Do you stim for RF?

[drrosenrosen]

I was trained to do sensory and motor stim at all levels. Searching for paresthesia at <=0.4 is a PITA sometimes. In my new practice, my partners do motor stim only to check for multifidus activation and no extremity stuff, and I've started doing that, too. I still do sensory for cervicals, but just motor for lumbar. Rarely do thoracic. And then, ISIS doesn't recommend stim at all (at least as far as their 2004 guidelines; I haven't been to any of their courses). What are all of you doing?

---

Members don't see this ad.

 

[Mister Mxyzptlk]

Like curve balls that don't curve and bumblebees that can't fly, I still think sensory stim helps. Judging from what I see in the literature and in posts here I must be doing something right because my success rate is very high and incidence of neuritis is very low. I'm not changing anything.

The actual act of obtaining them is often very frustrating, yet I still do it.

"Tell me when you feel it"
"Ok"
[turn up to 1 volt, no response]
"Do you feel it?"
"Yes."
"Tell me EXACTLY the time that you FIRST begin to feel it. We're going to try again. "
"Ok"
[turn up to 1 volt, no response]
"Do you feel it?"
"Yes."
"I need to know when you first start to feel that sensation. Let's try again."
[turn up to 1 volt, no response]
"Do you feel it?"
"Yes. In my arm."
"That's the blood pressure cuff. Focus on your back."
"Ok"
[turn up to 1 volt, no response]
dot dot dot


Veterinary sensory stim:

1.Turn voltage straight up to 2V.
2. Patient shows some sort of discomfort -> positive stim.

 

[Gauss]

"Unnecessary and superfluous" in ISIS guidelines, page 217 Appendix 1

 

[SSdoc33]

"Unnecessary and superfluous" in ISIS guidelines, page 217 Appendix 1

yes, well, we cant all be like bogduk, can we? i think stim is helpful, but dont kill myself to get optimal sensory stim when the anatomic flouro images are perfect.

i would add to MMs comment:

me: ok, tell me the first second when you feel the sensation
pt: ok, i feel it
me: we havent started yet.
pt: ok, sorry.
me: no problem. tell me the first second when you feel the sensation
pt: my nose itches
me: here's a tissue, lets focus here, ok?
pt: you got it doc.
me: ok, lets try aga....
pt: why do i have to go to the bathroom?
me: nurse, can you please stick this touhy in my eye?

 

[Aether2000]

Main problems with sensory stimulation:
1. You are effectively using an uninsulated needle. A 10mm active tip is enormous compared to the 0.37mm active tip of a EMG electrode or a stimulplex needle. With an uninsulated needle, the tip or shaft can be near the nerve or far away and have the same response.
2. All the tissues surrounding the needle are innervated by the same nerve: periosteum, fascia, multifidus and rotatory muscles, MAL, fat, etc. My patients lack the discriminative capacity to differentiate stimulation of the multifidus muscle vs the medial branch. Typically discrete paresthesias are not obtained from this lightly myelinated or unmyelinated nerve.

 

[Ligament]

I dont think there is anything wrong with sensory stim per se. I do not think it is particularly useful however.

 

[E Dubble]

I've wasted so much time earlier this year in fellowship trying to get optimal sensory numbers. Nowadays I usually crank it up until the patient feels something and then back down until they tell me when it goes away and use that number.
I've been told that the radiologists never use sensory stim

 

[SSdoc33]

I've wasted so much time earlier this year in fellowship trying to get optimal sensory numbers. Nowadays I usually crank it up until the patient feels something and then back down until they tell me when it goes away and use that number.
I've been told that the radiologists never use sensory stim

i wouldnt base my technique on what the "radiologists" do

 

[bedrock]

Main problems with sensory stimulation:
1. You are effectively using an uninsulated needle. A 10mm active tip is enormous compared to the 0.37mm active tip of a EMG electrode or a stimulplex needle. With an uninsulated needle, the tip or shaft can be near the nerve or far away and have the same response.
2. All the tissues surrounding the needle are innervated by the same nerve: periosteum, fascia, multifidus and rotatory muscles, MAL, fat, etc. My patients lack the discriminative capacity to differentiate stimulation of the multifidus muscle vs the medial branch. Typically discrete paresthesias are not obtained from this lightly myelinated or unmyelinated nerve.

