A recent Australian study, Progressive Brain Changes in Patients With Chronic Fatigue Syndrome: A Longitudinal MRI Study finds that CFS patients meeting both Fukuda and CCC have decreased grey and white matter volumes in the areas of the brain we use for language processing.
Interestingly, patients had increased grey matter volume in the supplementary motor area, and this correlated with patients’ subjective scores gauging neurological symptom severity. This supports CFS’s patients’ reports of requiring greater effort to coordinate movement: brain plasticity may allow CFS patients’ brains to compensate for loss in the parts of the brain that are usually primarily responsible for handling and coordinating these tasks.
Though many studies have examined MRI in ME/CFS patients, this is only the second longitudinal study that has been performed; the first, from the British Journal of Radiology, found no abnormalities (Perrin et al., 2010). Though Perrin’s study eliminated patients with psychiatric conditions, CFS patients were recruited based on the broad-based Fukuda criteria, whereas in Shan’s Progressive Brain Changes, patients had to meet both Fukuda and the Canadian Consensus Criteria to be included.
25 patients and 25 controls were recruited. CFS severity was measured by:
- The Bell’s CFS disability score
- A somatic symptom score
- A neurological symptom score
Patients’ brains were scanned 6 years apart on the same 1.5-Tesla scanner, and voxel-based morphometry was used to examine the results. Both T1- and T2-weighted signal intensities were examined.
CFS patients showed a decrease in white matter volume in the left IFOF (inferior fronto-occipital fasciculus) and arcuate fasciculus, while in controls, the white matter volume remained stable.
The IFOF is partly responsible for attention, language processing, and working memory; it also plays a role in goal orientation, ability to focus vision, and motor coordination. The IFOF connects many areas of the brain, allowing them to communicate with one another (Ashtari, 2012).
The arcuate fasciculus is partially responsible for language expression; patients with damage there can understand speech well, but sometimes have difficulty with language expression and repetition (Bernal, 2009). There is evidence this part of the brain is involved in short-term memory as well.
Inter-group comparisons also found decreased grey- and white matter volumes, coupled with increased white matter hyperintensities in and around the contralateral ILOF (left inferior longitudinal fasciculus), also thought to play a role in language processing (Mandonnet, 2007). White matter hyperintensities may reflect ischemia and hypoperfusion in those areas.
Additionally, grey matter volume and blood flow to the brain were found to correlate to better self-reported scores on SSS and NSS.
Shan et al. posited that brain damage could potentially be due to long-term ‘functional hypoxia’, or oxygen starvation, in the brain.
Since the IFOF region of the brain is continually organized and re-organized into early adulthood, this may be one of the factors that contribute to the typical age of onset in CFS, and the increased potential for vascular irregularities that are often part of the illness. Coupled with a finding of vascular endothelial growth factor (VEGF) as generally low in CFS (Landi, 2015), that may further increase patients’ vulnerability to incomplete or inappropriate vascular remodeling.