the neuro-cognitive deficits resulting from TLE can be widespread involving regions beyond the primary epileptic network. We hypothesize that this seemingly paradoxical findings can be explained by differences in connectivity between the primary epileptic region which is hyper-connected and its secondary influence on global connectome organization. This hypothesis is tested using regional and global graph theory metrics where we anticipate that regional mesial-temporal hyperconnectivity will be found and correlate with seizure frequency while global networks will be disorganized and be more closely associated with neuro-cognitive deficits. Resting-state fMRI was used to examine temporal lobe regional connectivity and global functional connectivity from 102 patients with TLE and 55 controls. Connectivity matrices were calculated for subcortical volumes and cortical parcellations. Graph theory metrics (global clustering coefficient (GCC), degree, closeness) were compared between groups and in relation to neuropsychological profiles and disease covariates using permutation testing and causal analysis. In TLE there was a decrease in GCC (p = 0.0345) associated with a worse neuropsychological profile (p = 0.0134). There was increased connectivity in the left hippocampus/amygdala (degree p = 0.0103, closeness p = 0.0104) and a decrease in connectivity in the right lateral temporal lobe (degree p = 0.0186, closeness p = 0.0122). A ratio between the hippocampus/amygdala and lateral temporal lobe-temporal lobe connectivity ratio (TLCR) revealed differences between TLE and controls for closeness (left p = 0.00149, right p = 0.0494) and for degree on left p = 0.00169; with trend on right p = 0.0567. Causal analysis suggested that "Epilepsy Activity" (seizure frequency, anti-seizure medications) was associated with increase in TLCR but not in GCC, while cognitive decline was associated with decreased GCC. These findings support the hypothesis that in TLE there is hyperconnectivity in the hippocampus/amygdala and hypoconnectivity in the lateral temporal lobe associated with "Epilepsy Activity." While, global connectome disorganization was associated with worse neuropsychological phenotype.
颞叶癫痫(TLE)被认为是一种具有离散神经生物学焦点的局灶性疾病,可以很好地对其进行靶向切除或消融。相比之下,TLE 引起的神经认知缺陷可能广泛存在,涉及原发性癫痫网络以外的区域。我们假设,这种看似矛盾的发现可以通过原发性癫痫区域的连接性差异来解释,原发性癫痫区域的连接性过度活跃,并且对全球连接组组织具有继发性影响。我们使用区域和全局图论度量来检验这一假设,预计会发现内侧颞叶的区域性过度连接,并与癫痫发作频率相关,而全局网络则会紊乱,并与神经认知缺陷更为密切相关。我们使用静息态 fMRI 检查了 102 例 TLE 患者和 55 例对照者的颞叶区域连接性和全局功能连接性。为皮质下体积和皮质分区计算了连接矩阵。使用置换检验和因果分析,比较了两组之间以及与神经心理学特征和疾病协变量相关的图论度量(全局聚类系数(GCC)、度数、接近度)。在 TLE 患者中,GCC 降低(p=0.0345),与神经心理学特征恶化相关(p=0.0134)。左侧海马体/杏仁核的连接性增加(度数 p=0.0103,接近度 p=0.0104),右侧外侧颞叶的连接性降低(度数 p=0.0186,接近度 p=0.0122)。TLE 患者与对照组之间的海马体/杏仁核与外侧颞叶-颞叶连接比(TLCR)的比率在接近度上存在差异(左侧 p=0.00149,右侧 p=0.0494),在度数上存在差异(左侧 p=0.00169,右侧 p=0.0567)。因果分析表明,“癫痫活动”(发作频率、抗癫痫药物)与 TLCR 的增加相关,但与 GCC 的增加无关,而认知能力下降与 GCC 的减少相关。这些发现支持了这样一种假设,即在 TLE 中,海马体/杏仁核过度活跃,外侧颞叶连接减少,与“癫痫活动”有关。而全局连接组的紊乱与较差的神经心理学表型相关。