Jiruska Premysl, Proks Jan, Otáhal Jakub, Mares Pavel
Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
Seizure. 2007 Oct;16(7):627-35. doi: 10.1016/j.seizure.2007.05.004. Epub 2007 Jun 12.
Bilateral synchronous epileptiform discharges registered in patients with partial epilepsies may be generated by different pathophysiological mechanisms. Differentiation between underlying mechanisms is often crucial for correct diagnosis and adequate treatment in clinical epileptology. The aim of this study was to model in rats two possible mechanisms--secondary bilateral sychrony and interaction between multiple epilepic foci. Furthermore, to describe in detail semiology, laterality and differences in motor phenomena. Secondary bilateral synchrony was modeled by unilateral topical application of bicuculline methiodide (BMI) over the sensorimotor cortex. Bilateral symmetric application of BMI was used as a model of multiple epileptic foci. Electrographic and behavioural phenomena were recorded for 1h following the application of BMI. Electroencephalogram in both groups was characterized by presence of bilateral synchronous discharges. Myoclonic and clonic seizures involving forelimb and head muscles represented the most common motor seizure pattern in both groups. Significant differences were found in the laterality of motor phenomena. Motor seizures in unilateral foci always started in the contralateral limbs whereas symmetrical foci exhibited bilateral independent onset of convulsions. Similar lateralization was observed in interictal motor phenomena (myoclonic jerks). An important influence of posture on epileptic motor phenomena was demonstrated. Active or passive changes in animal posture (verticalization to bipedal posture) caused conversion from unilateral myoclonic jerks or clonic seizures to bilaterally synchronous (generalized) motor phenomena in both groups.
在部分性癫痫患者中记录到的双侧同步癫痫样放电可能由不同的病理生理机制产生。在临床癫痫学中，区分潜在机制对于正确诊断和恰当治疗通常至关重要。本研究的目的是在大鼠中模拟两种可能的机制——继发性双侧同步和多个癫痫病灶之间的相互作用。此外，详细描述症状学、偏侧性以及运动现象的差异。通过在感觉运动皮层单侧局部应用甲硫酸荷包牡丹碱（BMI）来模拟继发性双侧同步。双侧对称应用BMI作为多个癫痫病灶的模型。在应用BMI后记录1小时的脑电图和行为现象。两组的脑电图均以双侧同步放电为特征。涉及前肢和头部肌肉的肌阵挛性和阵挛性发作是两组中最常见的运动性发作模式。在运动现象的偏侧性方面发现了显著差异。单侧病灶的运动性发作总是始于对侧肢体，而对称病灶则表现为双侧独立的惊厥发作起始。在发作间期运动现象（肌阵挛性抽搐）中也观察到了类似的偏侧化。证实了姿势对癫痫运动现象有重要影响。动物姿势的主动或被动改变（直立为双足姿势）导致两组中从单侧肌阵挛性抽搐或阵挛性发作转变为双侧同步（全身性）运动现象。
