Canadian finds new blood test for concussions
Quick results show degree of brain injury
OTTAWA – A Canadian doctor has found a promising way to detect concussions using a simple blood test that can tell within the first hour after a blow to the head how severe the injury may be.
In what could soon become the world’s first blood test for the brain, Dr. Linda Papa, a Montreal native now leading a U.S. National Institutes of Health-funded research project at American trauma centres, has shown certain proteins released by the brain after a head injury can be detected in blood. Every year, at least 1.7 million people in the U.S. alone sustain a traumatic brain injury, or TBI, Papa and her coauthors write in the Journal of
Trauma.
“More than 1.4 million of these are treated and released from emergency departments across the country.”
Concussions, or mild traumatic brain injury, can be difficult to diagnose. Even CT scans can miss subtle, tiny, micro hemorrhages, or bleeds in the brain that, if not picked up, can lead to “second impact syndrome” — potentially fatal brain swelling — if the person suffers another head injury before recovering from the first.
“Some of these patients actually go home and they don’t feel quite right,” said Papa, an emergency physician and director of research for Orlando Regional Medical Center in Orlando, Fla. “They’re forgetful.
They have trouble concentrating. They become very anxious and they don’t know why. Everybody tells them,: ‘You’re fine. Your CT scan was fine.’ And so they’re not offered therapy.”
Concern is growing around unnecessary exposure to radiation from repeated scans of the head. The study found high levels of this protein was associated with having an abnormal CT scan.
Earlier studies in rats found a number of proteins are released in the brain after traumatic brain injury.
After a head trauma, the barrier around the brain also gets damaged, and the proteins leach out into the blood.
The new study enrolled 295 people — 96 of whom had a mild or moderate concussion. They were compared to two “control” groups: normal adult volunteers without any injuries whatsoever, and “nonhead injured” patients treated in emergency after a car crash or with a broken bone, but no head trauma.
Some earlier proteins studied in brain injuries have also been found in bones. “So if a patient has multiple trauma with a broken leg and head injury, we can’t tell if the protein is coming from the broken leg, or the brain,” Papa said.
Her team found two proteins were higher only in the blood of patients with a brain injury. “Patients who walked off the street had almost no levels of marker in their blood — we detected almost nothing,” she said.
They took it to the next level by comparing the blood tests to CT scans. The more severe the brain lesions, the higher the protein levels in blood.
Papa said the proteins are detectable in blood within an hour of injury; up to four hours later, they remain elevated. The study also found these protein levels were higher in patients who needed urgent surgery.
“We have all these blood tests for different organs in our body, but we don’t have anything for the brain,” Papa said. More research is needed to validate the findings. But Papa believes a blood test for concussions will be available in emergency departments within five years.