Barrett G
Department of Psychology, National Hospital for Neurology and Neurosurgery, London, U.K.
J Clin Neurophysiol. 1992 Oct;9(4):495-508.
Jerk-locked averaging (JLA) is used to record the timing and distribution of brain activity preceding brisk involuntary movements such as those observed in patients with myoclonus. JLA is capable of revealing a premyoclonus spike in the absence of paroxysmal activity in the routine EEG. The technique of JLA is described together with a consideration of the way in which the presence or absence of premyoclonus activity and the somatosensory evoked potential (SEP) can help to classify patients with involuntary movement disorders. The relationship between the premyoclonus spike and the N25-P33 complex of the SEP is discussed. Although the most common finding in patients with myoclonus of cortical origin is a large, well-defined positive-negative spike with the positive peak occurring about 20 ms before electromyographic onset, a wide variety of time relationships and topographies has been observed in other disorders of involuntary movement and some of these are described. The lack of correlation between the apparent origin of the premyoclonus spike in motor cortex and pathology in patients with myoclonus is discussed.
抽搐锁定平均法（JLA）用于记录在诸如肌阵挛患者中观察到的快速不自主运动之前的脑活动时间和分布。JLA能够在常规脑电图无阵发性活动的情况下揭示肌阵挛前棘波。本文描述了JLA技术，并探讨了肌阵挛前活动的有无以及体感诱发电位（SEP）如何有助于对不自主运动障碍患者进行分类。讨论了肌阵挛前棘波与SEP的N25 - P33复合波之间的关系。尽管皮质源性肌阵挛患者最常见的发现是一个大的、界限清晰的正负棘波，其正峰出现在肌电图开始前约20毫秒，但在其他不自主运动障碍中也观察到了多种时间关系和地形图，本文对其中一些进行了描述。还讨论了肌阵挛患者运动皮层中肌阵挛前棘波的明显起源与病理学之间缺乏相关性的问题。
