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Plos One: Reduced Cardiac Vagal Modulation Impacts on CFS

Firestormm

Senior Member
Messages
5,055
Location
Cornwall England
I meant to post this the other day and forgot. Sorry. Comments from Charles Shepherd follow accompanied by a link to Julia Newton's latest work, and a video of her recent presentation.

Reduced Cardiac Vagal Modulation Impacts on Cognitive Performance in Chronic Fatigue Syndrome

14 November 2012: http://www.plosone.org/article/info:doi/10.1371/journal.pone.0049518 in full.

Alison Beaumont1, Alexander R. Burton1, Jim Lemon1, Barbara K. Bennett2,3, Andrew Lloyd4, Uté Vollmer-Conna1*

1 School of Psychiatry, University of New South Wales, Sydney, New South Wales, Australia, 2 School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia, 3 Department of Medical Oncology, Prince of Wales Hospital, Sydney, New South Wales, Australia, 4 Inflammation and Infection Research Centre, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
Background

Cognitive difficulties and autonomic dysfunction have been reported separately in patients with chronic fatigue syndrome (CFS). A role for heart rate variability (HRV) in cognitive flexibility has been demonstrated in healthy individuals, but this relationship has not as yet been examined in CFS. The objective of this study was to examine the relationship between HRV and cognitive performance in patients with CFS.
Methods

Participants were 30 patients with CFS and 40 healthy controls; the groups were matched for age, sex, education, body mass index, and hours of moderate exercise/week. Questionnaires were used to obtain relevant medical and demographic information, and assess current symptoms and functional impairment. Electrocardiograms, perceived fatigue/effort and performance data were recorded during cognitive tasks. Between–group differences in autonomic reactivity and associations with cognitive performance were analysed.
Results

Patients with CFS showed no deficits in performance accuracy, but were significantly slower than healthy controls. CFS was further characterized by low and unresponsive HRV; greater heart rate (HR) reactivity and prolonged HR-recovery after cognitive challenge. Fatigue levels, perceived effort and distress did not affect cognitive performance. HRV was consistently associated with performance indices and significantly predicted variance in cognitive outcomes.
Conclusions

These findings reveal for the first time an association between reduced cardiac vagal tone and cognitive impairment in CFS and confirm previous reports of diminished vagal activity.

Charles Shepherd ME Association Facebook 15 December 2012:

Interesting new study from Australia that adds further weight to the link between autonomic dysfunction and cognitive dysfunction in ME/CFS - also links in with what Julia Newton et al are doing in Newcastle..
Julia is a highly respected clinician and researcher at the University of Newcastle. She has several other research interests besides ME/CFS (e.g. primary biliary cirrhosis) and her research is published in very reputable peer reviewed journals. The group that she works with in Newcastle is the nearest thing that we currently have in the UK to a Centre of Excellence for ME/CFS research - which is why the MEA Ramsay Research Fund is very willing to help fund the research programme there, which also extends to muscle research. As you are probably aware the MRC has awarded two of their new grants to Newcastle University - a further study of autonomic dysfunction and the one looking for an immunological marker for debilitating central fatigue - using people with Sjogren's Syndrome to start with...

Julia Newton and POTS: http://forums.phoenixrising.me/inde...-characteristics-of-novel-subgroup-cfs.20807/

Julia Newton presentation and overview of NICE sponsored research: November 2012: http://forums.phoenixrising.me/inde...-characteristics-of-novel-subgroup-cfs.20807/
 

Marco

Grrrrrrr!
Messages
2,386
Location
Near Cognac, France
Yes - very interesting. The finding of cognitive accuracy but reduced processing speed in ME/CFS is an old one and reduced heart rate variability is a common finding in MDD and ADHD to name a few (which doesn't concern me).

The question is, how the two are connected and what it implies for ME/CFS the condition.

Given the known associations of reduced heart rate variability and cognitive dysregulation could researchers not speculate as to what they believe might be going on or does it just fall under 'interesting - there you go!'?.
 

Firestormm

Senior Member
Messages
5,055
Location
Cornwall England
Yes - very interesting. The finding of cognitive accuracy but reduced processing speed in ME/CFS is an old one and reduced heart rate variability is a common finding in MDD and ADHD to name a few (which doesn't concern me).

The question is, how the two are connected and what it implies for ME/CFS the condition.

Given the known associations of reduced heart rate variability and cognitive dysregulation could researchers not speculate as to what they believe might be going on or does it just fall under 'interesting - there you go!'?.

I'm not even sure that Newton associates autonomic dysfunction with cognitive difficulties, Marco. I can't remember (lol) whether this came up in her presentation or not. Am transcribing - so will find out in due course and post accordingly.

The more these studies acknowledge the difficulties though the greater the weight behind our anecdotal evidence I guess. Though I agree some answers or direction would be nice.
 

Marco

Grrrrrrr!
Messages
2,386
Location
Near Cognac, France
I'm not even sure that Newton associates autonomic dysfunction with cognitive difficulties, Marco. I can't remember (lol) whether this came up in her presentation or not. Am transcribing - so will find out in due course and post accordingly.

Charles Shepherd's commentary does though which, if he's suggesting that ANS dysfunction is causing cognitive difficulties, is not a safe assumption to make. Both could be symptoms of the underlying root cause.

It would be interesting if Julia Newton considers them causally linked or indicative of something else.
 

Seven7

Seven
Messages
3,444
Location
USA
In my case I am 100% sure that the cognitive issues are tied to my autonomic dysfunction. I can provoke my episodes (I am doing OI training) and I note what symptoms go with it: Dizziness, Head buzz and Fog, Nausea, numbness, tingling.... Also when you get the tilt table test, pay attention to what your feeling, it will help you isolate the OI issues.

Also, If I lay down, After a while I can think better.
 

Firestormm

Senior Member
Messages
5,055
Location
Cornwall England
In my case I am 100% sure that the cognitive issues are tied to my autonomic dysfunction. I can provoke my episodes (I am doing OI training) and I note what symptoms go with it: Dizziness, Head buzz and Fog, Nausea, numbness, tingling.... Also when you get the tilt table test, pay attention to what your feeling, it will help you isolate the OI issues.

Also, If I lay down, After a while I can think better.

Very interesting. Thanks Inester. I'm not sure if I remember Newton saying that the 'tilt table' was the preferred or indeed only means to determine autonomic dysfunction. I'm rather a novice when it comes to all of this. Will know more when I finish my transcript I suppose. But I do seem to recollect that performing the 'tilt table test' is not something all physicians are willing to do. Is there a more acceptable alternative? Or are they (we) waiting for the science to point the way?
 

mellster

Marco
Messages
805
Location
San Francisco
Good find! While mine was very mild, it def matched the slow response/HRV and delayed recovery at that time which leads me to continue to believe that the heart is structurally sound in most patients, but it is simply not well regulated by the nervous/metabolic/hormonal system.