Paradigm shift to disequilibrium in the genesis of orthostatic intolerance in patients with chronic fatigue syndrome (2019) Miwa

Paradigme shift to disequilibrium in the genesis of orthostatic intolerance in patients with chronic fatigue syndrome
K Miwa
European Heart Journal, Volume 40, Issue Supplement_1, October 2019

https://doi.org/10.1093/eurheartj/ehz746.0311

 

This is the Abstract for this article

 

I use a wheelchair but if I'm sitting in it waiting for the kettle to boil, I can reduce the sensation of OI by swaying gently.

 

This is a conference presentation rather than an article - which is why there is just an abstract and the spelling and grammar are dodgy.

This seems a reasonable idea - we have discussed it here before - but the data presented do not seem to tell us much other than some people with ME are wobbly if they stand for a time.

 

I tried to boil this down. I hope I got it right.

• POTS did not seem to predict whether a patient had disequilibrium.
• Disequilibrium (and signs which seem related to disequilibrium) were much more prevalent among patients who failed the 10 minute active standing test.
• Six patients who had previously passed the test failed it after developing disequilibrium.

The first point is probably the most interesting. The others seem to be what you'd expect.

I guess my question would be if there are other forms of OI, or other impairments of blood flow unrelated to OI, that might be causing disequilibrium.

 

When i am sicker and just standing, i feel my quads filling with lactic acid. This just happened. I am not dizzy, i am stable on my feet, i simply feel the strong urge to lay down and if i don’t the symptoms will escalate, and in this recent example, my heart rate increased and i was slightly short of breath. This all got better upon returning to horizontal.

in my n=1 experience, disequilibrium and OI are different symptoms. I got OI and POTS early in my illness. My Romberg tests were negative. it was only 2 years ago that i had positive Rombergs.

OI in my view is not disequilibrium. People may have one or the other, or both.

Lastly continuing on my n=1 experience, One astute doctor found eye movement abnormality which qualified for a neuro-ophtalmologist consultation, and after MRI it was found i have a cyst on my cerebellum which would explain i get brief moments of dizziness when i bend forward just a bit. I was Explained by the specialist that this happens because there is a shift in CSF around that cyst which will cause that dizziness. It is a benign cyst and we are simply watching, it had not grown in a 6 month interval.

 

I have the suspicion that some symptoms associated with upright posture are being neglected.

We focus on measurable things like heart rate and blood pressure that have a relatively clear trigger, but I think that I've had subtle orthostatic intolerance for a long time, possibly since illness onset, and that it didn't initially involve heart rate or blood pressure.

I get a gradually increasing, vague feeling of feeling unwell that makes activities unpleasant. There are also has some mental effects, there is a decrease in speed, interest, awareness and ability to pay attention and participate.

I think that sitting mitigates but doesn't entirely prevent this, and that the onset is gradual and therefore not easily recognized as having to do with orthostatic intolerance.

It's possible I'm wrong but now that I have more well defined orthostatic intolerance I think I can make more sense of my symptoms.

Back when my illness started, this contributed to problems with school attendance and performance. Sitting still for hours becomes unpleasant and draining. Rather than assessing children with school difficulties for psychosocial problems, I think we should check whether they have orthostatic intolerance.

 

I think it's possible that new PWME don't realise they have OI because of the emphasis on HR/ BP. I've never had HR/BP changes but OI was my first symptom.
Surely the questions a doctor needs to ask ( if we can get them trained!!) are "Do you NEED to lie down to reduce symptoms? Can you think better lying down?"

My mum has had persistent fatigue ( vasculitis) for 20 years and has never had to lie down to reduce it. Giving this example to try to illustrate that it's not the fatigue forcing us to lie down.

 

I think that is absolutely right if the question is about orthostatic intolerance. Orthostatic intolerance simply means difficulty maintaining a standing up position and may have 100 causes. It is not a specific cardiovascular diagnosis.

 

@Snow Leopard In CPET studies, do researchers ever divide the subjects into OI( nonPoTS) and PoTs cohorts?

 

I'd agree that doctors rarely take the big picture view of orthostatic intolerance as "I feel better lying down". If they don't see any heart rate or blood pressure changes they're typically not interested.

For years I've noticed that I can be lying down with a very active mind, composing emails in my head. By the time I get to the computer and start typing my mind has gone blank.

I also believe that slow onset ME/CFS cohort is particularly good at compensating for symptoms, largely at a subconscious level because of that "vague feeling of unwell" that strategist mentioned. The behaviours I had before I had a clue about an ME/CFS diagnosis included:

Not wanting to stand in a lineup.
Having a two hour limit for house parties.
Getting home from work and insisting on spending an hour suntanning completely prone on the deck.
Always pulling up a chair to talk to students in the computer lab, or even sitting on the floor if no chair was available.
Avoiding the slow shopping amble.
Watching TV prone on the couch.
Continually popping up to put away a cup, take a plate to kitchen, etc way of using minimal exercise to disperse the unwell feeling.

I keep reminding people that sitting up is a physical activity, let alone standing.

When I look back I'm amazed at how many of my behaviours seem tied to a subtle long term illness.

 

to add . . .

why do some of feel better after 6pm? I am able to stand and sit upright for much longer periods of time, and go out for a power walk when I'm feeling better. I'm unable to do this earlier in the day.

 

Most studies did not have sufficient sample size for that to be meaningful.

Max Nelson notably hypothesised that there might be differences in the rate of heart rate increase upon standing after the 2nd day CPET, but did not find differences (unpublished). See related study in athletes: https://www.jsams.org/article/S1440-2440(19)31102-8/abstract

 

Now published in:
International Journal of Cardiology Hypertension
https://www.sciencedirect.com/science/article/pii/S2590086220300094

It gives more than just the abstract (compared to the original post?)