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Carpal Tunnel Syndrome
19 Plays6 days ago
Time to talk about good ol' carpal tunnel syndrome! In this episode, Dr. Michael Powers discusses key considerations of managing carpal tunnel syndrome, including the importance of patient history and the use of evidence-based practice in clinical-decision making. He also highlights the importance of knowing your anatomy, including knowing the unforgiving structure of the carpal tunnel (how many flexor tendons are squeezed in there?) and recalling peripheral nerves are complex structures composed of multiple neurons functionally grouped together in fascicles. This episode is a must-listen if you're wanting to improve your confidence in applying the evidence toward the diagnosis, prognosis, and management of carpal tunnel syndrome!
References
- Global and Regional Prevalence of Carpal Tunnel Syndrome
- Carpal Tunnel Syndrome
- Teach Me Anatomy: The Carpal Tunnel
- A Self-administered Hand Diagram for the Diagnosis of Carpal Tunnel Syndrome
- A Handy Review of Carpal Tunnel Syndrome
- Median Nerve Injury
- CPR for Carpal Tunnel Syndrome
- Carpal Tunnel Syndrome: A Summary of Clinical Practice Guideline Recommendations - Using the Evidence of Guide Physical Therapy Practice
- Electrodiagnostic Evaluation of Carpal Tunnel Syndrome
- Recent Advances in Ultrasound Diagnosis of Carpal Tunnel Syndrome
- Surgical vs. Non-surgical Treatment for Carpal Tunnel Syndrome
All music courtesy of Free Music Archive and used via attribution 4.0 international license.
- Intro and Outro: Stylin' by JMHBM
- Transitional: Our Reality by Ketsa
Connect
- Email: neuropowerhour@drmichaelpowers.com
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Transcript
Introduction and Dr. Powers' Background
00:00:10
Speaker
Welcome to the NeuroPowerHour. I'm your host and neurological navigator, Dr. Michael Powers, physical therapist, board certified in neurologic physical therapy and clinical electrophysiology. Let's get started.
Understanding Carpal Tunnel Syndrome
00:00:22
Speaker
Today I'll be talking about carpal tunnel syndrome. This is a topic that's near and dear to my heart. Previously, when I was working on the Navajo Reservation performing electrodiagnostic testing, carpal tunnel syndrome was the most common condition I would see in terms of performing EMGs and nerve conduction studies.
00:00:39
Speaker
And this testing was done to determine whether someone was appropriate for surgery or not, because although carpal tunnel syndrome is the most common focal entrapment neuropathy, on the reservation, there was such a high proportion of patients with diabetes that it was very important to rule out competing diagnoses such as diabetic peripheral neuropathy.
Diagnosis Complexities and Evidence-Based Practices
00:01:01
Speaker
Carpal tunnel syndrome, then, I think is an excellent topic to really think about clinical decision making because, as I previously mentioned, although it's the most common focal entrapment neuropathy, it can mimic other conditions.
00:01:15
Speaker
And it's a syndrome, so there's no one specific test that's best able to diagnose the syndrome. So it really pulls in considerations of evidence-based practice in terms of what test item clusters you're looking at to perform and how you go about thinking ruling in carpal tunnel syndrome, but also ruling out competing diagnoses. Also, we want to think about what does the evidence say in terms of what treatments are best for this syndrome.
00:01:40
Speaker
In addition, carpal tunnel syndrome really gets you thinking about your anatomy and physiology in terms of what's truly going on in terms of nerve compression and or traction, What are the stages of nerve injury and repair?
00:01:55
Speaker
And what can we expect prognostically based on what's actually been damaged in terms of nerve and neuron structure?
Anatomy and Prevalence of Carpal Tunnel Syndrome
00:02:02
Speaker
So without further ado, let's start talking about carpal tunnel syndrome.
