Children with traumatic brain injury, particularly in cases of abusive head trauma, have a high likelihood of developing seizures within the first week postinjury.
SAVANNAH, GA—Nearly 10% of children with moderate to severe traumatic brain injury (TBI) show evidence of subclinical seizures, according to a report presented at the 40th Annual Meeting of the Child Neurology Society.
Jason T. Lerner, MD, from the Brain Injury Research Center and Department of Pediatrics at the University of California in Los Angeles, and colleagues followed a group of pediatric patients with moderate to severe TBI, and they determined that a significant portion of these children had evidence of subclinical seizures on video EEG monitoring.
Characterizing Posttraumatic Seizure Occurrence in a Pediatric TBI Population
“Nonconvulsive (subclinical) seizures have been demonstrated in adults after TBI and have been shown to be associated with additional physiologic problems such as increased intracranial pressure,” the researchers noted. However, “the incidence, risk factors, and subsequent effects of these seizures are unknown in children.”
Dr. Lerner and his colleagues sought to determine the frequency of subclinical and clinical early posttraumatic seizures in a pediatric population with moderate to severe TBI, using continuous video EEG monitoring.
The team of investigators prospectively collected data from all children admitted to a pediatric intensive care unit with moderate to severe TBI. All patients underwent at least 24 hours of video EEG telemetry monitoring and were followed for at least two years as outpatients. Early posttraumatic epilepsy was defined as seizures occurring within the first week after injury, and late posttraumatic epilepsy was defined as seizures occurring after the first week postinjury.
To date, 67 patients (age range, 1 month to 17 years) were enrolled in the study. “One patient was in subclinical status epilepticus with seizures lasting up to 90 seconds,” the investigators reported. Twenty-nine patients had severe TBI, and 38 had moderate TBI. Posttraumatic seizures occurred in 27 (40%) patients; six of these cases were identified only as subclinical. The most common mechanisms of injury were a fall (23 cases), abusive head trauma (20), and motor vehicle accident (14).
Risk Factors for Posttraumatic Epilepsy After TBI
Dr. Lerner and his colleagues found that the mean age of patients with seizures was significantly lower than for those without seizures (4.7 vs 6.9). Patients who experienced abusive head trauma were six times more likely to have seizures than were those with any other mechanism of injury, making abusive head trauma a significant risk factor for posttraumatic epilepsy.
TBI in the pediatric population is a leading cause of morbidity and mortality, the researchers noted. “Seizures are a common morbidity associated with TBI and may in themselves contribute to additional morbidity,” stated the study authors. “The incidence of seizures after TBI is approximately 10% to 20%. However, the exact number is not known, because seizures in children can be particularly difficult to detect.
“Abusive head trauma and younger age were risk factors for early posttraumatic seizures,” Dr. Lerner and colleagues concluded. “The use of video EEG monitoring for pediatric TBI may permit targeting of prophylactic anticonvulsant therapy to children who require it mostand may spare other children the potential toxicities of such medications.”
—Ariel Jones