Article

MRI-Based Measurement of Hippocampal Volume in Patients with Combat-Related Posttraumatic Stress Disorder

Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
American Journal of Psychiatry (Impact Factor: 13.56). 08/1995; 152(7):973-81.
Source: PubMed

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.

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    • "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. "
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    • "Studies investigating the neural correlates of PTSD are also of particular interest for the present article. Beginning with Bremner et al.'s (1995) study of Vietnam combat veterans suffering from PTSD, an elevated number of neuroimaging studies (Bremner et al., 1997, 2003; Lindauer et al., 2004; Stein, Koverola, Hanna, Torchia, & McClarty, 1997; Villarreal et al., 2002; Wignall et al., 2004) have demonstrated that PTSD patients show a significant reduction in the volume of their hippocampus relative to control subjects. Specifically, in a recent metaanalysis of 13 studies using magnetic resonance imaging, Smith (2005) estimated that PTSD individuals had a 6.6% smaller right hippocampal volume and a 6.9% smaller left hippocampal volume in comparison with well-matched control participants , encompassing both trauma-exposed individuals who did not develop PTSD and subjects without significant trauma exposure. "
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    • "This parallels human functional imaging data that show greater amygdala activation in human populations with PTSD (Liberzon et al., 1999; Shin, Rauch, & Pitman, 2006). Moreover, it has been observed that there is a reduction in hippocampal volume in PTSD patients (Bremner et al., 1995; Woon, Sood, & Hedges, 2010), but despite this, many functional imaging studies have reported greater hippocampal activation in this patient population (Osuch et al., 2001; Sachinvala, Kling, Suffin, Lake, & Cohen, 2000; Shin et al., 2006; Thomaes et al., 2009; Werner et al., 2009). These outcomes observed in humans with PTSD parallel what many have observed following chronic stress considering dendritic atrophy in the hippocampus as an indirect measure of volume (Hoffman et al., 2011; Tata & Anderson, 2010; Watanabe, Gould, & McEwen, 1992 "
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