“While the two disorders are often confused because of similar behavioural symptoms, the data shows that they are very distinct,” says Dr. Margot Taylor, co-investigator of the research and Director of Functional Neuroimaging and Senior Scientist at SickKids. “This research could lead to faster diagnosis based on an objective measure rather than having a soldier self-identify, which according to Canadian Forces Health Services is an ongoing challenge.”
Currently PTSD and mTBI are diagnosed clinically based on emotional and psychological symptoms. The symptoms of these two conditions show considerable overlap, and particularly in the military setting, are often both present and difficult to distinguish.
The tasks used in this study were based on the cognitive difficulties commonly associated with these two conditions, and included tests of memory, inhibition, mental flexibility, emotional processing, as well as recordings of brain activity in a resting-state.
The team led by Dr. Taylor and Dr. Elizabeth Pang, who is Neurophysiologist and Associate Scientist at SickKids, studied not only soldiers with PTSD and civilians with mTBI but also had a control group of soldiers with similar military experience who did not have PTSD or mTBI. The difference in brain activity was remarkable in both groups. While all groups demonstrated significant brain responses to the cognitive tests, the soldiers without PTSD could return to a rested state while those with PTSD remained highly activated even in a rested state.
“The ultimate goal of providing objective diagnostic testing for PTSD and mTBI is to not only better understand the conditions and make fast, accurate diagnoses, but also to be able to test the individual to determine if he or she gotten better and can safely return to service,” says Taylor.
Taylor adds that this work also helps to advance our understanding of PTSD and traumatic brain injury in children and the general population.
This research was conducted in partnership with Defense Research and Development Canada and by Canadian Forces Health Services. It was presented at the symposium “Mental Health Research Magnetoencephalography & Neuroimaging in PTSD and mTBI” hosted by SickKids at the Peter Gilgan Centre for Research and Learning on February 14, 2014.
The Hospital for Sick Children (SickKids).