Radiculopathy

[spondy14]

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For those of you out there doing EMG, what percentage of your exams (in general) are normal for radic......be honest. Which also brings up a good point, are paraspinals helpful and what role do they play in the diagnosis..

 

[PMR 4 MSK]

For those of you out there doing EMG, what percentage of your exams (in general) are normal for radic......be honest. Which also brings up a good point, are paraspinals helpful and what role do they play in the diagnosis..

Maybe 1 in 20, maybe less than that. Probably 50% or less of radics will be picked up on exam. I don't use EMG routinely for radic, only for questionable ones, or if a referring doc wants it.

Paraspinals are helpful mainly for deciding radic vs distal. If peripheral exam is normal, I don't do paraspinals.

 

[lobelsteve]

How many people see outside reports positive for radics with normal neuro exam, no compressive lesions on MRI, and study done by Neuro?

Most often it is f-wave abnormalities.
Sometimes they report PSW b/l TA, RF, and AH.

I just don't get it.

 

[axm397]

those mobile neuro units and the neural scams i mean neural scans are infiltrating - i have seen positive radic called only based on H reflex and no EMG, etc. They especially love that in MVA-legal cases. diagnose a "radic" based only on NCS, do series of 3 ESIs, facets, MBBs, RFAs, disco, IDET then send to surgeon for a multilevel fusion. Makes a simple MVA case into a multi-million dollar settlement.

We have some chiros in town doing these "neural scans" - typically all 4 limbs, f waves, h reflex on everyone and no EMG. Apparently, there is a neurologist "reading" the study off site.

 

[RUOkie]

NeuroMax, the company that marketed the mobile units most frequently used was recently sued and lost a fairly large class settlement about false adveritising. There are now special CPT codes for using automated NCS, and they are excluded by most insurers and by all Medicare FI's. The AANEM/AAPMR/AAN did their jobs well with this one. There are some mobile EMGs still being done, but if you find them, report it to your state board and to the advocacy council at AANEM. Most of us are trying to cut down on that crap. Make sure the interpreting physican is licensed in your state. If not, he/she is guilty of practicing medicine without a license!

 

[RUOkie]

OP in response to your question, few. I don't have actual numbers. That said, I have diagnosed a cervical meningioma for "cervical radiculopathy" sent to me for EMG by primary care. She had Bilateral C8 radiculopathies by EMG but little to no neck pain. We sent her to get a MRI, had surgery (it was a HUGE meningioma) and was cured!

Also, I tend to do lumbar paraspinals in most patiets. The cervicals only if the limb muscles are abnormal. It is just more difficult to relax the cervical paraspinals, so the infomation is less reliable.

 

[nvrsumr]

Ive called an L3 radic with positive adductors on EMG and paraspinal mapping based on technique described in article.

 

[spondy14]

Maybe 1 in 20, maybe less than that. Probably 50% or less of radics will be picked up on exam. I don't use EMG routinely for radic, only for questionable ones, or if a referring doc wants it.

Paraspinals are helpful mainly for deciding radic vs distal. If peripheral exam is normal, I don't do paraspinals.

1 in 20 are normal or 1 in 20 show spontaneous activity??

 

[SSdoc33]

i generally dont trust EMG reports unless i do the EMG myself or know the person performing the study. there is way too much crap and bad studies out there.

 

[Ludicolo]

spondy14 – can you clarify your original question? Are you talking what percentage of bogus referrals for “r/o radic” end up w/ a normal study? For me, I get quite a few of these. Or are you asking what percentage of patients with a clinically suspected radic (based on H&P, or MRI, or whatever gold standard you want to use) actually end up with a normal study – like in a radic affecting only pre-ganglionic sensory fibers?

RE: paraspinals. I fall into the PMR 4 MSK camp, assuming SNAPs are normal. If the limb EMG is normal, no point in checking the paraspinals, doesn't really help with localization (paraspinal mapping aside). If multiple muscles w/in the same myotome/different peripheral nerve abnormal – no point in checking the paraspinals. Sometimes though, only one limb muscle is abnormal, and I’ll use the paraspinals as a tie-breaker if you will.

