Classification accuracy of serum Apo A-I and S100B for the diagnosis of mild traumatic brain injury and prediction of abnormal initial head computed tomography scan.

The objective of the current study was to determine the classification accuracy of serum S100B and apolipoprotein (apoA-I) for mild traumatic brain injury (mTBI) and abnormal initial head computed tomography (CT) scan, and to identify ethnic, racial, age, and sex variation in classification accuracy. We performed a prospective, multi-centered study of 787 patients with mTBI who presented to the emergency department within 6 h of injury and 467 controls who presented to the outpatient laboratory for routine blood work. Serum was analyzed for S100B and apoA-I. The outcomes were disease status (mTBI or control) and initial head CT scan. At cutoff values defined by 90% of controls, the specificity for mTBI using S100B (0.899 [95% confidence interval (CI): 0.78-0.92]) was similar to that using apoA-I (0.902 [0.87-0.93]), and the sensitivity using S100B (0.252 [0.22-0.28]) was similar to that using apoA-I (0.249 [0.22-0.28]). The area under the receiver operating characteristic curve (AUC) for the combination of S100B and apoA-I (0.738, 95% CI: 0.71, 0.77), however, was significantly higher than the AUC for S100B alone (0.709, 95% CI: 0.68, 0.74, p=0.001) and higher than the AUC for apoA-I alone (0.645, 95% CI: 0.61, 0.68, p<0.0001). The AUC for prediction of abnormal initial head CT scan using S100B was 0.694 (95%CI: 0.62, 0.77) and not significant for apoA-I. At a S100B cutoff of <0.060 µg/L, the sensitivity for abnormal head CT was 98%, and 22.9% of CT scans could have been avoided. There was significant age and race-related variation in the accuracy of S100B for the diagnosis of mTBI. The combined use of serum S100B and apoA-I maximizes classification accuracy for mTBI, but only S100B is needed to classify abnormal head CT scan. Because of significant subgroup variation in classification accuracy, age and race need to be considered when using S100B to classify subjects for mTBI.

Predicting postconcussion syndrome after mild traumatic brain injury in children and adolescents who present to the emergency department.

OBJECTIVE: To determine the acute predictors associated with the development of postconcussion syndrome (PCS) in children and adolescents after mild traumatic brain injury. DESIGN: Retrospective analysis of a prospective observational study. SETTING: Pediatric emergency department (ED) in a children's hospital. PARTICIPANTS: Four hundred six children and adolescents aged 5 to 18 years. MAIN EXPOSURE: Closed head trauma. MAIN OUTCOME MEASURES: The Rivermead Post Concussion Symptoms Questionnaire administered 3 months after the injury. RESULTS: Of the patients presenting to the ED with mild traumatic brain injury, 29.3% developed PCS. The most frequent PCS symptom was headache. Predictors of PCS, while controlling for other factors, were being of adolescent age, headache on presentation to the ED, and admission to the hospital. Patients who developed PCS missed a mean (SD) of 7.4 (13.9) days of school. CONCLUSIONS: Adolescents who have headache on ED presentation and require hospital admission at the ED encounter are at elevated risk for PCS after mild traumatic brain injury. Interventions to identify this population and begin early treatment may improve outcomes and reduce the burden of disease.

Ability of S100B to predict severity and cranial CT results in children with TBI.

OBJECTIVES: To evaluate the ability of S100B to predict severity of TBI and abnormal cranial CT results for children with TBI. METHODS: This is a secondary analysis of a previously established cohort of consecutive patients presenting to the emergency department with TBI limited to children <19 years of age, who arrived within 6 hours of injury, received a cranial CT scan and consented to blood drawn for S100B. RESULTS: A total of 109 children were included in this cohort. The mean S100B levels were higher in children with moderate/severe TBI as compared to children with mild TBI based GCS score (0.281 µg L(-1), 95%CI = 0.101, 0.461 vs 0.053, 95%CI = 0.010, 0.095). S100B levels were significantly elevated in children following TBI with abnormal cranial CT as compared to children with a normal cranial CT (0.210 µg L(-1), SD = 0.313 vs 0.036 µg L(-1), SD = 0.046, p = 0.03). Area under the curve for S100B was also significant (0.72, 95%CI = 0.58, 0.86) for prediction of abnormal cranial CT for children with TBI. S100B did not predict abnormal cranial CT for children following TBI with a GCS of 15 (AUC = 0.53, 95%CI = 0.36, 0.71). CONCLUSIONS: For children following TBI, S100B appears to predict severity of TBI; however, it may not be clinically useful as an independent screening test to select children with mild TBI who need a cranial CT.

