The feasibility of fNIRS as a diagnostic tool for pediatric TBI: A pilot study.

BACKGROUND: Functional near-infrared spectroscopy (fNIRS) enables assessment of prefrontal hemodynamic response. This study explored the feasibility of fNIRS in determining hemodynamic changes related to cognitive task performance in pediatric traumatic brain injury (TBI) in order to assess its potential as a diagnostic tool. METHODS: We measured changes in oxygenated hemoglobin [O2Hb] during a verbal fluency task (VFT), which activates frontal brain regions involved in working memory, in 15 TBI patients and 21 healthy controls using a 3-channel fNIRS system. Baseline and absolute changes in [O2Hb] during the VFT were compared to the rest condition to obtain effect-scores. Patients were tested in the acute phase and six weeks after injury. Task-related fNIRS responses were categorized into positive, negative, and no response. RESULTS: For patients and controls, a positive response was observed in 61% (n = 22), a negative response in 19% (n = 7), and no response in 19% (n = 7). Patients showed a mean [O2Hb] effect-score of 2.18 compared to 2.52 in the control group (p = 0.743) in the acute phase after injury. Follow-up effect-scores did not differ significantly (p = 0.721). Decreased task performance was associated with a higher effect-score in controls compared to decreased task performance with lower effect-score in the patient group. DISCUSSION: Our study shows that it is feasible to assess hemodynamic response with fNIRS in pediatric TBI patients. A trend of reduced prefrontal hemodynamic response in patients in the acute phase after injury was found suggesting impairment in cognitive performance that warrants further study.

Influence of guidelines on management of paediatric mild traumatic brain injury: CT-assessment and admission policy.

BACKGROUND: The annual number of paediatric injury-related emergency visits and application of computed tomography (CT) has substantially increased, with associated higher risk of malignancies. In 2010, a guideline for CT-assessment based on risk factors for patients with mild traumatic brain injury (mTBI) became effective in all Emergency Departments (ED) in the Netherlands. This study evaluated the influence of this guideline on the frequency of CT-assessments, hospital admissions and factors that are related to guideline adherence. METHODS: Retrospective cohort study of paediatric mTBI (<18 years), defined by Glasgow Coma Scale score of 13-15 admitted to the ED of the University Medical Center Groningen from 2008 to 2014. Data before (pre-GL) and after (post-GL) introduction of the guideline were evaluated. Primary outcome parameters were frequency of CT-assessments and hospital admissions after ED. RESULTS: In total 633 patients were enrolled and data from pre-GL (n = 216) and post-GL (n = 315) were compared. Mean age was 7.9 years (SD 5.9), 59% were male. CT-assessments increased from 32% to 46% (p = .001), mostly in children aged 6-18 years. Hospital admissions increased from 38% to 54% (p < .001), mostly in children <6 years. No significant increase in CT-abnormalities is seen. Guideline adherence was 57%, although CT-assessments varied from 44 to 100% depending on presence of specific major risk factors. CONCLUSIONS: Introduction of a new guideline on management of paediatric mTBI showed significant increase in CT-assessments and more hospital admissions. In clinical practice, despite increase of guideline adherence the applications of cranial CT-scan varies within age groups and depends on the weighing of risk factors.

GFAP and S100B in the acute phase of mild traumatic brain injury.

OBJECTIVE: The biomarkers glial fibrillary acid protein (GFAP) and S100B are increasingly used as prognostic tools in severe traumatic brain injury (TBI). Data for mild TBI are scarce. This study aims to analyze the predictive value of GFAP and S100B for outcome in mild TBI and the relation with imaging. METHODS: In 94 patients biomarkers were determined directly after admission. Collected data included injury severity, patient characteristics, admission CT, and MRI 3 months postinjury. Six months postinjury outcome was determined with Glasgow Outcome Scale Extended (GOSE) and return to work (RTW). RESULTS: Mean GFAP was 0.25 µg/L (SD 1.08) and S100B 0.54 µg/L (SD 1.18). In 63% GFAP was not discernible. GFAP was increased in patients with an abnormal CT (1.20 µg/L, SD 2.65) compared to normal CT (0.05 µg/L, SD 0.17, p < 0.05). Also in patients with axonal injury on MRI GFAP was higher (0.65 µg/L, SD 0.91 vs 0.07 µg/L, SD 0.2, p < 0.05). GFAP was increased in patients with incomplete RTW compared to complete RTW (0.69 µg/L, SD 2.11 vs 0.12 µg/L, SD 0.38, p < 0.05). S100B was not related to outcome or imaging studies. In multivariate analysis GFAP was not predictive for outcome determined by GOSE and RTW. CONCLUSIONS: A relation between GFAP with imaging studies and outcome (determined by RTW) was found in contrast to S100B. As the positive predictive value of GFAP is limited in this category of TBI patients, this biomarker is not suitable for prediction of individual patient outcome.