Khatamian Yasha Borna, Fahoum Firas, Gotman Jean
Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Canada H3A 2B4.
Epilepsy Res. 2011 May;94(3):177-88. doi: 10.1016/j.eplepsyres.2011.01.018. Epub 2011 Feb 25.
Two-dimensional temporal clustering analysis (2D-TCA) is a relatively new functional MRI (fMRI) based technique that breaks blood oxygen level dependent activity into separate components based on timing and has shown potential for localizing epileptic activity independently of electroencephalography (EEG). 2D-TCA has only been applied to detect epileptic activity in a few studies and its limits in detecting activity of various forms (i.e. activation size, amplitude, and frequency) have not been investigated. This study evaluated 2D-TCA's ability to detect various forms of both simulated epileptic activity and EEG-fMRI activity detected in patients. When applied to simulated data, 2D-TCA consistently detected activity in 6min runs containing 5 spikes/run, 10 spikes/run, and one 5s long event with hemodynamic response function amplitudes of at least 1.5%, 1.25%, and 1% above baseline respectively. When applied to patient data, while detection of interictal spikes was inconsistent, 2D-TCA consistently produced results similar to those obtained by EEG-fMRI when at least 2 prolonged interictal events (a few seconds each) occurred during the run. However, even for such cases it was determined that 2D-TCA can only be used to validate localization by other means or to create hypotheses as to where activity may occur, as it also detects changes not caused by epileptic activity.
二维时间聚类分析（2D-TCA）是一种相对较新的基于功能磁共振成像（fMRI）的技术，它根据时间将血氧水平依赖活动分解为单独的成分，并已显示出独立于脑电图（EEG）定位癫痫活动的潜力。二维时间聚类分析仅在少数研究中应用于检测癫痫活动，其在检测各种形式活动（即激活大小、幅度和频率）方面的局限性尚未得到研究。本研究评估了二维时间聚类分析检测模拟癫痫活动和患者中检测到的脑电图-功能磁共振成像活动的各种形式的能力。当应用于模拟数据时，二维时间聚类分析在包含5次/运行尖峰、10次/运行尖峰和一个5秒长事件的6分钟运行中始终检测到活动，其血液动力学响应函数幅度分别比基线高至少1.5%、1.25%和1%。当应用于患者数据时，虽然发作间期尖峰的检测不一致，但当运行期间至少发生2次延长的发作间期事件（每次持续几秒）时，二维时间聚类分析始终产生与脑电图-功能磁共振成像获得的结果相似的结果。然而，即使对于这种情况，也确定二维时间聚类分析只能用于通过其他方法验证定位或对活动可能发生的位置提出假设，因为它也检测到不是由癫痫活动引起的变化。