I actually find that checking the paraspinals is more useful in post-DRG cases like brachial plexopathies (documenting normal paraspinal findings to r/o root avulsion), or in cases where a patient could have both a radic and a peripheral neuropathy, or a polyradiculoneuropathy like GBS.

 

[PMR 4 MSK]

1 in 20 are normal or 1 in 20 show spontaneous activity??

1/20 abnormal enough to call a radic

 

[kurt rambis]

PMR,

If I remeber right, you do a lot of EDX studies. If you aren't doing that many radic studies what are you doing mostly? Entrapment neuropathies? I know you are with an ortho group. Is that where you get your referrals? I am in my second month of practice and am looking to focus on growing my EDX practice. I am with you that I don't plan on self referring that many radic studies secondary to the sensitivity. Our hand surgeons don't typically get CTS studies before they operate. Most of the studies that I am doing now are referrals from spine surgery for radics. Many thanks

 

[PMR 4 MSK]

PMR,

If I remeber right, you do a lot of EDX studies. If you aren't doing that many radic studies what are you doing mostly? Entrapment neuropathies? I know you are with an ortho group. Is that where you get your referrals? I am in my second month of practice and am looking to focus on growing my EDX practice. I am with you that I don't plan on self referring that many radic studies secondary to the sensitivity. Our hand surgeons don't typically get CTS studies before they operate. Most of the studies that I am doing now are referrals from spine surgery for radics. Many thanks

Around 1/2 of mine are from our 3 hand surgeons - so mostly R/O CTS, CuTS (cubital). Others are from the shoulder guys for R/o brachial plexopathy vs radic (often normal), from the rheumatologists and podiatrists for R/o PPN, and then misc from others. Only 10% are from outside docs, but I'm working strongly to increase that %.

 

[axm397]

PMR,

If I remeber right, you do a lot of EDX studies. If you aren't doing that many radic studies what are you doing mostly? Entrapment neuropathies? I know you are with an ortho group. Is that where you get your referrals? I am in my second month of practice and am looking to focus on growing my EDX practice. I am with you that I don't plan on self referring that many radic studies secondary to the sensitivity. Our hand surgeons don't typically get CTS studies before they operate. Most of the studies that I am doing now are referrals from spine surgery for radics. Many thanks

could u talk to the hand surgeons about referring them to you? or maybe if u catch a CTS refer the patient to them, then call them to "follow up"?

 

[spondy14]

spondy14 – can you clarify your original question? Are you talking what percentage of bogus referrals for “r/o radic” end up w/ a normal study? For me, I get quite a few of these. Or are you asking what percentage of patients with a clinically suspected radic (based on H&P, or MRI, or whatever gold standard you want to use) actually end up with a normal study – like in a radic affecting only pre-ganglionic sensory fibers?

Yes, the vast majority of my cases are legitimate radic (MRI, history) and preganglionic (since the EMG is normal). It is surprising to me anymore when I see positive waves in the uppers even with large protrusions...

 

[Ludicolo]

Yes, the vast majority of my cases are legitimate radic (MRI, history) and preganglionic (since the EMG is normal). It is surprising to me anymore when I see positive waves in the uppers even with large protrusions...

Depends on when you're catching the radic as well. Are you relying solely on fibs/PSWs to call radics? While fibs certainly provide more definitive evidence, can't you use chronic MUP changes, or reduced recruitment, within a given myotome to also identify radics?

But ultimately if everything is normal I agree, these "sensory radiculopathies" aren't very satisfying.

 

[latinman]

I agree with Ludicolo. Sometimes in calling a radiculopathy, the only changes you will appreciate are Chronic MUAP changes (ie., Polyphasic motor units or Big motor units for the selected muscle, with decreased recruitment). Always make sure that you evaluate different peripheral nerves with the same root if possible. I read somewhere that the majority of radiculopathies involve sensory fibers > motor fibers. As a result, sometimes you won't pick these up with needle EMG, and you won't appreciate muscle weakness either.

