ObjectiveTo investigate the efficacy and safety of Stereotactic electroencephalogram (SEEG)-guided Radiofrequency-thermocoagulation (RF-TC) in the treatment of refractory insular epilepsy in children.MethodsThe clinical data of 7 children with SEEG-confirmed insular epilepsy admitted to the Epilepsy Center of the Children’s Hospital Affiliated to Shandong University from January 2021 to May 2022, were retrospectively analyzed (3 males and 4 females; average age, 6.6±3.5 years). All patients underwent stage I pre-operative evaluation, and were implanted with SEEG electrodes for video EEG monitoring. The radiofrequency thermocoagulation contacts were determined according to SEEG and imaging results, and radiofrequency thermocoagulation was performed via electrode contacts. The patients were followed up at 3, 6, 12 and 18 months after operation by outpatient review or via telephone interview. The clinical efficacy was evaluated by Engel classification and complications were recorded. ResultsSix cases (6/7) were characterized by nocturnal seizures, and four cases (4/7) exhibited hypermotor or complex motor seizures. Three cases (3/7) showed focal ankylosis; only 1 patient had aura. All of the 7 cases showed interictal scalp EEG consistent with the side of surgery: 6 cases showed distribution in the perilateral fissure region, and 1 case showed confinement to the temporal region. In MRI, 4 cases showed negative signal, 2 cases showed unclear gray-white matter boundary, and 1 case showed thickening of the insular cortex. All of the 7 patients received electrode implantation and completed follow-up for over 6 months [6.0~22.0 (12.3±5.3) months]. At the last follow-up, 5 of the 7 children were seizure free (Engel class la), and 2 still had seizures after surgery, with no postoperative long-term complications.ConclusionChildren with insular epilepsy rarely show an aura, but have prominent motor symptoms, and the scalp electroencephalogram is mainly distributed in the perilateral fissured area. SEEG-guided RF-TC has good safety and efficacy in the treatment of drug‐resistant insular epilepsy.
ObjectiveTo investigate the application of stereoelectroencephalography (SEEG) in the refractory epilepsy related to periventricular nodular heterotopia (PNH). MethodsTen patients with drug-resistant epilepsy related to PNHs from Guangdong Sanjiu Brain Hospital and the First Affiliated Hospital of Jinan University from April 2017 to February 2021 were studied. Electrodes were implanted based on non-invasive preoperative evaluation. Then long-term monitoring of SEEG was carried out. The patterns of epileptogenic zone (EZ) were divided into four categories based on the ictal SEEG: A. only the nodules started; B. nodules and cortex synchronous initiation; C. the cortex initiation with early spreading to nodules; D. only cortex initiation. All patients underwent SEEG-guided radiofrequency thermocoagulation (RFTC), with a follow-up of at least 12 months. ResultsAll cases were multiple nodules. Four cases were unilateral and six bilateral. Eight cases were distributed in posterior pattern, and one in anterior pattern and one in diffused pattern, respectively. Seven patients had only PNH (pure PNH) and three patients were associated with other overlying cortex malformations (PNH plus). The EZ patterns of all cases were confirmed by the ictal SEEG: six patients were in pure type A, two patients were in pure type B, one patient in type A+B and one in type A+B+C, respectively. In eight patients SEEG-guided RF-TC was targeted only to PNHs; and in two patients RFTC was directed to both heterotopias and related cortical regions. The mean follow up was (33.4±14.0) months (12 ~ 58 months). Eight patients (in pure type A or type A included) were seizure free. Two patients were effective. None of the patients had significant postoperative complications or sequelae. ConclusionThe epileptic network of Epilepsy associated with nodular heterotopia may be individualized. Not all nodules are always epileptogenic, the role of each nodule in the epileptic network may be different. And multiple epileptic patterns may occur simultaneously in the same patient. SEEG can provide individualized diagnosis and treatment, be helpful to prognosis.
ObjectivesPost-encephalitic epilepsy could be of great chance of pharmaco-resistant, even surgery may not achieve seizure free. The aim of this study is to mapping epileptogenic area of pharmaco-resistant post-encephalitic temporal lobe epilepsy, to find whether "temporal plus" epilepsy is the main type and its surgery outcome, based on stereo-EEG(SEEG) study.MethodWe retrospectively studied 15 patients with pharmaco-resistant temporal lobe epilepsy. Scalp EEG, seizure semiology, MRI, FDG-PET, and SEEG were reviewed for all patients. According to epileptogenic area which was analysed by SEEG, 15 patients were divided into 2 groups, temporal lobe epilepsy(TLE) group and temporal plus epilepsy(TPE) group. Clinical characteristics were compared with each group, by t-test or Fisher exact test when data needed.ResultsThere were 8 patients in TLE group, with 6 mesial TLE, 1 lateral TLE, 1 mesial-lateral TLE. And 7 patients in TPE group. Age of seizure onset (P=0.548), duration of epilepsy (P=0.099), age of remote encephalitis (P=0.385), type of semiology (P=0.315) and lateralization of MR lesions (P=1.000), interictal FDG-PET hypometabalism (P=1.000) or intracranial implantation (P=0.619) were of no statistically difference between TLE group and TPE group. Surgery was performed in all patients. Better outcome was obtained in TLE group(5/8 class Ⅰ), and poor was in TPE group(3/7class Ⅰ).ConclusionMesial-TLE and temporal plus epilepsy were common types of pharmaco-resistant post-encephalitic TLE. There was no way to differentiate clinically, except by SEEG. Mesial-TLE had a better outcome after surgery, but temporal plus epilepsy did not.
Epileptic seizures and the interictal epileptiform discharges both have similar waveforms. And a method to effectively extract features that can be used to distinguish seizures is of crucial importance both in theory and clinical practice. We constructed state transfer networks by using visibility graphlet at multiple sampling intervals and analyzed network features. We found that the characteristics waveforms in ictal periods were more robust with various sampling intervals, and those feature network structures did not change easily in the range of the smaller sampling intervals. Inversely, the feature network structures of interictal epileptiform discharges were stable in range of relatively larger sampling intervals. Furthermore, the feature nodes in networks during ictal periods showed long-term correlation along the process, and played an important role in regulating system behavior. For stereo-electroencephalography at around 500 Hz, the greatest difference between ictal and the interictal epileptiform occurred at the sampling interval around 0.032 s. In conclusion, this study effectively reveals the correlation between the features of pathological changes in brain system and the multiple sampling intervals, which holds potential application value in clinical diagnosis for identifying, classifying, and predicting epilepsy.
For refractory epilepsy requiring surgical treatment in clinic, precise preoperative positioning of the epileptogenic zone is the key to improving the success rate of clinical surgical treatment. Although the use of electrical stimulation to locate epileptogenic zone has been widely carried out in many medical centers, the preoperative implantation evaluation of stereoelectroencephalography (SEEG) and the interpretation of electrical stimulation induced EEG activity are still not perfect and rigorous. Especially, there are still technological limitations and unknown areas regarding electrode implantation mode, stimulation parameters design, and surgical prognosis correlation. In this paper, the clinical background, application status, technical progress and development trend of SEEG-based stereo-electric stimulation-induced cerebral electrical activity in the evaluation of refractory epilepsy are reviewed, and applications of this technology in clinical epileptogenic zone localization and cerebral cortical function evaluation are emphatically discussed. Additionally, the safety during both of high-frequency and low-frequency electrical stimulations which are commonly used in clinical evaluation of refractory epilepsy are also discussed.