Small fiber neuropathy in the post-COVID condition and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Clinical significance and diagnostic challe

[SWAlexander]

Abstract​

Background​

Patients with post-COVID condition (PCC) and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) experience symptoms potentially associated with small fiber neuropathy (SFN).

Methods​

A sample of 90 participants, comprising 30 PCC patients, 30 ME/CFS patients, and 30 healthy controls (HC), matched by sex and age, was assessed. Neuropathic, autonomic, and fatigue symptoms were measured with TaskForce Monitor, the Sudoscan, heat and cold evoked potentials, In Vivo Corneal Confocal Microscopy (IVCCM), and specialized questionaries.

Results​

PCC and ME/CFS patients demonstrated significantly higher levels of autonomic symptoms (H = 39.89, p < 0.001), neuropathic symptoms (H = 48.94, p < 0.001), and fatigue (H = 49.29, p < 0.001) compared to HC. Quantitative sensory testing revealed significant differences in heat detection thresholds between PCC patients and HC (F = 4.82; p < 0.01). Regarding corneal small fiber tortuosity, there were statistically significant differences between patients and HC (F = 6.80; p < 0.01), indicating pathological responses in patients. Small fiber tortuosity in IVCCM was identified as the main discriminator between patients and HC (AUC = 0.720; p < 0.01).

Conclusion​

PCC and ME/CFS patients demonstrated sensory SFN, as evidenced by impaired heat detection and increased tortuosity of small fibers in the central corneal subbasal plexus. The findings underscore the importance of a multimodal approach to comprehensively detect and characterize SFN. This study provides valuable scientific insights into the neuropathic manifestations associated with these conditions.
https://onlinelibrary.wiley.com/doi/10.1111/ene.70016

 

[cfs since 1998]

I am starting to be think that ME/CFS _IS_ small fiber neuropathy, perhaps a type that preferentially affects nerve fibers that innervate blood vessels rather than the painful skin nerve degeneration that diabetics experience.

Exertion intolerance/PEM is often thought of as unique to ME/CFS (heck the ICC is trying to rename it Systemic Exertion Intolerance Disease) but it isn't. It's also a symptom of SFN.

From "Biomarkers in small fiber neuropathy" (Chan et. al. 2022):

 

[Wishful]

I read the wiki for SFN, and it doesn't seem to fit my ME. My temporary remission test: would someone with SFN be able to switch in or out of that state over the span of minutes?

 

[cfs since 1998]

I read the wiki for SFN, and it doesn't seem to fit my ME. My temporary remission test: would someone with SFN be able to switch in or out of that state over the span of minutes?

You're the only person who reports an ability to do this.

 

[Wishful]

You're the only person who reports an ability to do this.

I think a couple of other people have reported the same thing. I haven't kept records of who did, but it's not just me experiencing this.

 

[Rufous McKinney]

My temporary remission test: would someone with SFN be able to switch in or out of that state over the span of minutes?

Symptoms I have all the time: numbness and tingling on my extreme right side. This marches down my entire body. My right breast, outer right hand, right elbow, upper right thigh, right side of my foot. That I can feel most of the time. Ten years ago I blamed this on the computer Mouse. My hand lived there.

Next, I experience a daily cycle of extensive numbness, tingling, etc, on the bottom of my feet and heels Both Sides.

Walking is very awkward in this state. PEM triggers a more intense version. Right now at noon, I can't feel this issue at all. it's always worse when I go out because I don't feel well enough to be going out. So this tingling pain thing turns on, sooner.

So WHAT the HECK causes such a daily cycle of numbness?

 

[Rufous McKinney]

specialized questionaries.

I was curious about this questionnaire, so I went forth and found it and answered it for myself.

I love the scene in the film Cloud Atlas, wherein a person from the Future World, is capable of healing many many things, using a very simple electronic portable device.

Looking at this questionnaire, I feel like our Medicine is still parked in Kindergarten.

https://www.wasog.org/dynamic/media/78/documents/Questionairres/679743_ILD_SFNSL_Lijst_English.pdf

 

[Rufous McKinney]

So WHAT the HECK causes such a daily cycle of numbness?

I'm trying to see a neurologist on Monday. Trying to get an RX for Naltrexone. Gosh I hope this is going to work. But meanwhile, I'm going to try to ask that question.

And to get really personal, my right nipple is no longer viable anatomy. And that is never listed as a symptom of anything by anyone.

. But there it is. Nipples have "structure" and that structure is gone in my case (on my right side only), and numbness set in. And if I get more run down, I can feel really "sick" in this tissue- it's very subtle and hard to explain the nature of it, but it makes me also sort of want to also throw up.