Frontal lobe gray matter density decreases in bipolar I disorder.
BACKGROUND
This study was conducted to explore differences in gray and white matter density between bipolar and healthy comparison groups using voxel-based morphometry (VBM).


METHODS
Brain magnetic resonance imaging was performed for 39 subjects with bipolar I disorder and 43 comparison subjects. Images were registered into a proportional stereotaxic space and segmented into gray matter, white mater, and cerebrospinal fluid. Statistical parametric mapping was used to calculate differences in gray and white matter density between groups.


RESULTS
Bipolar subjects had decreased gray matter density in left anterior cingulate gyrus (Brodmann's area [BA] 32, 7.3% decrease), an adjacent left medial frontal gyrus (BA 10, 6.9% decrease), right inferior frontal gyrus (BA 47, 9.2% decrease), and right precentral gyrus (BA 44, 6.2% decrease), relative to comparison subjects.


CONCLUSIONS
The observation of a gray matter density decrease in the left anterior cingulate, which processes emotions, in bipolar subjects is consistent with prior reports that used region-of-interest analytic methods. Decreased gray matter density in the right inferior frontal gyrus, which processes nonverbal and intrinsic functions, supports nondominant hemisphere dysfunction as a component of bipolar disorder.
Lyoo
In Kyoon
IK
Brain Imaging Center, McLean Hospital, Belmont, Massachusetts 02478, USA.
Kim
Minue J
MJ
Stoll
Andrew L
AL
Demopulos
Christina M
CM
Parow
Aimee M
AM
Dager
Stephen R
SR
Friedman
Seth D
SD
Dunner
David L
DL
Renshaw
Perry F
PF
D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000473:pathology* / Q000503:physiopathology; D001931:Brain Mapping; D002452:Cell Count / Q000379:methods; D005260:Female; D005625:Frontal Lobe / Q000473:pathology*; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged