Event-Related Functional Magnetic Resonance Imaging in Post-Traumatic Stress Disorder

Park, Jong Ik; Hong, Jin Pyo; Cho, Young Rae; Park, Ji Kang; Lee, Ho Gyu; Kim, Chang Yoon; Han, Oh Su

Abstract

OBJECTIVE
Symptom provocation paradigms using event-related functional magnetic resonance imaging(fMRI) can be an important tool to visualize neuroanatomic correlates of PTSD symptoms. The purpose of this study is to measure regional changes of brain upon exposure to fear stimulus and elucidate the probable relation between signal changes and fear response in PTSD. METHOD: Event-related fMRI was performed during a task where traffic accident-related photos and checkerboards were presented in 9 women with PTSD and 9 woman normal controls in unpredictable order. MRI data were acquired on a 1.5 T GE vision system with a head volume coil. Stimuli were presented on a mirror mounted on the head coil. A total of 200 functional images were taken during a 10-minute scanning session. TR was 3 seconds and inter-stimulus time was varing 4.5 to 11.5 seconds. Data was analyzed using SPM99.
RESULTS
In PTSD group, the fear conditions versus the neutral conditions showed activations in both occipital cortex, both fusiform gyrus, left parietal lobule, both insula, right cerebellar tonsil, right putamen, right claustrum, but deactivations in both prefrontal gyrus(p<0.001). In normal control group, activation were found for the fear conditions as compared with the neutral conditions in left fusiform gyrus, both occipital cortex, left parietal lobule, right frontal lobule(p<0.001).
CONCLUSIONS
Emotion provocation paradigm using event-related functional magnetic resonance imaging can be applied to illustrate fear response mechanism in PTSD. The result suggests that insula, limbic lobe, cerebellum may play a role in mediating fear response in PTSD.