biopsy for small nerve fiber

Posted by jan64 @jan64, Sep 19 5:29pm

I was referred by rheumatologist to a doctor at a pain clinic for small nerve muscle biopsy. When I finally got the call from them to make the appointment, I was told I would have the biopsy. When I got there today, I was told by the PA that they would have to check the insurance first, order a "Kit" and go from there. She then asked where I wanted to have my injection. I said I just wanted the biopsy to determine what type of PN I have. She said it didn't matter, the treatments are all the same. I live in PA. I just scheduled with a CRNP (got a cancellation) in
Pittsburgh in the building with top neurologists . I am hoping she can make referrals and schedule the biopsy. I have had so many disappointments trying to figure out why I went from very fit and healthy to being on fire almost everywhere in 8 weeks. I had telemedicine appointment and a 30 minute in person appointment with neurologists. No answers. On 1800 mg gabapentin which I think is helping. I sure don't want to test whether it is or not! I am still not functioning at even 50% of where I was in July. I've posted before; I have had MRI and lots of blood work. X-rays show arthritis, but I never had much pain before all this started. I am limited to UPMC network, so hoping someone can recommend neurologists in Pittsburgh.

Interested in more discussions like this? Go to the Neuropathy Support Group.

Hello, amkie (@amkie),& cc julbpat (@julbpat), John @johnbishop),

You’re quite right, I’m one of the fellows with large fiber neuropathy. Thanks to lots of reading, I arrived at that conclusion largely on my own, only to have my layman’s diagnosis confirmed by my doctor when I straightforwardly asked him, ‘Mine is large fiber, is it not?’ I was surprised – and a little amused – to hear him replay, ‘Well, of course, Ray, it’s large fiber!’ I drove away thinking, ‘Mmm, if I hadn’t done all that reading and then flat-out asked (large, or small?), I might never have been told.

As John and others on the Forum know, my assessment of my neuropathy (symptoms, progression, effectiveness of the EB-N5 supplement I was prescribed and have been taking for 15 months) has been clouded by the onset of a sepsis infection last March, which resulted in several symptoms similar to those caused by the neuropathy. Recently, if friends ask, ‘So, how are you feeling nowadays?’ I have little choice but to say, ‘About the same.’ If they go on to ask, ‘Is it your neuropathy or your sepsis?’ I again have to answer as honestly as I can: ‘I don’t know – because the symptoms overlap.’

At this time, the most I can say is my balance is still wonky, especially early morning, if I’ve been seated too long (20-30 minutes), and late at night. I keep a cane nearby but use it only when I think it’s necessary. I find early morning, after sitting, and late at night, if I rise, stand in place for a count of 15 (1, one thousand, 2, one thousand, 3 … etc.), aim my body in the direction I’m about to head, then step off slowly but with a certain amount of deliberation (eyes up, not on the ground,), after about 30-50 steps I’m able to go about with reasonably good balance. It’s as if it takes the 25 seconds, the 3-0-50 steps, etc., for my brain to snap into action. (I just finished reading Jill Bolte Taylor’s ‘Stroke of Insight,’ so, at the moment, I’m all rah-rah about brain plasticity.)

A second symptom that I’m dealing with every day (be it my neuropathy, my sepsis, or a sinister combo of the two) is poor endurance. I’ve reason to suspect that my nagging shortness of breath is a gift solely from my sepsis; I never experienced shortness of breath like this in my pre-sepsis days, when I was only contending with my neuropathy. As a symptom, it’s lessened (I’m breathing more easily now) compared to my early sepsis days, but it’s still bothersome.

That, in a nutshell, is my life with large fiber sensory-leaning (maybe a little small fiber in there, too) polyneuropathy. Sepsis has been a complication, making it harder for me to speak with clarity about the neuropathy – but I’m happy to say even more/answer questions/whatever might be helpful. In the meantime, with sincerity …

Best wishes & Cheers!
Ray (@ray666)

REPLY
@amkie

Thank you for your remarks. The neurologists think I may have two things
that have interplay between them. Like not one zebra but two (rare
things)my primary neurologist told me.
I do have a professionally fitted OFA. It restricts the amount of normal
movement I do have so I am hesitant to wear it. A hightop sneaker seems to
work better but not great either.

