A concussion can do serious damage — unfortunately, it’s becoming more and more clear that symptoms vary from person to person, so identifying one isn’t easy. Researchers from Orlando Health, however, might have a solution. They have found evidence of concussions in patients who sustained a head injury up to seven days prior using a simple blood test. And it seems to work on people of all ages.

"Symptoms of a concussion, or a mild to moderate traumatic brain injury, can be subtle and are often delayed, in many cases by several days," said Dr. Linda Papa, the lead author of the study and an emergency medicine physician at Orlando Health, in a statement. "This could provide doctors with an important tool for simply and accurately diagnosing those patients, particularly children, and making sure they are treated properly."

Papa and her colleagues focused their attention on a biomarker known as glial fibrillary acidic protein. After an injury, the glial cells that surround neurons in the brain release the protein, which has the unique ability to pass through the blood-brain barrier and enter the bloodstream. The research team gave blood tests to nearly 600 patients 18 years and older and cross-checked the results with their CT scans. The researchers had previously tested this technique on children; this was the first time they recruited adults.

This blood test detected mild to moderate traumatic brain lesions with up to 97 percent accuracy. Seven of the patients also found out that they were in need of life-saving neurosurgery. Levels of the glial protein were found in the bloodstream up to a week after the injury. That’s important because most people who suffer a concussion don’t seek treatment until days after the injury.

"If patients are not diagnosed properly and treated appropriately, it could lead to long-term problems," said Papa. “This test could take the guesswork out of making a diagnosis by allowing doctors to simply look for a specific biomarker in the blood."

Besides diagnosing concussions, this blood test will also reduce the need for CT scans, the current standard for identifying brain lesions, which are fairly expensive and expose patients to harmful radiation.

"Physicians really want to minimize the amount of CTs in patients, especially children, who are a lot more sensitive to radiation and the side effects that can come with it. Fortunately, this simple blood test appears to give us nearly the same information as a CT scan."

While the NFL grabs all the headlines when it comes the concussion epidemic, concussions occur among players of every age and every sport. Papa and her team conducted a similar study in November 2015 where they screened 153 children who had suffered a concussion within six hours; the blood test identified mild to moderate traumatic brain injuries with 94 percent accuracy.

"This could ultimately change the way we diagnose concussions, not only in children, but in anyone who sustains a head injury," Papa added. "We have so many diagnostic blood tests for different parts of the body, like the heart, liver, and kidneys, but there's never been a reliable blood test to identify trauma in the brain. We think this test could change that.”

Usually, traumatic brain injuries can only be diagnosed through symptoms such as vomiting, loss of balance, blurred vision, or headaches. Many people incorrectly assume magnetic resonance imaging can effectively diagnose a concussion. Even CT scans can be unreliable.

The only true way to identify a concussion is through series of neurological examinations that gauge our vision, hearing, balance, coordination, and reflexes. This is problematic seeing as every minute counts when it comes to treating a head injury. This new test could give doctors the ability to diagnose patients before their symptoms appear.

Source: Brophy G, Welch R, Papa L, et al. Time Course and Diagnostic Accuracy of Glial and Neuronal Blood Biomarkers GFAP and UCH-L1 in a Large Cohort of Trauma Patients With and Without Mild Traumatic Brain Injury. JAMA Neurology . 2016.