Division of Neurology, The Hospital for Sick Children, Toronto, Canada.
Department of Neurosurgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
Epilepsia. 2019 Sep;60(9):1849-1860. doi: 10.1111/epi.16295. Epub 2019 Aug 13.
We analyzed the features of fast oscillations (FOs) and connectivity in hypsarrhythmia to identify biomarkers for predicting seizure outcomes after total corpus callosotomy (TCC) in children with pharmacoresistant infantile spasms (IS). We hypothesize that the power of FOs and connectivity of slow waves in hypsarrhythmia would indicate the prognosis of IS.
We retrospectively identified 42 children with pharmacoresistant IS who underwent TCC from 2009 to 2014 at Nagasaki Medical Center. We collected preoperative hypsarrhythmia for 200 seconds from each child. Children were categorized into three groups with interictal epileptic discharges on EEG at 6 months after TCC: group A, no epileptic discharge; group B, lateralized epileptic discharges; and group C; bilateral epileptic discharges. We analyzed spectral power and phase synchronization in preoperative hypsarrhythmia among the three groups.
We found 10 children in group A, 10 children in group B, and 22 children in group C. All group A and 1 in group B achieved seizure freedom after TCC. Six (67%) of 9 group B children who underwent further surgeries achieved seizure freedom. Ten (45%) of group C children had seizure reduction >50% after TCC, and 13 (87%) of 15 children who underwent further surgeries had residual seizures. The clinical profiles of the three groups did not differ significantly. The power of FOs (≥45 Hz) in hypsarrhythmia was significantly stronger in group C at the midline and temporal regions than in groups B and A (P = .014). The connectivity of theta (4-9 Hz) and FOs (29-70 Hz) tended to increase in group C, compared with the increased connectivity of 1-2 Hz in group A (P = .08).
The increased power and connectivity of FOs in hypsarrhythmia may correlate with pharmacoresistant and surgically resistant seizures in IS. The existence and connectivity of FOs are associated with unilateral/bilateral cortical epileptogenicity in hypsarrhythmia. Prominent slow waves and connectivity without FOs might correlate with seizure freedom after TCC. Modulation of the callosal system with subcortical/cortical epileptic discharges might play a role in generating hypsarrhythmia and IS.
我们分析了高度失律中的快振荡（FOs）和连通性特征，以确定预测药物难治性婴儿痉挛（IS）患儿全胼胝体切开术（TCC）后癫痫发作结局的生物标志物。我们假设高度失律中 FOs 的功率和慢波的连通性将表明 IS 的预后。
我们回顾性地确定了 2009 年至 2014 年间在长崎医疗中心接受 TCC 的 42 名药物难治性 IS 患儿。我们从每个孩子那里收集了术前 200 秒的高度失律。根据 TCC 后 6 个月的脑电图（EEG）上有无发作间期癫痫放电，将患儿分为三组：A 组无癫痫放电；B 组局灶性癫痫放电；C 组双侧癫痫放电。我们分析了三组患儿术前高度失律中的频谱功率和相位同步。
我们发现 A 组 10 例，B 组 10 例，C 组 22 例。A 组和 B 组各 1 例患儿 TCC 后癫痫发作完全消失。进一步手术的 9 例 B 组患儿中有 6 例（67%）癫痫发作消失。TCC 后 10 例（45%）C 组患儿癫痫发作减少>50%，15 例进一步手术的患儿中 13 例（87%）仍有残留癫痫发作。三组患儿的临床特征无显著差异。与 B 组和 A 组相比，C 组中线和颞区高度失律中的 FOs（≥45 Hz）功率明显更强（P =.014）。与 A 组 1-2 Hz 连通性增加相比，C 组的θ（4-9 Hz）和 FOs（29-70 Hz）连通性有增加趋势（P =.08）。
高度失律中 FOs 的增加功率和连通性可能与 IS 中的药物难治性和手术抵抗性癫痫发作相关。FOs 的存在和连通性与高度失律中的单侧/双侧皮质致痫性相关。没有 FOs 的明显慢波和连通性可能与 TCC 后癫痫发作消失相关。与皮质下/皮质癫痫放电的胼胝体系统调制可能在产生高度失律和 IS 中发挥作用。
