A prospective study of posttraumatic epilepsy

Clinical, EEG and neuroimaging data obtained from 4 serial assessments from the acute phase to one year later in 104 head injured adult patients were used for a prospective study of risk factors for post-traumatic epilepsy. Severe or moderate head injuries (HI) were prevalent among the entire group (68.3%) in which early seizures (ES) occurred in 9.4% and late seizures (LS) in 17.3%. Crises were considered LS when they occurred after 4 weeks from HI. Coma duration, ES: temporal lobe lesions shown by CT in the acute traumatic phase and focal gliosis with or without haemosiderin shown by MRI one year later were significantly prevalent in patients with LS who also developed an early slow wave or epileptiform EEG focus in significantly higher percentages than patients without LS. Moreover, the EEG focus preceded the first late seizure with a mean time interval of one month