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Functional MRI of sustained attention in bipolar mania.

Fleck DE, Eliassen JC, Durling M, Lamy M, Adler CM, DelBello MP, Shear PK, Cerullo MA, Lee JH, Strakowski SM - Mol. Psychiatry (2010)

Bottom Line: Instead of differential activation in prefrontal cortex over time, as predicted in hypothesis 3, the BP group progressively decreased activation in subcortical regions of striatum and thalamus relative to the HC group.These results suggest that regional activation decrements in dorsolateral prefrontal cortex accompany sustained attention decrements in both bipolar and healthy individuals.Differential striatal and thalamic deactivation in bipolar disorder is interpreted as a loss of amygdala (emotional brain) modulation by the ventrolateral prefrontal-subcortical circuit, which interferes with attentional maintenance.

View Article: PubMed Central - PubMed

Affiliation: Division of Bipolar Disorders Research, Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0583, USA. fleckde@email.uc.edu

ABSTRACT
We examined sustained attention deficits in bipolar disorder and associated changes in brain activation assessed by functional magnetic resonance imaging (fMRI). We hypothesized that relative to healthy participants, those with mania or mixed mania would (1) exhibit incremental decrements in sustained attention over time, (2) overactivate brain regions required for emotional processing and (3) progressively underactivate attentional regions of prefrontal cortex. Fifty participants with manic/mixed bipolar disorder (BP group) and 34 healthy comparison subjects (HC group) received an fMRI scan while performing a 15-min continuous performance task (CPT). The data were divided into three consecutive 5-min vigilance periods to analyze sustained attention. Composite brain activation maps indicated that both groups activated dorsal and ventral regions of an anterior-limbic network, but the BP group exhibited less activation over time relative to baseline. Consistent with hypotheses 1 and 2, the BP group showed a marginally greater behavioral CPT sustained attention decrement and more bilateral amygdala activation than the HC group, respectively. Instead of differential activation in prefrontal cortex over time, as predicted in hypothesis 3, the BP group progressively decreased activation in subcortical regions of striatum and thalamus relative to the HC group. These results suggest that regional activation decrements in dorsolateral prefrontal cortex accompany sustained attention decrements in both bipolar and healthy individuals. Stable amygdala overactivation across prolonged vigils may interfere with sustained attention and exacerbate attentional deficits in bipolar disorder. Differential striatal and thalamic deactivation in bipolar disorder is interpreted as a loss of amygdala (emotional brain) modulation by the ventrolateral prefrontal-subcortical circuit, which interferes with attentional maintenance.

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Related in: MedlinePlus

Regions of the anterior-limbic network mask overlaid on T1-weighted anatomic image. Colors represent eleven regions of interest (ROI) including midline cerebellum (orange), bilateral amygdala (red), bilateral inferior frontal gyrus (light blue), bilateral striatum (green), bilateral globus pallidus (pink), and bilateral thalamus (dark blue). Not shown is bilateral superior frontal gyrus representing the final two ROIs.
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Figure 2: Regions of the anterior-limbic network mask overlaid on T1-weighted anatomic image. Colors represent eleven regions of interest (ROI) including midline cerebellum (orange), bilateral amygdala (red), bilateral inferior frontal gyrus (light blue), bilateral striatum (green), bilateral globus pallidus (pink), and bilateral thalamus (dark blue). Not shown is bilateral superior frontal gyrus representing the final two ROIs.

Mentions: Figure 2 depicts an anterior-limbic network region-of-interest (ROI) mask created based on our definition of this network. The ROI mask was applied to each individual’s fMRI data in order to obtain the average activation within an ROIs. The anterior-limbic ROIs included bilateral IFG (analogous to VLPFC), striatum (including caudate and putamen), globus pallidus, thalamus, amygdala, and midline cerebellum (i.e., cerebellar vermis). We adopted the anatomical regions defined36 on the Montreal Neurological Institute single-subject template brain,37 except for the cerebellar ROI, which was created in the vermis as an 8 mm radius sphere centered on coordinate x=5 mm left, y=53 mm posterior, and z=34 mm inferior to the anterior commissure. Additionally, we included a bilateral SFG ROI (analogous to DLPFC) because this region is implicated for CPT measures of sustained attention.17 A SFG mask was created based on the boundaries of Yamasaki et al.16 and Jha and McCarthy38 and spanned 10–33 mm anterior to the anterior commissure. The average activation within each ROI was extracted from each participant’s fMRI deconvolution results and used as input to the statistical analyses of brain activation described below. Although only group differences in frontal cortex and amygdala were hypothesized, we included other subcortical ROIs with direct connections to these structures to provide a network approach to the analysis.


