Background: Slow-wave activity (SWA) during non-rapid eye movement (NREM) sleep reflects synaptic potentiation during preceding wakefulness. Epileptic activity may induce increases in state-dependent SWA in human brains, therefore, localization of SWA may prove useful in the presurgical workup of epileptic patients. We analyzed high-density electroencephalography (HDEEG) data across vigilance states from a reflex epilepsy patient with a clearly localizable ictal symptomatogenic zone to provide a proof-of-concept for the testability of this hypothesis. Methods: Overnight HDEEG recordings were obtained in the patient during REM sleep, NREM sleep, wakefulness, and during a right facial motor seizure then compared to 10 controls. After preprocessing, SWA (i.e., delta power; 1–4 Hz) was calculated at each channel. Scalp level and source reconstruction analyses were computed. We assessed for statistical differences in maximum SWA between the patient and controls within REM sleep, NREM sleep, wakefulness, and seizure. Then, we completed an identical statistical comparison after first subtracting intrasubject REM sleep SWA from that of NREM sleep, wakefulness, and seizure SWA. Results: The topographical analysis revealed greater left hemispheric SWA in the patient vs. controls in all vigilance states except REM sleep (which showed a right hemispheric maximum). Source space analysis revealed increased SWA in the left inferior frontal cortex during NREM sleep and wakefulness. Ictal data displayed poor source-space localization. Comparing each state to REM sleep enhanced localization accuracy; the most clearly localizing results were observed when subtracting REM sleep from wakefulness. Conclusion: State-dependent SWA during NREM sleep and wakefulness may help to identify aspects of the potential epileptogenic zone. Future work in larger cohorts may assess the clinical value of sleep SWA to help presurgical planning.

中文翻译：

---

反射性癫痫患者局部睡眠慢波活动与发作性症状区共定位：一项高密度脑电图研究

背景：非快速眼动 (NREM) 睡眠期间的慢波活动 (SWA) 反映了之前清醒期间的突触增强。癫痫活动可能会导致人脑中状态依赖性 SWA 的增加，因此，SWA 的定位可能在癫痫患者的术前检查中被证明是有用的。我们分析了来自具有明显可定位发作症状区的反射性癫痫患者在警觉状态下的高密度脑电图 (HDEEG) 数据，以提供对该假设可测试性的概念证明。方法：在 REM 睡眠、NREM 睡眠、清醒和右侧面部运动癫痫期间获得患者的隔夜 HDEEG 记录，然后与 10 名对照组进行比较。预处理后，计算每个通道的 SWA（即增量功率；1-4 Hz）。计算头皮水平和源重建分析。我们评估了 REM 睡眠、NREM 睡眠、觉醒和癫痫发作中患者和对照组之间最大 SWA 的统计差异。然后，我们首先从 NREM 睡眠、觉醒和癫痫发作 SWA 减去受试者内 REM 睡眠 SWA 后完成了相同的统计比较。结果：地形分析显示，在除 REM 睡眠（显示右半球最大值）之外的所有警觉状态下，患者的左半球 SWA 均高于对照组。源空间分析显示在 NREM 睡眠和清醒期间左侧下额叶皮层的 SWA 增加。Ictal 数据显示源空间定位较差。将每个状态与 REM 睡眠进行比较，提高了定位精度；当从清醒中减去 REM 睡眠时，观察到最清晰的定位结果。结论：NREM 睡眠和觉醒期间的状态依赖性 SWA 可能有助于识别潜在致癫痫区的各个方面。在更大的队列中的未来工作可能会评估睡眠 SWA 的临床价值，以帮助术前计划。