I have seen several interesting S1 radiculopathies involving motor fibers. Usually atrophy of gastrocsoleus complex is appreciated, and clinically many times during gait evaluation you will appreciate knee buckling. Rx an AFO with dorsiflexion spring sometimes help these people.

Today I got hammered by my Attending with this C5 radic. I thought the pt had MPS/whiplash, since she was complaining of headaches, had tender muscle points, and cramping in the right arm. At no time could I clinically appreciate muscle weakness or sensory abnormalities (either subjectively or on exam). It turns out that after evaluating her, when I came back into the room with my attending the pt was doing a "Abduction relief sign" (relief of pain when the arm is placed overhead) which apparently is pathognomonic for C5 radic. The C5 reflex were trace bilaterally so it was hard for me to call it just based on reflex exam. Good learning case, and it makes u aware that proximal Cervical, proximal Lumbar and Thoracic radics can also take place, and we should always think about them.

Interesting website:
http://eorif.com/Spine/CervicalRadicul.html

You guyz take care,

 

[RUOkie]

Despite having a very active EMG practice, I tend not to use electrodiagnostics as my initial test when I suspect radiculopathy. I tend to use imaging first.

I will use EMG in the workup in a few situations
1. When I have a strong suspicion and there is a contraindication towards MRI--but only when planning to proceed with myelogram/surgery.
2. When imaging shows DDD without foraminal stenosis/HNP and the patient is convinced "something is wrong" and I am expecting a normal study.
3. When I see a progressive neurologic deficit, the patient is refusing surgery, and I am trying to convince the patient that the nerves "are dying" (ie. to document the severity of the neurologic problem)
4. When I suspect neuropathy/myopathy/etc. as a contributing factor in the diagnosis.

of course there are others, but those are the biggies.

 

[Ludicolo]

If it’s my patient, I tend to go clinical eval first. If it looks and smells like a radic, treat it as such. You know, the whole “avoid unnecessary testing, these patients tend to get better anyway, yada yada yada” sort of thing. Plus – this tends to be the answer they’re looking for on oral boards… 😉

I’ll tend to order MRI next. Especially if there are “red flags” – h/o trauma, cancer, fevers/night sweats, progressive neuro findings, pain out of proportion, etc. I’ll EMG if it could change management (like if they’re not improving w/ conservative treatment); or if there aren’t enough clues from H&P and imaging; or if the patient’s really claustrophobic, or if they have unsecured metal thingies inside them, or if they are way too big for the MRI machine.

A lot of my EMGs for “r/o radic” though are from referrals – pain docs, surgeons – that are looking for a specific level to target. Usually, their patients’ MRIs show multilevel badness. Or, just as likely, they are completely pristine. I kinda hafta do these studies.

Re: the shoulder abduction relief sign. I didn’t think it was pathognomonic for a specific root level. Seen it positive in C6 and C7 radics as well.

 

[PMR 4 MSK]

I also EMG in medico-legal cases - Work comp, MVA.

I thought the abductor relief was more for C7.

 

[RUOkie]

A lot of my EMGs for "r/o radic" though are from referrals – pain docs, surgeons – that are looking for a specific level to target. Usually, their patients' MRIs show multilevel badness. Or, just as likely, they are completely pristine. I kinda hafta do these studies.

Re: the shoulder abduction relief sign. I didn't think it was pathognomonic for a specific root level. Seen it positive in C6 and C7 radics as well.

I am sorry I was not clear. I certainly do the studies for radiculopathy when they are sent to me for that purpose. It would be practice suicide not to! That is usually where my normals come from.

