MRI-Based Measurement of Hippocampal Volume in Patients with Combat-Related Posttraumatic Stress Disorder
ABSTRACT Studies in nonhuman primates suggest that high levels of cortisol associated with stress have neurotoxic effects on the hippocampus, a brain structure involved in memory. The authors previously showed that patients with combat-related posttraumatic stress disorder (PTSD) had deficits in short-term memory. The purpose of this study was to compare the hippocampal volume of patients with PTSD to that of subjects without psychiatric disorder.
Magnetic resonance imaging was used to measure the volume of the hippocampus in 26 Vietnam combat veterans with PTSD and 22 comparison subjects selected to be similar to the patients in age, sex, race, years of education, socioeconomic status, body size, and years of alcohol abuse.
The PTSD patients had a statistically significant 8% smaller right hippocampal volume relative to that of the comparison subjects, but there was no difference in the volume of other brain regions (caudate and temporal lobe). Deficits in short-term verbal memory as measured with the Wechsler Memory Scale were associated with smaller right hippocampal volume in the PTSD patients only.
These findings are consistent with a smaller right hippocampal volume in PTSD that is associated with functional deficits in verbal memory.
Full-textDOI: · Available from: John Seibyl, Sep 29, 2015
- SourceAvailable from: Aikaterini Fotopoulou
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- "cits in their declarative memory, even for events that have nothing to do with the original trauma (Bremner et al., 1995, 1997). These deficits are the result of lasting damage to the hippocampus, due to synaptic loss caused by adrenal steroids; such people are especially prone to further hippocampal damage caused by ongoing high levels of stress (reviewed in Kandel, 1999, and LeDoux, 1996). "
ABSTRACT: Recent advances in the cognitive, affective and social neurosciences have enabled these fields to study aspects of the mind that are central to psychoanalysis. These developments raise a number of possibilities for psychoanalysis. Can it engage the neurosciences in a productive and mutually enriching dialogue without compromising its own integrity and unique perspective? While many analysts welcome interdisciplinary exchanges with the neurosciences, termed neuropsychoanalysis, some have voiced concerns about their potentially deleterious effects on psychoanalytic theory and practice. In this paper we outline the development and aims of neuropsychoanalysis, and consider its reception in psychoanalysis and in the neurosciences. We then discuss some of the concerns raised within psychoanalysis, with particular emphasis on the epistemological foundations of neuropsychoanalysis. While this paper does not attempt to fully address the clinical applications of neuropsychoanalysis, we offer and discuss a brief case illustration in order to demonstrate that neuroscientific research findings can be used to enrich our models of the mind in ways that, in turn, may influence how analysts work with their patients. We will conclude that neuropsychoanalysis is grounded in the history of psychoanalysis, that it is part of the psychoanalytic worldview, and that it is necessary, albeit not sufficient, for the future viability of psychoanalysis. Copyright © 2015 Institute of Psychoanalysis.The International Journal of Psychoanalysis 07/2015; DOI:10.1111/1745-8315.12332 · 0.86 Impact Factor
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- "Reduced vmPFC volumes have been observed in patients with PTSD (Hartley et al., 2011; Milad et al., 2005), which could be a risk factor (as well as a maintaining factor) in PTSD due to the role it plays in mediating effects of the hippocampus on the amygdala. Morphologic alterations in PTSD have also been found in the amygdala (Morey et al., 2012) and the hippocampus (Bremner et al., 1995), further pointing to the usefulness of circuit-level analysis to understand neural dysfunctions in this disorder. The circuit-level approach to understand contextual control of fear might also inform the representation of fear memories in the brain such that the orchestration of a hippocampal– dmPFC–amygdala network represents a core, systems-level engram of the contextual retrieval of threat cues. "
ABSTRACT: The maintenance of anxiety disorders is thought to depend, in part, on deficits in extinction memory, possibly due to reduced contextual control of extinction that leads to fear renewal. Animal studies suggest that the neural circuitry responsible fear renewal includes the hippocampus, amygdala, and dorsomedial (dmPFC) and ventromedial (vmPFC) prefrontal cortex. However, the neural mechanisms of context-dependent fear renewal in humans remain poorly understood. We used functional magnetic resonance imaging (fMRI), combined with psychophysiology and immersive virtual reality, to elucidate how the hippocampus, amygdala, and dmPFC and vmPFC interact to drive the context-dependent renewal of extinguished fear. Healthy human participants encountered dynamic fear-relevant conditioned stimuli (CSs) while navigating through 3-D virtual reality environments in the MRI scanner. Conditioning and extinction were performed in two different virtual contexts. Twenty-four hours later, participants were exposed to the CSs without reinforcement while navigating through both contexts in the MRI scanner. Participants showed enhanced skin conductance responses (SCRs) to the previously-reinforced CS+ in the acquisition context on Day 2, consistent with fear renewal, and sustained responses in the dmPFC. In contrast, participants showed low SCRs to the CSs in the extinction context on Day 2, consistent with extinction recall, and enhanced vmPFC activation to the non-reinforced CS-. Structural equation modeling revealed that the dmPFC fully mediated the effect of the hippocampus on right amygdala activity during fear renewal, whereas the vmPFC partially mediated the effect of the hippocampus on right amygdala activity during extinction recall. These results indicate dissociable contextual influences of the hippocampus on prefrontal pathways, which, in turn, determine the level of reactivation of fear associations. Copyright © 2015. Published by Elsevier Inc.NeuroImage 07/2015; 122. DOI:10.1016/j.neuroimage.2015.07.051 · 6.36 Impact Factor
- "The central nervous system arousal is emphatically limbic, especially of the hippocampus and particularly of certain nuclei such as the locus ceruleus. Imaging studies show that when the disorder is chronic, these over-aroused areas become atrophied—particularly the right hippocampus (Bremner, 1995) and, in addition, there is some less significant frontal lobe atrophy. The negative PTSD phenomena I consider associated with the brain atrophy, especially in the right hippocampus, are reduced short term memory and reduced memory for early periods of childhood. "
Research: Toward a Unifying Theory of PTSD[Show description] [Hide description]
DESCRIPTION: An effort to integrate data from videotaped interviews of severely traumatized persons (especially children) with physiological, imaging, and psychological studies in light of evolutionary theory of altruism.