Cantello R, Civardi C, Cavalli A, Varrasi C, Tarletti R, Monaco F, Migliaretti G
Neurology and *Statistics Units, Department of Medical Sciences, School of Medicine, "Amedeo Avogadro" University, Novara, Italy.
Epilepsia. 2000 Jun;41(6):694-704. doi: 10.1111/j.1528-1157.2000.tb00230.x.
To assess whether single-and paired-pulse transcranial magnetic stimulation (TMS) can measure the interictal brain excitability of medicated patients with cryptogenic localization related epilepsy (CLE). Changes in the balance between excitation and inhibition are the core phenomena in focal epileptogenesis. TMS can assess this balance in the primary motor cortex.
We selected 18 patients with CLE and similar clinical features in whom we located the epileptogenic area reliably, with 11 age-and sex-matched healthy controls. For both motor cortices, we determined the threshold to TMS, the duration of the cortical silent period, and the corticocortical inhibition and facilitation curve.
TMS was safe. The more antiepileptic drugs (AEDs) taken by the patients, the higher their threshold to TMS. The silent period duration failed to show significant changes. On paired TMS, a cluster analysis identified a homogeneous subgroup of patients (n = 7) who showed a significantly defective corticocortical inhibition and excess facilitation. With respect to the epileptogenic area, the phenomenon was bilateral in four of these patients, ipsilateral in two, and contralateral in one. The phenomenon was independent of AEDs and many other clinical variables. However, this patient group had a higher seizure frequency and a higher proportion of electroencephalograms (EEGs) showing interictal generalized epileptic discharges than the rest of the patients.
Paired TMS provided a valuable pathophysiologic insight into the interictal excitatory state of the cortex in CLE. This method can potentially supply useful prognostic clinical information.
评估单脉冲和双脉冲经颅磁刺激（TMS）能否测量隐源性定位相关癫痫（CLE）药物治疗患者的发作间期脑兴奋性。兴奋与抑制平衡的变化是局灶性癫痫发生的核心现象。TMS可评估初级运动皮层的这种平衡。
我们选择了18例具有相似临床特征且能可靠定位致痫区的CLE患者，以及11名年龄和性别匹配的健康对照者。对于双侧运动皮层，我们测定了TMS阈值、皮层静息期持续时间以及皮质皮质抑制和易化曲线。
TMS是安全的。患者服用的抗癫痫药物（AED）越多，其TMS阈值越高。静息期持续时间未显示出显著变化。在双脉冲TMS中，聚类分析确定了一组同质的患者亚组（n = 7），他们表现出明显的皮质皮质抑制缺陷和过度易化。关于致痫区，其中4例患者的这种现象是双侧的，2例是同侧的，1例是对侧的。这种现象与AED及许多其他临床变量无关。然而，该患者组的癫痫发作频率较高，脑电图（EEG）显示发作间期广泛性癫痫放电的比例也高于其他患者。
双脉冲TMS为CLE患者发作间期皮层兴奋状态提供了有价值的病理生理学见解。该方法可能提供有用的预后临床信息。
