Biochemical pathogenesis of post-traumatic epilepsy

Head trauma is often followed by epilepsy and may be related to the breakdown of red blood cells and hemoglobin within the CNS. Injection of hemoglobin or iron salts into the rat cortex is known to induce a chronic epileptic focus. We observed the formation of superoxide anion (O₂) and hydroxyl radical (·OH) after ferric chloride injection into the rat cerebral cortex and suggest that these radicals, especially ·OH, may be responsible for the initiation of lipid peroxidation in neuronal membranes and for the accelerated production of guanidine compounds in the brain, which may in turn lead to epileptogenicity. Then, we found that treatment with epigallocatechin (EGC) or a phosphate diester of vitamins E and C (EPC), which are potent ·OH scavengers, significantly inhibited the formation of malondialdehyde and epileptic discharges in the iron-induced epileptic focus. This study was supported by a grant-in-aid for scientific research from the Japanese Ministry of Education, Science, and Culture.