From the NeuroTec (E.v.M., S.L.A., C.F.-M., K.W., S.F., M.F., A.T., K.S., M.O.B.), Center for Sleep-Wake-Epilepsy, Center for Experimental Neurology, Department of Neurology, Inselspital Bern, University Hospital, and Institute of Computer Science (S.L.A., A.T.), University of Bern; Wyss Center for Bio and Neuroengineering (J.R.d.C., A.S., I.V., J.Z., T.B., G.K.), Geneva; Department of Neurosurgery (S.L.B., W.J.Z.G., C.P.), Inselspital Bern, University Hospital, University of Bern, Switzerland; and Department of Neuroscience (J.D.), Brown University, Providence, RI.
Neurology. 2024 Jun 25;102(12):e209428. doi: 10.1212/WNL.0000000000209428. Epub 2024 Jun 6.
Current practice in clinical neurophysiology is limited to short recordings with conventional EEG (days) that fail to capture a range of brain (dys)functions at longer timescales (months). The future ability to optimally manage chronic brain disorders, such as epilepsy, hinges upon finding methods to monitor electrical brain activity in daily life. We developed a device for full-head subscalp EEG (Epios) and tested here the feasibility to safely insert the electrode leads beneath the scalp by a minimally invasive technique (primary outcome). As secondary outcome, we verified the noninferiority of subscalp EEG in measuring physiologic brain oscillations and pathologic discharges compared with scalp EEG, the established standard of care.
Eight participants with pharmacoresistant epilepsy undergoing intracranial EEG received in the same surgery subscalp electrodes tunneled between the scalp and the skull with custom-made tools. Postoperative safety was monitored on an inpatient ward for up to 9 days. Sleep-wake, ictal, and interictal EEG signals from subscalp, scalp, and intracranial electrodes were compared quantitatively using windowed multitaper transforms and spectral coherence. Noninferiority was tested for pairs of neighboring subscalp and scalp electrodes with a Bland-Altman analysis for measurement bias and calculation of the interclass correlation coefficient (ICC).
As primary outcome, up to 28 subscalp electrodes could be safely placed over the entire head through 1-cm scalp incisions in a ∼1-hour procedure. Five of 10 observed perioperative adverse events were linked to the investigational procedure, but none were serious, and all resolved. As a secondary outcome, subscalp electrodes advantageously recorded EEG percutaneously without requiring any maintenance and were noninferior to scalp electrodes for measuring (1) variably strong, stage-specific brain oscillations (alpha in wake, delta, sigma, and beta in sleep) and (2) interictal spikes peak-potentials and ictal signals coherent with seizure propagation in different brain regions (ICC >0.8 and absence of bias).
Recording full-head subscalp EEG for localization and monitoring purposes is feasible up to 9 days in humans using minimally invasive techniques and noninferior to the current standard of care. A longer prospective ambulatory study of the full system will be necessary to establish the safety and utility of this innovative approach.
clinicaltrials.gov/study/NCT04796597.
目前的临床神经生理学实践仅限于使用传统 EEG 进行短期记录（数天），无法在更长的时间范围内（数周）捕捉到大脑的各种（功能障碍）。未来优化管理慢性脑疾病（如癫痫）的能力取决于寻找在日常生活中监测脑电活动的方法。我们开发了一种全头皮下脑电（Epios）设备，并在此处测试了通过微创技术安全地将电极引线插入头皮下的可行性（主要结果）。作为次要结果，我们验证了与头皮 EEG 相比，亚头皮 EEG 在测量生理脑振荡和病理放电方面的非劣效性，头皮 EEG 是目前的护理标准。
8 名药物难治性癫痫患者在颅内 EEG 手术中接受了亚头皮电极，这些电极通过定制工具在头皮和颅骨之间的隧道中插入。术后在住院病房中监测安全性，最长可达 9 天。使用窗口多谱勒变换和频谱相干性对来自亚头皮、头皮和颅内电极的睡眠-觉醒、发作和发作间期 EEG 信号进行定量比较。通过 Bland-Altman 分析测量偏倚和计算组内相关系数（ICC），对相邻亚头皮和头皮电极的配对进行非劣效性检验。
作为主要结果，通过在大约 1 小时的手术中进行 1 厘米头皮切口，可以安全地将多达 28 个亚头皮电极放置在整个头部。观察到的 10 例围手术期不良事件中有 5 例与研究程序有关，但均不严重，且均已解决。作为次要结果，亚头皮电极有利地经皮记录 EEG，无需任何维护，并且在测量（1）变化强度、特定阶段的脑振荡（清醒时的阿尔法、德尔塔、西格玛和睡眠时的贝塔）和（2）发作间期棘波峰电位和与不同脑区癫痫传播一致的发作信号时，与头皮电极一样具有非劣效性（ICC>0.8，无偏差）。
使用微创技术，在人类中进行全头皮下脑电记录以进行定位和监测是可行的，最长可达 9 天，并且与当前的护理标准不劣。需要进行更长时间的前瞻性门诊研究，以确定这种创新方法的安全性和实用性。
clinicaltrials.gov/study/NCT04796597。
