Central Autonomic Network Disturbance in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Pilot Study, 2021, Zinn, Zinn and Jason

ABSTRACT

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). Post-exertional 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 non-invasive 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 7 patients with ME/CFS and 6 neurotypical healthy controls (HCs). Resting EEG was recorded at pre-, post- handgrip, and 24 hours later. Findings showed that significant differences occurred immediately post-test, which were most pronounced after 24 hours, particularly in the low alpha (8-10 Hz) and low beta (13-18 Hz) frequency sub-bands. Together, the present findings offer support for EEG source localization techniques to investigate PEM. If confirmed, this study could provide a useful instrument for functional diagnosis and evaluation of treatment outcomes.

Open access, https://www.neuroregulation.org/article/view/21387

 

Err, what????

"Post-exertional 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."

 

I interpret this as meaning that minor exertion induces PEM, and that with PEM your ability to do stuff is even less than usual (e.g. on day 2 of a repeat CPET). Which, while somewhat limited, is a fair enough description and makes sense in the context of what they're looking at in this study.

As for the study itself, I don't know anything about eLORETA or EEG, or how well or how badly they've applied the techniques here - but I am pleased somebody's looking at less exhausting ways than CPET to study the aftereffects of exertion.

 

The problem, for me, is that you, as a knowledgeable and sadly experienced ME patient, have had to interpret that - I understand that, maybe, they have emphasised an aspect of PEM that is most relevant to their study, but to say that it is the characteristic feature of PEM is concerning to me. I would not want any researchers new to the ME field reading this paper and taking away the 'fact' that the main issue that PEM causes is a reduction in stamina.