Kaplan Peter W
Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, Maryland 21224, USA.
Epilepsia. 2005 Jun;46(6):977-9. doi: 10.1111/j.1528-1167.2005.00405.x.
Pseudoperiodic lateralized epileptiform discharges (PLEDs) usually produce "negative" neurologic findings. This contrasts with seizures which typically induce cortical activation with "positive" clinical manifestations. Gaze preference may arise from ipsilateral frontal eye fields (FEFs) damage because of the unopposed action of an intact contralateral FEF. Epileptic nystagmus (EN) and gaze deviation (GD) can also occur with focal temporo-parieto-occipital or hemispheric seizures in awake or obtunded patients. A patient with old right frontal and parieto-temporal cerebral infarctions manifested leftward gaze preference and deviation (without nystagmus) while alert and talking. Digitized EEG demonstrated PLEDs at approximately 1 Hz over the right fronto-central region, without electrographic seizures. This report illustrates that PLEDs without seizures may excite frontal regions proximate to the FEFs to produce contraversive gaze preference in an awake patient, and discusses putative mechanisms. Gaze deviation, in this case, was the principal clinical feature of PLEDs.
假性周期性一侧痫样放电（PLEDs）通常会产生“阴性”神经系统表现。这与癫痫发作形成对比，癫痫发作通常会引起具有“阳性”临床表现的皮质激活。凝视偏侧可能源于同侧额叶眼区（FEFs）受损，因为完整的对侧FEFs会产生无对抗的作用。癫痫性眼球震颤（EN）和凝视偏斜（GD）也可能出现在清醒或意识模糊的患者中，与局灶性颞顶枕叶或半球性癫痫发作有关。一名患有陈旧性右侧额叶和颞顶叶脑梗死的患者在清醒并交谈时表现出向左凝视偏侧和偏斜（无眼球震颤）。数字化脑电图显示右侧额中央区有频率约为1Hz的PLEDs，无脑电图癫痫发作。本报告表明，无癫痫发作的PLEDs可能会刺激FEFs附近的额叶区域，在清醒患者中产生对侧凝视偏侧，并讨论了可能的机制。在这种情况下，凝视偏斜是PLEDs的主要临床特征。
