The good news: cause of muscle weakness ME/CFS discovered

[SWAlexander]

Google Translation:
Original Text: https://www.tagesspiegel.de/gesundh...ache-der-muskelschwache-entdeckt-9008578.html

The good news: cause of muscle weakness ME/CFS discovered

Muscle sodium levels in ME/CFS patients are higher than in healthy individuals. This is said to be the reason why sufferers experience a setback after minor physical exertion.
Muscle sodium levels in ME/CFS patients are higher than in healthy individuals. This could be the reason why sufferers experience a setback after low physical exertion. Time and again, patients suffering from chronic fatigue (ME/CFS) have to deal with doctors telling them their symptoms are psychosomatic. And then treat them wrongly, for example with an "activating" treatment with increasing physical stress that risks worsening the symptoms.
It is therefore good news for those affected when research identifies organic causes behind the complex disease ME/CFS. And not just to reject the wrong therapy offers, but also because active ingredients can be developed to counteract organic causes.

Muscle sodium levels before and after exercise were higher in ME/CFS than controls.

Now researchers at the Charité, together with scientists from the Center for Cardiovascular Research and the German Heart Center, have found a cause for the persistent muscle weakness and the so-called Post-Exertional Malaise (PEM for short) that plagues patients with ME/CFS. PEM means that the sufferers experience an aggravation of the symptoms even after minor physical exertion.

 

[SWAlexander]

Just found this:
Muscle sodium content in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
Abstract
Background
Muscle fatigue and pain are key symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Although the pathophysiology is not yet fully understood, there is ample evidence for hypoperfusion which may result in electrolyte imbalance and sodium overload in muscles. Therefore, the aim of this study was to assess levels of sodium content in muscles of patients with ME/CFS and to compare these to healthy controls.
Methods
Six female patients with ME/CFS and six age, BMI and sex matched controls underwent 23Na-MRI of the left lower leg using a clinical 3T MR scanner before and after 3 min of plantar flexion exercise. Sodium reference phantoms with solutions of 10, 20, 30 and 40 mmol/L NaCl were used for quantification. Muscle sodium content over 40 min was measured using a dedicated plugin in the open-source DICOM viewer Horos. Handgrip strength was measured and correlated with sodium content.
Results
Baseline tissue sodium content was higher in all 5 lower leg muscle compartments in ME/CFS compared to controls. Within the anterior extensor muscle compartment, the highest difference in baseline muscle sodium content between ME/CFS and controls was found (mean ± SD; 12.20 ± 1.66 mM in ME/CFS versus 9.38 ± 0.71 mM in controls, p = 0.0034). Directly after exercise, tissue sodium content increased in gastrocnemius and triceps surae muscles with + 30% in ME/CFS (p = 0.0005) and + 24% in controls (p = 0.0007) in the medial gastrocnemius muscle but not in the extensor muscles which were not exercised. Compared to baseline, the increase of sodium content in medial gastrocnemius muscle was stronger in ME/CFS than in controls with + 30% versus + 17% to baseline at 12 min (p = 0.0326) and + 29% versus + 16% to baseline at 15 min (p = 0.0265). Patients had reduced average handgrip strength which was associated with increased average muscle tissue sodium content (p = 0.0319, R2 = 0.3832).
Conclusion
Muscle sodium content before and after exercise was higher in ME/CFS than in healthy controls. Furthermore, our findings indicate an inverse correlation between muscle sodium content and handgrip strength. These findings provide evidence that sodium overload may play a role in the pathophysiology of ME/CFS and may allow for potential therapeutic targeting.
Read more: https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03616-z

 

[Diwi9]

If these sodium levels are indicative of over-exertion, it would be amazing to have some kind of a sensor that could indicate when a patient's exertion is about to reach over-exertion. It strange how certain symptoms have been ignored for decades. Like everyone is focussed on fatigue, but the crippling muscle weakness and spasms are part of the picture too.

 

[Consul]

There is already a thread about this study, made by SWAlexander on dec 10th.

 

[Sad Dad]

cause of muscle weakness ME/CFS discovered

Correct me if I'm wrong, but my reading of this is simply that increased muscle sodium content is yet another comorbidity associated with ME/CFS, and the researchers were just speculating as to what might be causing the increased muscle sodium content:

Sodium is removed from the muscle by the Na+/K+-ATPase at the expense of ATP consumption. We assume that the removal of sodium is further impaired due to dysfunction of the ß2 adrenergic receptor which leads to an insufficient stimulation of the Na+/K+-ATPase

I don't mean to criticize, I just don't want anyone to be overly optimistic about the results.

 

[marcjf]

Is muscle weakness even part of the Canadian diagnostic criteria for ME/CFS?
I never noticed muscle weakness myself. I am a bit puzzled.

I mean, if your severity is higher, you will deveop sarcopenia eventually.

 

[wabi-sabi]

Correct me if I'm wrong, but my reading of this is simply that increased muscle sodium content is yet another comorbidity associated with ME/CFS, and the researchers were just speculating as to what might be causing the increased muscle sodium content:

I don't mean to criticize, I just don't want anyone to be overly optimistic about the results.

Yep. Increased sodium is a downstream effect of impaired ATP production and adrenergic receptor autoantibodies. Part of the picture, but not "the" cause. Impaired ATP production could be due to impaired tissue oxygenation as other researchers have found. Impaired tissue oxygenation could in turn be cased by neurovascular dysregulation.

