Research abstract:
Cortical hypoactivation during resting EEG suggests central nervous system pathology in patients with chronic fatigue syndrome, by MA Zinn, ML Zinna, I Valencia, LA Jason, JG Montoya in Biological Psychology Vol 136, July 2018, Pages 87-99
We investigated central fatigue in 50 patients with chronic fatigue syndrome (CFS) and 50 matched healthy controls (HC).
Resting state EEG was collected from 19 scalp locations during a 3 min, eyes-closed condition. Current densities were localized using exact low-resolution electromagnetic tomography (eLORETA).
The Multidimensional Fatigue Inventory (MFI-20) and the Fatigue Severity Scale (FSS) were administered to all participants. Independent t-tests and linear regression analyses were used to evaluate group differences in current densities, followed by statistical non-parametric mapping (SnPM) correction procedures.
Significant differences were found in the delta (1–3 Hz) and beta-2 (19–21 Hz) frequencybands. Delta sources were found predominately in the frontal lobe, while beta-2 sources were found in the medial and superior parietal lobe. Left-lateralized, frontal delta sources were associated with a clinical reduction in motivation.
The implications of abnormal cortical sources in patients with CFS are discussed.
5. Conclusions
Overall, the present study revealed a pattern of global central nervous system hypoactivation in patients with CFS. Most research points to a common finding of cognitive slowing in CFS and we identified this with quantifiable increases in delta and decreases in beta-2 frequency bands. Focal increases in delta sources in regions with language and limbic underpinnings were related to a reduced motivation factor of
fatigue.
Our findings add to the existing literature demonstrating evidence of central nervous system involvement in patients with CFS.
Identifying the subtle aspects of brain dysfunction underscores the need for studies of CFS examining EEG signals that reflect cellular electrical conductivity without time-delay and different frequency bands for added information about synchronous brain region activities.
Finally, our study demonstrates that eLORETA is a promising tool for recognizing CFS pathogenesis in spatial locations of the brain on a time scale of milliseconds (Pascual-Marqui et al., 2011; Zinn et al., 2016a)
