Dr. Adams
01-13-2007, 02:00 PM
"Military veterans with posttraumatic stress disorder (PTSD) show reduced pain sensitivity compared with healthy controls, and altered pain processing may be responsible, according to findings from a functional imaging study.
Previous studies have yielded conflicting results regarding pain perception in PTSD patients, with some showing increased sensitivity and others showing the opposite.
12 male veterans with PTSD and 12 matched veterans without PTSD who underwent functional MRI. During imaging, fixed and variable temperatures were applied to the subjects' hands and they were asked to rate the pain experienced.
When exposed to the same temperatures, PTSD patients rated them as being less painful than did controls. Similarly, the temperatures that elicited the same subjective pain rating were higher in PTSD than in controls.
During fixed-temperature testing, PTSD patients displayed increased activation in the left hippocampus and decreased activation in the right amygdala and the bilateral ventrolateral prefrontal cortex. During variable temperature testing, heightened activation in the right putamen and bilateral insula were noted along with decreased activation in the right amygdala and right precentral gyrus.
All of these brain regions are associated with cognitive and affective pain processing.
The neural pattern with decreased activity in the right amygdala and the bilateral ventrolateral prefrontal cortex may reflect altered pain regulation mechanisms in patients with PTSD."
Arch Gen Psychiatry 2007;64:76-85.
Previous studies have yielded conflicting results regarding pain perception in PTSD patients, with some showing increased sensitivity and others showing the opposite.
12 male veterans with PTSD and 12 matched veterans without PTSD who underwent functional MRI. During imaging, fixed and variable temperatures were applied to the subjects' hands and they were asked to rate the pain experienced.
When exposed to the same temperatures, PTSD patients rated them as being less painful than did controls. Similarly, the temperatures that elicited the same subjective pain rating were higher in PTSD than in controls.
During fixed-temperature testing, PTSD patients displayed increased activation in the left hippocampus and decreased activation in the right amygdala and the bilateral ventrolateral prefrontal cortex. During variable temperature testing, heightened activation in the right putamen and bilateral insula were noted along with decreased activation in the right amygdala and right precentral gyrus.
All of these brain regions are associated with cognitive and affective pain processing.
The neural pattern with decreased activity in the right amygdala and the bilateral ventrolateral prefrontal cortex may reflect altered pain regulation mechanisms in patients with PTSD."
Arch Gen Psychiatry 2007;64:76-85.