FDA approves the first blood test to diagnose concussion

The news headlines are filled with stories of professional football players suffering from brain damage, but you do not to have to participate in sports to sustain a concussion – it is an everyday occurrence. In the US, in 2013 there were 2.8 million concussion-related emergency room visits and hospitalizations with 50,000 people dying from brain injuries. Three out of four concussions are mild. However, even mild concussion can cause impaired thinking or memory, poor concentration and emotional problems.

The U.S. Food and Drug Administration has recently approved the first blood test to evaluate concussion in adults. The diagnosis of concussion or in medical lingo, mild traumatic brain injury (mTBI), has been based purely on the description of symptoms by the patient, neurological examination, including the 15-point Glasgow Coma Scale, and brain imaging, such as CT scan to detect brain damage or bleeding. The majority of patients with a concussion have normal MRI and CT scans. This new blood test will help health care providers decide if a CT scan is necessary. This will avoid unnecessary scans which expose patients to radiation. It should also save money.

The Brain Trauma Indicator developed by Banyan Biomarkers, Inc. works by measuring levels of proteins, known as UCH-L1 and GFAP, that are released from the brain into blood and measured within 12 hours of head injury. Levels of these blood proteins after mTBI can help predict which patients may have brain lesions visible by CT scan and which won’t. Test results can be available within 3 to 4 hours.

The FDA based their approval on the data from a study of 1,947 patients with a suspected concussion. The Brain Trauma Indicator was able to predict the presence of intracranial lesions on a CT scan 97.5 percent of the time and those who did not have intracranial lesions on a CT scan 99.6 percent of the time.

It is not clear how this test will be used in the real world. If someone is sick enough to be brought to an ER, they are likely to get a CT scan, which is faster and avoids the 3-4 hour wait for the blood test results and the added cost of the blood test. People with a mild concussion who are not taken to an ER will not need the test because they are very unlikely to have visible brain injury on the CT scan. If symptoms persist for a while and the patient comes to our headache clinic, we obtain an MRI scan, which is more informative and avoids radiation, although it is more expensive.