Jump to this post

You might be interested in this AFO: https://www.flintrehab.com/product/afo/
I looked into it for my dad, but it’s not enough support for him (he had a stroke) but out hope is he’ll be able to use it one day.

We also like they’re FitMi program.

REPLY
@emo

You might be interested in this AFO: https://www.flintrehab.com/product/afo/
I looked into it for my dad, but it’s not enough support for him (he had a stroke) but out hope is he’ll be able to use it one day.

We also like they’re FitMi program.

Jump to this post

Thank you.

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@ray666

Hello, amkie (@amkie),& cc julbpat (@julbpat), John @johnbishop),

You’re quite right, I’m one of the fellows with large fiber neuropathy. Thanks to lots of reading, I arrived at that conclusion largely on my own, only to have my layman’s diagnosis confirmed by my doctor when I straightforwardly asked him, ‘Mine is large fiber, is it not?’ I was surprised – and a little amused – to hear him replay, ‘Well, of course, Ray, it’s large fiber!’ I drove away thinking, ‘Mmm, if I hadn’t done all that reading and then flat-out asked (large, or small?), I might never have been told.

As John and others on the Forum know, my assessment of my neuropathy (symptoms, progression, effectiveness of the EB-N5 supplement I was prescribed and have been taking for 15 months) has been clouded by the onset of a sepsis infection last March, which resulted in several symptoms similar to those caused by the neuropathy. Recently, if friends ask, ‘So, how are you feeling nowadays?’ I have little choice but to say, ‘About the same.’ If they go on to ask, ‘Is it your neuropathy or your sepsis?’ I again have to answer as honestly as I can: ‘I don’t know – because the symptoms overlap.’

At this time, the most I can say is my balance is still wonky, especially early morning, if I’ve been seated too long (20-30 minutes), and late at night. I keep a cane nearby but use it only when I think it’s necessary. I find early morning, after sitting, and late at night, if I rise, stand in place for a count of 15 (1, one thousand, 2, one thousand, 3 … etc.), aim my body in the direction I’m about to head, then step off slowly but with a certain amount of deliberation (eyes up, not on the ground,), after about 30-50 steps I’m able to go about with reasonably good balance. It’s as if it takes the 25 seconds, the 3-0-50 steps, etc., for my brain to snap into action. (I just finished reading Jill Bolte Taylor’s ‘Stroke of Insight,’ so, at the moment, I’m all rah-rah about brain plasticity.)

A second symptom that I’m dealing with every day (be it my neuropathy, my sepsis, or a sinister combo of the two) is poor endurance. I’ve reason to suspect that my nagging shortness of breath is a gift solely from my sepsis; I never experienced shortness of breath like this in my pre-sepsis days, when I was only contending with my neuropathy. As a symptom, it’s lessened (I’m breathing more easily now) compared to my early sepsis days, but it’s still bothersome.

That, in a nutshell, is my life with large fiber sensory-leaning (maybe a little small fiber in there, too) polyneuropathy. Sepsis has been a complication, making it harder for me to speak with clarity about the neuropathy – but I’m happy to say even more/answer questions/whatever might be helpful. In the meantime, with sincerity …

Best wishes & Cheers!
Ray (@ray666)

