Identification of inflicted traumatic brain injury in well-appearing infants using serum and cerebrospinal markers: A possible screening tool

OBJECTIVE. Inflicted traumatic brain injury (iTBI) is the leading cause of death from TBI in infants. Misdiagnosis of iTBI is common and results in increased morbidity and mortality. Biomarkers may be able to assist in screening infants who are at high risk for iTBI and whose injury might otherwise be missed. We investigated whether serum and/or cerebrospinal fluid (CSF) concentrations of neuron-specific enolase (NSE), S100B, and myelin-basic protein (MBP) are sensitive and specific for iTBI in high-risk infants. METHODS. A prospective case-control study was conducted of 98 well-appearing infants who presented with nonspecific symptoms and no history of trauma. Serum or CSF was collected. NSE, S100B, and MBP concentrations were measured by enzyme-linked immunosorbent assay. Abnormal marker concentrations were defined a priori. Patients were followed for 12 months to assess for subsequent abuse. RESULTS. Fourteen patients received a clinical diagnosis of iTBI. Using preestablished cutoffs, NSE was 77% sensitive and 66% specific and MBP was 36% sensitive and 100% specific for iTBI. S100B was neither sensitive nor specific for iTBI. Five patients who were not identified with iTBI at enrollment were identified at follow-up as being possible victims of abuse; 4 had an increased NSE concentration at enrollment. CONCLUSIONS. Serum and/or CSF concentrations of NSE and MBP may be useful as a screening test to identify infants who are at increased risk for iTBI and may benefit from additional evaluation with a head computed tomography scan. S100B is neither sensitive nor specific for iTBI in this study population. The ability to identify iTBI that might otherwise be missed has important implications for decreasing the morbidity and the mortality from iTBI.