Enter Your Email Address to Receive a
Copy of MedicExhange Member Demograhpics

Combat veterans with damage to certain brain regions are less likely to experience post-traumatic stress disorder (PTSD), suggesting that these areas play a critical role in pathogenesis of the condition.

Combat veterans with damage to certain brain regions are less likely to experience post-traumatic stress disorder (PTSD), suggesting that these areas -- the amygdala or ventromedial prefrontal cortex (vmPFC) -- play a critical role in pathogenesis of the condition, researchers report in an advance online publication of Nature Neuroscience.

In fact, senior investigator Dr. Jordan Grafman told Reuters Health, "If you are evaluating for PTSD in brain-injured patients in a triage circumstance, focus first on patients with posterior brain injuries before injuries including the amygdala or vmPFC."

Dr. Grafman of the National Institute of Neurological Disorders and Stroke in Bethesda, Maryland, and colleagues studied 193 Vietnam War veterans who had incurred brain injuries and experienced emotionally traumatic events. Of these, 62 had PTSD and 131 did not. Also involved were 52 combat veterans without brain injury.

Analysis of lesion distribution showed that PTSD was diagnosed in 18 per cent of patients with vmPFC damage, but not in any of those with amygdala damage. The prevalence in veterans with damage to other brain areas was 40 per cent, and in those without brain damage, it was 48 per cent.

"Individual differences in hippocampal function are unlikely to predict PTSD, whereas amygdala and vmPFC seem critical," continued Dr. Grafman, "PTSD may affect hippocampal functions if not treated effectively."

"Studying patients with lesions," he added, "can help provide definitive findings in certain circumstances where functional neuroimaging is ambiguous."

As to treatment of PTSD, Dr. Grafman concluded, "consider trying transcranial magnetic stimulation or drugs that can modulate the activity of the amygdala or vmPFC, or behavioral therapy that can modulate emotion or the context in which the traumatic events occurred.