Na/K ATP pump failure is hugely important. It goes to show how the most fundamental stuff breaks when there's no ATP. However...

Increased sodium is a good explanation of one of the many things that goes wrong when your tissues don't get enough oxygen, but we need to look a few turtles past the sodium.

 

[wabi-sabi]

Here's my funny analogy:

1) You're on a space station and some bit of space junk hits your solar panel knocking out power generation. (Are space stations powered by solar? No idea, but they are in my fantasy.)

2) All systems start to fail, since no energy is being provided.

3) Life support starts to fail. Scotty calls to the bridge "Captain, oxygen levels are dropping and carbon dioxide levels are rising. I don't know how much more of this we can take!"

4) Captain Kirk "So, you mean all of these problems are caused by carbon dioxide build up?"

5) Scotty "No!! I can rig up some air scrubbers with the back up generator, but we have to get the warp engines back online."

Or maybe i just watch too much sci fi.

 

[Rufous McKinney]

a few turtles past the sodium.

thats a perfect description!

 

[Rufous McKinney]

My hip flexors seem almost constantly a big vulnerable weak muscle area.
I've had episodes of- almost can't lift your arm or flex your hand (in major crashes/PEM Acute)

Thinking about the Poisoned Feeling.

Lets list Some Possibilities:

SODIUM

Ammonia

LPS

Everything else leaking from the gut

microRNAs produced

Oh I"m tired now and suspect this list could be ten times this long...

 

[Wishful]

I like the "one turtle down" description too. Their assumption of why sodium is high is just an assumption, and needs testing. Is there a (ME-affected) brain-generated hormone controlling sodium metabolism? Could faulty nerve signals cause the excess sodium?

As with marcjf, I never experienced muscle weakness from ME, so it's not an inherent part of ME. Thus I think it's not a good candidate for finding the root cause of ME. It certainly is worth following up on, since we don't have any better leads, and the mechanism might be involved in other diseases/disorders too.

 

[Rufous McKinney]

Could faulty nerve signals cause the excess sodium?

or : it takes "energy" or related somethings in short supply, to pump out sodium and so its a simple we can't quite do the lift.

 

[wabi-sabi]

Could faulty nerve signals cause the excess sodium?

Proper sodium levels are maintained by the Na/K ATPase pump. Without that pump working, the nerve can't send signals. This pump powers quite a lot in cells.

aculty.washington.edu/chudler/ap.html#:~:text=Action%20potentials%20are%20caused%20when,ions%20rush%20into%20the%20neuron.

 

[Gingergrrl]

Although the pathophysiology is not yet fully understood, there is ample evidence for hypoperfusion which may result in electrolyte imbalance and sodium overload in muscles.

Furthermore, our findings indicate an inverse correlation between muscle sodium content and handgrip strength.

@SWAlexander Do you know if this sodium overload in muscles is related in any way to the calcium channel issues in LEMS (Lambert Eaton Myasthenic Syndrome) that cause muscle weakness or if they are two totally unrelated things?

 

[wabi-sabi]

In LEMS the body attacks the calcium channels in the nerve endings with autoantibodies. I'm not sure we have a clear idea of what the immune system is doing wrong yet in ME/CFS. I've seen somewhere (can't remember now) that it may be the innate immune system that's gone awry in ME/CFS.

Dr. Scheibenbogen has been looking at autoantibodies on ME/CFS, but they are autoantibodies to a different part of the nervous system than in LEMS. The ME/CFS autoantibodies would mess up the way the blood vessels work, meaning cells don't get enough oxygen, meaning the can't make ATP. If this is correct, then muscles are weak in ME/CFS because the have no fuel to power contraction. In LEMS, muscles are weak because the signal to contract isn't getting sent properly. Dr. S's hypothesis would fit with excess sodium in muscle cells, because the pump that is supposed to get rid of the sodium can't run, because it doesn't have any fuel either.

 

[lenora]

I have had this illness for 35++ years now (you really do forget!), and I've heard so many "reasons". Most fade in the netherworld, but many are resurrected years later. Perhaps they're like piece of an enormous jigsaw and will one day make a complete picture.

In the meantime, researchers don't forget the part they're working on and we'll hope for a completed puzzle. This one can even be hung on someone's wall. We'll pay for the frame! Enjoy all of the magical things you'll be able to do WHEN a cure is found. It will happen....probably too late for me, but that's OK. Yours Lenora

 

[SWAlexander]

I just don't want anyone to be overly optimistic about the results.

You are right. As they say, if high muscle-sodium levels in can be seen, it would reduce the label "psychosomatic".

 

[SWAlexander]

two totally unrelated things?

Very good point. Thanks. I think MG muscle reaction/energy is different.
Myasthenia Gravis Fact Sheet

I´ll look into this when I´m over my really bad flu.

 

[Alvin2]

Very good point. Thanks. I think MG muscle reaction/energy is different.
Myasthenia Gravis Fact Sheet

I´ll look into this when I´m over my really bad flu.

I was tested for Myasthenia Gravis, i don't have it.
So at least for me its not the cause of my ME/CFS symptoms.

 

[SWAlexander]

I was tested for Myasthenia Gravis,

I also was tested for MG. The results were inconclusive.