Neurometabolites in anterior cingulate cortex in chronic fatigue syndrome: A magnetic resonance spectroscopy study at 7 Tesla

Abstract:

Background: Chronic fatigue syndrome (CFS) is a disorder characterized by prolonged physical and mental fatigue that cannot be explained by another established medical diagnosis. The anterior cingulate cortex (ACC) and putamen are two regions involved in frontal-striatal neural circuitry, which may be related to the pathophysiology of CFS. The aim of this study was to investigate the concentrations of neurometabolites, including glutamate, gamma-aminobutyric acid (GABA) and glutathione, in the ACC and putamen, using magnetic resonance spectroscopy (MRS) at 7 Tesla (7T). In addition, this study also aimed to evaluate resting-state functional connectivity in CFS with functional magnetic resonance imaging (fMRI).

Methods: This study involved 12 patients who met the Oxford criteria for CFS and 25 healthy controls. Participants rated themselves on the Chalder Fatigue Questionnaire (CFQ) and the Beck Depression Inventory (BDI). All participants had a single proton (1H) MRS and resting-state fMRI scan with a 7T Siemens MAGNETOM scanner (Siemens, Erlangen, Germany) with a Nova Medical 32 channel receive array head coil. Spectra were measured from voxels in the ACC (20 × 20 × 20 mm), putamen (10 × 16 × 20 mm) and occipital cortex (20 × 20 × 20 mm). Spectra were analysed with LCModel to obtain absolute concentrations of the neurochemicals. Differences in functional connectivity between CFS and healthy participants were tested using multivariate exploratory linear optimized decomposition into independent components (MELODIC) and dual regression.

Results: Concentrations of putamen glutamate and glutamate+glutamine (Glx) were increased in CFS while that of ACC GABA was decreased. Putamen Glx and ACC glutamine were negatively associated with the severity of self-reported fatigue. There were main effects of CFS diagnosis on glutathione (GSH) and total creatine, indicating decreases of these neurometabolites in all the regions studied in CFS patients. In addition, the CFS patients demonstrated elevated functional connectivity between the default mode network and right supracalcarine cortex, precuneus cortex and dorsolateral prefrontal cortex.

Conclusions: The increased putamen glutamate, decreased ACC GABA and elevated resting state functional connectivity of the default mode network suggest a hyperactive brain status in CFS. The global decrease of GSH and total creatine also suggest that CFS patients may have an abnormal bioenergetic status with higher oxidative stress.

Source: Chi Chen. Neurometabolites in anterior cingulate cortex in chronic fatigue syndrome: A magnetic resonance spectroscopy study at 7 Tesla. Oxford University Research Archive. September 22, 2017. (Open access article) https://ora.ox.ac.uk/objects/uuid:60ff242e-2ccd-4f23-ac7d-16553d864e8b

Supplementation with Guanidinoacetic Acid in Women with Chronic Fatigue Syndrome

Abstract:

A variety of dietary interventions has been used in the management of chronic fatigue syndrome (CFS), yet no therapeutic modality has demonstrated conclusive positive results in terms of effectiveness. The main aim of this study was to evaluate the effects of orally administered guanidinoacetic acid (GAA) on multidimensional fatigue inventory (MFI), musculoskeletal soreness, health-related quality of life, exercise performance, screening laboratory studies, and the occurrence of adverse events in women with CFS.

Twenty-one women (age 39.3 ± 8.8 years, weight 62.8 ± 8.5 kg, height 169.5 ± 5.8 cm) who fulfilled the 1994 Centers for Disease Control and Prevention criteria for CFS were randomized in a double-blind, cross-over design, from 1 September 2014 through 31 May 2015, to receive either GAA (2.4 grams per day) or placebo (cellulose) by oral administration for three months, with a two-month wash-out period.

No effects of intervention were found for the primary efficacy outcome (MFI score for general fatigue), and musculoskeletal pain at rest and during activity.

After three months of intervention, participants receiving GAA significantly increased muscular creatine levels compared with the placebo group (36.3% vs. 2.4%; p < 0.01). Furthermore, changes from baseline in muscular strength and aerobic power were significantly greater in the GAA group compared with placebo (p < 0.05). Results from this study indicated that supplemental GAA can positively affect creatine metabolism and work capacity in women with CFS, yet GAA had no effect on main clinical outcomes, such as general fatigue and musculoskeletal soreness.

 

Source: Ostojic SM, Stojanovic M, Drid P, Hoffman JR, Sekulic D, Zenic N. Supplementation with Guanidinoacetic Acid in Women with Chronic Fatigue Syndrome. Nutrients. 2016 Jan 29;8(2):72. doi: 10.3390/nu8020072. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4772036/ (Full article)