Sex differences in outcome after mild traumatic brain injury.

The objective of this study was to estimate the independent association of sex with outcome after mild traumatic brain injury (mTBI). We performed an analysis of a subset of an established cohort involving 1425 mTBI patients presenting to an academic emergency department (ED). The associations between sex and three outcomes determined 3 months after the initial ED visit were examined: post-concussive symptom (PCS) score (0, 1-5, 6-16, and >16), the number of days to return of normal activities (0, 1-7, and >7), and the number of days of work missed (0, 1-7,and >7). Logistic regression analyses were used to determine the relationship between sex and each outcome after controlling for 12 relevant subject-level variables. Of the 1425 subjects, 643 (45.1%) were female and 782 (54.9%) were male. Three months after mTBI, males had significantly lower odds of being in a higher PCS score category (odds ratio [OR] 0.62, 95% confidence interval [CI]: 0.50, 0.78); this association appeared to be more prominent during child-bearing years for females. Males and females did not significantly differ with respect to the odds of poorer outcome as defined by the number of days to return of normal activities or the number of days of work missed. Female sex is associated with significantly higher odds of poor outcome after mTBI, as measured by PCS score, after control for appropriate confounders. The observed pattern of peak disability for females during the child-bearing years suggests disruption of endogenous estrogen or progesterone production. Attempts to better understand how mTBI affects production of these hormones acutely after injury and during the recovery period may shed light on the mechanism behind poorer outcome among females and putative therapeutic interventions.

Serum S-100B and cleaved-tau are poor predictors of long-term outcome after mild traumatic brain injury.

PRIMARY OBJECTIVE: To determine the relationship of serum S-100B and C-tau levels to long-term outcome after mild traumatic brain injury (mild TBI). RESEARCH DESIGN: A prospective study of 35 mild TBI subjects presenting to the emergency department. METHODS AND PROCEDURES: Six hour serum S-100B and C-tau levels compared to 3-month Rivermead Post Concussion Questionnaire (RPCQ) scores and post-concussive syndrome (PCS). MAIN OUTCOMES AND RESULTS: The linear correlation between marker levels and RPCQ scores was weak (S-100B: r = 0.071, C-tau: r = -0.21). There was no statistically significant correlation between marker levels and 3-month PCS (S-100B: AUC = 0.589, 95%CI. 038, 0.80; C-tau: AUC = 0.634, 95%CI 0.43, 0.84). The sensitivity of these markers ranged from 43.8-56.3% and the specificity from 35.7-71.4%. CONCLUSIONS: Initial serum S-100B and C-tau levels appear to be poor predictors of 3-month outcome after mild TBI.

Accuracy of mild traumatic brain injury case ascertainment using ICD-9 codes.

OBJECTIVES: To determine the accuracy of mild traumatic brain injury (TBI) case ascertainment using International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes proposed by the Centers for Disease Control and Prevention (CDC) in a 2003 Report to Congress. METHODS: This was a prospective cohort study of all patients presenting to an urban academic emergency department (ED) over six months in 2003. A real-time clinical assessment of mild TBI was compared with the ICD-9 codes assigned after ED or hospital discharge for a determination of sensitivity and specificity. RESULTS: Of the 35,096 patients presenting to the ED, 516 had clinically defined mild TBI and 1,000 were assigned one or more of the mild TBI ICD-9 codes proposed by the CDC. The sensitivity of these codes was 45.9% (95% confidence interval [95% CI] = 41.3% to 50.2%) with a specificity of 97.8% (95% CI = 97.6% to 97.9%). CONCLUSIONS: The identification of mild TBI patients using retrospectively assigned ICD-9 codes appears to be inaccurate. These codes are associated with a significant number of false-positive and false-negative code assignments. Mild TBI incidence and prevalence estimates using these codes should be interpreted with caution. ICD-9 codes should not replace a clinical assessment for mild TBI when accurate case ascertainment is required.