Functional MRI of sustained attention in bipolar mania.

Fleck DE, Eliassen JC, Durling M, Lamy M, Adler CM, DelBello MP, Shear PK, Cerullo MA, Lee JH, Strakowski SM - Mol. Psychiatry (2010)

Regions of the anterior-limbic network mask overlaid on T1-weighted anatomic image. Colors represent eleven regions of interest (ROI) including midline cerebellum (orange), bilateral amygdala (red), bilateral inferior frontal gyrus (light blue), bilateral striatum (green), bilateral globus pallidus (pink), and bilateral thalamus (dark blue). Not shown is bilateral superior frontal gyrus representing the final two ROIs.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3037439&req=5

Figure 2: Regions of the anterior-limbic network mask overlaid on T1-weighted anatomic image. Colors represent eleven regions of interest (ROI) including midline cerebellum (orange), bilateral amygdala (red), bilateral inferior frontal gyrus (light blue), bilateral striatum (green), bilateral globus pallidus (pink), and bilateral thalamus (dark blue). Not shown is bilateral superior frontal gyrus representing the final two ROIs.
Mentions: Figure 2 depicts an anterior-limbic network region-of-interest (ROI) mask created based on our definition of this network. The ROI mask was applied to each individual’s fMRI data in order to obtain the average activation within an ROIs. The anterior-limbic ROIs included bilateral IFG (analogous to VLPFC), striatum (including caudate and putamen), globus pallidus, thalamus, amygdala, and midline cerebellum (i.e., cerebellar vermis). We adopted the anatomical regions defined36 on the Montreal Neurological Institute single-subject template brain,37 except for the cerebellar ROI, which was created in the vermis as an 8 mm radius sphere centered on coordinate x=5 mm left, y=53 mm posterior, and z=34 mm inferior to the anterior commissure. Additionally, we included a bilateral SFG ROI (analogous to DLPFC) because this region is implicated for CPT measures of sustained attention.17 A SFG mask was created based on the boundaries of Yamasaki et al.16 and Jha and McCarthy38 and spanned 10–33 mm anterior to the anterior commissure. The average activation within each ROI was extracted from each participant’s fMRI deconvolution results and used as input to the statistical analyses of brain activation described below. Although only group differences in frontal cortex and amygdala were hypothesized, we included other subcortical ROIs with direct connections to these structures to provide a network approach to the analysis.

Bottom Line: Instead of differential activation in prefrontal cortex over time, as predicted in hypothesis 3, the BP group progressively decreased activation in subcortical regions of striatum and thalamus relative to the HC group.These results suggest that regional activation decrements in dorsolateral prefrontal cortex accompany sustained attention decrements in both bipolar and healthy individuals.Differential striatal and thalamic deactivation in bipolar disorder is interpreted as a loss of amygdala (emotional brain) modulation by the ventrolateral prefrontal-subcortical circuit, which interferes with attentional maintenance.

View Article: PubMed Central - PubMed

Affiliation: Division of Bipolar Disorders Research, Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0583, USA. fleckde@email.uc.edu

ABSTRACT
We examined sustained attention deficits in bipolar disorder and associated changes in brain activation assessed by functional magnetic resonance imaging (fMRI). We hypothesized that relative to healthy participants, those with mania or mixed mania would (1) exhibit incremental decrements in sustained attention over time, (2) overactivate brain regions required for emotional processing and (3) progressively underactivate attentional regions of prefrontal cortex. Fifty participants with manic/mixed bipolar disorder (BP group) and 34 healthy comparison subjects (HC group) received an fMRI scan while performing a 15-min continuous performance task (CPT). The data were divided into three consecutive 5-min vigilance periods to analyze sustained attention. Composite brain activation maps indicated that both groups activated dorsal and ventral regions of an anterior-limbic network, but the BP group exhibited less activation over time relative to baseline. Consistent with hypotheses 1 and 2, the BP group showed a marginally greater behavioral CPT sustained attention decrement and more bilateral amygdala activation than the HC group, respectively. Instead of differential activation in prefrontal cortex over time, as predicted in hypothesis 3, the BP group progressively decreased activation in subcortical regions of striatum and thalamus relative to the HC group. These results suggest that regional activation decrements in dorsolateral prefrontal cortex accompany sustained attention decrements in both bipolar and healthy individuals. Stable amygdala overactivation across prolonged vigils may interfere with sustained attention and exacerbate attentional deficits in bipolar disorder. Differential striatal and thalamic deactivation in bipolar disorder is interpreted as a loss of amygdala (emotional brain) modulation by the ventrolateral prefrontal-subcortical circuit, which interferes with attentional maintenance.

Show MeSH
Related in: MedlinePlus