Autonomic nervous system function, activity patterns, and sleep after physical or cognitive challeng

[Cheesus]

Autonomic nervous system function, activity patterns, and sleep after physical or cognitive challenge in people with chronic fatigue syndrome

Abstract
Objective
To explore changes in autonomic functioning, sleep, and physical activity during a post-exertional symptom exacerbation induced by physical or cognitive challenge in participants with chronic fatigue syndrome (CFS).

Methods
Thirty-five participants with CFS reported fatigue levels 24-h before, immediately before, immediately after, and 24-h after the completion of previously characterised physical (stationary cycling) or cognitive (simulated driving) challenges.

Participants also provided ratings of their sleep quality and sleep duration for the night before, and after, the challenge. Continuous ambulatory electrocardiography (ECG) and physical activity was recorded from 24-h prior, until 24-h after, the challenge.

Heart rate (HR) and HR variability (HRV, as high frequency power in normalized units) was derived from the ECG trace for periods of wake and sleep.

Results
Both physical and cognitive challenges induced an immediate exacerbation of the fatigue state (p < 0.001), which remained elevated 24-h post-challenge.

After completing the challenges, participants spent a greater proportion of wakeful hours lying down (p = 0.024), but did not experience significant changes in sleep quality or sleep duration.

Although the normal changes in HR and HRV during the transition from wakefulness to sleep were evident, the magnitude of the increase in HRV was significantly lower after completing the challenge (p = 0.016).

Conclusion
Preliminary evidence of reduced nocturnal parasympathetic activity, and increased periods of inactivity, we found during post-exertional fatigue in a well-defined group of participants with CFS.

Larger studies employing challenge paradigms are warranted to further explore the underlying pathophysiological mechanisms of post-exertional fatigue in CFS.


https://www.sciencedirect.com/science/article/pii/S0022399917304981

Unable to find it on Sci-Hub unfortunately.

 

[RogerBlack]

Very interesting, I look forward to reading the whole paper. >24h post would have been nice, but this seems interesting.

 

[boombachi]

Thanks for posting. Finally an abstract I can actually understand. I might read the whole thing. Interesting that sleep didn't increase after the exertion. I definitely sleep more with PEM.

 

[Marco]

I'm looking forward to reading the full paper as this might partly explain the 2-day CPET results.

 

[Jenny TipsforME]

I’d say this matches my lived experience. Having to lie flat more but getting less sleep as a result of exertion, and can be physical or mental exertion.

 

[Murph]

I just found this paper on pubmed and then got it off sci-hub.

(Attached. Sci-hub has been banned by US courts but it was still working at the .bz domain yesterday)

Looks like a modest little project. Perhaps somebody's PhD. Measures reported sleep and autonomic nervous system and finds mostly null results, except for time lying down and the difference in hrv.

They have the hrv difference as p=.016 but I'm a trifle surprised as the effect size is not large as you can see below (bottom right). Sample was medium-sized at 35 people but the 'whiskers' on the box plot suggest substantial overlap between pre challenge and post challenge so I'm not sure this result is really telling us too much?

While we're talking HRV, a patient claims by measuring her HRV she can very effectively figure out her energy reserves and thereby control her symptoms.