Neural Bases of Cognitive Impairments in Post-Traumatic Stress Disorders: A Mini-Review of Functional Magnetic Resonance Imaging Findings

Abstract

Introduction: Post-Traumatic Stress Disorder (PTSD) is often associated with impairments in emotional and cognitive domains. Contrarily to the emotional sphere, neural basis underpinnings to cognitive impairments are still not well known. Methods: We performed a bibliographic search on PUBMED of all the studies investigating the cognitive impairments in PTSD individuals. We considered only studies that applied cognitive tasks using a functional Magnetic Resonance Imaging technique. The inclusion criteria were met by nine studies. Results: Overall, PTSD individuals reported significant impairments in the dorsolateral prefrontal cortex, anterior cingulate cortex, inferior frontal gyrus, insula, inferior temporal cortex, supplement motor area, and Default Mode Network (DMN). Moreover, abnormal activity was reported in subcortical structures (e.g. hippocampus, amygdala, thalamus) and in the cerebellum. Limitations: Cognitive functioning was assessed using different cognitive tasks. Potential confounding factors such as age, sex, symptoms intensity, and comorbidities might have influenced the results. Conclusion: So far, the evidence reported that PTSD is characterized by cognitive impairments in several domains, such as attention, memory and autonomic arousal, which may be due to selective dysfunctions in brain regions that are part of cortical networks, the limbic system and DMN. However, further studies are needed in order to better assess the role of cognitive impairments in PTSD and to develop more targeted therapeutic approaches.

Association of Autonomic Activation with traumatic reminder challenges in posttraumatic stress disorder: A co‐twin control study

“…Chronic PTSD may influence several key brain structures, including the hippocampus, which has been found to be smaller in PTSD due to the effects of chronic stress. Changes like these, in turn, may influence baseline autonomic activity and its reactivity to stress (Dossi et al, 2020). The associations of acute PTSD symptoms with DC and LF HRV emphasize the importance of particular structures involved in parasympathetic function (DC), such as the nucleus ambiguus and the dorsal vagal nucleus, as well as the baroreflexes, like the insular cortex, anterior cingulate cortex, medial prefrontal cortex, amygdala and cerebellum (Kimmerly, 2017).…”

Diverse therapeutic developments for post-traumatic stress disorder (PTSD) indicate common mechanisms of memory modulation

“…Patients with PTSD had higher functional connectivity between the dACC with regions in the sensorimotor network in comparison to trauma-exposed and healthy controls, which may be related to preparing for the fight or flight response. On the other hand, patients with PTSD showed decreased functional connectivity between the dACC with the bilateral middle frontal gyrus and inferior frontal gyrus -areas important for response inhibition (Dossi, Delvecchio, Prunas, Soares, & Brambilla, 2020) -compared to individuals who were also exposed to trauma but did not develop PTSD. In addition, decreased functional connectivity between the dACC with the right hippocampus was found for both trauma-exposed groups but was more severe in the PTSD group.…”

Cortical complexity in world trade center responders with chronic posttraumatic stress disorder

“…In the years after 9/11, approximately 23% of these responders continued reported symptoms of chronic post-traumatic stress disorder [PTSD] [ 1 , 22 , 23 ]. Several studies by our group [ 2 , 3 , 24 , 25 ] and other investigators [ 26 – 29 ] have shown that PTSD is a risk factor for cognitive impairment (CI). Neuroimaging studies have identified neurobiological changes in the brains of patients with PTSD [ 30 ].…”