Departments of Neurology and Neurosurgery, Weill-Cornell Medical, New York-Presbyterian Hospital, New York, NY, USA.
Neuromodulation. 2013 Jul-Aug;16(4):355-61; discussion 362. doi: 10.1111/ner.12039.
Responsive cortical electrical stimulation with implanted devices is under investigation for seizures. While designed to terminate seizures, might this stimulation also affect the underlying epileptic process of seizure generation?
Four patients undergoing intracranial electroencephalogram (EEG) for seizure localization had an external responsive neurostimulator (eRNS) connected to their seizure-onset zones. The eRNS detected interictal EEG spikes and stimulated at the focus. We quantified spikes at three locations: (1) near stimulation, (2) remote but in the same lobe as stimulation, and (3) in different lobe from stimulation. Ten-minute windows were analyzed at three times: (1) baseline, (2) after the first four hours of stimulation, and (3) poststimulation. One blinded investigator performed manual spike counts. Quantitative measures were total spikes, spike-free intervals (continuous ten-sec segments with no spikes), and spike clusters (one-sec intervals with three or more spikes).
Some changes in spikes occurred in each patient, but no uniform pattern emerged. Two general observations were made: (1) spike counts within a given patient exhibited internally consistent changes with stimulation; (2) across patients, the nature of spike count changes varied, indicating patient-to-patient variability. For example, poststimulation, two patients had more and two patients had fewer total spikes. However, when spikes decreased near stimulation, they decreased at other sites, and when spikes increased near stimulation, they increased at other sites.
Changes in spike occurrence, organization, and topography with stimulation suggest the eRNS affected spike generation and may affect the underlying interictal epileptic process. Case-to-case variability may be due to individual patient factors, and its significance is yet to be determined.
植入式设备的响应性皮质电刺激正在研究用于治疗癫痫发作。虽然这种刺激旨在终止癫痫发作，但它是否也会影响癫痫发作产生的潜在癫痫过程？
四名接受颅内脑电图 (EEG) 以定位癫痫发作的患者将外部响应性神经刺激器 (eRNS) 连接到他们的癫痫发作起始区。eRNS 检测到癫痫发作间期的 EEG 棘波并在焦点处进行刺激。我们在三个位置量化了棘波：(1) 靠近刺激部位，(2) 远离刺激部位但在刺激部位同侧的脑叶，以及 (3) 远离刺激部位的脑叶。在三个时间点分析了十分钟的窗口：(1) 基线，(2) 刺激后的前四个小时，以及 (3) 刺激后。一名盲法研究者进行了手动棘波计数。定量测量包括总棘波数、无棘波间隔（连续十秒无棘波的片段）和棘波簇（一秒内有三个或更多棘波的间隔）。
每个患者的棘波都发生了一些变化，但没有出现统一的模式。观察到两个一般结论：(1) 给定患者内的棘波计数表现出与刺激一致的内部变化；(2) 在患者之间，棘波计数变化的性质不同，表明患者之间存在变异性。例如，刺激后，两名患者的总棘波数增加，两名患者的总棘波数减少。然而，当刺激部位的棘波数量减少时，其他部位的棘波数量也会减少，而当刺激部位的棘波数量增加时，其他部位的棘波数量也会增加。
刺激时棘波发生、组织和分布的变化表明 eRNS 影响了棘波的产生，并可能影响潜在的癫痫发作间期过程。病例之间的变异性可能是由于个体患者因素引起的，其意义仍有待确定。
