RFA nerve regeneration

[caligas]

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This is an academic question, NOT asking for medical advice.

I had an RFA T5-7 with excellent results for 6 months, repeated with same result. Repeated again, now over a year out with no pain.

So have the median branch nerves given in and decided not to regenerate? Can they be permanently destroyed with a series of ablations?

 

[willabeast]

This is an academic question, NOT asking for medical advice.

I had an RFA T5-7 with excellent results for 6 months, repeated with same result. Repeated again, now over a year out with no pain.

So have the median branch nerves given in and decided not to regenerate? Can they be permanently destroyed with a series of ablations?

One of two possibilities. #1. Most likely is that the patient has fixed himself and no longer has the problem OR the patient has a new pain that is distracting him/her from the pain you treated. #2. you did a better job the second time, the pain will take longer to come back because you burned a longer area of nerve. IMHO most common is #1.

 

[caligas]

Thanks, that makes sense.

(to clarify, I’m an anesthesiologist but this was a procedure done on me by a Pain management physician for my MBB “proven” facet arthritis.

I was just curious about the physiology, whether it’s possible/likely to permanently destroy a median branch nerve with multiple RFAs.)

Trying to be careful not to violate user agreement, I’m very active on the anesthesia board. That’s why I mentioned that I’m not seeking medical advice, just academic knowledge.

 

[deleted993114]

This is an academic question, NOT asking for medical advice.

I had an RFA T5-7 with excellent results for 6 months, repeated with same result. Repeated again, now over a year out with no pain.

So have the median branch nerves given in and decided not to regenerate? Can they be permanently destroyed with a series of ablations?

Wow! Surprised you -

a. got approval for a thoracic rf

b. got good results

Generally, due to the variable course of the medial branch nerves in the thoracic spine, rf is ineffective in this region. Count your blessings if you got a positive response.

As above, I would agree that the patient probably got better on their own. To prove to yourself one way or another, you could order EMGs to see if the multifides were dennervated. Many years ago, we would get EMGs to confirm multifides denneravation after doing lumbar rf, but found this to be only academically interesting, but not clinically useful.

Might be interesting (just for fun) to see what the EMG shows.

 

[cowboydoc]

One of two possibilities. #1. Most likely is that the patient has fixed himself and no longer has the problem OR the patient has a new pain that is distracting him/her from the pain you treated. #2. you did a better job the second time, the pain will take longer to come back because you burned a longer area of nerve. IMHO most common is #1.

#3 the nerve "regenerates" but doesn't make it's way back to the joint.

All these are plausible, hard to prove any or a combo of these.

 

[Ligament]

Thanks, that makes sense.

(to clarify, I’m an anesthesiologist but this was a procedure done on me by a Pain management physician for my MBB “proven” facet arthritis.

I was just curious about the physiology, whether it’s possible/likely to permanently destroy a median branch nerve with multiple RFAs.)

Trying to be careful not to violate user agreement, I’m very active on the anesthesia board. That’s why I mentioned that I’m not seeking medical advice, just academic knowledge.

Here is another explanation:

The medial branches in the thoracic spine are distributed widely in space. They are not in a reliable, consistent location like in the c-spine and l-spine.

Therefore when we do RF in the thoracic spine, we often miss branches. We get some or most of them, but I'd say rarely all of them.

Since you had it repeated a few times, you have a partial cumulative scorched earth thing going on. Probably a lot of them are knocked out finally.

 

[painfree23]

Kind of along the same lines, is there a max # of RFAs u can do in someone’s life? I have a patient who I did cervical RFA - great results 9 months out. Now wants lower thoracic? What about if she needs lumbar later?

 

[Ligament]

Kind of along the same lines, is there a max # of RFAs u can do in someone’s life? I have a patient who I did cervical RFA - great results 9 months out. Now wants lower thoracic? What about if she needs lumbar later?

There is no max #, can be repeated as needed. I have a good number of patients who I've done cervical, thoracic, lumbar RFs on.

Only theoretical concern is doing "too many" bilateral cervical medial branch rfs.

There are a handful of reports of "dropped head syndrome" from doing multi level bilateral cervical RFs. THe last time I checked, about 8 total cases reported? Thats out of hundreds of thousands treated.

 

[clubdeac]

There is no max #, can be repeated as needed. I have a good number of patients who I've done cervical, thoracic, lumbar RFs on.

Only theoretical concern is doing "too many" bilateral cervical medial branch rfs.

