Increase trend of correlation and phase synchrony of microwire iEEG before macroseizure onset
Increase trend of correlation and phase synchrony of microwire iEEG before macroseizure onset
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DOI：
10.1007/s11571-013-9270-0
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发表时间：
2014-04
影响因子：
3.7
通讯作者：
Sanqing Hu;Jianfen Chi;Jianhai Zhang;Wanzeng Kong;Yu Cao;Bin He
中科院分区：
文献类型：
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作者：
Sanqing Hu;Jianfen Chi;Jianhai Zhang;Wanzeng Kong;Yu Cao;Bin He
在癫痫患者中植入微/大电极记录的微/大导线颅内脑电图（iEEG）信号受到了广泛的关注，与皮质电极记录的头皮脑电图相比，它们被认为包含了癫痫发作过渡期间神经元活动的更多信息。微电极比大电极与神经元的接触更近，对神经元活动的变化比大电极更敏感。在揭示导致癫痫发作的神经元机制方面，微线脑电图记录不可避免地优于大线脑电图记录。在这项研究中，我们研究了从微线脑电图记录中产生的癫痫发作，并讨论了微线脑电图在四个频段的同步：α (1 - 30 Hz), γ (30 - 80 Hz)，纹波（80 - 250 Hz）和快速纹波（>250 Hz），通过两个测量：相关和相位同步。我们发现，在大癫痫发作之前，相关性或相位同步的增加趋势主要存在于伽玛和纹波带，在不同的癫痫发作中，前兆状态的持续时间不等，最长可达几秒（几分钟）。这一发现与众所周知的结果相反，即在宏观癫痫发作之前，宏观域的同步减少存在。这一发现表明，只有当癫痫发作已经聚集了足够多的周围脑组织时，信号才会变得足够强，可以在临床大电极上观察到，从而支持微癫痫发作区域逐渐合并的假设。这种对微尺度癫痫发作活动的早期检测的潜在后果可能会在癫痫发作活动完全建立之前对其进行可能的破坏，从而为治疗打开一扇新的窗口。
Micro/macrowire intracranial EEG (iEEG) signals recorded from implanted micro/macroelectrodes in epileptic patients have received great attention and are considered to include much information of neuron activities in seizure transition compared to scalp EEG from cortical electrodes. Microelectrode is contacted more close to neurons than macroelectrode and it is more sensitive to neuron activity changes than macroelectrode. Microwire iEEG recordings are inevitably advantageous over macrowire iEEG recordings to reveal neuronal mechanisms contributing to the generation of seizures. In this study, we investigate the seizure generation from microwire iEEG recordings and discuss synchronization of microwire iEEGs in four frequency bands: alpha (1−30 Hz), gamma (30−80 Hz), ripple (80–250 Hz), and fast ripple (>250 Hz) via two measures: correlation and phase synchrony. We find that an increase trend of correlation or phase synchrony exists before the macroseizure onset mostly in gamma and ripple bands where the duration of the preictal states varied in different seizures ranging up to a few seconds (minutes). This finding is contrast to the well-known result that a decrease of synchronization in macro domains exists before the macroseizure onset. The finding demonstrates that it is only when the seizure has recruited enough surrounding brain tissue does the signal become strong enough to be observed on the clinical macroelectrode and as a result support the hypothesis of progressive coalescence of microseizure domains. The potential ramifications of such an early detection of microscale seizure activity may open a new window on treatment by making possible disruption of seizure activity before it becomes fully established.