Alteration of GABAergic neurons and abnormality of NKCC1/KCC2 in focal cortical dysplasia (FCD) type â ¡ lesions.

BACKGROUND: The current conclusions of molecular genetics still cannot satisfactorily explain the pathogenesis of focal cortical dysplasia (FCD) and the reason for drug resistance. The interneurons of GABA deserve attention. To observe the distribution and changes of GABAergic neurons and to explore the expression of cation chloride cotransporter NKCC1/KCC2 in focal cortical dysplasia (FCD) type II lesions is a highly significant job. METHODS: The expressions of GAD67(a marker of active GABAergic neuron), NKCC1 and KCC2 were detected by immunohistochemistry and immunohistochemistry double staining in 10 cases of FCD Ⅱa and 10 cases of FCD Ⅱb. The number of GAD67 positive neurons was counted, and the average absorbance (IA) of NKCC1 positive expression was measured, using Image Pro-Plus7.0 software. The data were statistically analyzed. RESULTS: The density of GABAergic neuron in focal dysplastic regions was significantly lower than that in the histologically "normal" cerebral cortex, regions from the same specimen (p < 0.0001, t-test). Compared to the NKCC1 staining intensity of neurons in the control group (measuring 1000 cells each), the IA value of dysmorphic neurons was significantly increased (p < 0.05, t'-test Cochran & Cox method). Intracytoplasmic concentration of KCC2 was evident in dysmorphic neurons but not in the other mature neurons. Most of the balloon cells were negative for NKCC1, except for few balloon cells showing sparse colored particles. The expression of KCC2 was negative in all balloon cells. CONCLUSIONS: The changes in the expression of NKCC1 and KCC2 may indicate that dysmorphic neurons were in a state similar to that of immature neurons. This state may be related to the abnormal electrophysiology of epilepsy. The difference between the number of GAD67 positive cells in the lesion site and the remote site of the same case may be an evaluation index of the effectiveness of surgery.

Ganglioglioma: a clinicopathological study of 19 cases / 临床与实验病理学杂志

Purpose To study the clinicopathologic features of ganglioglioma. Methods The clinicopathologic data of the cases pathologically diagnosed as ganglioglioma that underwent resection of epileptic focus were retrospectively analyzed. Results In the 19 cases studied, the mean onset age was 9.1 years, and the duration of disease was 9.3 years. MRI images showed abnormal signals. The majority of the site was temporal lobe (14/19, 73.7％). The tumors showed heterogeneity and often accompanied by focal cortical dysplasias (13/19, 68.4％). Immunohistochemical staining showed CD34 positive in 18 cases, Nestin positive in 16 cases, and BRAF-V600E positive in 6 case. The positive expression rate of CD34 and Nestin did not have significant differences. Conclusion The diagnosis of ganglioglioma relies on pathological observations combined with clinical features and neuroradiological examinations. Differential diagnosis should be done from other tumors or cortical dysplasia. Immunohistochemical staining of CD34 and Nestin can help diagnosis.