Gambardella A, Aguglia U, Oliveri R L, Russo C, Zappia M, Quattrone A
Institute of Neurology, School of Medicine of Catanzaro, Italy.
Epilepsia. 1997 Jul;38(7):819-23. doi: 10.1111/j.1528-1157.1997.tb01469.x.
Epileptic negative myoclonus (ENM) has been increasingly recognized in different epilepsies, but the reasons for its appearance and prognosis remain uncertain. We report 3 patients who developed de novo, almost continuous ENM, triggered by antiepileptic drug (AED) tapering, that resolved with treatment.
Three patients aged 16, 19, and 65 years with a 13- to 36-year history of partial epilepsy were receiving a therapeutic dosage of carbamazepine or phenobarbital plus either clobazam (CLB) or valproate (VPA). None had previously had ENM. Forty-eight to 72 h after CLB or VPA withdrawal, the habitual seizures recurred. The patient also began to report repetitive postural lapses of one or more limbs that interfered with eating or writing. At this time, each patient underwent polygraphy with simultaneous surface electromyography (EMG) of deltoid, biceps, and triceps muscles and of the wrist extensor and flexor bilaterally.
In all patients, EEGs demonstrated almost continuous epileptiform discharges whose spatial distribution was similar to that observed before ENM appearance. Polygraphic recordings showed repetitive loss of postural EMG activity in one or more limbs, 100-400 ms in duration, which occurred in conjunction with the spike-waves. One milligram of clonazepam intravenously always terminated ENM status, which has not recurred in the ensuing 9-36 months.
ENM may emerge as a new type of seizure due to tapering of AED therapy. This effect is possibly related to the great activation of epileptiform activity with consequent interference with cortical activity.
癫痫性负性肌阵挛（ENM）在不同类型的癫痫中越来越受到关注，但其出现的原因及预后仍不明确。我们报告3例患者，他们在抗癫痫药物（AED）逐渐减量过程中出现了新发的、几乎持续的ENM，经治疗后缓解。
3例患者年龄分别为16岁、19岁和65岁，有13至36年的部分性癫痫病史，正在接受卡马西平或苯巴比妥的治疗剂量，加用氯巴占（CLB）或丙戊酸（VPA）。此前均无ENM病史。在停用CLB或VPA后48至72小时，习惯性癫痫发作复发。患者还开始报告一个或多个肢体反复出现姿势性失用，影响进食或书写。此时，每位患者均接受了多导记录，同时双侧三角肌、肱二头肌、肱三头肌以及腕伸肌和屈肌进行表面肌电图（EMG）检查。
所有患者的脑电图均显示几乎持续的癫痫样放电，其空间分布与ENM出现前观察到的相似。多导记录显示一个或多个肢体的姿势性EMG活动反复丧失，持续时间为100至400毫秒，与棘波同时出现。静脉注射1毫克氯硝西泮总能终止ENM状态，在随后的9至36个月中未再复发。
ENM可能作为AED治疗逐渐减量导致的一种新型发作形式出现。这种效应可能与癫痫样活动的大量激活以及随之对皮质活动的干扰有关。
