Regional brain gray matter volume differences in patients with bipolar disorder as assessed by optimized voxel-based morphometry.
BACKGROUND
Structural magnetic resonance imaging (MRI) studies of regions of interest in brain have been inconsistent in demonstrating volumetric differences in subjects with bipolar disorder (BD). Voxel-based morphometry (VBM) provides an unbiased survey of the brain, can identify novel brain areas, and validates previously hypothesized regions. We conducted both optimized VBM, comparing MRI gray matter volume, and traditional VBM, comparing MRI gray matter density, in 11 BD subjects and 31 healthy volunteers. To our knowledge, these are the first VBM analyses of BD.


METHODS
Segmented MRI gray matter images were normalized into standardized stereotactic space, modulated to allow volumetric analysis (optimized only), smoothed, and compared at the voxel level with statistical parametric mapping.


RESULTS
Optimized VBM showed that BD subjects had smaller volume in left ventromedial temporal cortex and bilateral cingulate cortex and larger volume in left insular/frontoparietal operculum cortex and left ventral occipitotemporal cortex. Traditional VBM showed that BD subjects had less gray matter density in left ventromedial temporal cortex and greater gray matter density in left insular/frontoparietal operculum cortex and bilateral thalamic cortex. Exploratory analyses suggest that these abnormalities might differ according to gender.


CONCLUSIONS
Bipolar disorder is associated with volumetric and gray matter density changes that involve brain regions hypothesized to influence mood.
Lochhead
Richard A
RA
Department of Neuroscience, New York State Psychiatric Institute, New York, New York 10032, USA.
Parsey
Ramin V
RV
Oquendo
Maria A
MA
Mann
J John
JJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012727:Sex Characteristics