Objective: To investigate the expression of cation chloride cotransporter (NKCC1/KCC2) in the neurons from cerebral lesions of children with focal cortical dysplasia (FCD) type Ⅱ, to provide a morphological basis for revealing the possible mechanism of epilepsy. Methods: Eight cases of FCD type Ⅱ diagnosed at Beijing Haidian Hospital, Beijing, China and 12 cases diagnosed at Xuanwu Hospital, Capital Medical University, Beijing, China from February 2017 to December 2019 were included. The expression of NKCC1 and KCC2 in FCD type Ⅱa and FCD type Ⅱb was detected using immunohistochemistry and double immunohistochemical stains. The average optical density of NKCC1 in dysmorphic neurons and normal neurons was also determined using immunohistochemical staining in FCD type Ⅱa (10 cases). Results: The patients were all younger than 14 years of age. Ten cases were classified as FCD type IIa, and 10 cases as FCD type Ⅱb. NKCC1 was expressed in the cytoplasm of normal cerebral cortex neurons and KCC2 expressed on cell membranes. In dysmorphic neurons of FCD type Ⅱa, expression of NKCC1 increased, which was statistically higher than that of normal neurons (P<0.01). Aberrant expression of KCC2 in dysmorphic neurons was also noted in the cytoplasm. In the FCD Ⅱb type, the expression pattern of NKCC1/KCC2 in dysmorphic neurons was the same as that of FCD type Ⅱa. The aberrant expression of NKCC1 in balloon cells was negative or weakly positive on the cell membrane, while the aberrant expression of KCC2 was absent. Conclusions: The expression pattern of NKCC1/KCC2 in dysmorphic neurons and balloon cells is completely different from that of normal neurons. The NKCC1/KCC2 protein-expression changes may affect the transmembrane chloride flow of neurons, modify the effect of inhibitory neurotransmitters γ-aminobutyric acid and increase neuronal excitability. These effects may be related to the occurrence of clinical epileptic symptoms.
Child ; Humans ; Brain/pathology* ; Cations/metabolism* ; Chlorides/metabolism* ; Epilepsy/metabolism* ; Malformations of Cortical Development, Group I/metabolism* ; Solute Carrier Family 12, Member 2/metabolism* ; Symporters/metabolism*

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*

In 2011, the International League against Epilepsy (ILAE) proposed a first international consensus of the classification of focal cortical dysplasia (FCD). This FCD classification had been widely used in worldwide. In this review paper, the authors would like to give helpful comments for better understanding of the current FCD classification. Especially, the basic concepts of FCD type I, such as “radial”, “tangential” and “microcolumn” will be discussed with figures. In addition, the limitations, genetic progress and prospect of FCD will be suggested.
Classification ; Consensus ; Embryology ; Epilepsy ; Humans ; Malformations of Cortical Development ; Pathology

Happle-Tinschert syndrome is a disorder causing unilateral segmentally arranged basaloid follicular hamartomas of the skin associated with ipsilateral osseous, dental and cerebral abnormalities including tumors. Although a case with hemimegalencephaly was previously described, this is the first report of Happle-Tinschert syndrome with discrepant short left leg, ipsilateral skin lesions, hemimegalencephaly and frontal polymicrogyria.
Basal Cell Nevus Syndrome/diagnosis ; Child ; Dental Enamel/abnormalities ; *Frontal Lobe/pathology ; Hamartoma/*diagnosis/pathology ; Humans ; Leg Length Inequality/*diagnosis ; Magnetic Resonance Imaging ; Male ; Malformations of Cortical Development/*diagnosis ; Skin Diseases/*diagnosis/pathology ; Syndrome

OBJECTIVETo investigate whether mammalian target of rapamycin (mTOR) kinase was abnormally activated in maldeveloped balloon cells and dysmorphic neurons of focal cortical dysplasia (FCD) with refractory epilepsy.

METHODSA total of 12 archival cases of FCD typeIIwith medically intractable epilepsy treated between 2008 and 2010 were retrieved. Perilesional brain tissue was used as control specimens (n = 8). The expression of phosphorylated p-AKT (Ser473), p-mTOR (Ser2448) and p-P70S6K (Thr389) was investigated by imunocytochemistry.

RESULTSThe expression of p-AKT (Ser473), p-mTOR (Ser2448) and p-P70S6K (Thr389) was found in meldeveloped balloon cells and dysmorphic neurons of FCD. A weak stain in a small amount of pyramid neurons was also found in the control group.