Ditto to Algo's comments.

I've never noticed a difference in outcomes whether I did or didn't check sensory stim.

I did however notice a difference whether or not I performed RF with good ISIS technique, as that is the most predictable variable for good clinical outcomes.

I do feel safer checking motor stim before lesioning, though.

 

[PMR 4 MSK]

The biggest PITA I find with sensory stim is when you get it at one or more levels, then can't get it at another level, the patient gets all anxious about it, assuming there is something wrong, you are not doing it right, etc.

 

[mille125]

I do a lot of RF (more than anyone else in my area) and I must say that I have had a few case where I was very glad that I did sensory and motor stim...

 

[lonelobo]

I do a lot of RF (more than anyone else in my area) and I must say that I have had a few case where I was very glad that I did sensory and motor stim...

Why? In regards to sensory

 

[Mister Mxyzptlk]

It's interesting to me that the objections to sensory stim are based not on data but theory, something Bogduk usually abhors. Apparently this rule can be set aside when he is doing the theorizing.

I have two clinical observations to offer:

1. If the above objections were true you should be able to produce sensory paresthesias just about anywhere in the approximate area at any time. Instead you have to search for them, sometimes quite aggressively. If this large needle can produce false positives all over the place why is it so damn hard to actually produce it?

2. In addition, in cases of partial relief I have gone back in, done sensory stim at each level, found ONE live nerve and burned it with appropriate results. According to the "pan-stimulation" theory this type of effort should be no more successful than randomly picking a level to burn.

Although #2 is anecdotal, I would imagine everyone here has experienced difficulty eliciting paresthesias. If the large needle theory is correct it should be child's play.

 

[willabeast]

I do a lot of RF (more than anyone else in my area) and I must say that I have had a few case where I was very glad that I did sensory and motor stim...

when i first started out doing RF i relied on stim a lot, it definitely helped.
once i got to know the anatomy better virtually all my stims were good.
so in a way i do not need it anymore, but some of the people i work with
get higher testosterone levels with lower stims so the first question asked when a RF does not work is "what was the stim number".
anything over 0.5 V means you must have testosterone levels too low to measure.
not sure what will happen if we get a female colleague.

 

[clubdeac]

Am I missing something? Testosterone affecting stim thresholds?? ehh

 

[willabeast]

Am I missing something? Testosterone affecting stim thresholds?? ehh

other way around. in the interventionalist. sorry - way too much caffeine on that post.

 

[Jcm800]

other way around. in the interventionalist. sorry - way too much caffeine on that post.

dude i still dont get it...

 

[facets]

I believe he is implying that wusses use stim thresholds, real men with high testosterone levels don't need it.

 

[Mister Mxyzptlk]

Now that you mention it, I've had this strong urge to stop doing sensory stim ever since I started hormone replacement therapy. Has anyone tried DHEA?

I tried taking Viagra before procedures but I couldn't get close enough to the table to do the injection unless they elevated it 5 feet.

 

[willabeast]

I believe he is implying that wusses use stim thresholds, real men with high testosterone levels don't need it.

that is closer...
this is what we need to do to get this published.
measure testoserone levels in interventionalists before and after
rhizotomies. see if there is a correlation between low stim numbers and elevated testosterone levels. i read somewhere that if your favorite football team wins your testosterone level goes up for a while. this is the same thing. i have always thought it is the docs that need to be studied, not the patients.

here you go
http://oak.ucc.nau.edu/propper/bio425_docs/testosterone home court advantage.pdf

 

[painstop]

Now that you mention it, I've had this strong urge to stop doing sensory stim ever since I started hormone replacement therapy. Has anyone tried DHEA?

I tried taking Viagra before procedures but I couldn't get close enough to the table to do the injection unless they elevated it 5 feet.

Mxyzptlk,

I hope you didn't take Twitter pictures of this 'situation' and send it to random people or Wolf Blitzer will be interviewing you on CNN soon.