Feature: Neuroimaging may unlock secrets of PTSD + TBI
MEG - 381.07 Kb
Source: Wake Forest Baptist Health, copyright 2011, used by permission
Researchers at Wake Forest Baptist Medical Center and the U.S. Department of Veterans Affairs (VA) have launched a collaborative project that uses magnetoencephalography (MEG) to study military personnel suffering from post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI) and better define the mechanism of the relationship between the two conditions.

PTSD and TBI are often comorbid, Dwayne W. Godwin, PhD, a neuroscientist at Wake Forest in Winston-Salem, N.C., told Health Imaging. Godwin and colleagues at W.G. Hefner VA Medical Center in Salisbury, N.C., aim to determine if there is an interactive effect between the two conditions, and if the symptoms of PTSD are exaggerated in an individual who also has TBI, as opposed to an individual without it.

There are multiple other unknowns with PTSD. “Diagnosis can be uncertain for PTSD, especially mild cases, which is where our study is focused,” Godwin said. Diagnosis is based on symptoms, such as irritability, hypervigilance and an exaggerated startle response that are emblematic functions of the prefrontal cortex.

The researchers’ goal is to access, measure and visualize how brains of veterans with PTSD differ from those who do not have the disorder. Godwin and colleagues are leveraging MEG, which detects minute changes in the magnetic field generated by the brain.

The researchers are conducting a battery of neurological tests on military veterans with and without a PTSD diagnosis, and with varying levels of impairment, while in the scanner. They compare the images of brain activity from individuals with PTSD and/or mild TBI with the images of individuals without the condition to see whether the prefrontal cortex and other regions of the brains function differently in people with and without the disorder.

MEG allows researchers to analyze the brain as a network. Godwin and colleagues are assessing the connections between the prefrontal cortex and other systems such as the amygdala and hippocampus to determine if there is disruption or dysfunction in the activity or if the lines of connections between the prefrontal cortex and other regions have changed after exposure to life-altering events.

“The advantage of MEG is that it is nearly instantaneous between the event and the readout. When there is an underlying change in the brain activity, we see an immediate brain response,” said Godwin. Another advantage of MEG is that improvements in analyses have produced spatial resolution similar to functional MRI.

The researchers have started scanning individuals and hope to have early results in 2012, said Godwin.