CONCLUSIONAbnormal activation of mTOR in maldeveloped balloon cells and dysmorphic neurons of FCD may be a key molecular mechanism underlying the histological changes and repeated seizures.

Adolescent ; Adult ; Brain Diseases ; metabolism ; pathology ; Child, Preschool ; Epilepsy ; metabolism ; pathology ; Female ; Glial Fibrillary Acidic Protein ; metabolism ; Humans ; Immunohistochemistry ; Male ; Malformations of Cortical Development ; metabolism ; pathology ; Malformations of Cortical Development, Group I ; Nestin ; metabolism ; Neurons ; metabolism ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Ribosomal Protein S6 Kinases, 70-kDa ; metabolism ; TOR Serine-Threonine Kinases ; metabolism ; Young Adult

This study was performed to assess the usefulness of magnetoencephalography (MEG) as a presurgical evaluation modality in Korean pediatric patients with lesional localization-related epilepsy. The medical records and MEG findings of 13 pediatric patients (6 boys and 7 girls) with localization-related epilepsy, who underwent epilepsy surgery at Seoul National University Children's Hospital, were retrospectively reviewed. The hemispheric concordance rate was 100% (13/13 patients). The lobar or regional concordance rate was 77% (10/13 patients). In most cases, the MEG spike sources were clustered in the proximity of the lesion, either at one side of the margin (nine patients) or around the lesion (one patient); clustered spike sources were distant from the lesion in one patient. Among the patients with clustered spike sources near the lesion, further extensions (three patients) and distal scatters (three patients) were also observed. MEG spike sources were well lateralized and localized even in two patients without focal epileptiform discharges in the interictal scalp electroencephalography. Ten patients (77%) achieved Engel class I postsurgical seizure outcome. It is suggested that MEG is a safe and useful presurgical evaluation modality in pediatric patients with lesion localization-related epilepsy.
Adolescent ; Brain/radionuclide imaging ; Brain Diseases/pathology ; Child ; Child, Preschool ; Epilepsies, Partial/pathology/*surgery ; Female ; Ganglioglioma/pathology ; Humans ; Infant ; Magnetic Resonance Imaging ; *Magnetoencephalography ; Male ; Malformations of Cortical Development/pathology ; Neoplasms, Neuroepithelial/pathology ; Positron-Emission Tomography ; Retrospective Studies ; Seizures/diagnosis

Aicardi syndrome is a rare neurodevelopmental disease characterised by congenital chorioretinal lacunae, corpus callosum dysgenesis, seizures, polymicrogyria, cerebral callosum, chorioretinopathy and electroencephalogram abnormality. We present a case of Aicardi syndrome with callosal hypogenesis in a 4.5-month-old baby who presented with infantile spasms. Ophthalmoscopy revealed chorioretinal lacunae. The clinical and magnetic resonance imaging features were diagnostic of Aicardi syndrome.
Agenesis of Corpus Callosum ; diagnosis ; Aicardi Syndrome ; diagnosis ; Brain ; diagnostic imaging ; pathology ; Choroid ; abnormalities ; Cornea ; physiopathology ; Female ; Humans ; Infant ; Magnetic Resonance Imaging ; methods ; Malformations of Cortical Development ; diagnosis ; Ophthalmoscopy ; methods ; Radiography ; Retina ; abnormalities ; Spasms, Infantile ; diagnosis

OBJECTIVETo investigate the clinicopathologic features of the brain tissue diagnosed as ulegyria from modified anatomic hemispherectomy for refractory epilepsy.

METHODSThe clinical and pathologic findings were reviewed in 39 patients who underwent modified anatomic hemispherectomy and diagnosed as ulegyria in the Epilepsy Center of Tsinghua University Yuquan Hospital from 2007 to 2011.

RESULTSAll patients including 30 males and 9 females had medically intractable seizures, and the mean age of seizure onset and disease duration were 4.0 years and 7.3 years respectively. Significant history included febrile seizure in 14 patients (35.9%), cerebral hemorrhage in 8 patients (20.5%), fetal distress and surgical trauma each in 6 patients (15.4%), vascular malformation and cerebral hemorrhage in 1 patient (2.6%), and unclear history in 4 patients (10.2%). Histologically, all cases were characterized by cortical destruction, with neuronal loss and gliosis. All cases were accompanied by varying degree of cortical dysplasia, which were diagnosed as focal cortical dysplasia IIId. Hippocampus sclerosis was identified in 2 cases. Seizure outcome after surgery revealed 37 patients (94.9%) had an Engel grade I, two patients (5.1%) had an Engel grade II.

