White matter abnormalities in children with and at risk for bipolar disorder.
OBJECTIVE
Diffusion tensor magnetic resonance imaging (DT-MRI) assesses the integrity of white matter (WM) tracts in the brain. Children with bipolar disorder (BPD) may have WM abnormalities that precede illness onset. To more fully examine this possibility, we scanned children with DSM-IV BPD and compared them to healthy peers and children at risk for BPD (AR-BPD), defined as having a first-degree relative with the disorder.


METHODS
Ten children with BPD, eight healthy controls (HC), and seven AR-BPD, similar in age, had MRI scans on a 1.5 Tesla GE scanner, including a standard DT-MRI sequence (T2-EPI) with 25 axial slices. Fractional anisotropy (FA) values were compared between groups to determine regions of significant difference (p < 0.05).


RESULTS
Compared to HC, children with BPD had decreased FA in right and left superior frontal tracts, including the superior longitudinal fasciculus I (SLF I) and the cingulate-paracingulate WM (CG-PAC(WM)). In addition, the BPD group had reduced FA in left orbital frontal WM and the right corpus callosum body. Compared to AR-BPD, children with BPD showed reduced FA in the right and left CG-PAC(WM). Both the BPD and AR-BPD groups showed reduced FA relative to HC in bilateral SLF I.


CONCLUSIONS
The bilateral SLF I finding in both the BPD and AR-BPD groups may represent a trait-based marker or endophenotype of the disorder. The finding of decreased FA in the right and left CG-PAC(WM) in children with BPD compared to the other two groups may represent a disease-state related finding.
Frazier
Jean A
JA
Department of Psychiatry, Harvard Medical School, Boston, USA. jfrazier@challiance.org
Breeze
Janis L
JL
Papadimitriou
George
G
Kennedy
David N
DN
Hodge
Steven M
SM
Moore
Constance M
CM
Howard
James D
JD
Rohan
Michael P
MP
Caviness
Verne S
VS
Makris
Nikos
N
D000293:Adolescent; D001714:Bipolar Disorder / Q000453:epidemiology* / Q000473:pathology*; D001931:Brain Mapping; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009457:Neuroglia / Q000473:pathology*; D011569:Psychiatric Status Rating Scales; D012306:Risk