Risk factors for late-onset seizures related to cerebral contusions in adults with a moderate traumatic brain injury.

Objectives: This prospective study compares the characteristics of patients with a moderately severe traumatic brain injury (TBI) and cerebral contusions who develop late-onset seizures to those who do not.

Patients And Methods: Thirty-nine adult TBI patients with cerebral contusions, who did not need a neurosurgical treatment, could be followed up for more than 3years. Fourteen patients developed seizures during that period and 25 did not. The Glasgow Coma Scale (GCS) score on admission and the modified Rankin (mR) score on discharge from the hospital, the computed tomography (CT) and/or magnetic resonance imaging (MRI) findings, the electroencephalogram (EEG) patterns as well as the vascular and habit risk factors were compared between both groups.

Results: The mean GCS and mR scores were moderately severe and comparable between both groups. Early-onset seizures represented 21.4%. The overall seizure recurrence was 85.7% after treatment with carbamazepine or valproate sodium. Still 3 patients did not remain seizure-free after addition of another antiepileptic drug. The average number of brain contusions on CT/MRI was approximately the same. Vascular risk factors and alcohol abuse were more observed in the seizure patients. Abnormal EEG findings on discharge from the hospital were significantly more frequent in the patients who developed late-onset seizures afterward (P<0.05).

Conclusions: Seizures after non-complicated cerebral contusions are difficult to treat. Vascular risk factors and alcohol abuse may also predispose to their occurrence. The EEG findings after the TBI are highly predictive.