Dikmen, Sureyya

Glial fibrillary acidic protein (GFAP) is cleared by the Food and Drug Administration (FDA) to determine need for head computed tomography (CT) within 12 h after mild traumatic brain injury (TBI) (Glasgow Coma Score [GCS] 13–15); S100 calcium-binding protein B (S100B) serves this function in Europe. This phase 1 biomarker cohort analysis of the multi-center, observational Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study compares GFAP's diagnostic performance, measured on a rapid point-of-care platform, against protein S100B to predict intracranial abnormalities on CT within 24 h post-injury across the spectrum of TBI (GCS 3–15). Head CT scan performed in TBI subjects and blood was collected for all consenting subjects presenting to 18 United States level 1 trauma centers. Plasma was analyzed on a point-of-care device prototype assay for GFAP and serum was analyzed for S100B. In 1359 patients with TBI (GCS 3–15), mean (standard deviation [SD]) age = 40.1 (17.0) years; 68% were male. Plasma GFAP levels were significantly higher in CT+ TBI subjects (median = 1358 pg/mL, interquartile range [IQR]: 472–3803) than in CT- TBI subjects (median = 116 pg/mL, IQR: 26–397) or orthopedic trauma controls ( n = 122; median = 13 pg/mL, IQR: 7–20), p < 0.001. Serum S100B levels were likewise higher in CT+ TBI subjects (median = 0.17 μg/L, IQR: 0.09–0.38) than in CT- TBI subjects (median = 0.10 μg/L, IQR: 0.06–0.18), p < 0.001. Receiver operating characteristic curves were generated for prediction of intracranial injury on admission CT scan; area under the curve (AUC) for GFAP was significantly higher than for S100B in the same cohort (GFAP AUC – 0.85, 95% confidence interval [CI] 0.83–0.87; S100B AUC – 0.67, 95% CI 0.64-0.70; p < 0.001). GFAP, measured on a point-of-care platform prototype assay, has high discriminative ability to predict intracranial abnormalities on CT scan in patients with TBI across the full injury spectrum of GCS 3–15 through 24 h post-injury. GFAP substantially outperforms S100B.

Headache is one of the most frequently reported symptoms following traumatic brain injury (TBI). Little is known about how these headaches change over time. We describe the natural history of headache in individuals with moderate to severe TBI over 5 years after injury. A total of 316 patients were prospectively enrolled and followed at 3, 6, 12, and 60 months after injury. Individuals were 72% male, 73% white, and 55% injured in motor vehicle crashes, with an average age of 42. Pre-injury headache was reported in 17% of individuals. New or worse headache prevalence remained consistent with at least 33% at all time points. Incidence was >17% at all time points with first report of new or worse headache in 20% of participants at 60 months. Disability related to headache was high, with average headache pain (on 0–10 scale) ranging from 5.5 at baseline to 5.7 at 60 months post-injury, and reports of substantial impact on daily life across all time points. More than half of classifiable headaches matched the profile of migraine or probable migraine. Headache is a substantial problem after TBI. Results suggest that ongoing assessment and treatment of headache after TBI is needed, as this symptom may be a problem up to 5 years post-injury.