Increased fronto-temporal perfusion in bipolar disorder.
OBJECTIVE
Previous imaging reports showed over-activation of fronto-limbic structures in bipolar patients, particularly in response to emotional stimuli. In this study, for the first time, we used perfusion weighted imaging (PWI) to analyze lobar cerebral blood volume (CBV) in bipolar disorder to further explore the vascular component to its pathophysiology.


METHODS
Fourteen patients with DSM-IV bipolar disorder (mean age+/-SD=49.00+/-12.30 years; 6 males, 8 females) and 29 normal controls (mean age+/-SD=45.07+/-10.30 years; 13 males, 16 females) were studied. PWI images were obtained following intravenous injection of paramagnetic contrast agent (Gadolinium-DTPA), with a 1.5 T Siemens magnet using an echo-planar sequence. The contrast of enhancement (CE), was calculated pixel by pixel as the ratio of the maximum signal intensity drop during the passage of contrast agent (Sm) by the baseline pre-bolus signal intensity (So) (CE=Sm/So*100) for frontal, temporal, parietal, and occipital lobes, bilaterally, on two axial images. Higher CE values correspond to lower CBV and viceversa.


RESULTS
Bipolar patients had significantly lower CE values in left frontal and temporal lobes (p=0.01 and p=0.03, respectively) and significantly inverse laterality index for frontal lobe (p=0.017) compared to normal controls. No significant correlations between CE measure and age or clinical variables were found (p>0.05).


CONCLUSIONS
This study found increased left frontal and temporal CBV in bipolar disorder. Fronto-temporal hyper-perfusion may sustain over-activation of these structures during emotion modulation, which have been observed in patients with bipolar illness.
Agarwal
N
N
Department of Medical and Morphological Researches, Section of Radiology, University of Udine, Udine, Italy.
Bellani
M
M
Perlini
C
C
Rambaldelli
G
G
Atzori
M
M
Cerini
R
R
Vecchiato
F
F
Pozzi Mucelli
R
R
Andreone
Nicola
N
Balestrieri
M
M
Tansella
M
M
Brambilla
P
P
D001714:Bipolar Disorder / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003287:Contrast Media / Q000008:administration & dosage; D035061:Control Groups; D017352:Echo-Planar Imaging / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply* / Q000000981:diagnostic imaging; D007839:Functional Laterality / Q000502:physiology; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009778:Occipital Lobe / Q000098:blood supply / Q000000981:diagnostic imaging; D010296:Parietal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011877:Radionuclide Imaging; D012039:Regional Blood Flow / Q000502:physiology; D013702:Temporal Lobe / Q000098:blood supply* / Q000000981:diagnostic imaging
D003287:Contrast Media; D019786:Gadolinium DTPA