Article Index

Advances in brain research

PET scanning

Neuroscience of fatigue and CFS/ME using PET was presented by Yasuyoshi Watanabe (Osaka, Japan). PET molecular and functional imaging is used to demonstrate brain dysfunction. Results of large studies in Japan showed reduced binding potential of 5HTT in CFS/ME patients, and this correlated with the pain scores. PET scanning could also be used for differential diagnosis. There were correlations between gastrointestinal symptoms and binding potential of 5HTT, and PET studies on neuroinflammation corresponded to activated microglia. fMRIs showed changes or reversible atrophy in the prefrontal cortex and a mirror system of fatigue (MEG). There were also changes in circulation from acute to chronic phases. Watanabe stressed now the need to look more at what is happening in healthy people.

EEG peak alpha frequency

Marcie and Mark Zinn (California, USA) then discussed their work on EEG peak alpha frequency associated with CFS/ME, as disabling fatigue and cognitive impairment are cardinal symptoms. The first presentation was to evaluate the relationship between EEG peak alpha frequency in CFS/ME compared to matched controls. Findings were consistent with reduced efficiency of thalamo-cortical connections in CFS/ME patients. And this correlated with reduced ability to coordinate cognitive symptoms. There may be prognostic value to facilitate the evaluation of CFS/ME as part of the diagnostic regimen. The second presentation looked at cortical hypoactivation during resting EEG in those with CFS/ME, and suggested central nervous system pathology. Exact low resolution electromagnetic tomography (ELORETA) could be applied to the understanding of brain fog. There were elevated delta sources in CFS/ME, with the highest percentage of voxel activations mainly in the left hemisphere regions of interest. Implications of abnormal delta sources can include speech difficulties, as Broca’s area is involved, and a possible indication of limbic encephalitis. No patients with psychiatric comorbidity were included in these studies.

Meta-analysis of cognitive functioning

Susan Cockshell (Adelaide, Australia) had investigated cognitive functioning in CFS/ME, using meta-analysis of previous studies and using that information to study a group of those with CFS/ME. Out of 4000 abstracts, 50 reported cognitive symptoms. She then studied 50 patients and matched controls. The main cognitive deficit found in those with CFS/ME appears to be a slowing in information processing speed. All were motivated to perform well. After testing it took 2-3 days for the CFS/ME patients to recover from the resultant fatigue.