Rodgers Krista M, Dudek F Edward, Barth Daniel S
Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309, and.
Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, Utah 84108.
J Neurosci. 2015 Jun 17;35(24):9194-204. doi: 10.1523/JNEUROSCI.0919-15.2015.
Variable-duration oscillations and repetitive, high-voltage spikes have been recorded in the electrocorticogram (ECoG) of rats weeks and months after fluid percussion injury (FPI), a model of traumatic brain injury. These ECoG events, which have many similarities to spike-wave-discharges (SWDs) and absence seizures, have been proposed to represent nonconvulsive seizures characteristic of post-traumatic epilepsy (PTE). The present study quantified features of SWD episodes in rats at different time points after moderate to severe FPI, and compared them with age-matched control rats. Control and FPI-injured rats at 1 year of age displayed large-amplitude and frequent SWD events at frontal and parietal recording sites. At 3-6 months, SWDs were shorter in duration and less frequent; extremely brief SWDs (i.e., "larval") were detected as early as 1 month. The onset of the SWDs was nearly always synchronous across electrodes and of larger amplitude in frontal regions. A sensory stimulus, such as a click, immediately and consistently stopped the occurrence of the SWDs. SWDs were consistently accompanied by behavioral arrest. All features of SWDs in control and experimental (FPI) rats were indistinguishable. None of the FPI-treated rats developed nonconvulsive or convulsive seizures that could be distinguished electrographically or behaviorally from SWDs. Because SWDs have features similar to genetic absence seizures, these results challenge the hypothesis that SWDs after FPI reflect PTE.
在创伤性脑损伤模型——液压冲击伤（FPI）后的数周及数月，大鼠的皮层脑电图（ECoG）中记录到了持续时间可变的振荡以及重复性的高压尖峰。这些ECoG事件与棘波-慢波放电（SWDs）和失神发作有许多相似之处，有人提出它们代表了创伤后癫痫（PTE）的非惊厥性发作特征。本研究对中度至重度FPI后不同时间点大鼠的SWD发作特征进行了量化，并将其与年龄匹配的对照大鼠进行了比较。1岁的对照大鼠和FPI损伤大鼠在额叶和顶叶记录部位表现出大幅度且频繁的SWD事件。在3 - 6个月时，SWDs的持续时间较短且频率较低；早在1个月时就检测到了极短暂的SWDs（即“幼虫型”）。SWDs的发作几乎总是在电极之间同步，且在额叶区域幅度更大。诸如咔哒声之类的感觉刺激能立即且持续地阻止SWDs的发生。SWDs总是伴有行为停止。对照大鼠和实验（FPI）大鼠中SWDs的所有特征都无法区分。没有一只接受FPI治疗的大鼠出现可在脑电图或行为上与SWDs区分开的非惊厥性或惊厥性发作。由于SWDs具有与遗传性失神发作相似的特征，这些结果对FPI后SWDs反映PTE这一假说提出了挑战。