I usually use the shoulder abduction relief sign as a non-specific sign for cervical radiculopathy, not a specific level. If anyone has some references that would be great. I did a quick pubmed search and didn't find much (but I was very brief😳)

 

[spondy14]

Depends on when you're catching the radic as well. Are you relying solely on fibs/PSWs to call radics? While fibs certainly provide more definitive evidence, can't you use chronic MUP changes, or reduced recruitment, within a given myotome to also identify radics?

But ultimately if everything is normal I agree, these "sensory radiculopathies" aren't very satisfying.

Now the discussion gets interesting. This is one of my issues with EMG and Radic. If the patient has pain and no weakness, the chances of PSW/fibs are very low, and in these cases what is the purpose of checking for chronic changes??? What does polyphasia and large amplitudes have to do with pain? and if the MRI shows no compression...what are the chances of having any acute or chronic changes...next to none in my experience. What is the point of evaluating chronic changes in a patient with acute radicular pain?? So if someone has pain in a C6 pattern and have polyphasia in the pronator and FCR..calling a chronic C6 radic is going to somehow help with the diagnosis? Will it help the patient get a surgery..or will it help guide therapy....not sure about the importance.

The shoulder abduction relief sign?? Aka Bakody's sign? Seen it with C5, 6, and 7..not specific for 5.

 

[axm397]

I had a patient that was referred to me for cervical radiculopathy - only objective exam finding was APB weakness and numb thumb. MRI showed multi-level disc herniations, facet arthropathy, osteophytes, and spondylolisthesis of C5 on 6 and C6 on 7. I put him in PT cuz not much pain except some non-specific pain in posterior arm area into elbow and maybe forearm achiness. Injection not indicated. When his weakness didn't get better after about 3 weeks of PT - did an EMG - looks like some kind of median nerve entrapment somewhere above the pronator teres. (PSWs and fibs in pronator teres, FCR, and APB only, everything else clean, all NCS "normal" although in hindsight should've compared the median nerve study side-to-side) MRI showed pronator teres denervation and signal change suggestive of pronator terres syndrome vs more proximal. Am going to xray his elbow to look for possible supracondylar bone spur or something - and send back to the ortho guy who referred him to me. Not sure what else to do?

 

[SSdoc33]

how often do we see EMG reports from some bonehead that says something like C5,6, and 7 radiculopathy? they are essentially calling this a radiculopathy based on chronic changes (polyphasia) which can be pretty subjective. i personally rarely comment on polyphasia in my report, because quite frankly, i dont think surgeons and PCPs really understand it. if they see "radiculopathy" on the report, it can green-light an unnecessary surgery. fibs/sharp waves in 2 separate nerves at the same myotome = radic. dont fall for the polyphasia argument, you arent doing anyone any favors.

 

[SSdoc33]

as far as "when do you get an EMG"? i find that docs who dont really have any other interventions to offer -- neurologists and non-interventional physiatrists tend to do more electrodiagnostic studies as they arent as familiar with treatment algorithms that work. ill see patients who seen the neurologist for a radic, and more often than not, they have been on some crazy neuro drug (keppra, ropirinole, one time i saw sinemet. really? sinemet) and have had an EMG. meanwhile, the EMG rarely helps in the treatment --either PT or an ESI. i generally agree with the MRI first if possible, then EMG if dx is in doubt, if there may be co-existing neuropathy, or if something doesnt add up clinically. i also do the studies to confirm/quantify the presence of nerve damage when i think something is pretty substantial.

 

[Finally M3]

how often do we see EMG reports from some bonehead that says something like C5,6, and 7 radiculopathy? they are essentially calling this a radiculopathy based on chronic changes (polyphasia) which can be pretty subjective. i personally rarely comment on polyphasia in my report, because quite frankly, i dont think surgeons and PCPs really understand it. if they see "radiculopathy" on the report, it can green-light an unnecessary surgery. fibs/sharp waves in 2 separate nerves at the same myotome = radic. dont fall for the polyphasia argument, you arent doing anyone any favors.

