Abstracts

Rationale: Traumatic brain injury (TBI) in the pediatric population is a significant cause of morbidity and mortality. One form of morbidity is posttraumatic seizures that can be seen early (<7 days) or late (>7 days) after an injury. While subclinical seizures have been reported in patients after TBI, the incidence, risk factors and subsequent effects are unknown in children. Our primary goal is to determine the frequency of subclinical and clinical early post-traumatic seizures (EPTS) in children with moderate-severe TBI, using continuous video EEG monitoring. Secondary goals are to evaluate the risk factors for EPTS and to measure the global functional outcomes of those children with EPTS. Methods: In January 2009 we began to prospectively track all consecutive pediatric patients admitted to UCLA for TBI. Continuous video EEG monitoring was initiated at the time of admission for 24 hours and extended if seizures were captured. In addition we collected comprehensive data including demographics, hourly physiological data, CT scan results and performed global outcome. We are continuing to follow these patients after discharge. Results: To date, 40 patients have been consented (13 females and 27 males), 3 mild, 31 moderate and 6 severe TBI, ages 0.2-17.2 years. Fall was the most common mechanism followed by motor vehicle accident and inflicted TBI. Early PTS was documented in 12 (30%) patients. No relationships were found between injury severity, EPTS, age at injury and intraaxial blood. Subclinical seizures were seen in 3 (7.5%) patients, all less than 0.6 years old. All had moderate severity, fracture on CT scan and intraaxial blood. All seizures were focal and two of the patients had interictal findings in similar locations. All 3 patients had multiple seizures during the first 24 hours of the study, and one was in subclinical status epilepticus with seizures lasting up to 90 minutes. Conclusions: Seizures, both clinical and subclinical are seen in a significant proportion of pediatric patients after TBI. In our cohort, of which the majority was moderate in severity, 30% had EPTS and 7.5% had subclinical EPTS. The 3 patients with subclinical seizures did not have clinical seizures, and without video EEG monitoring these would have gone undiagnosed. In our study, subclinical seizures were only seen in infants. The absence of statistically significant additional risk factors may be related to the small population as well as the large number of moderate injuries to the general exclusion of other severities, an unexpected finding. Future investigations of this cohort will seek to identify risk factors for EPTS and LPTS, the relationship between early physiological disturbances and EPTS and the effect of PTS on long term outcomes. Seizures, both clinical and subclinical, are seen in a significant proportion of pediatric patients after TBI. Continuous video EEG monitoring may be required to properly diagnose all of these patients.