Epilepsy Center, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Clin Neurophysiol. 2012 Feb;123(2):252-60. doi: 10.1016/j.clinph.2011.06.030. Epub 2011 Jul 28.
To better understand pathological neuronal excitation in epilepsy by comparing cortico-cortical evoked potential (CCEP) responses in regions with different ictal onset patterns: focal paroxysmal fast (PF) and repetitive spiking (RS).
Fourteen patients undergoing invasive monitoring (six patients with PF and eight with RS) were studied with CCEPs. A repetitive 1 Hz bipolar electrical stimulus was applied to both the ictal onset region (iCCEP) and to a control region (nCCEP) and CCEPs were recorded from the surrounding electrodes. The two groups were compared by subtracting the amplitude of nCCEP from that of iCCEP (CCEP(ictal-control)) at each stimulus intensity, and then normalizing the amplitudes of iCCEP at maximum stimulus intensity by dividing by nCCEP (CCEP(ictal/control)).
The CCEP response to stimulation in the ictal onset region was significantly larger than to control stimulation for both ictal patterns (paroxysmal fast: P=0.02, repetitive spiking: P<0.01), with repetitive spiking group amplitudes higher than the paroxysmal fast group (CCEP(ictal-control): P<0.01 and CCEP(ictal/control): P=0.04).
Pro-epileptic excitability is more accentuated in regions showing an ictal repetitive spiking pattern than a paroxysmal fast pattern.
These findings confirm in a new way that cortical excitability varies depending on the ictal onset pattern.
通过比较具有不同发作起始模式（局灶性阵发性快（PF）和重复尖波（RS））的区域中的皮质-皮质诱发电位（CCEP）反应，更好地理解癫痫中的病理性神经元兴奋。
对 14 名接受侵袭性监测的患者（6 名 PF 患者和 8 名 RS 患者）进行了 CCEP 研究。对发作起始区域（iCCEP）和对照区域（nCCEP）施加 1 Hz 双极重复电刺激，并从周围电极记录 CCEPs。通过从每个刺激强度的 nCCEP 中减去 iCCEP 的振幅（CCEP（发作-对照）），然后通过将最大刺激强度下 iCCEP 的振幅除以 nCCEP（CCEP（发作/对照））来比较两组。
对于两种发作模式（阵发性快：P=0.02，重复尖波：P<0.01），刺激发作起始区域的 CCEP 反应明显大于对照刺激，重复尖波组的振幅高于阵发性快波组（CCEP（发作-对照）：P<0.01 和 CCEP（发作/对照）：P=0.04）。
与阵发性快模式相比，具有重复尖波发作模式的区域中致癫痫兴奋性更为明显。
这些发现以一种新的方式证实，皮质兴奋性取决于发作起始模式。
