Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
Department of Neurology, Christian-Doppler-Klinik, Paracelsus Medical University of Salzburg, Salzburg, Austria.
Epilepsia. 2018 Mar;59(3):523-529. doi: 10.1111/epi.13996. Epub 2018 Jan 11.
Clinical absences are now classified as "generalized nonmotor (absence) seizures" by the International League Against Epilepsy (ILAE). The aim of this paper is to critically review the concept of absences and to put the accompanying focal and motor symptoms into the context of the emerging pathophysiological knowledge.
For this narrative review we performed an extensive literature search on the term "absence," and analyzed the plethora of symptoms observed in clinical absences.
Arising from the localization and the involved cortical networks, motor symptoms may include bilateral mild eyelid fluttering and mild myoclonic jerks of extremities. These motor symptoms may also occur unilaterally, analogous to a focal motor seizure with Jacksonian march. Furthermore, electroencephalography (EEG) abnormalities may exhibit initial frontal focal spikes and consistent asymmetries. Electroclinical characteristics support the cortical focus theory of absence seizures. Simultaneous EEG/functional magnetic resonance imaging (fMRI) measurements document cortical deactivation and thalamic activation. Cortical deactivation is related to slow waves and disturbances of consciousness of varying degrees. Motor symptoms correspond to the spike component of the 3/s spike-and-wave-discharges. Thalamic activation can be interpreted as a response to overcome cortical deactivation. Furthermore, arousal reaction during drowsiness or sleep triggers spikes in an abnormally excitable cortex. An initial disturbance in arousal mechanisms ("dyshormia") might be responsible for the start of this abnormal sequence.
The classification as "generalized nonfocal and nonmotor (absence) seizure" does not covey the complex semiology of a patient's clinical events.
国际抗癫痫联盟（ILAE）现在将临床失神发作归类为“全面性非运动（失神）发作”。本文的目的是批判性地回顾失神的概念，并将伴随的局灶性和运动症状置于新兴的病理生理学知识背景下。
为了进行这篇叙述性综述，我们对“失神”一词进行了广泛的文献检索，并分析了在临床失神中观察到的大量症状。
源自定位和涉及的皮质网络，运动症状可能包括双侧轻度眼睑颤动和轻度肢体肌阵挛性抽搐。这些运动症状也可能单侧发生，类似于具有杰克逊进展的局灶性运动性发作。此外，脑电图（EEG）异常可能表现出初始额部局灶性棘波和一致的不对称性。电临床特征支持失神发作的皮质焦点理论。同时进行脑电图/功能磁共振成像（fMRI）测量记录皮质去激活和丘脑激活。皮质去激活与不同程度的慢波和意识障碍有关。运动症状与 3/s 棘波-慢波放电的棘波成分相对应。丘脑激活可以解释为克服皮质去激活的反应。此外，在嗜睡或睡眠期间的觉醒反应会在异常兴奋的皮质中引发棘波。觉醒机制的初始障碍（“dyshormia”）可能是导致这种异常序列开始的原因。
将其归类为“全面性非局灶性和非运动（失神）发作”并不能涵盖患者临床事件的复杂症状。