There are a handful of reports of "dropped head syndrome" from doing multi level bilateral cervical RFs. THe last time I checked, about 8 total cases reported? Thats out of hundreds of thousands treated.

I had a case of drop head after a bilateral C3-6 Rf. It wasn’t cool! Be careful up there. I used to burn everything I could thinking it was safer than a CESI until that happened. It’s still safer though

 

[painfree23]

I had a case of drop head after a bilateral C3-6 Rf. It wasn’t cool! Be careful up there. I used to burn everything I could thinking it was safer than a CESI until that happened. It’s still safer though

Did you do the burns together?

 

[MD87]

I had a case of drop head after a bilateral C3-6 Rf. It wasn’t cool! Be careful up there. I used to burn everything I could thinking it was safer than a CESI until that happened. It’s still safer though

How long did the weakness last?

 

[deleted993114]

Here is another explanation:

The medial branches in the thoracic spine are distributed widely in space. They are not in a reliable, consistent location like in the c-spine and l-spine.

Therefore when we do RF in the thoracic spine, we often miss branches. We get some or most of them, but I'd say rarely all of them.

Since you had it repeated a few times, you have a partial cumulative scorched earth thing going on. Probably a lot of them are knocked out finally.

They do regenerate- so it is unlikely that there is a cumulative effect.

I agree that the course of the medial branch nerves is quite variable in the thoracic spine. I believe that many insurers no longer reimburse for thoracic rf due to poor results. I stopped doing them several years ago due to relative poor efficacy and difficulty in reimbursement.

Regarding a "floppy neck" with bilateral cervical rf, that is ONE of the reasons I never do bilateral cervical rf at the same time. Bilateral lumbar is okay, but not cervical.

 

[Orin]

This is an academic question, NOT asking for medical advice.

I had an RFA T5-7 with excellent results for 6 months, repeated with same result. Repeated again, now over a year out with no pain.

So have the median branch nerves given in and decided not to regenerate? Can they be permanently destroyed with a series of ablations?

Pain is a difficult phenotype, so I ask folks not to chase the reason sometimes. In this case, if you want a mechanistic answer, peripheral nerve regeneration is a function of length of injury/lesion, mechanism of injury/lesion, and overall health of the regenerative processes. You can permanently destroy things or have them destroyed to the point they don't reconnect to certain structures. You know this as you've seen paralyzed patients after positioning injuries. Normally though, the DRG where the soma is would have to be injured to ensure permanent deficit, but a large enough lesion of a peripheral nerve can lead to a permanent deficit, especially if the two nerve ends are no longer aligned/able to heal.

It may be that the facet joint is no longer innervated and never will be, but without a provocative test, we wouldn't be able to tell, i.e. injecting capsaicin into the joint or hydro-distending the joint capsule.

It may be that the body has compensated for arthritic changes in the joint with other things, with the patient working aggressively with PT.

It may be that the patient is no longer somatically hypervigilant because life is less stressful or there's something more important to pay attention to.

 

[clubdeac]

How long did the weakness last?

I think a few months. I burned one side then brought them back 2 weeks later and burned the other. No symptoms until I knocked out both sides

 

[MD87]

I think a few months. I burned one side then brought them back 2 weeks later and burned the other. No symptoms until I knocked out both sides

Perfect. Yet another thing for me to be paranoid about!

 

[Ligament]

I had a case of drop head after a bilateral C3-6 Rf. It wasn’t cool! Be careful up there. I used to burn everything I could thinking it was safer than a CESI until that happened. It’s still safer though

You are the only person I've talked to that has seen this personally. Sorry it happened!
Can I ask some questions:
1. How did you recognize it? Was it gradual in onset or immediate?
2. How did you manage it?
3. Did it resolve? if so, how long and how much?

Thanks!

 

[Ligament]

You are the only person I've talked to that has seen this personally. Sorry it happened!
Can I ask some questions:
1. How did you recognize it? Was it gradual in onset or immediate?
2. How did you manage it?
3. Did it resolve? if so, how long and how much?

Thanks!

BTW I had one case in which I THOUGHT it was developing, and got her in aggressive PT and frequent FU. Never fully manifested thankfully. Patient was complaining of inability to hold up her head...even though she could.

 

[deleted131481]

What size burn are you all using for cervical rfa? I've been doing 20-g with 10mm active tip. I've heard some advocate for 5mm active tip. Haven't had issues with the 10-mm tip but that's anecdotal and I've been out only a year.

