Earn honorarium from paid medical surveys

Modern MedEd partners with MD for Lives to bring you paid online surveys.
Get a $20 bonus just for signing up. For medical professionals only.

Earn unlimited CME on your phone at the point-of-care

Modern MedEd partners with MDCalc to bring you no-hassle CME that you can earn on your phone at the point of care. Earn CME just for using clinical calculators. No post-test required!

Get up to 100 quick & easy category 1 CME credits

Modern MedEd partners with Board Vitals to bring you up to 100 AMA PRA Category 1™ CME Credits in over 30 specialties. Save $125 with promo code MODERN125 before your CME stipend expires!

Get Unlimited Category 1 CME credits for up to 3 years

Modern MedEd partners with VisualDx to bring you unlimited AMA PRA Category 1™ CME Credits in over a dozen specialties. Get our exclusive deal of 2 years for $999 or 3 years for $1,499 before your CME stipend expires!
Updated: July 28, 2022
By Jordan P. Roberts, PA-C

The ‘Concussion Blood Test' – Everything You Need to Know

Concussion Blood Test Brain Trauma Indicator

The so-called concussion blood test may not replace the need for a head CT, but there are situations where is it more useful than not.

The Concussion Blood Test: Needs Assessment

Discovering a biomarker to identify a mild traumatic brain injury (mTBI) is the holy grail of concussion research. A so-called concussion blood test that can distinguish between concussed and non-concussed individuals, especially days to weeks later, would be a dream come true for clinicians and researchers alike. 

Because this remains such a public health concern and coupled with the fact that many states require certain practitioners to earn dedicated concussion CME each year, we thought we'd share an update on something near and dear to our brains.

Most concussion research to date has focused on sports-related concussion (SRC), which occurs most often in relatively young athletes. Sports-related concussion is a complex and often notoriously difficult diagnosis to make on the field or in the emergency department. Further complicating matters, the clinical presentation and evolution of the condition can vary greatly from patient to patient.

Because these patients are usually otherwise healthy and full of potential, the possibility of a permanent, devastating neurological outcome makes pediatric traumatic brain injury (TBI) a medico-legal landmine.

Concussion Medicolegal Issues

The initial investigation may consist of a head CT in the emergency department. However, expose too many young people to radiation, and someone might try to blame you for their cancer in 50 years. On the other hand, if you don't scan the kid who dies of an epidural hematoma, it'll haunt you forever. 

And don't forget about your adult head trauma patients. This population is more likely to be injured at work, through violence, or other means different from your pediatric patients.

Fortunately, guidelines and algorithms such as the PECARN criteria exist to help clinicians make evidence-based medicine choices. Theoretically, this should reduce the use of CT scans in the pediatric emergency department. The downside (to some) is that many of these decision making tools still rely (somewhat) on clinical subjectivity.

However, in February of 2018, the US Food and Drug Administration (FDA) granted marketing approval to a new laboratory assay that uses a blood draw to ‘aid concussion evaluation.’

Some media outlets (who forgot to have a clinician double-check their headlines) quickly wrote all about the so-called concussion blood test. One might even think that this assay will dramatically reduce young athletes’ CT-induced radiation exposure.

It could change the workup in the emergency department. But when ‘to scan or not to scan’ is not your main decision point, it may not be as helpful. Also, you'll get the results of the CT scan faster than the results of the current generation assay. I'll explain that below.

Despite the issue of time sensitivity, many of us are wary about scanning young kids and their developing organs. Because we think radiation dosage is cumulative, too much gets a bad rap. Usually. And for good reason; treating pediatric radiation-deficiency has fallen out of favor lately. 

The Concussion Blood Test: The Brain Trauma Indicator

Developed by Banyan Biomarkers, Inc, it measures two proteins; Ubiquitin C-terminal Hydrolase-L1 (UCH-L1) and Glial Fibrillary Acidic Protein (GFAP). Scientists believe these biomarkers can be detected in the serum of patients with visible intracranial lesions on CT after a TBI. You may remember that patients with concussions don't really have visible intracranial lesions.

So is this a concussion blood test or not?

Before we get there, remember the question we should always be asking ourselves first is “how does this change my management?”

What Is the Brain Trauma Indicator (BTI)?

The Brain Test Indicator (BTI) is the blood test developed by Banyan Biomarkers that is getting all the hype for being the first of its kind. It identifies the neural proteins Ubiquitin C-terminal Hydrolase-L1 (UCH-L1) and Glial Fibrillary Acidic Protein (GFAP) in the serum of adult patients with a traumatic brain injury.

