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) are increased in cerebrospinal fluid (CSF) in adults after TBI; however, studies in pediatric head trauma are lacking. We hypothesized that CSF glutamate, aspartate, and glycine would be increased after TBI in children and that these increases would be associated with age, child abuse, poor outcome, and 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 punctures to rule out meningitis.


RESULTS
Peak and mean CSF glycine and peak CSF glutamate levels were increased versus control values. Subgroups of patients with TBI were compared by using univariate regression analysis. Massive increases in CSF glutamate were found in children <4 years old and in child abuse victims. Increased CSF glutamate and glycine were associated with poor outcome. A trend toward an 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 glutamate concentrations after TBI. A possible role for excitotoxicity after pediatric TBI is supported.
Ruppel
R A
RA
Department of Anesthesiology, Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Kochanek
P M
PM
Adelson
P D
PD
Rose
M E
ME
Wisniewski
S R
SR
Bell
M J
MJ
Clark
R S
RS
Marion
D W
DW
Graham
S H
SH
D000293:Adolescent; D000367:Age Factors; D001224:Aspartic Acid / Q000134:cerebrospinal fluid*; D001930:Brain Injuries / Q000134:cerebrospinal fluid* / Q000000981:diagnostic imaging / Q000209:etiology* / Q000401:mortality; D002545:Brain Ischemia / Q000209:etiology; D016022:Case-Control Studies; D002552:Cerebral Ventricles; D002648:Child; D002649:Child Abuse / Q000706:statistics & numerical data; D002675:Child, Preschool; D006233:Persons with Disabilities / Q000706:statistics & numerical data; D018846:Excitatory Amino Acids / Q000134:cerebrospinal fluid*; D015600:Glasgow Coma Scale; D023261:Glasgow Outcome Scale; D018698:Glutamic Acid / Q000134:cerebrospinal fluid*; D005998:Glycine / Q000134:cerebrospinal fluid*; D006801:Humans; D007223:Infant; D011379:Prognosis; D016019:Survival Analysis; D013997:Time Factors; D014057:Tomography, X-Ray Computed
D018846:Excitatory Amino Acids; D001224:Aspartic Acid; D018698:Glutamic Acid; D005998:Glycine