Blumenfeld Hal, Westerveld Michael, Ostroff Robert B, Vanderhill Susan D, Freeman Jason, Necochea Alexandro, Uranga Paula, Tanhehco Tasha, Smith Arien, Seibyl John P, Stokking Rik, Studholme Colin, Spencer Susan S, Zubal I George
Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
Neuroimage. 2003 Aug;19(4):1556-66. doi: 10.1016/s1053-8119(03)00204-0.
Are "generalized" seizures truly generalized? Generalized tonic-clonic seizures are classified as either secondarily generalized with local onset or primarily generalized, without known focal onset. In both types of generalized seizures widespread regions of the nervous system engage in abnormally synchronous and high-frequency neuronal firing. However, emerging evidence suggests that all neurons are not homogeneously involved; specific nodes within the network may be crucial for the propagation and behavioral manifestations of generalized tonic-clonic seizures. Study of human tonic-clonic seizures has been limited by problems with patient movement and variable seizure types. To circumvent these problems, we imaged generalized tonic-clonic seizures during electroconvulsive therapy, in which seizure type and timing are well controlled. (99m)Tc-hexamethylpropylene amine oxime injections during seizures provide a "snapshot" of cerebral blood flow that can be imaged by single photon emission computed tomography (SPECT) after seizure termination. Here we show that focal regions of frontal and parietal association cortex show the greatest relative signal increases. Involvement of the higher-order association cortex may explain the profound impairment of consciousness seen in generalized seizures. In addition, focal involvement of the dominant temporal lobe was associated with impaired retrograde verbal memory. Similar focal increases were also seen in imaging of spontaneous secondarily generalized tonic-clonic seizures. Relative sparing of many brain regions during both spontaneous and induced seizures suggests that specific networks may be more important than others in so-called generalized seizures.
“全身性”癫痫发作真的是全身性的吗？全身性强直阵挛性发作分为局灶性起始继发全身性发作或原发性全身性发作（无已知局灶性起始）。在这两种全身性癫痫发作类型中，神经系统的广泛区域都会出现异常同步且高频的神经元放电。然而，新出现的证据表明，并非所有神经元都同等程度地参与其中；网络中的特定节点可能对全身性强直阵挛性发作的传播和行为表现至关重要。对人类强直阵挛性发作的研究受到患者运动问题和癫痫发作类型多变的限制。为了规避这些问题，我们在电惊厥治疗期间对全身性强直阵挛性发作进行成像，在电惊厥治疗中癫痫发作类型和时间得到了很好的控制。癫痫发作期间注射（99m）锝 - 六甲基丙烯胺肟可提供脑血流的“快照”，在癫痫发作终止后可通过单光子发射计算机断层扫描（SPECT）进行成像。我们在此表明，额叶和顶叶联合皮质的局灶区域显示出最大的相对信号增加。高级联合皮质的参与可能解释了全身性癫痫发作中所见的意识深度受损。此外，优势颞叶的局灶性受累与逆行性言语记忆受损有关。在自发性继发全身性强直阵挛性发作的成像中也观察到了类似的局灶性增加。在自发性和诱发性癫痫发作期间许多脑区相对未受影响，这表明在所谓的全身性癫痫发作中，特定网络可能比其他网络更重要。
