Neuroimaging in bipolar disorder.
OBJECTIVE
The authors reviewed neuroimaging studies of bipolar disorder in order to evaluate how this literature contributes to the current understanding of the neurophysiology of the illness.


METHODS
Papers were reviewed as identified, using the NIMH PubMed literature search systems that reported results of neuroimaging studies involving a minimum of five bipolar disorder patients compared with healthy comparison subjects.


RESULTS
Structural neuroimaging studies report mixed results for lateral and third ventriculomegaly. Recent studies suggest subcortical structural abnormalities in the striatum and amygdala, as well as the prefrontal cortex. Proton spectroscopic studies suggest that abnormalities in choline metabolism exist in bipolar disorder, particularly in the basal ganglia. Additionally, phosphorous MRS suggests that there may be abnormalities in frontal phospholipid metabolism in bipolar disorder. Functional studies have identified affective state-related changes in cerebral glucose metabolism and blood flow, particularly in the prefrontal cortex during depression, but no clear abnormalities specific to bipolar disorder have been consistently observed.


CONCLUSIONS
The current literature examining the neurophysiology of bipolar disorder using neuroimaging is limited. Nonetheless, abnormalities in specific frontal-subcortical brain circuits seem likely. Additional targeted studies are needed to capitalize on this burgeoning technology to advance our understanding of the neurophysiology of bipolar disorder.
Bipolar and Psychotic Disorders Research Program, Department of Psychiatry, University of Cincinnati College of Medicine, OH 45267-0559, USA. strakosm@email.uc.edu
S M
SM
Strakowski
M P
MP
DelBello
C
C
Adler
D M
DM
Cecil
K W
KW
Sax
D001479:Basal Ganglia / Q000378:metabolism; D001714:Bipolar Disorder / Q000175:diagnosis*; D001921:Brain / Q000002:abnormalities* / Q000098:blood supply / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000502:physiology; D002794:Choline / Q000378:metabolism; D005625:Frontal Lobe / Q000098:blood supply / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D010743:Phospholipids / Q000378:metabolism; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon
D010743:Phospholipids; D002794:Choline