00:02:06
Speaker
And let's begin by looking at the general overview in terms of incidence and prevalence. Previously mentioned, carpal tunnel syndrome is the most common focal mononeuropathy. So it's the most common source of upper extremity, tingling, maybe hand weakness that you're going to find.
00:02:23
Speaker
The global prevalence is estimated to be around 14%, and prevalence means the proportion of the population that has the condition at any given time.
00:02:34
Speaker
So prevalence is estimated around 14%, whereas the incidence is estimated to be between 1 and 5%. And incidence is the proportion of new cases that are coming out at any given time.
00:02:48
Speaker
A nice analogy that I previously heard is the bathtub analogy. So we can think of the faucet, the water coming out of the faucet, as incidence. It's new cases being added.
00:03:00
Speaker
And we can think of the water that's in the bathtub as the prevalence. So that's the current cases at any given point. What we have with carpal tunnel syndrome then is we've got more water in the bathtub than we have new cases coming in.
00:03:14
Speaker
And this will make sense because as we look at outcomes and general time course of carpal tunnel syndrome, Typically, we're looking at timeframes of six months to a year or longer.
00:03:25
Speaker
So this is a condition that once someone has it, it may take a little while to resolve, regardless of whether the treatment is conservative or surgical management. So again, prevalence going to be a little higher than incidence. Prevalence is about 14% in the global population.
00:03:41
Speaker
couple other things I want to mention here in terms of initial presentation. It's a condition that's more common in females by about a 2 to 1 or 3 to 1 ratio, and it's more common in patients who are obese and also tends to show up in patients between the ages 40 60.
Factors Contributing to Carpal Tunnel Syndrome
00:03:58
Speaker
Now, I'll keep coming back to concepts of evidence-based practice throughout today's show, and I want us to really center ourselves on this pretest probability that someone who's got hand tingling and complaints maybe of some hand clumsiness, our initial thought is, well, if carpal tunnel's got about a 14% prevalence, that we can set as our baseline pretest likelihood.
00:04:22
Speaker
If our patient then is female, overweight and or between the ages of 40 to 60 that's going to shift our pretest likelihood even higher and i really keep coming back to these concepts of evidence-based practice because we don't have one single test for carpal tunnel syndrome it is a syndrome so the more cluster of positive findings that we can find and the more we can use evidence-based practice the less uncertainty we're going to have that we're actually arriving at the correct conclusion. I mentioned previously that carpal tunnel syndrome is a syndrome, and most researchers identify that there's likely multiple contributing factors, such as personal, occupational, social, and or environmental issues.
00:05:06
Speaker
It's much different than, let's say, someone falls and breaks a bone and you can see it clearly on the x-ray. Hey, that's a broken bone. Here's what's happening. Here's what we need to do. In carpal tunnel syndrome, yes, we've got some diagnostic tests such as EMG and or ultrasound, and we'll talk more about those later.
00:05:24
Speaker
But again, it's a syndrome. And unless the nerve is significantly damaged to where we see thenar atrophy, there's probably some wiggle room in terms of treatment.
00:05:34
Speaker
So carpal tunnel syndrome, the long and the short of it is, yes, there is compression and or traction affecting the median nerve as it goes through the carpal tunnel, but there's likely multifactorial contributors with multiple individual and environmental and social aspects as well.
00:05:50
Speaker
From an anatomic perspective, We want to keep in mind what's happening to the median nerve as it passes through the carpal tunnel. We've got the flexor retinaculum at the top of the tunnel, so we've got a pretty unforgiving tunnel or a pretty unforgiving space.
00:06:05
Speaker
And through the carpal tunnel, not only does the median nerve need to travel there, but we have nine flexor
Nerve Damage and Treatment Approaches
00:06:12
Speaker
tendons passing through the tunnel. So it's getting pretty crowded in there, and if you've got some swelling, a lot of repetitive use, you can see that it's pretty easy for some compressive forces to be put on the median nerve, and that's going to result in some difficulty or some challenges for the nerve. One thing I do want to mention that I think is easy to lose sight of when we talk about a nerve, we're actually talking about multiple neurons bundled together in functional units.
