Gotman J, Grova C, Bagshaw A, Kobayashi E, Aghakhani Y, Dubeau F
Montreal Neurological Institute and Department of Neurology and Neurosurgery, McGill University, 3801 University Street, Montréal, QC, Canada H3A 2B4.
Proc Natl Acad Sci U S A. 2005 Oct 18;102(42):15236-40. doi: 10.1073/pnas.0504935102. Epub 2005 Oct 10.
Our objective was to evaluate the brain regions showing increased and decreased metabolism in patients at the time of generalized bursts of epileptic discharges in order to understand their mechanism of generation and effect on brain function. By recording the electroencephalogram during the functional MRI, changes in the blood oxygenation level-dependent signal were obtained in response to epileptic discharges observed in the electroencephalogram of 15 patients with idiopathic generalized epilepsy. A group analysis was performed to determine the regions of positive (activation) and negative (deactivation) blood oxygenation level-dependent responses that were common to the patients. Activations were found bilaterally and symmetrically in the thalamus, mesial midfrontal region, insulae, and midline and bilateral cerebellum and on the borders of the lateral ventricles. Deactivations were bilateral and symmetrical in the anterior frontal and parietal regions and in the posterior cingulate gyri and were seen in the left posterior temporal region. Activations in thalamus and midfrontal regions confirm known involvement of these regions in the generation or spread of generalized epileptic discharges. Involvement of the insulae in generalized discharges had not previously been described. Cerebellar activation is not believed to reflect the generation of discharges. Deactivations in frontal and parietal regions remarkably followed the pattern of the default state of brain function. Thalamocortical activation and suspension of the default state may combine to cause the actual state of reduced responsiveness observed in patients during spike-and-wave discharges. This brief lapse of responsiveness may therefore not result only from the epileptic discharge but also from its effect on normal brain function.
我们的目的是评估在癫痫放电全身性爆发时患者大脑中代谢增加和减少的区域，以了解其产生机制及其对脑功能的影响。通过在功能磁共振成像（fMRI）期间记录脑电图（EEG），在15例特发性全身性癫痫患者的脑电图中观察到癫痫放电时，获得了血氧水平依赖（BOLD）信号的变化。进行了组分析以确定患者共有的正向（激活）和负向（失活）BOLD反应区域。在丘脑、内侧额中部区域、脑岛、中线和双侧小脑以及侧脑室边界发现了双侧对称的激活。在前额叶和顶叶区域以及后扣带回中发现了双侧对称的失活，并且在左后颞叶区域也观察到了失活。丘脑和额中部区域的激活证实了这些区域在全身性癫痫放电的产生或传播中的已知作用。脑岛在全身性放电中的作用此前尚未被描述。小脑激活不被认为反映放电的产生。额叶和顶叶区域的失活明显遵循脑功能默认状态的模式。丘脑皮质激活和默认状态的暂停可能共同导致在棘波和慢波放电期间患者观察到的反应性降低的实际状态。因此，这种短暂的反应性丧失可能不仅是由癫痫放电引起的，还可能是由其对正常脑功能的影响导致的。
