University of Pennsylvania, Department of Bioengineering, 210 S. 33rd Street, Philadelphia, PA, 19104, USA.
University of Pennsylvania, Department of Bioengineering, 210 S. 33rd Street, Philadelphia, PA, 19104, USA.
Brain Stimul. 2023 Nov-Dec;16(6):1709-1718. doi: 10.1016/j.brs.2023.11.005. Epub 2023 Nov 16.
Longitudinal EEG recorded by implanted devices is critical for understanding and managing epilepsy. Recent research reports patient-specific, multi-day cycles in device-detected epileptiform events that coincide with increased likelihood of clinical seizures. Understanding these cycles could elucidate mechanisms generating seizures and advance drug and neurostimulation therapies.
OBJECTIVE/HYPOTHESIS: We hypothesize that seizure-correlated cycles are present in background neural activity, independent of interictal epileptiform spikes, and that neurostimulation may temporarily interrupt these cycles.
We analyzed regularly-recorded seizure-free data epochs from 20 patients implanted with a responsive neurostimulation (RNS) device for at least 1.5 years, to explore the relationship between cycles in device-detected interictal epileptiform activity (dIEA), clinician-validated interictal spikes, background EEG features, and neurostimulation.
Background EEG features tracked the cycle phase of dIEA in all patients (AUC: 0.63 [0.56-0.67]) with a greater effect size compared to clinically annotated spike rate alone (AUC: 0.55 [0.53-0.61], p < 0.01). After accounting for circadian variation and spike rate, we observed significant population trends in elevated theta and beta band power and theta and alpha connectivity features at the cycle peaks (sign test, p < 0.05). In the period directly after stimulation we observe a decreased association between cycle phase and EEG features compared to background recordings (AUC: 0.58 [0.55-0.64]).
Our findings suggest that seizure-correlated dIEA cycles are not solely due to epileptiform discharges but are associated with background measures of brain state; and that neurostimulation may temporarily interrupt these cycles. These results may help elucidate mechanisms underlying seizure generation, provide new biomarkers for seizure risk, and facilitate monitoring, treating, and managing epilepsy with implantable devices.
通过植入设备记录的纵向脑电图对于理解和治疗癫痫至关重要。最近的研究报告称，在设备检测到的癫痫样事件中存在患者特异性的多日周期，这与临床发作的可能性增加有关。了解这些周期可以阐明引发癫痫发作的机制，并推进药物和神经刺激疗法的发展。
目的/假设：我们假设在背景神经活动中存在与癫痫发作相关的周期，这些周期独立于发作间期癫痫样尖波，并且神经刺激可能会暂时中断这些周期。
我们分析了 20 名植入反应性神经刺激（RNS）设备至少 1.5 年的患者的无癫痫发作的定期记录数据，以探索设备检测到的发作间期癫痫样活动（dIEA）、临床验证的发作间期尖波、背景脑电图特征和神经刺激之间的关系。
在所有患者中，背景脑电图特征都与 dIEA 的周期相位相关（AUC：0.63 [0.56-0.67]），与仅基于临床注释尖波率的相关性相比具有更大的效应量（AUC：0.55 [0.53-0.61]，p<0.01）。在考虑了昼夜节律变化和尖波率后，我们观察到在周期峰值时，θ和β频段功率以及θ和α连通性特征的显著群体趋势（符号检验，p<0.05）。在刺激后的直接时期，我们观察到与背景记录相比，周期相位与 EEG 特征之间的关联减弱（AUC：0.58 [0.55-0.64]）。
我们的研究结果表明，与癫痫发作相关的 dIEA 周期不仅是由于癫痫样放电引起的，还与大脑状态的背景测量有关；并且神经刺激可能会暂时中断这些周期。这些结果可能有助于阐明癫痫发作产生的机制，为癫痫发作风险提供新的生物标志物，并促进使用植入设备进行癫痫的监测、治疗和管理。
