CHICAGO—Researchers have identified a biomarker that may predict patient prognosis after a mild traumatic brain injury (MTBI), or concussion, according to a study presented Nov. 26 at the annual meeting of the Radiological Society of North America (RSNA).

“Concussion is not some psychological, mystical thing. It’s an actual, physical brain injury,” said Michael Lipton, MD, PhD, associate director of the Gruss Magnetic Resonance Research Center at the Albert Einstein College of Medicine and medical director of MRI at Montefiore Medical Center in New York City.

Using MRI diffusion tensor imaging (DTI), Lipton and colleagues set out to determine post-concussion symptoms and health-related quality of life for a group of patients with MTBI one year post-injury.

A total of 17 patients underwent DTI within two weeks of their injury, with the researchers measuring the fractional anisotropy (FA), or uniformity of water flow, throughout the brain. Areas of low FA are indicative of axonal injury.

“Once those axons degenerate, there is no capacity for repair or regrowth or regeneration of these nerve elements and axons in the human brain,” said Lipton.

But the researchers discovered that some patients demonstrated areas of abnormally high FA, which they believe is evidence of the brain actively compensating for its injuries. One year after injury, patients completed two standard questionnaires to assess post-concussion symptoms, and the presence of abnormally high FA was a predictor of fewer symptoms and higher functioning.

Lipton said more research is needed, but the findings could lead to methods for more effective treatment of MTBI. The majority of people fully recover from a concussion, which accounts for approximately three out of four cases of traumatic brain injury, but as many as 30 percent of patients have symptoms that persist for months or years.

“There’s a major conundrum of what do you do with someone with one of these injuries,” said Lipton. “I think what we’re seeing here is one more piece of evidence that is building toward an understanding that these types of imaging techniques may be used to define what someone’s outcome is going to be.”