00:06:39
Speaker
Think about individual neurons. They're grouped together in fascicles. These fascicles then are working together, and you have multiple fascicles that actually make up the peripheral nerve.
00:06:50
Speaker
And I bring this up because if you just think, well, this is the median nerve, it's a wire, it's sending a signal, that is blatantly incorrect. What we've got is the median nerve, but it's comprised of sensory and motor neurons.
00:07:04
Speaker
These neurons are grouped together within fascicles. So let's take an individual neuron. Think about how it's wrapped in that myelin sheath. The Schwann cells in the myelin is going to be covered by endoneurium, some protective connective tissue.
00:07:19
Speaker
you then have multiples of these neurons stacked together within a fascicle. So think about a tube with multiple neurons running into that tube. That's your fascicle.
00:07:31
Speaker
Around each fascicle is going to be the perineurium, another layer of connective tissue, and then around the entire nerve, so and around all the fascicles, is going to be the epineurium.
00:07:42
Speaker
So multiple layers of connective tissue here as well. Reason I bring this up is when we think about what's actually happening to the media nerve when it's damaged. Most cases, you're not going to have a complete nerve transection, especially if the lesion is due to compression.
00:07:58
Speaker
What you're going have instead is preferential damage to certain neurons. Certain fascicles may be more prone to compressive damage than others. So maybe you get some tingling or some sensory disturbances without loss of strength.
00:08:13
Speaker
Then as compression progresses, maybe you do start to get some strength loss, but you're rarely going to have a complete disruption of all the neurons within a nerve. More common, and this is what I saw performing EMGs in electrodiagnostic testing, is you're going to get some sparing of nerve function.
00:08:31
Speaker
So you'll see some demyelination or you'll see partial axon loss. It's rare with carpal tunnel syndrome that the entire nerve is knocked out. And that may lend itself to why treatment-wise, there's technically a lot of wiggle room in terms of how we're going approach this.
00:08:47
Speaker
But again, please keep your anatomy in mind. A nerve is not one wire. It's composed of multiple neurons bundled together in fascicles. And between the fascicles, you have that perineurium, and then the entire nerve is going to be surrounded by the epineurium.
00:09:02
Speaker
And this is important prognostically because as we think about, well, if there's axon loss here, as long as those supporting connective tissue structures are intact, as long as we've got the perineurium and the endoneurium, I'm sorry, the epineurium intact, greater chance for nerve recovery.
00:09:25
Speaker
Let's talk about common patient complaints or the subjective history for patients who have carpal tunnel syndrome. There's some classic findings that patients may mention, and these can really be helpful in shifting your pretest likelihood or getting you to the point where you think, I really do think this is carpal tunnel syndrome. I'm going to do a targeted clinical exam, but I'm moving towards really thinking this person has carpal tunnel syndrome. Classically, tingling, in the distribution of the median nerve, specifically digits 1 through 3 and part of the fourth digit, with digit 1 being the thumb, is going to be a classic presentation.
00:10:03
Speaker
Initially starts out as tingling, as it progresses may move to numbness, and sensory disturbances in that pattern is classically referred to as the CATS hand diagram, K-A-T-Z,
00:10:16
Speaker
So if you give someone a picture of a hand and ask them to label where do they feel sensory disturbances, if it's in the distribution of the median nerve, that's considered a positive cat's hand diagram. My experience is that typically patients with carpal tunnel syndrome complain more of sensory problems such as tingling, later numbness,
00:10:35
Speaker
Pain's not necessarily a primary complaint, although it can be a complaint, but anecdotally in my EMG experience, if someone's complaining more about pain, I'm shifting away from thinking it's a nerve problem towards maybe a different type of musculoskeletal problem.
