Wong P K
Department of Diagnostic Neurophysiology, B.C. Children's Hospital, Vancouver, Canada.
Brain Topogr. 1989 Fall-Winter;2(1-2):31-6. doi: 10.1007/BF01128841.
The interictal spike discharges present in rolandic epilepsy has a dominant horizontal dipolar topography, centered near the rolandic area. In order to examine the generator configuration of this focus, we investigated the variation of spike topography in 20 children with rolandic epilepsy of childhood by the dipole localization method (DLM). A quantitative measure ("stability index" or SI) of the degree of source fluctuation was devised, based on the consistency of the source parameters (location, direction and magnitude) over contiguous time points. A high SI was associated with overlapping source locations and parallel directions over many time points, while a low SI was seen with poor and variable solutions. At the peak and trough of the spike, the corresponding sources were found to have different locations. If the patients were separated into those with and without neurological findings, the mean times at which stable sources existed were significantly different: 35 and 150 ms respectively after the spike apex. Further, the group without abnormal neurological findings tended to have higher values of SI. These results suggest that such stability analysis allows measurement of the spatial and temporal extents of source estimates. These results further support the hypothesis that the topographic behaviour of a spike focus is closely associated with its clinical characteristics.
罗兰多癫痫发作间期的棘波放电具有以罗兰多区附近为中心的优势水平偶极分布。为了研究该病灶的发生器结构，我们采用偶极定位法（DLM）对20例儿童罗兰多癫痫患者棘波分布的变化进行了研究。基于相邻时间点源参数（位置、方向和大小）的一致性，设计了一种源波动程度的定量测量方法（“稳定性指数”或SI）。高SI与多个时间点上重叠的源位置和平行方向相关，而低SI则与较差且多变的解相关。在棘波的峰值和谷值处，发现相应的源具有不同的位置。如果将患者分为有和没有神经学发现的两组，稳定源存在的平均时间显著不同：分别在棘波顶点后35毫秒和150毫秒。此外，没有异常神经学发现的组往往具有较高的SI值。这些结果表明，这种稳定性分析能够测量源估计的空间和时间范围。这些结果进一步支持了这样的假说，即棘波病灶的分布行为与其临床特征密切相关。