CONCLUSIONSFebrile seizure, cerebral hemorrhage, fetal distress and surgical trauma in childhood can lead to refractory epilepsy. Histopathological change in the brain is ulegyria accompanied by focal cortical dysplasia IIId. Modified anatomic hemispherectomy is an effective therapy to treat those patients with extensive changes of one hemisphere.

Adolescent ; Adult ; CD3 Complex ; metabolism ; Cerebral Cortex ; abnormalities ; pathology ; surgery ; Child ; Child, Preschool ; Epilepsy ; metabolism ; pathology ; surgery ; Female ; Follow-Up Studies ; Hemispherectomy ; methods ; Humans ; Infant ; Magnetic Resonance Imaging ; Male ; Malformations of Cortical Development ; metabolism ; pathology ; surgery ; Retrospective Studies ; Young Adult

OBJECTIVETo investigate the expression of TSC1, TSC2, p-mTOR, p-4E-BP1, p-p70S6K and p-S6 in refractory epilepsy associated malformation of cortical development (MCD) tissues.

METHODSA total of 43 cases of refractory epilepsy were involved in the study, and all the patients were treated in Xuanwu Hospital during 2005 - 2008, including focal cortical dysplasia type IIa (11 cases) and type IIb (11 cases), tuberous sclerosis complex (10 cases) and ganalioglioma (11 cases), and other 12 cases were used as control. These cases were divided into 7 study groups and immunohistochemical EnVision method was used. To detect the location and intensity of TSC1, TSC2, p-mTOR, p-4E-BP1, p-p70S6K and p-S6 expression in every group. Then the Image-Pro Plus 6.0 image processing and analysis software were used to measure the number, area, integrating absorbance (IA) of positive cells in every samples. The statistical software SPSS 16.0 was used to analyze the data.

RESULTSThe immunolocalization of TSC1 and TSC2 was similar. It could be observed the expression of various levels in the cytoplasm of dysmorphic neurons, balloon cells, giant cells, ganglioglioma cells and normal neurons. TSC1 staining in normal neurons was more notably than others but TSC2 staining in giant cells was weaker than other samples. p-mTOR mainly presented in giant cells, which could also be observed in astrocyte. P-4E-BP1 presented in the cytoplasm and nuclear membrane of balloon cells, giant cells and ganglioglioma cells, the staining of giant cells was stronger than balloon cells, but their staining were weaker than ganglioglioma cells. P-p70S6K mainly expressed in giant cells and less commonly presented in balloon cells. P-S6 typically presented in all abnormal glioneuronal cells and it nearly did not present in the normal neurons of N-CTX group.

CONCLUSIONSPI3K pathway, at least in part, involves in the occurrence of MCD, and may play an important role in the pathogenesis.

Adaptor Proteins, Signal Transducing ; metabolism ; Adolescent ; Adult ; Child ; Epilepsy ; metabolism ; pathology ; Female ; Ganglioglioma ; metabolism ; pathology ; Humans ; Male ; Malformations of Cortical Development ; metabolism ; pathology ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphoproteins ; metabolism ; Ribosomal Protein S6 Kinases ; metabolism ; Ribosomal Protein S6 Kinases, 70-kDa ; metabolism ; Signal Transduction ; TOR Serine-Threonine Kinases ; metabolism ; Tuberous Sclerosis ; metabolism ; pathology ; Tumor Suppressor Proteins ; metabolism ; Young Adult

Adolescent ; Adult ; Antigens, Nuclear ; metabolism ; Brain Diseases ; complications ; diagnosis ; pathology ; surgery ; Brain Neoplasms ; pathology ; Child ; Child, Preschool ; Diagnosis, Differential ; Epilepsy ; etiology ; Female ; Ganglioglioma ; pathology ; Glial Fibrillary Acidic Protein ; metabolism ; Humans ; Infant ; Magnetic Resonance Imaging ; Male ; Malformations of Cortical Development ; classification ; complications ; diagnosis ; pathology ; surgery ; Malformations of Cortical Development, Group I ; Microtubule-Associated Proteins ; metabolism ; Neoplasms, Neuroepithelial ; pathology ; Nerve Tissue Proteins ; metabolism ; Neurofilament Proteins ; metabolism ; Retrospective Studies ; Vimentin ; metabolism ; Young Adult