00:10:50
Speaker
Other key subjective findings is that patients will typically describe symptoms are worse with activity and or at night. Symptoms especially worse at night make sense because most of us move into some kind of physiologic flexion as we sleep. We sleep kind of curled up, and you can think about as we curl up, we're also flexing our wrists, and that can put prolonged compression and or pressure on the median nerve.
00:11:14
Speaker
Symptoms worse at night is a very common finding. Another key finding in the subjective exam is what's known as the flick sign, where the patient reports symptoms feel better with shaking of the hand.
00:11:28
Speaker
Now for this, I'd recommend don't ask a leading question. Don't ask the patient, hey, do you shake your hand to get rid of symptoms? Because I think that introduces some bias. So better off asking an open-ended question, is there anything you do to make your symptoms feel better? Or when your hand is tingling, there anything you do that helps?
00:11:46
Speaker
And if they show you that they flick their hand or they say, yeah, I shake my hands out, that's a positive flick sign. One thing I do want to mention is that the subjective history hopefully indicates that sensory symptoms are primarily in the median nerve distribution in the hand, but you may occasionally get people that will report that symptoms radiate a little bit proximally up the forearm, maybe they feel pain in the shoulder, then it'll be your job to determine, is this a possibility of a double crush injury, is something going on at the neck, could this be two separate issues?
00:12:20
Speaker
Maybe they've got carpal tunnel syndrome and some musculoskeletal shoulder pain and or tightness. So it's not a definitive finding in carpal tunnel syndrome to have proximal pain. But I would say in my experience, proximal symptoms aren't enough to have me rule out carpal tunnel syndrome. I've seen it pretty frequently that people will report some proximal symptoms.
00:12:41
Speaker
Another common finding is that sensory
Staging and Severity of Carpal Tunnel Syndrome
00:12:44
Speaker
symptoms usually precede motor symptoms, so tingling, maybe progressing to numbness is more common before someone reports weakness.
00:12:52
Speaker
Weakness from carpal tunnel syndrome should be mostly at the abductor pollicis brevis or median innervated muscles in the hand. You shouldn't be getting weakness of median innervated muscles in the forearm.
00:13:05
Speaker
If you do, now you're thinking maybe anterior interosseous nerve injury or maybe something going on more proximally. One quick check for this could be looking at the OK sign, asking if someone can touch the tip of their index finger and the tip of the thumb to make a round O for the OK sign.
00:13:23
Speaker
If that flattens out and they're not able to do it, that's suggestive of a difficulty using flexor digitorum profundus and flexor pollicis longus. Innervation is via the anterior interosseous nerve, and that's proximal to the carpal tunnel. So someone can't do the okay sign, you're not thinking that it's carpal tunnel.
00:13:42
Speaker
That's suggesting that the lesion is proximal to the carpal tunnel. Stages of carpal tunnel syndrome. Multiple authors have recommended staging carpal tunnel syndrome as mild, moderate, or severe.
00:13:53
Speaker
As someone who's performed many diagnostic tests on patients with carpal tunnel syndrome, I think this is pretty reasonable to stage it in terms of clinical severity. And for the most part, the clinical severity does match up to what you're going to find on the EMG.
00:14:07
Speaker
I've got a couple references I'll put in the show notes, and I think the references for the most part agree on the stages of carpal tunnel syndrome. Depending on the reference, they'll either call it mild, moderate, or severe, or first, second, and third stages. Those are essentially synonymous.
00:14:22
Speaker
Mild carpal tunnel syndrome would be mostly symptoms at night with no motor symptoms and or just intermittent symptoms. So here we're thinking symptoms come and go, they're mostly at night, no motor symptoms.
00:14:37
Speaker
moderate or second stage of carpal tunnel syndrome, you're going to be thinking daytime symptoms, symptoms are more constant, and maybe you get some hand clumsiness. So now it's encroached from nighttime into the daytime, maybe some clumsiness as well.
00:14:52
Speaker
Key thing here though, if you actually look at the thumb, we don't see any atrophy of the thenar muscles. So we don't have any true axon loss yet, which puts it in a moderate category instead of severe.
