Drug-refractory epilepsy (DRE) may be treated by surgical intervention. Intracranial EEG has been widely used to localize the epileptogenic zone (EZ). Most studies of epileptic network focus on the features of EZ nodes, such as centrality and degrees. It is difficult to apply those features to the treatment of individual patients. In this study, we proposed a spatial neighbor expansion approach for EZ localization based on a neural computational model and epileptic network reconstruction. The virtual resection method was also used to validate the effectiveness of our approach. The electrocorticography (ECoG) data from 11 patients with DRE were analyzed in this study. Both interictal data and surgical resection regions were used. The results showed that the rate of consistency between the localized regions and the surgical resections in patients with good outcomes was higher than that in patients with poor outcomes. The average deviation distance of the localized region for patients with good outcomes and poor outcomes were 15 mm and 36 mm, respectively. Outcome prediction showed that the patients with poor outcomes could be improved when the brain regions localized by the proposed approach were treated. This study provides a quantitative analysis tool for patient-specific measures for potential surgical treatment of epilepsy.
Humans ; Epilepsy/surgery* ; Brain/surgery* ; Electrocorticography/methods* ; Drug Resistant Epilepsy/surgery* ; Brain Mapping/methods* ; Electroencephalography/methods*

Temporal lobe epilepsy, with a variety of etiological, symptomatic, electrophysiological characteristics, has the highest incidence among all focal epilepsy, and a high rate of progression to refractory epilepsy. Surgery is an effective treatment, but traditional methods are usually difficult to accurately locate the epileptogenic zone, which may be resolved by stereotactic-electroencephalogram(SEEG) technique. Radiofrequency thermocoagulation and MRI-guided laser interstitial thermal therapy based on SEEG provide a new accurate and minimally invasive choice for refractory epilepsy patients with high surgical risk and difficulty.
Drug Resistant Epilepsy/surgery* ; Electrocoagulation/methods* ; Electroencephalography ; Epilepsy, Temporal Lobe/surgery* ; Humans ; Stereotaxic Techniques

Focal cortical dysplasia (FCD) is one of the most common causes of drug-resistant epilepsy. Dysmorphic neurons are the major histopathological feature of type II FCD, but their role in seizure genesis in FCD is unclear. Here we performed whole-cell patch-clamp recording and morphological reconstruction of cortical principal neurons in postsurgical brain tissue from drug-resistant epilepsy patients. Quantitative analyses revealed distinct morphological and electrophysiological characteristics of the upper layer dysmorphic neurons in type II FCD, including an enlarged soma, aberrant dendritic arbors, increased current injection for rheobase action potential firing, and reduced action potential firing frequency. Intriguingly, the upper layer dysmorphic neurons received decreased glutamatergic and increased GABAergic synaptic inputs that were coupled with upregulation of the Na⁺-K⁺-Cl^- cotransporter. In addition, we found a depolarizing shift of the GABA reversal potential in the CamKII-cre::PTEN^flox/flox mouse model of drug-resistant epilepsy, suggesting that enhanced GABAergic inputs might depolarize dysmorphic neurons. Thus, imbalance of synaptic excitation and inhibition of dysmorphic neurons may contribute to seizure genesis in type II FCD.
Animals ; Drug Resistant Epilepsy/surgery* ; Epilepsy/pathology* ; Malformations of Cortical Development/pathology* ; Malformations of Cortical Development, Group I ; Mice ; Neurons/pathology* ; Seizures/pathology*

OBJECTIVETo study the clinicopathologic features of tuberous sclerosis complex (TSC).

METHODSThe clinicopathologic data of the patients diagnosed as TSC with refractory epilepsy and resection of epileptic focus were retrospectively analyzed.

RESULTSFourteen cases were included, the mean age was (15.8±12.9) years, with a male predominance (male to female ratio=10:4). Frontal lobe was the most common (13/14) site of involvement. MRI showed multiple patchy long T1 and long T2 signals. CT images showed multiple subependymal high density calcified nodules in nine cases. Histology showed mild to severe disruption of the cortical lamination, cortical and subcortical tubers with giant cells and/or dysmorphic neurons. The giant cells showed strong immunoreactivity for vimentin and nestin, while the dysmorphic neurons partially expressed MAP2 and NF. Vimentin also stained strongly the "reactive" astrocytes. Thirteen cases had follow-up information: Engel class I in six cases, Engel class II in six cases, and Engel class III in one case.

CONCLUSIONSDiagnosis of TSC relies on combined pathologic, clinical and neuroradiological features. Immunohistochemical staining can be helpful. Resection of epileptic focus is an effective method to treat refractory epilepsy in TSC.

Adolescent ; Astrocytes ; chemistry ; pathology ; Child ; Drug Resistant Epilepsy ; surgery ; Epilepsy ; complications ; metabolism ; pathology ; Epilepsy, Frontal Lobe ; complications ; metabolism ; pathology ; Female ; Giant Cells ; chemistry ; pathology ; Humans ; Magnetic Resonance Imaging ; Male ; Nestin ; analysis ; Neurons ; metabolism ; pathology ; Retrospective Studies ; Tuberous Sclerosis ; complications ; metabolism ; pathology ; Vimentin ; analysis