[Results of prospective 24-hour EEG studies of patients after cranio-cerebral injuries]

In 26 patients 24-hour cassette EEG recording and routine EEG records were taken between 6 and 35 days and again between 6 and 12 months after craniocerebral trauma. Neurological examination and CT of the head demonstrated cerebral concussion in 11 cases and brain contusion in 15 cases. Early after trauma routine EEG was abnormal in 5 cases (19.2%) exclusively in those with brain contusion, and 24-hour EEG recording was abnormal in 16 cases (61.5%), including 7 with cerebral concussion and 9 with brain contusion. In the second half year after trauma 24-hour EEG was normal in 5 cases (19.2%) which had previously abnormal records, and abnormal EEG changes appeared in 6 cases (23.1%) with previously normal findings. Seizure activity was found in the first weeks after trauma in 9 (34.6%) 24-hour recordings. In the second half year after trauma seizure activity was no longer present in 2 cases, but appeared in 6 other cases. Thus 24-hour recording between 6 and 12 months after trauma demonstrated seizure activity in 50% of all patients. In 2 of them epileptic fits developed. The study shows that repeated 24-hour EEG recording after craniocerebral trauma may be important in early detection of patients who are at risk of epilepsy development.