Photosensitive epilepsy is associated with reduced inhibition of alpha rhythm generating networks
Photosensitive epilepsy is associated with reduced inhibition of alpha rhythm generating networks
复制标题
光敏性癫痫与α节律生成网络的抑制减少有关
作者：
A. Vaudano;Andrea Ruggieri;P. Avanzini;G. Gessaroli;G. Cantalupo;A. Coppola;S. Sisodiya;S. Meletti
关于这篇文章的科学评论，请参阅 Hamandi (doi:10.1093/awx049)。这种异常脑电图反应与视觉运动系统过度兴奋有关。在此，我们将评估这一网络的内在功能障碍是否存在于静息状态下的大脑活动中，而与任何刺激和任何阵发性脑电活动无关。为了解决这个问题，我们研究了光敏感患者和非光敏感患者自发α节律的血流动力学相关性，α节律被认为是大脑静息状态的标志。其次，我们评估了不同研究对象丘脑视觉核的全脑功能连接。44 名癫痫患者和 16 名健康对照组受试者在闭眼状态下接受了脑电图相关功能磁共振成像研究。研究对象包括以下患者群体(i) 遗传性全身性癫痫伴光敏感性，16 名受试者（平均年龄为 25 ± 10 岁）；(ii) 遗传性全身性癫痫无光敏感性，13 名受试者（平均年龄为 25 ± 11 岁）；(iii) 局灶性癫痫，15 名受试者（平均年龄为 25 ± 9 岁）。每个受试者的后阿尔法功率变化都与标准血液动力学反应函数相卷积，并用作回归因子。进行了组内和组间二级分析。根据血流动力学研究结果，对两个丘脑相关区域的全脑功能连接性进行了评估，这两个区域包括丘脑后部（pulvinar）和丘脑背内侧核。与对照组和其他癫痫组相比，遗传性全身性光敏性癫痫的平均α功率明显增大。在光敏性癫痫患者中，枕叶、感觉运动、前扣带回和辅助运动皮层中与α相关的血氧水平依赖性信号变化的下降幅度低于其他所有组别。与此相一致的是，只有光敏性癫痫患者的相同脑区与视觉丘脑的连接出现异常。正如预测的那样，我们的研究结果表明，在癫痫患者和视觉敏感患者中，产生静态α振荡的皮层-皮层下网络是不同的。这种差异包括视觉皮层和感觉运动网络在静息状态下与α相关的抑制作用减弱。这些发现代表了光敏反应临床表现（即肌阵挛）的基础。此外，我们的研究结果首次证明了触发视觉敏感现象的回路与产生后部α节律的回路之间存在功能性联系。
See Hamandi (doi:10.1093/awx049) for a scientific commentary on this article.Photosensitivity is a condition in which lights induce epileptiform activities. This abnormal electroencephalographic response has been associated with hyperexcitability of the visuo-motor system. Here, we evaluate if intrinsic dysfunction of this network is present in brain activity at rest, independently of any stimulus and of any paroxysmal electroencephalographic activity. To address this issue, we investigated the haemodynamic correlates of the spontaneous alpha rhythm, which is considered the hallmark of the brain resting state, in photosensitive patients and in people without photosensitivity. Second, we evaluated the whole-brain functional connectivity of the visual thalamic nuclei in the various populations of subjects under investigation. Forty-four patients with epilepsy and 16 healthy control subjects underwent an electroencephalography-correlated functional magnetic resonance imaging study, during an eyes-closed condition. The following patient groups were included: (i) genetic generalized epilepsy with photosensitivity, 16 subjects (mean age 25 ± 10 years); (ii) genetic generalized epilepsy without photosensitivity, 13 patients (mean age 25 ± 11 years); (iii) focal epilepsy, 15 patients (mean age 25 ± 9 years). For each subject, the posterior alpha power variations were convolved with the standard haemodynamic response function and used as a regressor. Within- and between-groups second level analyses were performed. Whole brain functional connectivity was evaluated for two thalamic regions of interest, based on the haemodynamic findings, which included the posterior thalamus (pulvinar) and the medio-dorsal thalamic nuclei. Genetic generalized epilepsy with photosensitivity demonstrated significantly greater mean alpha-power with respect to controls and other epilepsy groups. In photosensitive epilepsy, alpha-related blood oxygen level-dependent signal changes demonstrated lower decreases relative to all other groups in the occipital, sensory-motor, anterior cingulate and supplementary motor cortices. Coherently, the same brain regions demonstrated abnormal connectivity with the visual thalamus only in epilepsy patients with photosensitivity. As predicted, our findings indicate that the cortical-subcortical network generating the alpha oscillation at rest is different in people with epilepsy and visual sensitivity. This difference consists of a decreased alpha-related inhibition of the visual cortex and sensory-motor networks at rest. These findings represent the substrate of the clinical manifestations (i.e. myoclonus) of the photoparoxysmal response. Moreover, our results provide the first evidence of the existence of a functional link between the circuits that trigger the visual sensitivity phenomenon and those that generate the posterior alpha rhythm.
影响因子：
33.6
作者：
Brown RE;Basheer R;McKenna JT;Strecker RE;McCarley RW
通讯作者：
McCarley RW