Functional Connectivity Analysis of MRI-Negative Temporal Lobe Patients

目的：本研究旨在识别同为磁共振阴性颞叶癫痫患者中，存在功能异常的脑区，并进一步分析其功能连接模式，从而对颞叶癫痫的耐药性发生机制有更深入的了解，为该疾病的诊疗提供更进一步的理论依据。方法：收集符合纳入标准的30例颞叶癫痫患者，以及32例健康对照，并将癫痫组分为药物反应性和药物难治性两组，在进一步在此基础上采用种子点相关分析、局部静息态活动分析从而深入探究相在体素水平、脑区水平上的功能连接模式变化。结果：癫痫组和对照组ALFF值的显著组间差异主要分布在双侧梭状回。三组间FC值的显著差异主要分布在左侧的中央前回和右侧的旁中央小叶。事后检验显示，药物难治性组与药物反应性组的组间差异主要在于左侧额中回、中央前回及右侧旁中央小叶的功能连接降低。药物难治性组与对照的组间差异主要在左侧楔前叶和右侧的中央前回。结论：提示了海马其可能在磁共振阴性颞叶癫痫耐药性的发生机制中起到了重要作用，或者是难以控制的发作促使了发作侧对侧海马代偿功能的异常。且海马与默认模式网络内结构功能连接降低，表明默认网络异常中可能在磁共振阴性颞叶癫痫中起着核心干预作用，其深层次的病理生理机制需要进一步研究。Objective: In order to gain a deeper understanding of the mechanism of drug resistance in temporal lobe epilepsy and provide further theoretical basis for the diagnosis and treatment of this disease, this study aims to identify brain regions with functional abnormalities in patients with magnetic resonance negative temporal lobe epilepsy and analyze their functional connectivity patterns. Method: 30 patients with temporal lobe epilepsy who met the inclusion criteria and 32 healthy controls were collected and the epilepsy groups were divided into drug responsive and drug refractory groups. Based on this, seed-based analysis and resting state activity analysis were further used to explore the changes in functional connectivity patterns at the voxel and brain region levels. Result: The significant inter group differences in ALFF values between the epilepsy group and the control group were mainly distributed in the bilateral fusiform gyrus. The significant differences in FC values among the three groups were mainly distributed in the left precentral gyrus and the right paracentral lobule. Post-hoc analysis showed that the inter group differences of reduced functional connectivity between the drug resistant group and the drug responsive group were mainly distributed in the left precentral gyrus, left middle frontal gyrus and the right paracentral lobule. The inter group differences of reduced functional connectivity between the drug resistant group and the control group were mainly distributed in the left precuneus and the right precentral gyrus. Conclusion: This suggests that the hippocampus may play an important role in the mechanism of drug resistance in MRI negative temporal lobe epilepsy, or that uncontrollable seizures may lead to abnormal compensatory function in the contralateral hippocampus. Moreover, the reduced functional connectivity between the hippocampus and the default mode network suggested that the default network abnormalities may play a central intervention role in MRI negative temporal lobe epilepsy, and its underlying pathophysiological mechanisms need further investigation.