Effects of intracortical injection of blood and blood components on the electrocorticogram.

Long term effects of the intracortical implantation of blood and blood products on the electrocorticogram were studied in cats and guinea pigs. Focal epileptiform paroxysmal discharges developed after implantation of whole blood, hemolyzed erythrocytes, methemoglobin, ferritin, ferrous chloride, ferric chloride, fibrinogen, hemin, and cottonoid. In each group recurrent paroxysmal discharges became more prominent and more frequent after several months, suggesting a physiological change caused by a breakdown product of blood. The lesions were characterized by varying degrees of cell loss, iron deposition and glial proliferation. It is thought that posttraumatic epilepsy, which is frequently accompanied by extravasation of blood into the brain, might share a similar physiopathogenesis.