Jump to this post

Thank you Ray. I had read posts from you in the past regarding neuropathy
and sepsis. Quite the trial you are dealing with. 🫂
My biggest problem is balance or lack there of. It never is not a big
problem for me. I have used many tactics you mentioned and practice
prescribed excercises virtual every couple waking hours. My second biggest
problem is paresthesia in both my feet. Worse on L and up my entire left
leg to the middle of my body. Not pain exactly but burny and skin feels raw
- definitely worse in evening and very hard to ignore. Have tried
duclofenac tabs, ibuprofen and gable and Lyrica. Ibuprofen works as well
with less side effects. Cold packs to worst areas(at tge time) works pretty
good for me. My husband massages my feet and legs literally every night.
3rd biggest problem is worsening tremors of both hands. Betablocker seems
only thing that lessens the tremors, but it lowers my heart rate too much.
I usually only take it in a reduced dose (1/4) for when I'm going to be out
and about. These are not resting tremors, but rather action related. Very,
very annoying.
4th biggest problem is residual partial footdrop in my L foot. Combined
with my balance issue, it is completely nerve-wracking. LOL.
Other then those things, I'm great. I have good vision, hearing, I can
drive, I can walk steps again, and I have good strength in every other part
of my body. So I count my blessings but still totally miss things I can no
longer do. I try not to focus on those.Thanks for letting me process in
concrete language.
Warmest regards,
Ann

REPLY
@emo

Hi there- In the beginning of your post, you mentioned “small nerve muscle biopsy,” but when you quoted the NP about ordering a kit, it sounds like she was referring to what’s known as a skin punch biopsy. Do you know which biopsy they were recommending?

If your primary symptoms are small fiber sensory neuropathy, then it’s likely you’d need a skin punch biopsy. They take a small sample usually from two points on the most affected limb and count the small nerve fibers. It’s an outpatient procedure, but most clinics take the sample and then have it sent to an outside lab that processes it because not every hospital can process those samples, hence the need for a “kit” and provider trained to take the sample.

This also doesn’t necessarily tell you the type (meaning the cause) of neuropathy you have—mine was a long time ago but they counted the sensory nerves and nerves or glands that had to do with sweating (which is also involved with small fiber nerves).

I was told it can confirm small fiber neuropathy but it can also miss at least 30% of cases (per my neurologist). In my experience, the reason they say it won’t affect the treatment is because if they ruled out all other treatable causes of your SFN (B12 deficiency, excessive B6, current exposure to a chemical, etc.), the treatment remains the same. So some providers don’t even recommend or offer a skin punch biopsy because it may or may not help with diagnosis and it’s not always an option (you need a provider trained to take the sample).

I’m not familiar with the Pittsburgh area, but you’d want to look for a neuromuscular neurologist, usually. To be honest, I didn’t get much help from my neurologist except for diagnosis. Usually their role is to rule out other conditions and see if they can identify a cause of the SFN. If they can’t, then they go to managing symptoms: gabapentin or Lyrica, lidocaine patches, capsaicin or menthol cream, Cymbalta, I’m guessing you’ve heard the schpeel by now.

Definitely pursue further consultations if you don’t feel satisfied with the workup because if they are able to identify a treatable root cause (i.e. B12 deficiency) that’s meaningful. But if not, it goes to symptom management, which I completely recognize can be frustrating. But I personally wouldn’t count on a neurologist for assistance with symptoms management; it’s not usually the box they work in, whether it’s right or wrong.

There are a lot of active discussion here where others have shared what’s worked for them.

Personally for me, PT geared toward pain neuroscience, graded motor imagery (especially using the app Recognise for my lower limbs), topical peppermint oil, and a pain neuroscience treatment like the one used in the app Curable (just as an example—they also have a lot of free pain education resources), comfortable and well-fitting socks (Bombas brand) and shoes, and gentle yoga, is what helped me. But…everyone is different. And I’m afraid of gabapentin and Lyrica so I had to consider other things.

Pretty much none of those recommendations came from a neurologist, except I did have one who was great, but she relocated.

