Hur Yun Jung, Kim Heung Dong
Department of Pediatrics, Haeundae Paik Hospital, Inje University College of Medicine, Pusan, Republic of Korea.
Division of Pediatric Neurology, Department of Pediatrics, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Clin Neurophysiol. 2016 Aug;127(8):2862-2868. doi: 10.1016/j.clinph.2016.05.011. Epub 2016 May 25.
Callosotomy can reveal hidden primary epileptogenic areas in Lennox-Gastaut syndrome (LGS). We studied the significance of causal connectivity for identifying hidden epileptogenic areas in preoperative electroencephalography (EEG) and for making a decision regarding resective surgery.
We enrolled 18 LGS patients who underwent corpus callosotomy. Eight patients with unilateral epileptogenicity on post-callosotomy EEG underwent resective surgery (group A). Ten patients with independent bilateral epileptogenicity did not undergo resective surgery (group B). We analyzed generalized epileptiform discharges on pre-callosotomy EEG via direct directed transfer function (dDTF) and partial directed coherence (PDC).
All regions exhibiting unilaterality in group A and bilaterality identified by dDTF or PDC in group B were concordant with the lateralization of the irritative zone on post-callosotomy EEG and with the localization of the resective areas, except for one patient in group A. The regions identified by dDTF exhibited high concordance rates with the resective areas in patients with good outcomes.
Causal connectivity methods showed good concordance with hidden epileptogenic areas, and its concordance was associated with the prognosis of surgical outcome.
This study provides evidence that causal connectivity methods can be helpful in deciding which type of surgery will be suitable for an LGS patient.
胼胝体切开术可揭示Lennox-Gastaut综合征（LGS）中隐藏的原发性致痫区。我们研究了因果连接性在术前脑电图（EEG）中识别隐藏致痫区以及决定是否进行切除性手术方面的意义。
我们纳入了18例接受胼胝体切开术的LGS患者。8例胼胝体切开术后脑电图显示单侧致痫性的患者接受了切除性手术（A组）。10例具有独立双侧致痫性的患者未接受切除性手术（B组）。我们通过直接定向传递函数（dDTF）和部分定向相干性（PDC）分析了胼胝体切开术前脑电图上的全身性癫痫样放电。
A组中所有表现为单侧性的区域以及B组中通过dDTF或PDC确定为双侧性的区域，除A组中的1例患者外，均与胼胝体切开术后脑电图上刺激区的侧别以及切除区域的定位一致。dDTF确定的区域与预后良好的患者的切除区域显示出较高的一致性。
因果连接性方法与隐藏的致痫区显示出良好的一致性，并且其一致性与手术结果的预后相关。
本研究提供了证据，表明因果连接性方法有助于决定哪种类型的手术适合LGS患者。