And don’t try to tell me you don’t remember these from sleeping through neurology lectures! The UCH-L1 is found in high concentrations of neural tissue, comprising 1 to 5 percent of total neuronal protein. It functions to maintain axonal integrity, and is not found in high concentrations in other healthy tissue.

Defective UCH-L1 has also been implicated in neurodegenerative states, stroke, intracranial hemorrhage, high-grade glioma, pancreatic neuroendocrine tumors, and pediatric burn injuries.

GFAP is the main nanofilament found in astrocytes. It makes up a system that allows these cells to coordinate a response to central nervous system crises. Astrocytes take on this role in conditions such as stroke, neurodegeneration, and yes, CNS trauma.

These proteins escape the brain and head into the serum after a neurologic insult. This assay claims to measure the serum concentration of these molecules following a TBI. Although the catch is that you have to draw the sample within twelve hours of the injury. And then wait another three to four hours for the results. Longer if the lab is busy. But that isn't too different from a lot of labs we order now. So what did the regulators say?

Concussion Blood Test
The Brain Trauma Indicator measures serum UCH-L1 and GFAP

The FDA Approval of the Brain Trauma Indicator

According to their press release on February 14, 2018, “the FDA today permitted marketing of the first blood test to evaluate mild traumatic brain injury (mTBI), commonly referred to as concussion, in adults.”

Right off the bat we can see that this particular assay was not endorsed to be a part of the workup of sports-related concussions (SRC) in adolescents and younger children. 

In regards to the biomarkers, the FDA notes that “levels of these blood proteins after mTBI/concussion can help predict which patients may have intracranial lesions visible by CT scan and which won’t.”

The FDA also included this snippet below in their press release, which took me by surprise [emphasis mine]. Although it is a killer marketing move on the manufacturer’s part:

“These findings indicate that the test can reliably predict the absence of intracranial lesions and that health care professionals can incorporate this tool into the standard of care for patients to rule out the need for a CT scan in at least one-third of patients who are suspected of having mTBI.”

Standard of care, already? Slow down, there! We just met. And anyways, I’m not that kind of clinician. You at least have to buy me dinner and make me sit through a monotonous slide deck, first.

You Might Also Like:

Brain Computer Interface for Spinal Cord Injury Brings Hope to Paralyzed Patients

Evidence For The Brain Trauma Indicator

The clinical trial results are pending as of this publication, so there isn’t much we can say with a lot of confidence at this point. Here's some of the data that is available:

When measured up against head CT, the Brain Trauma Indicator correctly predicted the presence of intracranial lesions in 97.5 percent of cases.

It was also able to accurately identify those who did not have an intracranial lesion on a CT scan in 99.6 percent of cases.

Again, my only reference for this is the FDA press release, so be careful interpreting any results you haven’t personally verified. I'll add more information as I get it.

Evidence Update (September 2018)

A study published in the Lancet in September 2018 reveals some interesting analysis about these two biomarkers. 

Researchers evaluated data from nearly 2,000 subjects aged 18 years and older presenting within twelve hours of a non-penetrating traumatic brain injury. Here's what they found:

  • 125 (6%) had CT-detected intracranial injury
  • 8 (<1%) had neurosurgically manageable injuries
  • 1,288 (66%) had a positive UCH-L1 and GFAP test
  • 671 (34%) had a negative UCH and GFAP test
  • 3 (<1%) had a positive CT and negative blood test

This corresponds to a sensitivity of 97.6 percent and a negative predictive value of 99.6 percent. 

Of course, further studies are needed to determine how this study can best be clinically implemented.

By the way, for a brush-up on CT findings in patients with TBI as well as other neuroradiological principles, our partner MedMastery has a great CME activity and workshop on how to read head CT scans.

You Might Also Like:

PECARN for Pediatric Head Injury: A Clinical Decision-Making Tool

So, Do We Have A Concussion Blood Test?


When this test first came out, we would have flatly said no. However, as the evidence changes, so does our thinking.

This assay may have other value, too. It can help stratify adult patients into two groups: those who probably need a CT of the head anyway, and those who don’t.

However, it doesn’t tell you who has a concussion, who needs neurosurgery, and who might spend the rest of their life in the CT suite. Because only patients older than 18 years of age were included in this study, its use is limited in pediatrics. Therefore, this blood test won’t help diagnose or manage pediatric sports-related concussion in its current form.

However, it is a step in the right direction when it comes to brain trauma evaluation. It will be incredibly useful in resource-limited areas where the CT scanner is a three day journey rather than a three minute gurney ride down the hall. Like any tool, just be careful how you use and interpret it.

Concussion CME

Plus Other Concussion Resources for Physicians, PAs, & NPs

Clinicians from various specialties will be called on to care for patients with concussion. 