 

[Ligament]

What size burn are you all using for cervical rfa? I've been doing 20-g with 10mm active tip. I've heard some advocate for 5mm active tip. Haven't had issues with the 10-mm tip but that's anecdotal and I've been out only a year.

I curretly use a 20ga 10mm active tip. Used 18 and 16 ga in the past for cervical spine. Had two casses of cellulitis with the 16 ga needles in the neck only, and only with those 16 ga needles. Not sure if that was the cause but maybe. I don't see any advantage in a 5mm tip unless you are doing pulsed RF and need extreme specificity with localization, or gasserians, in which case I think they make a gasserian RF needle...1mm?

 

[lobelsteve]

20g10mm bent tip for all. Except gasserian. 22g 5mm bent tip.

 

[cowboydoc]

20g 10mm bent tip (venom) for cervicals.

 

[Ligament]

How much do you pay per venom cannulae?

 

[cowboydoc]

How much do you pay per venom cannulae?

I'm employed... But I think they are just south of $30.

 

[clubdeac]

You are the only person I've talked to that has seen this personally. Sorry it happened!
Can I ask some questions:
1. How did you recognize it? Was it gradual in onset or immediate?
2. How did you manage it?
3. Did it resolve? if so, how long and how much?

Thanks!

Well he could visible hold his head up almost to neutral so I didn’t think it was that big of a deal. However I didn’t know about drop head at that time. He was complaining of significant neck weakness and said his head felt like it weighed 100 lbs. I think I had him wear a soft cervical collar intermittently and got him into therapy and it slowly improved after a few months

 

[clubdeac]

And why is no one using 18g in the neck? Am I missing something?

 

[painfree23]

I have no Idea. Is this dropped head thing real?? We have one person reporting a case , any others? Definitely done bilateral rfas with 18g without this issue

 

[callmeanesthesia]

I have no Idea. Is this dropped head thing real?? We have one person reporting a case , any others? Definitely done bilateral rfas with 18g without this issue

There’s even a published case report of a patient requiring fusion for it (too lazy to look up the link right now). I discuss risk of significant neck weakness with patients when doing bilateral RF. That said I do them all the time (18g, 10mm bent tip).

 

[pmrmd]

And why is no one using 18g in the neck? Am I missing something?

I use 18g as well, every case. No issues other than usual post-RF neuritis.

 

[Extralong]

Man. Head drop is scary. I had a colleague that this happened to, burned bilateral C5,C6,c7. Each side one week apart. He braced the neck for 8 weeks and aggressive physical therapy. It resolved.

I had a patient c/o severe dizziness after TON, C3,C4 RFA each side 1 week apart. Like I mean, he couldn’t walk straight. Took him 3 months to slowly get his vertigo under control. My saving grace was that he was so happy with the results, that he was not mad, though his wife was pissed.

And then I learned the hard way to always include that they may have a sunburn sensation sometimes after high neck RFAs. But that goes away after 6 weeks.

 

[Extralong]

I use 18g as well, every case. No issues other than usual post-RF neuritis.

Doesn’t SIS talk about using 16g in their courses? Lol. Maybe it’s because I’m not as experienced as you, but I use 20g 10mm bent tip.

 

[deleted993114]

Man. Head drop is scary. I had a colleague that this happened to, burned bilateral C5,C6,c7. Each side one week apart. He braced the neck for 8 weeks and aggressive physical therapy. It resolved.

I had a patient c/o severe dizziness after TON, C3,C4 RFA each side 1 week apart. Like I mean, he couldn’t walk straight. Took him 3 months to slowly get his vertigo under control. My saving grace was that he was so happy with the results, that he was not mad, though his wife was pissed.

And then I learned the hard way to always include that they may have a sunburn sensation sometimes after high neck RFAs. But that goes away after 6 weeks.

Yep- they should get dizzy with the test blocks, however, then you usually choose not to do the rf.

The price of doing the higher levels is a higher incidence of neuritis. It goes away in about 6 weeks- just give oral prednisone and gabapentin to help them through it. The damn good thing about a neuritis is that they get a longer duration of relief than otherwise would be expected.

 

[Crybaby]

And why is no one using 18g in the neck? Am I missing something?

I use 20g as that is what the clinic I work at orders. I get good results, but typically will do 2- 3 lesions with slight repositioning. The gal that does the orders gets overwhelmed when I get too fancy and ask for special orders. And when I do ask, it usually ends up being more trouble than what its worth!