Excitatory amino acid concentrations in ventricular cerebrospinal fluid after severe traumatic brain injury in infants and children: The role of child abuse

Background: Excitotoxicity is an important mechanism in secondary neuronal injury after traumatic brain injury (TBI). Excitatory amino acids (EAAs) ar e increased in cerebrospinal fluid (CSF) in adults after TBI; however, stud ies in pediatric head trauma are lacking. We hypothesized that CSF glutamat e, aspartate, and glycine would be increased after TBI in children and that these increases would be associated with age, child abuse, poor outcome, a nd cerebral ischemia. Methods: EAAs were measured in 66 CSF samples from 18 children after severe TBI. Control samples were obtained from 19 children who received lumbar pu nctures to rule out meningitis. Results: Peak and mean CSF glycine and peak CSF glutamate levels were incre ased versus control values. Subgroups of patients with TBI were compared by using univariate regression analysis. Massive increases in CSF glutamate w ere found in children <4 years old and in child abuse victims. Increased CS F glutamate and glycine were associated with poor outcome. A trend toward a n association between high glutamate concentration and ischemic blood flow was observed. Conclusions: CSF EAAs are increased in infants and children with severe TBI . Young age and child abuse were associated with extremely high CSF glutama te concentrations after TBI. A possible role for excitotoxicity after pedia tric TBI is supported.