van 't Klooster M A, van Klink N E C, van Blooijs D, Ferrier C H, Braun K P J, Leijten F S S, Huiskamp G J M, Zijlmans M
Brain Center Rudolf Magnus, Department of Neurology and Neurosurgery, University Medical Center Utrecht, The Netherlands.
Brain Center Rudolf Magnus, Department of Neurology and Neurosurgery, University Medical Center Utrecht, The Netherlands.
Clin Neurophysiol. 2017 May;128(5):858-866. doi: 10.1016/j.clinph.2017.01.017. Epub 2017 Feb 6.
Spontaneous high frequency oscillations (HFOs; ripples 80-250Hz, fast ripples (FRs) 250-500Hz) are biomarkers for epileptogenic tissue in focal epilepsy. Single pulse electrical stimulation (SPES) can evoke HFOs. We hypothesized that stimulation distinguishes pathological from physiological ripples and compared the occurrence of evoked and spontaneous HFOs within the seizure onset zone (SOZ) and eloquent functional areas.
Ten patients underwent SPES during 2048Hz electrocorticography (ECoG). Evoked HFOs in time-frequency plots and spontaneous HFOs were visually analyzed. We compared electrodes with evoked and spontaneous HFOs for: percentages in the SOZ, sensitivity and specificity for the SOZ, percentages in functional areas outside the SOZ.
Two patients without spontaneous FRs showed evoked FRs in the SOZ. Percentages of evoked and spontaneous HFOs in the SOZ were similar (ripples 32:33%, p=0.77; FRs 43:48%, p=0.63), but evoked HFOs had generally a lower specificity (ripples 45:69%, p=0.02; FRs 83:92%, p=0.04) and higher sensitivity (ripples 85:70%, p=0.27; FRs 52:37%, p=0.05). More electrodes with evoked than spontaneous ripples were found in functional (54:30%, p=0.03) and 'silent' areas (57:27%, p=0.01) outside the SOZ.
SPES can elicit SOZ-specific FRs in patients without spontaneous FRs, but activates ripples in all areas.
SPES is an alternative for waiting for spontaneous HFOs, but does not warrant exclusively pathological ripples.
自发性高频振荡（HFOs；80 - 250Hz的涟漪，250 - 500Hz的快速涟漪（FRs））是局灶性癫痫中致痫组织的生物标志物。单脉冲电刺激（SPES）可诱发HFOs。我们假设刺激能够区分病理性涟漪和生理性涟漪，并比较了癫痫发作起始区（SOZ）和明确的功能区中诱发和自发性HFOs的出现情况。
10例患者在2048Hz皮层脑电图（ECoG）监测期间接受SPES。对时频图中的诱发HFOs和自发性HFOs进行视觉分析。我们比较了有诱发和自发性HFOs的电极在以下方面的情况：在SOZ中的百分比、对SOZ的敏感性和特异性、在SOZ以外功能区中的百分比。
两名无自发性FRs的患者在SOZ中出现了诱发FRs。SOZ中诱发和自发性HFOs的百分比相似（涟漪32:33%，p = 0.77；FRs 43:48%，p = 0.63），但诱发HFOs的特异性通常较低（涟漪45:69%，p = 0.02；FRs 83:92%，p = 0.04），敏感性较高（涟漪85:70%，p = 0.27；FRs 52:37%，p = 0.05）。在SOZ以外的功能区（54:30%，p = 0.03）和“静区”（57:27%，p = 0.01）中，发现有诱发涟漪的电极比有自发性涟漪的电极更多。
SPES可在无自发性FRs的患者中诱发SOZ特异性FRs，但会激活所有区域的涟漪。
SPES是等待自发性HFOs的一种替代方法，但不能保证仅诱发病理性涟漪。
