Table 1.
Sociodemographic and Clinical Characteristics of the Study Sample.
Table 2.
Symptoms of Fatigue in CFS and Control Subjects.
Figure 1.
Basal Ganglia Activation in the Gambling Task.
Left to right - Axial, coronal and transverse sections of the brain. The top row displays the activation for the Win-Lose contrast, for the pooled sample of chronic fatigue syndrome (CFS)+Control subjects, as a statistical parametric map thresholded at a p<0.05 corrected threshold and masked with the atlas-based anatomical regions of interest portrayed in the bottom row (putamen: purple; caudate: orange; globus pallidus: turquoise).
Figure 2.
Reduced Activation in Basal Ganglia Structures in CFS compared to Controls for the Win-Lose Contrast.
Box plot of activation [percent blood oxygen level-dependent (BOLD) signal change corresponding to the Win-Lose contrast averaged across all region of interest (ROI) voxels] in basal ganglia structures: blue = nonfatigued (NF) controls, red = chronic fatigue syndrome (CFS) subjects. Univariate analyses of group differences in specific ROIs revealed that CFS subjects exhibited significantly reduced neural activity compared to NF controls in the right caudate and right globus pallidus and each of these structures bilaterally (all p<0.05).
Figure 3.
Correlation between Fatigue and Globus Pallidus Activation in CFS and Controls.
Scores on the mental fatigue, general fatigue and reduced activity subscales of the Multidimensional Fatigue Inventory (MFI) are plotted against the percent BOLD signal change corresponding to the Win-Lose contrast averaged across all region of interest (ROI) voxels in the right globus pallidus: blue = nonfatigued (NF) controls, red = chronic fatigue syndrome (CFS) subjects. Relationships were assessed in each group separately using Bravais-Pearson correlations. Significant correlations were found between neural activity in the right globus pallidus and mental fatigue, general fatigue and reduced activity in CFS subjects (all p<0.05) but not in controls.