Valentin Antonio, Arunachalam Ramamurthy, Mesquita-Rodrigues Arvin, Garcia Seoane Jorge J, Richardson Mark P, Mills Kerry R, Alarcon Gonzalo
Department of Clinical Neuroscience, Institute of Psychiatry, King's College London, United Kingdom.
Epilepsia. 2008 Mar;49(3):470-80. doi: 10.1111/j.1528-1167.2007.01418.x. Epub 2007 Nov 19.
To evaluate the use of EEG responses to transcranial magnetic stimulation (TMS-EEG responses) as a noninvasive tool for the diagnosis of focal epilepsy.
Fifteen patients and 15 healthy subjects were studied. TMS at an intensity set at resting corticomotor threshold were delivered at the standard EEG electrode positions. For each position, EEG responses to TMS were evaluated before and after averaging EEG recordings synchronized with the TMS pulse.
Two types of TMS-EEG responses were seen: (A) early responses: consisting of a single slow wave seen after the TMS pulse; and (B) late TMS-EEG responses, which were subclassified into (b.1) delayed responses: waveforms resembling interictal epileptiform discharges induced by TMS; or (b.2) repetitive responses: onset of a new rhythym induced by TMS. Early responses were observed in patients and healthy subjects when stimulating at various sites and were considered normal responses to TMS. Late TMS-EEG responses were not seen in healthy subjects, whereas they were seen in 11 of the 15 epileptic patients. Late TMS-EEG responses occurred when stimulating the epileptogenic side in eight out of the nine patients who had lateralized late TMS-EEG responses. The combined use of late TMS-EEG responses and interictal scalp EEG would have suggested the diagnosis of focal epilepsy in all patients, despite the absence of late TMS-EEG responses in four patients and the presence of normal interictal scalp EEG in three.
TMS-EEG responses can identify epileptogenic cortex and may substantially improve the diagnosis of focal epilepsy, particularly, if combined with standard EEG studies.
评估脑电图对经颅磁刺激的反应（TMS - EEG反应）作为诊断局灶性癫痫的非侵入性工具的应用。
对15例患者和15名健康受试者进行研究。在标准脑电图电极位置以静息皮质运动阈值设定的强度进行经颅磁刺激。对于每个位置，在将脑电图记录与经颅磁刺激脉冲同步平均前后，评估脑电图对经颅磁刺激的反应。
观察到两种类型的TMS - EEG反应：（A）早期反应：由经颅磁刺激脉冲后出现的单个慢波组成；（B）晚期TMS - EEG反应，进一步分为（b.1）延迟反应：波形类似于经颅磁刺激诱发的发作间期癫痫样放电；或（b.2）重复反应：经颅磁刺激诱发的新节律的起始。在不同部位刺激时，患者和健康受试者均观察到早期反应，被认为是对经颅磁刺激的正常反应。健康受试者未观察到晚期TMS - EEG反应，而15例癫痫患者中有11例出现。在9例晚期TMS - EEG反应呈侧化的患者中，有8例在刺激致痫侧时出现晚期TMS - EEG反应。尽管4例患者没有晚期TMS - EEG反应，3例患者的发作间期头皮脑电图正常，但晚期TMS - EEG反应与发作间期头皮脑电图联合使用可提示所有患者的局灶性癫痫诊断。
TMS - EEG反应可识别致痫皮层，并可能显著改善局灶性癫痫的诊断，特别是与标准脑电图研究相结合时。