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After my neuro did the usual 1st steps in diagnosing any neuropathies NCT & EMG, he ordered a skin/nerve punch biopsy which is now routinely preformed at the lateral ankle, above the knee and upper thigh. When these three areas show decreased fiber density they compare the nerve fiber densities/mm to the normal readings and it will indicate whether one has the more common length dependant SFN (usually caused by diabetes, metabolic conditions, vitiman deficiencies, etc), or the more rare non lenght- dependant SFN which is more ofter caused by autoimmune diseases or other non-metabolic causes. This gives them a very good idea where to begin in looking for the cause and stopping the progression from small fiber to affecting large nerves.
In most cases, unless idiopathic, it is most important to find the cause in order to manage and treat that disease process more than simply treating treating the pain of the SFN as it will continue to progress most often without the cause being managed.

REPLY
@azgeorgie

After my neuro did the usual 1st steps in diagnosing any neuropathies NCT & EMG, he ordered a skin/nerve punch biopsy which is now routinely preformed at the lateral ankle, above the knee and upper thigh. When these three areas show decreased fiber density they compare the nerve fiber densities/mm to the normal readings and it will indicate whether one has the more common length dependant SFN (usually caused by diabetes, metabolic conditions, vitiman deficiencies, etc), or the more rare non lenght- dependant SFN which is more ofter caused by autoimmune diseases or other non-metabolic causes. This gives them a very good idea where to begin in looking for the cause and stopping the progression from small fiber to affecting large nerves.
In most cases, unless idiopathic, it is most important to find the cause in order to manage and treat that disease process more than simply treating treating the pain of the SFN as it will continue to progress most often without the cause being managed.

Jump to this post

I understand, but my experience was different. I had four neurologists tell me that at least 30% of skin punch biopsies are negative…despite patients still having symptoms. Maybe that’s the same percentage with idiopathic SFN, which is a huge number. My main neurologist told me this is why someone would say, “It won’t necessarily change the treatment.”

It’s important to find a cause, if one is findable, and the skin punch biopsy can help point to a cause, but in a lot of cases it does not. And even if one does find a cause, the treatment may be the same, i.e. it’s common with fibromyalgia but there’s no direct treatment for fibromyalgia, just symptoms management.

Mine was inconclusive (one sample was “low normal” and the others were not a good sample; I can’t remember exactly, but it wasn’t worth doing again), I have no history of diabetes, a normal glucose tolerance test, no exposure to a chemical, nor B12 deficiency, chemotherapy, never took any medications regularly until that point, etc. It was obvious it was length-dependent because in the time I waited for an appointment, the symptoms began in my feet and crept up higher. All of that was apparent before the skin punch biopsy.

I still decided to do it because I wanted certainty about whether I did or did not have small fiber neuropathy and not some other more resolvable condition. Sadly it didn’t give me that.

My small fiber neuropathy is assumed to be autoimmune because I have an assumed diagnosis of a seronegative inflammatory arthritis (no objective biomarker and joint damage would may not be apparent for decades without treatment despite severe pain) and an objective diagnosis of POTS, which affects the autonomic nervous system—which also relies on small fiber nerves. Treating the inflammatory arthritis improved the joint pain, but not the SFN. IVIG would be my “hail Mary” pass but it’s a toss-up.

REPLY
@amkie

Thank you Ray. I had read posts from you in the past regarding neuropathy
and sepsis. Quite the trial you are dealing with. 🫂
My biggest problem is balance or lack there of. It never is not a big
problem for me. I have used many tactics you mentioned and practice
prescribed excercises virtual every couple waking hours. My second biggest
problem is paresthesia in both my feet. Worse on L and up my entire left
leg to the middle of my body. Not pain exactly but burny and skin feels raw
- definitely worse in evening and very hard to ignore. Have tried
duclofenac tabs, ibuprofen and gable and Lyrica. Ibuprofen works as well
with less side effects. Cold packs to worst areas(at tge time) works pretty
good for me. My husband massages my feet and legs literally every night.
3rd biggest problem is worsening tremors of both hands. Betablocker seems
only thing that lessens the tremors, but it lowers my heart rate too much.
I usually only take it in a reduced dose (1/4) for when I'm going to be out
and about. These are not resting tremors, but rather action related. Very,
very annoying.
4th biggest problem is residual partial footdrop in my L foot. Combined
with my balance issue, it is completely nerve-wracking. LOL.
Other then those things, I'm great. I have good vision, hearing, I can
drive, I can walk steps again, and I have good strength in every other part
of my body. So I count my blessings but still totally miss things I can no
longer do. I try not to focus on those.Thanks for letting me process in
concrete language.
Warmest regards,
Ann