I just saw one of those; bilateral c5-7 radic based on polyphasia.

Perusing the report, the ulnar sensory had an amplitude of 150. Of course, the study was bilateral median, ulnar, and radial sensory nerves for unilateral symptoms. 🙄

 

[Ludicolo]

I agree, for patients whose sole complaint is acute pain, with an otherwise normal exam, EMG won’t be very helpful. Pain involves small, unmyelinated fibers, whereas NCS/EMG assesses larger fibers. However, in a more chronic, often dynamic process like a slowly herniating disc, or osteophytic foraminal stenosis, you can get intermittent axon loss, with subsequent motor unit remodeling. Pain and pre-ganglionic sensory fibers may well be more affected than motor fibers. If the degree of reinnervation matches the degree of denervation, you may not see any fibs.

So if a patient has multilevel disc/foraminal disease, and you’re able to isolate EMG findings (fibs or no fibs) to a specific nerve root, this could be helpful. Perhaps more helpful in the lumbosacral region, since most pain people don’t do selective blocks in the cervical spine. As an EMGer, I think you have to call findings (i.e. polyphasics) as you see ‘em, but when you write the report you need to interpret those findings in the appropriate clinical setting, and I’ll often try lead my referral source down the preferred treatment path. My reports are different depending on my audience, depending on if the referral is from a surgeon, pain doc (and whether they’re PM&R or anesthesia based), IM, neurologist, or physiatrist.

If the MRI is clean, and their exam is unrevealing, yes – I also see the bulk of my normal EMGs in this scenario. Documenting normalcy might be helpful in this case – reassures the patient, and keeps some of the surgeons away. And finding a non-radicular pathology which mimics a radic, as in axm’s case, is certainly useful. How many times have you done a study for r/o CTS, but it turns out to be a radic, or vice versa? As an aside – isolated symptoms of thenar weakness (C8-T1) and thumb numbness (C6) shouldn’t be thought of as radicular. But I digress.

In uncomplicated, mild, pain-only radics, does EMG change management or guide treatment? Not really. For the most part, localizing the lesion in these cases is more of a diagnostic and academic exercise. (Ick – I sound like a neurologist 😀 ). Doesn’t mean I still don’t do the study when it’s referred to me, because occasionally you do pick up stuff, radic or otherwise.

 

[RUOkie]

as far as "when do you get an EMG"? i find that docs who dont really have any other interventions to offer -- neurologists and non-interventional physiatrists tend to do more electrodiagnostic studies as they arent as familiar with treatment algorithms that work. .

Please don't lump us all in that group. Just because someone is not an intervetionalist, does not mean that he/she is not familiar with treatment algorithms that work. Sometimes the "interventionalists"(ie. some of the needle jockey's out there) use procedures that don't!(IDET, chymopapain, laser annuloplasty etc.) and don't use algorithms that do work (like PT, traction, ESI's etc.)!

 

[RUOkie]

I have also seen the opposite example, when a patient was referred to me for EMG for "radiculopathy" and PE revealed atrophy, visible fasics, and UMN signs. You know the rest 🙁 (especially with the recent death of Dr. Krivickas). (for those of you who don't know her, she was an electrodiagnostician and physiatrist at Harvard who very recently died from ALS.)

 

[SSdoc33]

Please don't lump us all in that group. Just because someone is not an intervetionalist, does not mean that he/she is not familiar with treatment algorithms that work. Sometimes the "interventionalists"(ie. some of the needle jockey's out there) use procedures that don't!(IDET, chymopapain, laser annuloplasty etc.) and don't use algorithms that do work (like PT, traction, ESI's etc.)!

didnt you just commit the same faux paus that you claim i did?

i find interventionalists dont really NEED the emg as much because it doesnt really change how they manage the patient.

 

[RUOkie]

didnt you just commit the same faux paus that you claim i did?

i find interventionalists dont really NEED the emg as much because it doesnt really change how they manage the patient.

It was intentional! 😛