Central Autonomic Network Disturbance in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Pilot Study

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease of the central nervous system known to be associated with multiple behavioral symptoms (fatigue, low stamina, dizziness, etc.) combined with autonomic nervous system (ANS) dysfunction, thus implicating the central autonomic network (CAN). Postexertional malaise (PEM) is a core feature of ME/CFS, characterized by a pathological reduction in stamina in response to performing minor physical or mental tasks, often lasting at least 24 hours. Exact low-resolution electromagnetic tomography (eLORETA) allows noninvasive investigation of cortical regions of interest that may contribute to better understanding of the role of the brain disturbances in behavioral manifestations of PEM. This pilot study therefore aimed to use eLORETA to characterize changes in current density in cortical structures related to the CAN following submaximal isometric handgrip exercise in seven patients with ME/CFS and six neurotypical healthy controls (HCs). Resting EEG was recorded at pre- and posthandgrip, and 24 hours later. Findings showed that significant differences occurred immediately posttest, which were most pronounced after 24 hours, particularly in the low alpha (8–10 Hz) and low beta (13–18 Hz) frequency subbands. Together, the present findings offer support for EEG source localization techniques to investigate PEM. If confirmed, this study could provide a useful instrument for aiding functional diagnosis and evaluation of treatment outcomes.