Friedman David E, Schevon Catherine, Emerson Ronald G, Hirsch Lawrence J
Comprehensive Epilepsy Center, Columbia University Medical Center, New York, New York, U.S.A.
Epilepsia. 2008 Feb;49(2):281-7. doi: 10.1111/j.1528-1167.2007.01327.x. Epub 2007 Sep 26.
Prolonged electroencephalographic monitoring has facilitated the detection of nonconvulsive seizures. Compressed displays of EEG frequency spectra (such as compressed spectral array, CSA) can facilitate interpretation of continuous EEG by allowing the reader to observe on a single screen patterns evolving over many minutes or hours.
Patients were identified retrospectively over a 4-year period as displaying a cycling pattern of seizures on CSA.
We describe a pattern of seizures recurring in a cyclic fashion in a series of 13 critically ill patients of all ages. Several patients had a gradual buildup of EEG power prior to each seizure.
We believe that while not rare, this pattern is difficult to recognize on standard EEG recording but it is readily apparent on CSA. The underlying pathophysiology of cyclic seizures is not known, but we speculate that cyclic seizures represent a form of status epilepticus in which the usual seizure terminating factors are present and transiently effective, but are inadequate to prevent resumption of the seizure activity. Studying these patients may provide insight into the pathophysiology of seizure initiation and cessation.
长时间脑电图监测有助于非惊厥性癫痫发作的检测。脑电图频谱的压缩显示（如压缩谱阵，CSA）可以通过让读者在单个屏幕上观察数分钟或数小时内演变的模式，从而便于对连续脑电图进行解读。
回顾性确定在4年期间内，在CSA上显示癫痫发作循环模式的患者。
我们描述了一系列各年龄段的13名重症患者中以循环方式反复出现的癫痫发作模式。几名患者在每次癫痫发作前脑电图功率逐渐增强。
我们认为，虽然这种模式并不罕见，但在标准脑电图记录上难以识别，但在CSA上很容易显现。循环性癫痫发作的潜在病理生理学尚不清楚，但我们推测循环性癫痫发作代表一种癫痫持续状态，其中通常的癫痫发作终止因素存在且短暂有效，但不足以防止癫痫活动的恢复。对这些患者的研究可能有助于深入了解癫痫发作起始和终止的病理生理学。
