Is POTS a central nervous system disorder? (Blitshteyn, 2021)

[Muon]

Is postural orthostatic tachycardia syndrome (POTS) a central nervous system disorder? (Blitshteyn, 2021)

Same thread on Dinet forum

Abstract
Postural orthostatic tachycardia syndrome (POTS), a disorder of the autonomic nervous system characterized by a rise in heart rate of at least 30 bpm from supine to standing position, has been traditionally viewed as a dysfunction of the peripheral nervous system. However, recent studies and evidence from overlapping conditions suggest that in addition to being considered a disorder of the peripheral nervous system, POTS should be viewed also as a central nervous system (CNS) disorder given (1) significant CNS symptom burden in patients with POTS; (2) structural and functional differences found on neuroimaging in patients with POTS and other forms of orthostatic intolerance; (3) evidence of cerebral hypoperfusion and possible alteration in cerebrospinal fluid volume, and (4) positive response to medications targeting the CNS and non-pharmacologic CNS therapies. This review outlines existing evidence of POTS as a CNS disorder and proposes a hypothetical model combining key mechanisms in the pathophysiology of POTS. Redefining POTS as a CNS disorder can lead to new possibilities in pharmacotherapy and non-pharmacologic therapeutic interventions in patents affected by this disabling syndrome.

 

[andyguitar]

Redefining POTS as a CNS disorder can lead to new possibilities in pharmacotherapy and non-pharmacologic therapeutic interventions in patents affected by this disabling syndrome.

Has nobody considered this before?

 

[ljimbo423]

This review outlines existing evidence of POTS as a CNS disorder and proposes a hypothetical model combining key mechanisms in the pathophysiology of POTS.

This makes a lot of sense to me. Especially given the research that shows neuroinflammation in ME/CFS and the large number of us with POTS.

 

[andyguitar]

(4) positive response to medications targeting the CNS and non-pharmacologic CNS therapies.

Unless those drugs are having an unknown effect outside the CNS then I'd take their usefulness to be a strong indication that POTS is a CNS disorder.

 

[ljimbo423]

Unless those drugs are having an unknown effect outside the CNS then I'd take their usefulness to be a strong indication that POTS is a CNS disorder.

Makes sense.

Since the brain controls everything in the body. I think CNS dysfunction from neuroinflammation causing POTS, isn't a big leap.

To me it also just makes more sense on a gut level. That probably won't make a random controlled study though.

 

[andyguitar]

Unless those drugs are having an unknown effect outside the CNS

But that's the caveat.

 

[ljimbo423]

But that's the caveat.

Yeah, there are usually caveats.

I do think that neuroinflammation is causing soooooo many symptoms in ME/CFS. So for me, it causing POTS makes sense. Studying low grade neuroinflammation is very difficult though. We just don't have really good technology, to do it with great accuracy and detail.

 

[bensmith]

I think so much/nearly all my stuff is nuerological inflammation. Feels so good to get it down although haven’t figured out how to reliably yet.

For me anyway pots from neuro inflam seems reasonable.

 

[Pyrrhus]

Has nobody considered this before?

If we're going to try to separate out peripheral and central mechanisms, (and I'm not sure we can) then we would have to break POTS down into two components:

Postural Orthostatic Tachycardia Syndrome (POTS) is:

1. Orthostatic Intolerance, which is generally seen as a failure of peripheral nerves that control blood vessels. This results in regional low blood pressure.
2. Tachycardia, which is a response of the central nervous system (brainstem) to the regional low blood pressure. By forcing the heart to beat faster, the brainstem is trying to raise the regional low blood pressure.

A lot of people with ME have the first, orthostatic intolerance.
But not as many people also get the second, tachycardia.

People who don't get tachycardia can be diagnosed with Orthostatic Hypotension if their blood pressure drops by a certain amount upon standing.

Of course, the presence of POTS can come with other neurological problems, like ME, so it's not at all surprising to find evidence of brain dysfunction with POTS.

Hope this helps.

EDIT: Emphasized that peripheral and central mechanisms work together, and can't always be fully separated.

 

[Pyrrhus]

If you're interested enough to want to learn about the author, here is her website:

Svetlana Blitshteyn, MD
https://www.dysautonomiaclinic.com/dr-blitshteyn/

 

[Rufous McKinney]

A lot of people with ME have the first, orthostatic intolerance.
But not as many people also get the second, tachycardia.

I've experienced really intense tachycardia during prolonged crashes and when I was Quite Bad off ME wise- (out of the country). I don' t notice it when I'm not real run down.

I think I was in a state of continuous PEM crash for three months while visiting my new grandchild.

