The global urgency to define and effectively treat traumatic brain injuries takes many roads. A new one, emerging from the United States, is a blood test, the Banyan Brain Trauma Indicator, that is said to be able to evaluate mild TBI (aka concussion) symptoms in adults. The US Food and Drug Administration was so taken with the test that it fast-tracked it through review and marketing authorisation procedures in less than six months as part of its Breakthrough Devices Program.

US FDA: supportive

The actual idea of the test is to decide whether a CT scan or other neuroimaging is necessary for the patient, to hopefully shield them from unnecessary radiation exposure. The idea is that once a victim of a suspected head injury has been through the usual 15-point Glasgow Coma Scale, they would have the blood test to pick up intracranial lesions that might not be visible in scans, so that a scan might not be required.

In a press release, the FDA Commissioner, Scott Gottlieb MD said: ‘Helping to deliver innovative testing technologies that minimize health impacts to patients while still providing accurate and reliable results to inform appropriate evaluation and treatment is an FDA priority. Today’s action supports the FDA’s Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging—an effort to ensure that each patient is getting the right imaging exam, at the right time, with the right radiation dose. A blood-testing option for the evaluation of mTBI/concussion not only provides health care professionals with a new tool, but also sets the stage for a more modernized standard of care for testing of suspected cases. In addition, availability of a blood test for mTBI/concussion will likely reduce the CT scans performed on patients with concussion each year, potentially saving our health care system the cost of often unnecessary neuroimaging tests.’

Jeffrey Shuren, M.D., director of the FDA’s Center for Devices and Radiological Health, said championing the test and permitting Banyan Biomarkers to begin marketing the Brain Trauma Indicator to Banyan Biomarkers, was all about helping the US Military.‘A blood test to aid in concussion evaluation is an important tool for the American public and for our Service Members abroad who need access to quick and accurate tests,’ he said.

Florey researchers: unconvinced

Closer to home, a spokesman for the Florey Institute for Neuroscience, Dr Tom Keeble, said the blood test needed more evaluation before being embraced.

‘This is an important first step but the test needs to be refined to be more specific for concussion, versus other non-injury related neurological conditions,’ he said. ‘The blood test measures damaged nerve fibres – from many different causes. In sport, for example, it will be useful if it helps assess a player’s readiness to return to the field, days, weeks or months after a concussion. At the moment, the blood test is unreliable and only useful for a few hours after a knock. The blood test will only help avoid about a third of those athletes needing a CT scan following a head injury.

‘We know concussion often are undetectable on a brain scan and this test may also miss mild concussions, the majority of sport-related concussion.’

Scientific American also quoted researchers outside the project expressing concern about the US FDA’s fast-push through. ‘The data aren’t as conclusive as we would have hoped, so I was surprised by the rapid FDA approval,” the University of Gothenburg’s Professor Henrik Zetterberg, a professor of neurochemistry said from Sweden.  While the Banyan blood test searches for UCH-L1, Zetterberg said he was unconvinced about the usefulness of that as a reliable concussion biomarker.

‘UCH-L1 might work at early time points, but if a sample is collected two to three days after an injury, perhaps other markers would be better,’ he said.