Neurologic Biological Marker Objectively Identifies PTSD

Specific neural interactions identified using magnetoencephalography (MEG) can serve as a functional neuromarker for posttraumatic stress disorder (PTSD), according to a new study.

Researchers at the University of Minnesota (UMN; Rochester, USA) and the Minneapolis veterans' affairs (VA) Medical Center (MN, USA) conducted a noninvasive measurement of magnetic fields in the brain (which assesses the functional interactions among neural populations), of synchronous neural interactions (SNI) in a group of 74 United States veterans. The researchers found that MEG could successfully differentiate PTSD patients from healthy control subjects with more than 90% accuracy, as determined by externally cross-validated, bootstrap-based analyses. In addition, all but one of 18 patients who were not receiving medications for their disease was correctly classified. The researchers were also able to judge the severity of the trauma, indicating that MEG could also be used to gauge how badly patients are impacted by other brain disorders. The study was published the February 7, 2010, issue of the Journal of Neural Engineering.

"These findings document robust differences in brain function between the PTSD and control groups that can be used for differential diagnosis, and which possess the potential for assessing and monitoring disease progression and effects of therapy,” concluded lead author Apostolos Georgopoulos, M.D., Ph.D., and colleagues of the Brain Sciences Center at UMN.

MEG is an imaging technique used to measure the magnetic fields produced by electrical activity in the brain via extremely sensitive devices such as superconducting quantum interference devices (SQUIDs). Typically, present-day MEG dewars are helmet-shaped and contain as many as 300 sensors that record the interactions in the brain on a millisecond by millisecond basis, much faster than current methods of evaluation such as functional magnetic resonance imaging (fMRI), which takes seconds to record. In order to generate a signal that is detectable, approximately 50,000 active neurons are needed.

Related Links:
University of Minnesota
Minneapolis VA Medical Center