表面肌电图在局灶性癫痫双侧强直发作中的定侧价值

Lateralizing value of surface electromyography in bilateral seizures of focal epilepsy

目的分析局灶性癫痫中双侧肢体强直发作的表面肌电图特点。方法将22例局灶性癫痫患者的74次双侧肢体强直发作作为观察组，6例全面性癫痫患者的57次发作作为对照组，对其同步表面肌电图进行定量、定性分析。结果典型的强直肌电图电位以递增（build—up）形式出现。观察组83．8％（62／74）的发作首先记录到强直肌电图电位的一侧位于致痫区对侧，观察组强直肌电图电位“build—up”时间为3S、双侧肢体强直电位时间差为2．44S，对照组分别为0．89s和0．14s，两组比较差异有统计学意义。观察组中外侧面皮层组强直肌电图正确定侧率高于矢状面皮层组（88．2％比73．9％）。结论表面肌电图是客观、敏感的侧向征象。双侧强直肌电图电位时间差值大于250Ins时，提示局灶性癫痫可能。

Objective To evaluate the characteristics of EMG on bilateral extremities tonic seizures in patients with localization-related epilepsy. Methods A total of 74 seizures in 22 localization-related epilepsy patients were included in observed group. 57 seizures of 6 patients who had generalized epileptic diseharge were included in control group. After quantitative and qualitative analysis of the EMG, the positive rate of lateralization and its signifieance were evaluated. Results During the typical tonic phase of seizures, the motor unit action potential of muscles appeared in the form of build-up. The initial EMG activities in 83.8%（62/74） seizures were of lateralizing signs to the side eontralateral to the seizure onset. In observed group, the build-up duration of initial tonic EMG activities was 3 s and the difference of bilateral tonic EMG activities was 2.44 s. While in control group, it was 0.89 s and 0.14 s. There were statistically significant differences between two groups. In observed group, the positive rate of lateralization based on BETS＇ s EMG in the lateral cortex epilepsy group was higher than that in parasagittal cortex epilepsy group （88.2% vs. 73.9%）. Conclusions The asymmetric EMG is an objective and sensitive lateralizing sign. When the difference of bilateral tonic EMG activities is longer than 250 ms, it is possible that the epilepsy has a focal origin.