Childhood Concussions Detected by Blood Test

Neither scenario gives doctors an objective indication of the severity of the injury.

Doctors at the Orlando Regional Medical Center (Orlando, FL, USA) performed computerized tomography (CT) scans on 152 children and compared the results of those scans with results from the blood test they developed. As expected, the high definition imagery from the CT scans was able to identify which patients had suffered visible traumatic brain injuries. However, the study showed that the blood test detected symptoms of concussions, even when brain injuries were not visible on the CT scan.

The biomarker this particular blood test looks for is known as glial fibrillary acidic protein (GFAP). These proteins are found in glial cells, which surround neurons in the brain. Serum GFAP levels were measured in duplicate for each sample using a validated enzyme-linked immunosorbent assay (ELISA) platform (Banyan Biomarkers Inc.; Alachua, FL, USA). The lower limit of quantification for this assay is 0.03 ng/mL and upper limit of quantification is 50 ng/mL. The limit of detection is 0.008 pg/mL. Any sample yielding a signal over the quantification or calibrator range was diluted and re-assayed.

The team then tested blood serum from the same patients, which was taken less than six hours after their injuries. The blood test detected symptoms of concussions, even when brain injuries were not visible on the CT scan and can detect even the most subtle signs of a concussion in children, correctly identifying the presence of traumatic brain injuries 94% of the time. The authors envision envisions the development of mobile devices that could diagnose concussions on the spot, much like the devices diabetics use to test their blood with a simple finger prick and a drop of blood. Performance for detecting intracranial lesions at a GFAP cutoff level of 0.15 ng/mL yielded a sensitivity of 94%, a specificity of 47%, and a negative predictive value of 98%.

Linda Papa, MDCM, MSc, an emergency medicine physician and lead author of the study, said, “We were looking at different types of brain lesions detected by the CT scans, ranging from mild to serious injuries, and found that the biomarker we tested for actually corresponded to the injuries. Levels of the biomarker were lower in mild cases, and were much more elevated in severe case. If we could find a simple test that takes the guess work out of diagnosing these kids that would completely change the way we approach concussions and would certainly give parents greater peace of mind.” The study was published in the November 2015 issue of the journal Academic Emergency Medicine.

Related Links:
Orlando Regional Medical Center 
Banyan Biomarkers Inc.