头皮脑电高频振荡波对继发性癫痫致痫灶的定位价值

Scalp high frequency oscillations helps identify epileptogenic zone in secondary epilepsy

目的通过比较继发性癫痫患者头皮脑电高频振荡波与棘尖波在激惹区和发作启动区（seizure onset zone,SOZ）内外的出现率和分布特点,探讨高频振荡波对致痫灶的定位价值。方法回顾性分析我院2011年9月至2012年9月37例继发性癫痫患者的视频脑电图,将发作间期痫样放电（interictal epileptiform discharges,IEDs）出现的导联定为A区（即激惹区）,无IEDs出现的导联定为B区,根据发作前10-30 s率先出现发作期放电（ictal discharge,ID）的导联定为C区（即SOZ）,无ID的导联定为D区。比较IEDs（滤波范围：1-30 Hz）和Ripples（滤波范围：80-250 Hz）的出现率、出现量及分布特点,并比较二者定位SOZ的敏感性、特异性、准确性。结果 137例患者IEDs和Ripples的总出现率分别为100.0%（37/37）、48.6%（18/37）,经χ^2检验IEDs明显高于Ripples（P〈0.01）。进一步分析A和B、C和D区中Ripples的出现量分别为每导联（0.08±0.15）、（0.03±0.03）、（0.12±0.29）、（0.04±0.06）次/min,经t检验A区大于B区,C区大于D区（P〈0.01）。237例患者IEDs和Ripples出现的平均导联数分别为（12.4±5.8）、（4.2±3.6）,经t检验Ripples的导联数明显少于IEDs（P〈0.01）。3IEDs和Ripples定位SOZ的敏感性分别为IEDs 81.6%,Ripples 51.1%;特异性分别为IEDs 57.1%,Ripples 87.9%;准确性分别为IEDs 54.0%,Ripples 80.6%。二者相比IEDs敏感性高于Ripples（P〈0.01）,特异性和准确性低于后者（P〈0.01）。结论继发性癫痫患者致痫灶中,高频振荡波与痫样放电关系密切,且特异性和准确性较高有助于IEDs定位致痫灶;但因敏感性太低,尚不能取代IEDs独立定位致痫灶。

Objective To compare the occurrence rate and distribution of spine sharp wave and high frequency oscillations inside and outside the irritative zone and seizure onset zone（ SOZ） in secondary epilepsy patients by scalp electroencephalography（ EEG） in order to evaluate the localization value for epileptogenic zone. Methods A retrospective analysis study of video electroencephalogram（ V-EEG） data in our hospital from September 2011 to September 2012 including 37 patients with secondary epilepsy was carried out. The channels with interictal epileptiform discharges（ IEDs） were defined as area A（ namely irritability area） and those without IEDs were defined as area B. The channels with ictal discharge（ ID） in 10 to 30 s before the seizure onset were defined as area C and those without ID were defined as area D. IEDs（ 1 to 30 Hz） and ripples（ 80 to 250 Hz） in each area were marked. We analyzed the occurrence rate,quantity,distribution and sensitivity,specificity and accuracy to determine the SOZ. Results（ 1） The total occurrence rate of IEDs and ripples was 100%（ 37 /37） and 48. 6%（ 18 /37） in 37 patients,respectively,and that of IEDs was significantly higher（ Chi-square test,P 0. 01）. The average rates（ times / min） of ripples in area A,B,C and D were 0. 08 ± 0. 15,0. 03 ± 0. 03,0. 12 ± 0. 29,and 0. 04 ± 0. 06,respectively,suggesting that the average rate of ripples of area A was greater than that of area B and area C greater than area D（ t test,P 0. 01）.（ 2） The average channel of ripples was 4. 2 ± 3. 6 in each patient,significantly less than that of IEDs12. 4 ± 5. 8（ t test,P 0. 01）.（ 3） Compared to the IEDs,the ripples were less sensitive（ ripples 51. 1% vs IEDs 81. 6%） but more specific（ ripples 87. 9% vs IEDs 57. 1%） and more accurate（ ripples 80. 6% vs IEDs54%） in determining the SOZ. Conclusion High frequency oscillations are closely associated with epileptiform discharges in the epileptogenic zone of secondary epilepsy patients,with higher specificity to identify SOZ. But the sensitivity is too low to replace IEDs to identify SOZ independently. High frequency oscillations help IEDs to localize epileptogenic zone.