应用因果分析方法对癫痫发作间期头皮脑电信号进行致痫灶定侧

Epileptic foci lateralization from interictal scalp EEG by applying causal analysis

目的利用因果分析方法对癫痫发作间期的头皮脑电信号进行致痫灶定侧。方法在频域因果分析方法——自适应直接传递函数（ADTF）的基础上提出功率谱加权ADTF（psADTF）法，以给定频段内信号的功率谱对ADTF的标准化做加权，以适应不同癫痫波频域信息不同的特点。利用该方法对2组共30例患者的头皮脑电信号进行分析，含组1癫痫手术患者15例，组2门诊癫痫患者15例。其中组1患者共截取癫痫波样本数104个，组2患者共截取癫痫波样本数98个。结果组1患者通过psADTF分析对致痫灶定侧与手术侧一致的有96个，平均单个癫痫波致痫灶定侧准确率可达92％；组2患者通过psADTF分析对致痫灶定侧与专家判读结果一致的有94个，平均单个癫痫波致痫灶定侧准确率达96％。结论发作间期头皮脑电癫痫波信号的psADTF分析能够很好地辅助临床致痫灶定侧。

Objective To lateralize epileptic foci in interictal electroencephalography （EEG） signal by using causal analysis method. Methods On the basis of frequency domain causal analysis, the adapted directed transfer function （ADTF）, power spectrum weighted ADTF（psADTF） method was proposed by applying the power spectrum information in defined frequency band with normalized ADTF, to fit the frequency information features of different epileptic wave. EEG signals of two groups of 30 epilepsy patients were analyzed by psADTF. Group I included 15 pre- surgical patients and 104 epilepsy spikes were picked from EEG signals. Group II included 15 outpatient patients and 98 epilepsy spikes were picked from EEG signals. Results 96 of 104 spikes of group I were lateralized properly by psADTF according to surgery sites, and the accuracy rate was 92%. 94 of 98 spikes of group II were lateralized properly by psADTF according to three technicians＇ judgments, with the accuracy rate of 96%. Conclusion Our results proves that the psADTF method over interictal EEG spikes can be a great help to clinical epileptic foci lateralization.