Abstracts

Rationale:
Post-traumatic epilepsy (PTE) is a common cause of morbidity in children after a traumatic brain injury (TBI), and occurs in 10-20% of children following severe TBI.1, 2 Most previous studies on PTE have focused on children with severe TBI. The present study analyzes the therapeutic outcome of children with epilepsy due to mild TBI.
Method:
We retrospectively studied 321 children with TBI at a tertiary pediatric referral center during a 10-year period. Patients were categorized into mild, moderate, or severe TBI based on clinical data. Mild TBI was defined as loss of consciousness (LOC) or amnesia < 30 minutes, moderate TBI as LOC or amnesia between 30 minutes -1 day, and severe TBI as LOC or amnesia > 1 day, subdural hemorrhage, or contusion. Multiple clinical variables were reviewed, including past and present antiepileptic drug(s), seizure control, neuroimaging results, and mode of injury. Post-TBI EEGs/prolonged video-EEGs were obtained acutely, subacutely, and/or chronically (range, day 1 to 3 years, median 1 month). Descriptive analyses were conducted using medians and ranges for continuous data. Categorical data were reported using frequencies and percentages, while comparisons between groups were made using Fisher’s Exact test for small sample sizes.
Results:
Forty-seven children were diagnosed with PTE: 8 children (17%) due to mild TBI, 39 children (83%) due to severe TBI (Table 1). No subject met the criteria for moderate TBI. For the 8 children with mild TBI, who all had an accidental trauma (non-inflicted), median follow-up period was 25 months (range 1.5 months to 84 months). Median age was 10 years (range 4-18 years) and median age at time of injury was 7 years (range: 23 months-13 years). No relevant previous medical history was present for 6 patients (75%), and two patients’ (25%) relevant previous medical histories were unknown. Seven patients (88%) had no previous history of seizures and patient #6 (12%) had unknown seizure history. No child who had mild TBI had epileptic spasms or had been a victim of nonaccidental trauma (NAT) (Table 2). Six (75%) of the 8 patients had normal routine EEG(s). Patient #6 had an abnormal VEEG showing epileptiform discharges in the left central, temporal and parietal regions 3 months after the initial normal routine EEG (Table 1). Patient #1 had an initial prolonged EEG 8 months after TBI showing 3Hz spike-and-slow waves with bi-frontal predominance (Table 1). Compared to the 39 patients with severe TBI 3, 31 (79%) of whom had abnormal EEGs (routine and/or prolonged with video), mild TBI patients were more likely to have normal EEGs, p=0.005 (table 3). In patients with mild TBI, no patient had both abnormal EEG/VEEG and head computed tomography; and no one was on more than one AED, p < 0.005 (table 4). Five patients (63%) had a seizure < 24 hours post-TBI, while the remaining 3 had seizures after the first week of injury.
Conclusion:
Children with epilepsy due to mild TBI, loss of consciousness or amnesia < 30 minutes, are more likely to have normal EEG, and confer a favorable outcome of being on 0-1 AED. Limitations of our study include the small sample size and retrospective design. The current findings add to the paucity of outcome data in children who suffer from epilepsy due to mild TBI.
Funding:
:none