Early and late posttraumatic seizures in traumatic brain injury rehabilitation patients: brain injury factors causing late seizures and influence of seizures on long-term outcome.

PURPOSE: To demonstrate risk factors involved in the origin of late posttraumatic seizures (LPTSs) in civilian traumatic brain injury (TBI) rehabilitation patients and the occurrence of LPTSs in this population, as well as the time of the first late seizures, and influence of these seizures on functional and occupational long-term outcome.

METHODS: A consecutive sample of 490 patients (age range, 0.8-71 years) with TBI, and with postinjury problems in their education and employment, were followed up for > or =5 years from the time of injury in a rehabilitation and reemployment program. The study was carried out at the outpatient neurologic clinic of the Kauniala Hospital, which specializes in brain injuries in Finland and works in close cooperation with the Department of Clinical Neurosciences at the Helsinki University Central Hospital. Main outcome measures were functional outcome, as measured on the Glasgow Outcome Scale (GOS), and the capacity for employment at the end of follow-up. Outcomes were studied separately among patients with late seizures and for the nonseizure group.

RESULTS: Children age 7 years or younger at time of injury more often had early posttraumatic seizures (EPTSs), than did adolescents or adults. The time elapsed between brain injury and the first late seizure also was longer in older age groups. EPTSs and depressed skull fracture had a statistically significant relation to the origin of LPTSs. Permanent posttraumatic neurologic deficit, linear skull fracture, and permanent local brain lesion documented on a computed tomography (CT) scan appeared clinically important as risk factors. Late seizures did worsen the functional outcome but had no significant influence on reemployment at the end of follow-up.

CONCLUSIONS: Young children are more prone to early seizures, and adolescents and adults, to late seizures. The main risk factors for LPTSs are early seizures and depressed skull fracture. Severity of brain injury, as measured by a low GCS score, prolonged unconsciousness, and posttraumatic amnesia (PTA) without local brain lesion, should not be considered risk factor for LPTSs. Thorough follow-up of patients with TBI with seizures and adequate antiepileptic therapy may help attain rehabilitation goals and reemployment.