A new blood test given within a dozen hours of a possible traumatic brain injury (TBI) could cut down dramatically on unneeded CT scans – but not all doctors agree.

The test measured levels of a pair of biomarker proteins found in the blood after a TBI and “correctly identified 99.6 percent of patients without intracranial injury on head CT scans in more than 1,900 adults showing up with mostly mild TBIs in EDs in both the U.S. and Europe,” researchers reported in the journal Lancet Neurology.

“This blood test meets an important public health need to reduce the number of unnecessary CT scans, particularly among those with mild TBI – also called concussion – who make up over 85 percent of all TBIs. In emergency medicine, CT scans are often used in evaluating these patients, even though fewer than 10 percent of scans reveal an abnormality,” lead author Dr. Jeffrey Bazarian, professor of emergency medicine at the University of Rochester Medical Center, said in a statement by the test's maker, Banyan Biomarkers.
In the study, patients had a head CT and the Banyan BTI blood test, looking for the brain proteins Ubiquitin Carboxy-terminal Hydrolase-L1 (UCH-L1) and Glial Fibrillary Acidic Protein (GFAP), to detect a brain bleed.

“When someone is hit in the head, if severe enough, the brain cells gets injured and release their component proteins,” Bazarian told the Daily Mail Online.

The results of his multicenter study suggested to him that “routine use of the new biomarker test in emergency departments could reduce head CT scans by a third in acutely head-injured patients thought to be in need of CT scanning, avoiding unnecessary CT-associated costs and radiation exposure, with a very low false-negative rate.”

The present practice with mild TBI cases is to look at signs and symptoms, using a guideline to determine if a CT is needed. In crowded EDs the need to examine and scan takes time and valuable resources.

“U.S. emergency departments are very crowded and one of the choke points is the CT scan,” Bazarian told the British paper, pointing out that “if someone is in the waiting room with a brain injury, they could have their blood drawn in the waiting room and can avoid even getting into the queue for the scan.”

In February, earlier unpublished findings from the study led the FDA to approve the blood-based brain biomarker test – the first such clinically approved test of its kind in the U.S.

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