Posttraumatic Epilepsy, Free Radicals and Antioxidant Therapy

Abstract

Each year, head injuries from car accidents and other causes result in a large population of patients with epileptic seizure disorders.The development of such posttraumatic epilepsy may be related to the breakdown of red blood cells and hemoglobin within the central nervous system. Subpial injection of hemoglobin or iron salts into rat cortex is known to induce a chronic epileptic focus. We observed the formation of superoxide anion and hydroxyl radical (•OH) after ferric chloride injection into rat cerebral cortex, and suggested that these radicals, especially •OH, may be responsible for the initiation of lipid peroxidation in neuronal membranes and for the accelerated production of endogenous convulsants, i.e., guanidino compounds, in the brain. These disorders may in turn lead to epileptogenicity. We found that treatment with epigallocatechin or a phosphate diester of vitamins E and C, which are potent •OH scavengers, significantly inhibited the formation of thiobarbituric acid-reactive substances and epileptic discharges in the iron-induced epileptic focus.