From sports medicine to primary care, pediatrics, and emergency clinicians acutely to neurology, neurosurgery, and psychiatry in the long term, not to mention nursing, allied health, and others, the physicians, PAs, and NPs of these specialties have an interest in knowing what's new.

Nobody “owns” concussion like some other conditions.

That's why we have put together the best sports medicine CME for primary care providers, pediatrics CME, emergency medicine CME, neurology CME, neurosurgery CME reviews, psychiatry CME, and nursing CE to meet this need.

We also have an extensive collection of concussion resources, many free, including articles, clinical decision support tools, slide decks, and other innovative tools to help you provide the best care possible to patients with concussion.

If you want to earn some CME and listen to smart people say funny things at the same time, you'll want to subscribe to Hippo Education's Primary Care Reviews and Perspectives. Check out episode 34 (aired in May of 2017) for my chapter on the non-sports concussion. 


Bazarian JJ, Biberthaler P, Welch RD, et al. Serum GFAP and UCH-L1 for prediction of absence of intracranial injuries on head CT (ALERT-TBI): a multicentre observational study. The Lancet Neurology. 2018;17(9):782-789. doi:10.1016/s1474-4422(18)30231-x

Bishop P, Rocca D, Henley JM. Ubiquitin C-terminal hydrolase L1 (UCH-L1): structure, distribution and roles in brain function and dysfunction. Biochemical Journal. 2016;473(16):2453-2462. doi:10.1042/bcj20160082

Evaluation of Biomarkers of Traumatic Brain Injury  – ClinicalTrials.gov. https://clinicaltrials.gov/ct2/show/record/NCT01426919?term=ALERT+TBI&rank=1.

GFAP glial fibrillary acidic protein [Homo sapiens (human)] – Gene – NCBI. National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/gene/2670.

Hol EM, Pekny M. Glial fibrillary acidic protein (GFAP) and the astrocyte intermediate filament system in diseases of the central nervous system. Current Opinion in Cell Biology. 2015;32:121-130. doi:10.1016/j.ceb.2015.02.004

Moore MD, Finnerty B, Gray KD, et al. Decreased UCHL1 expression as a cytologic biomarker for aggressive behavior in pancreatic neuroendocrine tumors. Surgery. 2018;163(1):226-231. doi:10.1016/j.surg.2017.04.040

UCHL1 ubiquitin C-terminal hydrolase L1 [Homo sapiens (human)] – Gene – NCBI. National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/gene/7345.

First Published: March 19, 2018

Further Reading

Quickly & Easily Find CME
Based on Your Learning Preferences

(18 modailties found)

Click the icon or title to go straight to the most relevant section of the website for that particular CME format.

Audio CME Courses

Listen to your CME while pretending you've found the secret to multitasking.

Clinical Decision Support CME

Experience next level CME with AI-powered clinical decision support tools.

CME Conferences

Miss CME meetings? Take a look at some real-life (and virtual) CME events!

CME with Gift Card Rewards

CME with gift cards and other rewards to stretch your CME allowance further than ever.

Medical Calculators that Earn CME

Earn CME credits at the point of care for using the tools you already know and trust.

Medical Spanish CME Tutoring

Take your communication to the next level and increase access to care for entire communities.

CME Subscriptions

Pay once, access CME for two or three years in dozens of specialties. Updates included.

Online CME Activities

Now that you know you don't HAVE to travel for CME anymore, why would you?

Psychedelic CME

Stay ahead of the game with the latest research in psychedelic medicine. Patients will be asking.

Procedural (Hands-On) CME

Learn essential procedures from home with the same professional materials more cost-effectively.

Question Bank CME

Engaging board-style vignettes with CME credit that adds up quickly and easily.

Travel CME

Learn about essential updates from somewhere you've never been before.

Unlimited CME Credits

Earn all the CME credits you could possibly need (or want) from one CME purchase.

Wilderness CME

Enhance your medical survival skills by practicing in real-life environments with experienced instructors.

Video CME

Visual learners have more options than ever for finding quality CME that speaks to their style.


Learn stuff. Ski. Repeat.
Get paid for claiming "SKI-M-E" credit.

CME Cruises

Earn CME on a river. Or earn CME credits at sea. Don't forget to claim your "SEA"-M-E.

Augmented Reality CME

Give it a few years and it'll be cool.
Just you watch.

Our CME Values: Quality Certified

We work with independent CME providers that do not accept industry funding.

ANy CME we recommend meets the following standards:

Providers not meeting these standards may be mentioned for sake of completeness or topic relevance.
Our relationship will be clearly disclosed.