Aihara M, Hatakeyama K, Koizumi K, Nakazawa S
Department of Pediatrics, Yamanashi Medical University, Japan.
Epilepsia. 1997 Jun;38(6):723-7. doi: 10.1111/j.1528-1157.1997.tb01243.x.
Ictal studies of atonic seizures in children with epilepsy are rare. To clarify the neurophysiologic mechanism of such seizures, we describe a cluster of atonic seizures in a 6-year-old girl with cortical dysplasia.
Ictal activity was recorded as slow-wave bursts beginning over the right frontocentral regions, where the cortical dysplasia was detected by magnetic resonance imaging (MRI), and propagating to the left hemisphere.
The polygraphic recording demonstrated that the atonia indicated by the sudden interruption of electromyogram (EMG) discharges corresponded to the bilaterally synchronous spike-and-wave complexes. An ictal single photon emission computed tomography (SPECT) study with 99mTc hexamethyl propylene amine oxime ([99mTc]HMPAO) simultaneously performed during EEG recording showed marked bilateral mesial frontal and right frontoparietal hyperperfusion.
Our findings suggest that the neurophysiological mechanism of the atonic seizures may be produced by a strong inhibition in the bilateral motor cortexes. Ictal SPECT is valuable in demonstrating the pathophysiology of both atonic seizures and secondary bilaterally synchronous spike-and-wave complexes in the EEG.
对癫痫患儿失张力发作的发作期研究较为罕见。为阐明此类发作的神经生理机制，我们描述了一名患有皮质发育异常的6岁女孩的一组失张力发作。
发作期活动记录为始于右侧额中央区的慢波爆发，磁共振成像（MRI）在该区域检测到皮质发育异常，且发作期活动向左侧半球扩散。
多导记录显示，肌电图（EMG）放电突然中断所提示的失张力与双侧同步的棘慢复合波相对应。在脑电图记录期间同时进行的一项使用99m锝六甲基丙烯胺肟（[99mTc]HMPAO）的发作期单光子发射计算机断层扫描（SPECT）研究显示，双侧额叶内侧和右侧额顶叶有明显的血流灌注增加。
我们的研究结果表明，失张力发作的神经生理机制可能是由双侧运动皮层的强烈抑制所致。发作期SPECT在阐明失张力发作以及脑电图中继发性双侧同步棘慢复合波的病理生理方面具有重要价值。