Jump to this post

You asked what worked for me. I take Tegretol for my burning pain. You can read my story about that on here. Basically my neuropathy pain started when I stopped taking Tegretol in 2014. I had been on it for many years (30?) for complex partial seizures. It took me years to connect these two things. I tried all the standard neuropathy drugs. A few years ago, I asked to try Tegretol again. My burning pain is 90% controlled.
As far as why I’m getting weaker, that’s harder to figure out. When I’m active, every tiny muscle is screaming. The neuropathy is progressing, as expected. My sister has the same symptoms.

REPLY
@julbpat

You asked what worked for me. I take Tegretol for my burning pain. You can read my story about that on here. Basically my neuropathy pain started when I stopped taking Tegretol in 2014. I had been on it for many years (30?) for complex partial seizures. It took me years to connect these two things. I tried all the standard neuropathy drugs. A few years ago, I asked to try Tegretol again. My burning pain is 90% controlled.
As far as why I’m getting weaker, that’s harder to figure out. When I’m active, every tiny muscle is screaming. The neuropathy is progressing, as expected. My sister has the same symptoms.

Jump to this post

Thank you again Ray.

REPLY
@amkie

Thank you again Ray.

Jump to this post

This is Julie! You’re welcome!

REPLY
@amkie

Thank you Ray. I had read posts from you in the past regarding neuropathy
and sepsis. Quite the trial you are dealing with. 🫂
My biggest problem is balance or lack there of. It never is not a big
problem for me. I have used many tactics you mentioned and practice
prescribed excercises virtual every couple waking hours. My second biggest
problem is paresthesia in both my feet. Worse on L and up my entire left
leg to the middle of my body. Not pain exactly but burny and skin feels raw
- definitely worse in evening and very hard to ignore. Have tried
duclofenac tabs, ibuprofen and gable and Lyrica. Ibuprofen works as well
with less side effects. Cold packs to worst areas(at tge time) works pretty
good for me. My husband massages my feet and legs literally every night.
3rd biggest problem is worsening tremors of both hands. Betablocker seems
only thing that lessens the tremors, but it lowers my heart rate too much.
I usually only take it in a reduced dose (1/4) for when I'm going to be out
and about. These are not resting tremors, but rather action related. Very,
very annoying.
4th biggest problem is residual partial footdrop in my L foot. Combined
with my balance issue, it is completely nerve-wracking. LOL.
Other then those things, I'm great. I have good vision, hearing, I can
drive, I can walk steps again, and I have good strength in every other part
of my body. So I count my blessings but still totally miss things I can no
longer do. I try not to focus on those.Thanks for letting me process in
concrete language.
Warmest regards,
Ann

Jump to this post

Good morning, Ann (@amkie)

I can also say that balance is my biggest problem. I mention poor endurance—shortness of breath, finding myself surprised at the oddest times by the need to sit or lie down, my knees being terribly weak—but poor endurance runs a distant second to the problem I have with my balance.

For my weak and often achy knees, I do take a diclofenac tab (75 mgs, I believe) twice a day. That, plus an occasional gel shot deep in my left knee (my right knee is prosthetic), has made reliance on my knees survivable, if still problematic.

You mention residual foot drop … to which I could shout, ‘Me, too!’ Some 15-20 years ago, I had a case of foot drop. I wore a Velcro brace for a month or so; the drop lessened almost totally, but to this day, I have moments when I know I still have some residual foot drop.

There’s so much more I would like to say, but I see the morning is getting on, and I’d best get this day underway. I wish you a pleasant, pain-free, spirit-ascending day.

Cheers!
Ray (@ray666)

REPLY
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