CORTICAL DYSPLASIA - AN IMMUNOCYTOCHEMICAL STUDY OF 3 PATIENTS

Human cortical dysplastic lesions are frequently associated with sever e partial epilepsies. We report an immunocytochemical investigation on cortical tissue from three surgically treated patients, 20, 38, and 1 4 years old, with intractable epilepsy due to cortical dysplasia. The studies were performed using antibodies recognizing cytoskeletal prote ins, calcium-binding proteins, and some subunits of glutamate receptor s. The specimens from the three patients displayed common features: (1 ) focal cytoarchitectural abnormalities with an increased number of gi ant pyramidal neurons through all cortical layers except layer I; (2) large, round-shaped balloon cells mainly concentrated in the deepest p art of the cortex and in the white matter; (3) a decrease of calcium b inding protein immunopositive gamma-aminobutyric acid (GABA)ergic neur ons; and (4) abnormal baskets of parvalbumin-positive terminals around the excitatory (pyramidal and large, round-shaped) neurons. These dat a provide evidence that the epileptogenicity in these types of cortica l dysplasia is due to an increase in excitatory neurons coupled with a decrease in GABAergic interneurons.