Point of Care: Handheld Device Shows Promise in Detecting Concussion from Blood Samples

A handheld portable device could be more effective than a CT scan in detecting mild traumatic brain injuries (TBI), according to a new study published in The Lancet Neurology. Because it is capable of detecting brain injuries within 15 minutes, as well as injuries that CT scans miss, this new technology may help fill a gap in emergency rooms, sporting events and the battlefield—by identifying patients who might otherwise have gone undiagnosed.

The TBI Diagnostic Challenge

More than 4.8 million people in the U.S. visit emergency rooms each year to be evaluated for brain injury. To detect brain injuries, doctors currently utilize physical examinations, CT scans and screening questions for cognitive and neurological symptoms. MRIs are more precise and can pick up injuries that physical exams and CT scans miss. Thus, some 30% of patients who had a normal CT scan were found to have signs of TBI when they were tested via MRI. But while MRIs are more accurate, they are not available at all hospitals. They are also relatively slow and considerably more expensive than CT scans and blood tests.

Because of the limitations of current tools for detecting brain injuries, it is estimated that half of concussions go undetected and undiagnosed. And missing or even waiting days for a diagnosis could have significant consequences for brain injury patients.

The New Device

When TBI occurs, damaged cells release glial fibrillary acidic proteins (GFAPs) that leak out of the brain and into the bloodstream. Thus, detecting elevated levels of GFAP biomarkers in a patient’s blood sample could be an effective way to diagnose TBI.

With this in mind, Abbott has manufactured a handheld, portable blood analyzer that produces test results within minutes right by a person’s side. Abbott’s i-STAT Alinity system measures GFAP proteins from the brain that are released into the blood after a brain injury—serving as a warning signal that further evaluation is needed. The i-STAT Alinity device is not yet commercially available in the U.S. but is commercially available in other markets. Meanwhile, Abbott has more than 120 scientists and engineers researching and developing its concussion assessment test.

The New Study

The new study comes from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI study), a collaborative research effort involving observational and interventional studies funded by the National Institute of Neurological Disorders and Stroke, the U.S. Department of Defense through U.S. Army Medical Research and Development Command and U.S. Army Medical Materiel Development Activity, with support from private and philanthropic partners.

TRACK-TBI researchers evaluated 450 patients admitted to the emergency department of 18 U.S. Level 1 trauma centers with a suspected TBI, and who also received a negative CT scan, to determine if the brain-specific GFAP protein could be a biomarker for detecting TBI. The study used Abbott’s i-STAT Alinity device and blood test under development to measure a patient’s GFAP protein level and then reviewed MRI scans taken later to confirm the TBI. Researchers found that among the 450 patients studied:

• GFAP levels were significantly higher in patients who had a positive MRI but a negative CT scan, compared to people with both negative CT and MRI scans;
• GFAP levels potentially could be used to predict the type of damage as well as the extent of injury;
• GFAP levels were not significantly elevated in the control groups of healthy individuals nor in those who had only orthopedic injuries.

The study also looked at three additional brain biomarkers to assess any association between elevated levels of those proteins and brain injury:

• S100 calcium-binding protein B (S100B);
• Ubiquitin C-terminal hydrolase L1 (UCH-L1); and
• Neuron-specific enolase (NSE) protein.

The researchers found that elevated GFAP levels were more sensitive for detecting brain injury in patients with a negative CT scan than were elevated levels of UCH-L1, S100B or NSE.

Takeaway: “Blood-based biomarkers are emerging as an important tool to detect TBI, and this research opens up the next chapter for how the condition is evaluated,” said Geoffrey T. Manley, M.D., Ph.D., principal investigator of TRACK-TBI, neurosurgeon and professor of neurosurgery, University of California, San Francisco. “Having these sensitive tools could provide physicians more real-time, objective information and improve the accuracy of detecting TBI. This research shows that blood tests have the potential to help physicians triage patients suspected of brain injury quickly and accurately.”