Researchers from the University of Pittsburgh Medical Center (UPMC) studying imaging results from post-concussion patients have suggested that there may be distinct injury patterns in the brains of those with concussion-related depression and anxiety.
The study, called “Evaluation of White Matter Injury Patterns Underlying Neuropsychiatric Symptoms after Mild Traumatic Brain Injury,” is published online in the journal Radiology. According to a release from the Radiological Society of North America, these findings may help lead to improved treatment and understanding of these common disorders.
The release explains that researchers obtained diffusion tensor imaging (DTI) and neurocognitive testing results for 45 post-concussion patients—including 38 with irritability, 32 with depression, and 18 with anxiety—and compared the results with those of 29 post-concussion patients who had no neuropsychiatric symptoms.
DTI, the release continues, is an MRI technique that measures the integrity of white matter—the brain’s signal-transmitting nerve fibers. Researchers studied these results to see if injuries to the nerves may be the root cause of post-concussion patients’ post-traumatic depression and anxiety symptoms.
Researchers note that they saw unique white matter injury patterns in the patients who had depression or anxiety, per the release.
Compared to controls, they continue in the release, patients with depression had decreased fractional anisotropy (FA), a measure of the structural integrity of white matter connections, around an area near the deep gray matter of the brain that is strongly associated with the brain’s reward circuit.
“The regions injured in concussion patients with depression were very similar to those of people with non-traumatic major depression disorder,” says Lea M. Alhilali, MD, assistant professor of radiology at UPMC and the study’s lead author, in the release.
“This suggests there may be similar mechanisms to non-trauma and trauma-dependent depression that may help guide treatment,” Alhilali continues.
Anxiety patients had diminished FA in a part of the brain called the vermis that helps modulate fear-related behaviors, per the release.
Since the vermis has not been associated with dysfunction in non-traumatic anxiety disorders, this finding may indicate that different treatment targets are required for patients with anxiety after trauma, the researchers say.
Post-concussion patients with irritability showed no regions of significantly decreased FA relative to the control subjects, per the release.
“There are two major implications for this study,” Alhilali says in the release. “First, it gives us insight into how abnormalities in the brain occur after trauma, and second, it shows that treatments for non-trauma patients with neuropsychological symptoms may be applicable to some concussion patients.”
Alhilali also notes in the release that the study raises the possibility that some people diagnosed with non-traumatic depression may actually have experienced a subclinical traumatic event at some point earlier in their lives that may have contributed to the development of depression.
In the future, the release concludes, the researchers hope to compare DTI findings in concussion patients with depression to those of people who have non-trauma-related depressive disorders.
[Source(s): Radiological Society of North America, EurekAlert]
