Neuroimaging technology aimed at better diagnosing and understanding concussion is developing rapidly but there is still much that  neuropsychologists don’t know about mild traumatic brain injuries, especially among younger children.

In a session entitled “New Ways of ‘Seeing’ Concussion in the Adolescent Brain,” presenters described some cutting-edge neuroimaging tools, including one new technique — near infrared spectroscopy — that can actually be used when a subject is performing a task. “It’s based on light refraction and properties of blood,” said Anthony Kontos, PhD, of the University of Pittsburgh Medical Center. Clinicians can actually see where blood is going in the brain, he said.

However, Kontos said there is still no clinical imaging protocol to assess and manage these injuries. “We can see stuff but we just don’t know what it means,” he said. “A lot of times, the findings say two different things. … We don’t have a clinically acceptable way to neuroimage concussion.” Indeed, he said, research has shown that more than 95 percent of concussion patients have “normal” imaging when subjected to CT scans or MRIs, for example.

Luke Henry, PhD, of the UPMC Sports Medicine Concussion Program at the University of Pittsburgh, described the differences in the development of gray matter and white matter in children’s and adults’ brains. However, he noted that most of the research on post-concussion brain change has been on adults, especially boxers and football players, not young children. That being said, one thing that researchers and clinicians know for sure about mTBI is that the effects are cumulative. “History matters,” he said. “If you’ve had a bunch of injuries in the past, that’s probably a bad thing for you.”

Two or more mild brain injuries in the past can result in long-term effects, he said, but “the exact nature of cumulative effects is up for debate.” And, he said, some groups are more vulnerable to these effects than others, and certain deficits are more apparent.