title: Decreased basal ganglia activation in subjects with chronic fatigue syndrome: association with symptoms of fatigue.
abstract: Reduced basal ganglia function has been associated with fatigue in neurologic disorders, as well as in patients exposed to chronic immune stimulation. Patients with chronic fatigue syndrome (CFS) have been shown to exhibit symptoms suggestive of decreased basal ganglia function including psychomotor slowing, which in turn was correlated with fatigue. In addition, CFS patients have been found to exhibit increased markers of immune activation. In order to directly test the hypothesis of decreased basal ganglia function in CFS, we used functional magnetic resonance imaging to examine neural activation in the basal ganglia to a reward-processing (monetary gambling) task in a community sample of 59 male and female subjects, including 18 patients diagnosed with CFS according to 1994 CDC criteria and 41 non-fatigued healthy controls. For each subject, the average effect of winning vs. losing during the gambling task in regions of interest (ROI) corresponding to the caudate nucleus, putamen, and globus pallidus was extracted for group comparisons and correlational analyses. Compared to non-fatigued controls, patients with CFS exhibited significantly decreased activation in the right caudate (p = 0.01) and right globus pallidus (p = 0.02). Decreased activation in the right globus pallidus was significantly correlated with increased mental fatigue (r2 = 0.49, p = 0.001), general fatigue (r2 = 0.34, p = 0.01) and reduced activity (r2 = 0.29, p = 0.02) as measured by the Multidimensional Fatigue Inventory. No such relationships were found in control subjects. These data suggest that symptoms of fatigue in CFS subjects were associated with reduced responsivity of the basal ganglia, possibly involving the disruption of projections from the globus pallidus to thalamic and cortical networks.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Miller
authors.affiliation: Chronic Viral Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: James F
authors.initials: JF
authors.lastname: Jones
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Drake
authors.affiliation: Chronic Viral Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Hao
authors.initials: H
authors.lastname: Tian
authors.affiliation: Chronic Viral Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Unger
authors.affiliation: Department of Neuroscience, Biomedical, Metabolic Sciences, Università Degli Studi Di Modena E Reggio Emilia, Modena, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pagnoni
mesh_terms: D000328:Adult; D002421:Caudate Nucleus / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015673:Fatigue Syndrome, Chronic / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D005917:Globus Pallidus / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance; D011859:Radiography