Late Breaking News
Fear Circuitry Never Rests in PTSD Patients
- Categorized in: July 2013
NEW YORK - In post-traumatic stress disorder (PTSD) sufferers, brain regions can over- or under-react in response to stressful tasks, such as recalling a traumatic event or reacting to a photo of a threatening face. Researchers at NYU School of Medicine, working with the Center for Imaging of Neurodegenerative Diseases at the VA Medical Center in San Francisco and other medical institutions, now have identified what happens in the brains of combat veterans with PTSD in the absence of external triggers. The results were published in Neuroscience Letters and presented earlier this year at the annual meeting of the American Psychiatry Association in San Francisco.1
The study, which focuses on areas of the brain that provoke traumatic symptoms, indicates that the effects of trauma persist in certain brain regions, even when combat veterans are not engaged in cognitive or emotional tasks, and face no immediate external threats.
“It is critical to have an objective test to confirm PTSD diagnosis as self reports can be unreliable,” said co-author Charles Marmar, MD, the Lucius N. Littauer NYU professor of psychiatry and head of the Steven and Alexandra Cohen Veterans Center for the Study of Post-Traumatic Stress and Traumatic Brain Injury at NYU Langone Medical Center.
The study, led by NYU research fellow Xiaodan Yan, used functional MRI, which measures blood-oxygen levels in the brain, to examine “spontaneous” or “resting” brain activity in 104 veterans of combat from the Iraq and Afghanistan wars.
Researchers discovered that spontaneous brain activity in the amygdala, a key structure in the brain’s “fear circuitry,” was significantly higher in the 52 combat veterans with PTSD than in the 52 combat veterans without PTSD.
In the PTSD group, brain activity also was elevated in the anterior insula, which regulates sensitivity to pain and negative emotions. Lower activity was noted, however, in the precuneus, which helps integrate information from the past and future, especially when the mind is wandering or disengaged from active thought.
Study authors noted that decreased activity in the precuneus correlates with more severe “re-experiencing” symptoms — such as when war veterans re-experience trauma over and over again through flashbacks, nightmares and frightening thoughts.
- Yan X, Brown AD, Lazar M, Cressman VL, et. al. Spontaneous brain activity in combat related PTSD. Neurosci Lett. 2013 May 2. doi:pii: S0304-3940(13)00391-1. 10.1016/j.neulet.2013.04.032. [Epub ahead of print] PubMed PMID: 23643995.