ABSTRACT
Objective:To analyze the characteristics of stereoelectroencephalography (SEEG) in children with drug-resistant epileptic spasms (ES), and to explore the surgical strategy of children with spastic seizure under the guidance of SEEG.Methods:The clinical data of 156 children with ES who were preoperatively evaluated in the Department of Neurosurgery Ward 3, Tsinghua University Yuquan Hospital from January 2014 to December 2021 were retrospectively reviewed.All children were evaluated in the second stage of stereotactic electrode placement after a non-invasive preoperative evaluation.The characteristics of intracranial EEG, surgical strategy and prognosis were analyzed.Results:A total of 19 eligible children were included, involving 13 boys and 6 girls.The age of first onset and surgical age of them ranged 1 month to 4 years, and 2 years to 13 years, respectively.The SEEG was divided into 3 types in children with ES at the onset.Five children were SEEG type A, presenting with the focal seizure discharges at the beginning and a gradual propagation to widespread fast-wave bursts.Ten children were SEEG type B, presenting a focal leading spike followed by diffused fast-wave bursts.Four children were SEEG type C, presenting a diffuse fast wave rhythm onset.Although some electrode discharges appeared slightly " leading", they covered more than one brain region.After focal resection or thermocoagulation, 13/19 patients did not have the onset of seizures, and 5/19 and 8/19 were graded as SEEG type A, and B, respectively.During the intermittent period of SEEG attacks in children with SEEG type A and B, a significant phenomenon of focal epileptic discharge consistent with the onset of the attack was observed, and surgical removal of these areas effectively controlled spastic seizures.Conclusions:Epileptic spasms may be triggered by a focal neocortical discharge.Intracranial EEG showed that the focal seizure onset evolves into spasm or a focal " leading spike" is a good indicator of surgical prognosis.
ABSTRACT
Objective To propose a novel stereo-electroencephalography(SEEG) quantitative measure analyzing ictal high frequency (60-90 Hz) and calculating high frequency epileptogenicity index (HFEI) to localize epileptogenic zone and evaluate epileptogenic network. Methods The clinical presurgical evaluation and SEEG data of 15 patients who were performed SEEG electrodes implantation from April 2015 to March 2016 were analyzed retrospectively. Post-implantation head CT images and 3D MRI data were fused for accurately identifying and locating each electrode contact. Ictal SEEG quantitative measure HFEI was calculated and threshold was set. The epileptogenic network was divided into focal, regional, multiple regional and bilateral ones and the results were compared with the pathological results.Results The epileptogenic network was focal for four patients, regional for four patients, multiple regional for six patients and bilateral for one patient (7/15). In terms of the pathology,two cases with hippocampal sclerosis both showed regional network. In four cases with cerebral malacia, two cases showed multiple regional network and the other two cases showed focal network. In six cases with cortical malformation, three cases showed multiple regional network, the other three cases showed focal, regional and bilateral networks respectively. Conclusions We explored a novel SEEG quantitative measure based on the high frequency power analysis,which is objective and could localize epileptogenic zone and evaluate the epileptic network.