Reduced hippocampal volume and total white matter volume in posttraumatic stress disorder.
BACKGROUND
Reduced hippocampal volumes in posttraumatic stress disorder (PTSD) patients are thought to reflect specific changes of this structure. Previous magnetic resonance imaging (MRI) studies have not consistently examined indices of overall brain atrophy, therefore it cannot be completely ruled out that hippocampal changes are explained by whole-brain atrophy. The purpose of this study was to assess hippocampal and whole-brain volume in civilian PTSD.


METHODS
Twelve subjects with PTSD and 10 control subjects underwent brain MRI. Hippocampal volumes were visually quantified using a computerized volumetric program. Whole-brain volumes were obtained with automated k-means-based segmentation.


RESULTS
No differences were found in intracranial volumes (ICV). Subjects with PTSD had higher cerebrospinal fluid (CSF)/ICV ratios and lower white matter/ICV ratios, consistent with generalized white matter (WM) atrophy. The effect of age on CSF/ICV was more pronounced in the PTSD group. Subjects with PTSD had smaller absolute and normalized bilateral hippocampal volumes. These differences persisted after adjusting for lifetime weeks of alcohol intoxication. Posttraumatic stress disorder and depression scores correlated negatively with left hippocampal volume, but PTSD scores were a better predictor of hippocampal volumes.


CONCLUSIONS
Our results replicate previous findings of reduced hippocampal volume in PTSD but also suggest independent, generalized, white matter atrophy.
Department of Psychiatry, University of New Mexico School of Medicine, Albuquerque, USA.
Gerardo
G
Villarreal
Derek A
DA
Hamilton
Helen
H
Petropoulos
Ira
I
Driscoll
Laura M
LM
Rowland
Jaqueline A
JA
Griego
Piyadasa W
PW
Kodituwakku
Blaine L
BL
Hart
Rodrigo
R
Escalona
William M
WM
Brooks
D000328:Adult; D000704:Analysis of Variance; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013313:Stress Disorders, Post-Traumatic / Q000473:pathology*