New imaging technique helps explain why concussions affect patients differently

Patients with concussions have unique spatial patterns of brain abnormalities that change over time, resulting in a wide variety of response to injury, according to a study published in Brain Imaging and Behavior.

The findings may help in predicting which head injuries are likely to have long-lasting neurological consequences and evaluating treatment effectiveness, according to an Albert Einstein College of Medicine of Yeshiva University news release.

“Most researchers have assumed that all people with concussions have abnormalities in the same brain regions,” lead study author Michael L. Lipton, MD, PhD, stated in the release. “But that doesn’t make sense, since it is more likely that different areas would be affected in each person because of differences in anatomy, vulnerability to injury and mechanism of injury.”

Lipton and his team performed used diffusion tensor imaging (DTI) on 34 patients with mild traumatic brain injury and 30 healthy, control subjects, according to the study abstract. Imaging was performed within 2 weeks of injury, and then again at the 3-month and 6-month marks. The researchers then analyzed the fractional anisotropy (FA) images for each patient, examining white matter diffusion through Enhanced Z-score Microstructural Assessment for Pathology (EZ-MAP). Uniformity of diffusion direction was used to determine FA for each patient.

According to the abstract, the authors found unique spatial patterns of white matter abnormalities for each patient, which they noted could be attributed to variability in anatomy, vulnerability to injury and mechanisms of injury.

“We found widespread high FA at every time point, all the way out to 6 months and even in patients more than 1 year out from their injury,” Lipton stated in the release. “We suspect that high FA represents a response to the injury. In other words, the brain may be trying to compensate for the injury by developing and enhancing other neural connections. This is a new and unexpected finding.”

Use of DTI, combined with EZ-MAP analysis, could offer a more objective measure for diagnosing concussion injuries — and predicting which patients will have persistent and progressive symptoms, the authors noted in the release.

Reference:

Lipton ML, Kim N, Park YK, et al. Robust detection of traumatic axonal injury in individual mild traumatic brain injury patients: Intersubject variation, change over time and bidirectional changes in anisotropy. Brain Imaging and Behavior. 2012. doi: 10.1007/s11682-012-9175-2