Posttraumatic epilepsy with special emphasis on prophylaxis and prevention

Abstract

Posttraumatic epileptic seizures have an incidence of about 10% in series of severe head injuries. Control of "early seizures", i.e. those occurring in the first week after injury, is mandatory. Attacks, especially if recurrent, may add secondary damage to the injured brain: intravenous phenythoin with therapeutic plasma level allows control of the attacks. Seizures occurring months or years after injury are called "late seizures": recurring "late seizures" make up the clinical syndrome of "posttraumatic epilepsy". "Prophylaxis" should mean that drug treatment, given for a more or less prolonged period of time, blocks permanently the ripening of the epileptogenic foci avoiding the occurrence of seizures. In animal "prophylaxis" by antiepileptic drugs seems efficacious in many experimental models including iron induced epilepsy which is considered a model of posttraumatic epilepsy and vice versa. In the human being "prophylaxis" has been attempted with: phenytoin, phenobarbital, carbamazepine, valproate but without success. During treatment period the occurrence of seizures is prevented but, after discontinuation of the drug, seizures occur just as in non treated patients. The ripening of the epileptic focus in posttraumatic epilepsy, as in iron induced epilepsy, seems to be due to a cascade of events beginning with haemorrhage, haemolysis, iron or heme compound liberation, free radical formation, peroxidation and cell death. Experimentally free radical scavengers and antiperoxidants have marked prophylactic effect. Some of them (phosphate diester of vitamin E and C, melatonin, vanillyl alcohol) may be employed in clinical practice, but up to date there is no controlled study in human beings.