I'm considering- going back down to see them again. But all that stuff: can't be happening. Must be banished.

 

[BlueCoffeeMug]

Has someone used standing EEG to diagnose OI?

I requested NCNED to add standing EEG for their next brain MRI research. I'm curious to see the result.

 

[Pyrrhus]

Has someone used standing EEG to diagnose OI?

That's an interesting idea- how would it work?

 

[BlueCoffeeMug]

That's an interesting idea- how would it work?

I'm thinking adding EEG to NASA's lean test. I'll wait and see if NCNED finds something with standing EEG, first.

 

[pattismith]

If we're going to try to separate out peripheral and central mechanisms, then we have to break POTS down into its two components:

Postural Orthostatic Tachycardia Syndrome (POTS) is:

1. Orthostatic Intolerance, which is a failure of peripheral nerves that control blood vessels. This results in regional low blood pressure.
2. Tachycardia, which is a response of the central nervous system to the regional low blood pressure. By forcing the heart to beat faster, the brain is trying to raise the regional low blood pressure.

Dont you think that blood vessels are under the control of the brain as well?


Normal autonomic neurophysiology of postural orthostatic tachycardia and recommended physiological assessments in postural orthostatic tachycardia syndrome (nih.gov)

Orthostatic hypotension with brainstem tumors - PubMed (nih.gov)

 

[BlueCoffeeMug]

Dont you think that blood vessels are under the control of the brain as well?

I don't know which comes first...
I had abnormal ECG results while in orthostatic distress. However, the following Echocardiogram tests (another day) while in supine position didn't show significant abnormality. I think standing ECG (heart) and EEG (brain) are the possible OI diagnostic tool for those patients who don't show significant abnormality with heart rate and blood pressure change.

I also had abnormal lung x-ray while standing, but not in supine position. (Possible asthma... Had misdiagnosed with COPD. IMHO, with COPD, lungs inflate while supine and it's opposite to OI.)

We need to think beyond heart rate and blood pressure to investigate OI in pwME.

 

[Pyrrhus]

Dont you think that blood vessels are under the control of the brain as well?

Yes, absolutely! Thank you for pointing that out.

The brainstem can control both heart rate and blood pressure by influencing peripheral nerves.

I had abnormal ECG results while in orthostatic distress.

Very interesting. If you don't mind me asking, what abnormal results did they see?

 

[BlueCoffeeMug]

Very interesting. If you don't mind me asking, what abnormal results did they see?

"Abnormal repolarisation, possible coronary ischemia."
These readings were taken when OI symptoms present while I collapsed in doctor's waiting room. But following investigations with Echocardiogram while I'm lying down (no symptom) didn't show anything.

 

[Pyrrhus]

possible coronary ischemia

"possible coronary ischemia" sounds like it might be "low right atrial pressure", which is the same regional low blood pressure seen by Systrom et al.:
https://forums.phoenixrising.me/thr...patients-with-me-cfs-joseph-et-al-2021.82907/

 

[Pyrrhus]

If we're going to try to separate out peripheral and central mechanisms, (and I'm not sure we can) then we would have to break POTS down into two components:

Postural Orthostatic Tachycardia Syndrome (POTS) is:

1. Orthostatic Intolerance, which is generally seen as a failure of peripheral nerves that control blood vessels. This results in regional low blood pressure.
2. Tachycardia, which is a response of the central nervous system (brainstem) to the regional low blood pressure. By forcing the heart to beat faster, the brainstem is trying to raise the regional low blood pressure.

A lot of people with ME have the first, orthostatic intolerance.
But not as many people also get the second, tachycardia.

As @pattismith pointed out, it can be difficult or even impossible to try to fully separate activity of the peripheral nervous system from activity of the central nervous system.

Case in point:
In number 2 in the above quote, I say that the tachycardia is a response of the central nervous system, when it is really a combination of both the peripheral and central nervous systems. In fact, it is a well-researched reflex called the baroreflex:

Decreased blood pressure decreases baroreflex activation and causes heart rate to increase and to restore blood pressure levels.[1] The baroreflex can begin to act in less than the duration of a cardiac cycle (fractions of a second) and thus baroreflex adjustments are key factors in dealing with postural hypotension, the tendency for blood pressure to decrease on standing due to gravity.

The system relies on specialized neurons, known as baroreceptors chiefly in the [major arteries] to monitor changes in blood pressure and relay them to the [brainstem]. Baroreceptors are stretch receptors and respond to the pressure induced stretching of the blood vessel in which they are found. Baroreflex induced changes in blood pressure are mediated by [...] the autonomic nervous system.

Source: https://en.wikipedia.org/wiki/Baroreflex