Study: Small area of brain could be key to PTSDby Lorna Benson, Minnesota Public Radio
St. Paul, Minn. — A new study suggests that a small area of the brain, just above the right ear, could be the key to understanding how post traumatic stress disorder works.
Researchers from the Minneapolis VA Medical Center say brain scans of PTSD patients show unusual activity in the part of the brain responsible for memory.
The same researcher team reported last January that they had developed a scan that can identify people with PTSD with 95 percent accuracy.
The researchers used a technique called Magnetoencephalography to measure magnetic fields in the brains of people diagnosed with PTSD. Eighty of the study subjects had active PTSD and 18 were in recovery. The researchers then compared those images with scans taken from 284 people who did not have PTSD.
The machine that researchers used is called MEG for short. It resembles a giant, beauty parlor hair dryer. It has 248 sensors that detect the very tiny voltages that occur on the surface of the brain when neurons "talk" to each other. MEG can record 1000 of these voltage readings per second, which is how fast these brain signals occur. Measuring these neuron signals gave researchers their first glimpse of a brain actively experiencing PTSD.
V.A. and University of Minnesota psychologist Brian Engdahl says when he looked at the scans, the cell communication problems were evident in the right temporal lobe of all of the PTSD patients, even though the study participants weren't actively engaging their brains. For the purposes of the experiment, researchers asked the participants to stare at a dot for 60 seconds.
"Even in that state there is a clear indication of over-connectivity to this area of the brain, which fits with what our patients tell us. And that is that these painful memories are very much with them at all times."
The results revealed a common pattern between active PTSD cases and those who were classified as recovered. Both groups had abnormal activity in their right temporal lobes - what researchers describe as cell miscommunication.
But the miscommunication was not as intense among people in the recovery group.
Engdahl believes the findings will help doctors come up with better treatments for PTSD that can be measured in future scans.
"It is going to help us track recovery. It is going to help us track different types of treatment and their effectiveness."
The research also might help convince more veterans to get help for their condition.
63-year-old Gary Lore of Minnetonka is a Vietnam veteran. He has had PTSD since returning from the war 42 years ago.
Lore participated in a previous VA study in which he also received a MEG brain scan. He says seeing the image of his brain made him more willing to try medications and behavior modification therapy.
"I think I was trying things, but I think my level of involvement, my level of belief in it rose, which obviously is going to make things work better if you really believe in it."
But some vets are reacting cautiously to the study and wonder if V.A. researchers are overstating their findings.
Tom Berger is Chair of the National PTSD & Substance Abuse Committee for Vietnam Veterans of America. He thinks the Minneapolis researchers are too quick to suggest that the right temporal lobe is the key to PTSD.
"It's fine research. Very good research. It just, it's pretty narrow given what we know about PTSD and what little we know about traumatic brain injury."
Berger says the study doesn't include anyone who suffered from traumatic brain injury.
"What about people who have suffered a loss of their right temporal lobe, but still continue to have PTSD?"
The V.A.'s Brian Engdahl says future studies will include veterans with mild traumatic brain injury. But he says it was important for his team to examine relatively uncomplicated PTSD patients first.
The study is published in the Journal of Neural Engineering. The research was funded by the U.S. Department of Veterans Affairs. Lorna Benson, Minnesota Public Radio News.
- Morning Edition, 10/28/2010, 8:35 a.m.