Neurofunctional correlates of posttraumatic stress disorder: a PET symptom provocation study

Abstract

Patients with combat-related posttraumatic stress disorder (PTSD) show altered cognitive and affective processing and symptomatic responding following exposure to trauma reminders. Previous symptom provocation studies using brain imaging have involved Vietnam veterans. In this study neural correlates were investigated in patients with PTSD resulting from trauma in more recent war zones. (15)Oxygen water and positron emission tomography were used to measure regional cerebral blood flow (rCBF) in patients with war- and combat-related chronic PTSD during exposure to combat and neutral sounds. Self-reports and heart rate confirmed symptomatic responding during traumatic stimulation. The war-related condition, as compared to the neutral, increased rCBF in the right sensorimotor areas (Brodmann areas 4/6), extending into the primary sensory cortex (areas 1/2/3), and the cerebellar vermis. RCBF also increased in the right amygdala and in the periaqueductal gray matter adjacent to the pons. During provocation rCBF was lowered in the right retrosplenial cortex (areas 26/29/30 extending into area 23). Symptom provocation in PTSD promote sensorimotor, amygdaloid and midbrain activation. We conclude that perceptually induced symptom activation in PTSD is associated with an emotionally determined motor preparation and propose that subcortically initiated rather than cortically controlled memory mechanisms determine this pattern.

Single-prolonged stress induces increased phosphorylation of extracellular signal-regulated kinase in a rat model of post-traumatic stress disorder

“…amygdala hyperresponsivity with apparent exaggerated responses in PTSd has been reported (10)(11)(12)(13)(14)(15)(16)(17)(18)(19). cui et al additionally found that behavioral changes in response to SPS may be attributed to the amygdala (20).…”

Functional neuroimaging studies in posttraumatic stress disorder: review of current methods and findings

“…In this way, neural activity can be studied when subjects are exposed to stimuli reminiscent of their traumatic past. Studies of Vietnam combat veterans have used combat sounds [Bremner et al, 1999b;Liberzon et al, 1999;Pissiota et al, 2002;Zubieta et al, 1999] and combat slides [Bremner et al, 1999b;Hendler et al, 2003] to induce trauma-related stress by symptom provocation. Other studies that include victims of sexual assault or abuse have used personal traumatic scripts [Britton et al, 2005;Gilboa et al, 2004;Lanius et al, 2001Lanius et al, , 2002Lanius et al, , 2005Liberzon, 2003;Rauch et al, 1996;Shin et al, 2004a] to elicit an emotional response.…”

How psychotherapy changes the brain – the contribution of functional neuroimaging

“…The latter technique induces traumatic imageries and thus mimics flashbacks of the aversive events (as evidenced by both subjective ratings and psychophysiological parameters) by reading accounts of their individual traumatic experiences to patients during functional imaging. 15 Increased activation of the right amygdala was found across provocation techniques and imaging modalities, [15][16][17] while medial prefrontal areas were consistently reported to be less active in PTSD patients than controls when traumatic events had to be recalled. 18,19 In regions of the medial temporal cortex commonly associated with memory retrieval and visual association areas involved in mental imagery both higher and lower activation have been reported for PTSD patients, possibly reflecting the heterogeneity of patient samples across studies.…”