00:15:05
Speaker
The clumsiness from a pathology perspective or a nerve anatomy perspective could be due to either the decreased sensation, where the patient doesn't have the tactile information and they feel clumsy. It's very common for someone to say, I can't pick up a coffee cup in my affected hand.
00:15:21
Speaker
i have to use my other hand to help support the coffee cup. So it could be from lack of sensation. The clumsiness could also be if there's demyelination of the media nerve, so much so that there's a conduction block.
00:15:34
Speaker
Some of the action potentials are getting blocked to reaching the thenar muscles, and so you don't get a full contraction and you don't have a full signal getting to the thenar muscles. You can then, you would see weakness, but there wouldn't be any muscle atrophy because the neuromuscular junction is still intact. So clinically, you would not see any muscle wasting of the thumb. That's a key consideration.
00:15:57
Speaker
Reason that's a key consideration because the hallmark of the third stage or the severe stage is atrophy of the thenar eminence. And I'll tell you as an EMG-er, as soon as I see atrophy really anywhere, I will sit up and take notice.
00:16:11
Speaker
Not that I would be bored before I see atrophy, but atrophy is a hard finding that really tells you there's some amount of axon damage and or that there's been disruption of the neuromuscular junction.
00:16:22
Speaker
The muscle stays viable and healthy via that connection from the neuromuscular junction to the muscle and that release of acetylcholine across the neuromuscular junction. Once that's been disrupted, very quickly, you're going to see atrophy. So rapid atrophy, you're immediately starting to think this is a lower motor neuron condition.
00:16:44
Speaker
and there's been axon loss and or disruption of the neuromuscular
Differential Diagnosis and Evidence-Based Diagnosis
00:16:48
Speaker
junction. In this stage of carpal tunnel syndrome as well, if there's atrophy of the thenar muscles, sensory distribution or sensory symptoms might actually progress from tingling towards numbness because if we've got complete axon damage here, we're not getting a sensory signal coming back in.
00:17:05
Speaker
The tingling we get when there's demyelination, maybe some conduction block, is because we're getting some sensory information, but it's not all of the sensory information. We have a tough time processing that. But if there's no sensory information coming in at all in cases of severe carpal tunnel syndrome, we're going to feel numbness in the distribution of the median nerve.
00:17:26
Speaker
Let's move on to thinking about differential diagnoses for carpal tunnel syndrome. Really, you're thinking any conditions that may cause motor and or sensory disturbances in the hand. We know that carpal tunnel syndrome is the most common focal neuropathy, but we should have other conditions on our radar that we're at least going to screen for and rule out.
00:17:45
Speaker
One thing right off the bat, especially being a neuro person, I want to rule out any central causes of hand numbness, tingling, and weakness. A relatively easy or straightforward way to do this is to perform your upper motor neuron screen.
00:17:57
Speaker
So you'll be looking at your Hoffman's, your Babinski, checking your reflexes, maybe looking at tone. All your upper motor neuron findings should be normal if it's truly carpal tunnel syndrome.
00:18:08
Speaker
So you can rule out possible central causes such as stroke, multiple sclerosis, cervical myelopathy with your upper motor neuron screen. Now, again, as someone who maybe has a central condition, their background, their subjective history, probably not going to be consistent with carpal tunnel syndrome. So you may already be leaning away from carpal tunnel syndrome based on patient history.
00:18:29
Speaker
However, the upper motor neuron screen is so quick and it gives you a high yield. Even if you're thinking based on history, this is carpal tunnel syndrome, I'd recommend doing your upper motor neuron screen. Go ahead and rule out possible central causes.
00:18:42
Speaker
Rule out upper motor neuron conditions. Now, more likely, if someone comes in with a history that's suggested of carpal tunnel syndrome, your differentials are going to be more along the lines of other lower motor neuron conditions or other peripheral nerve conditions.
00:18:57
Speaker
Maybe those such as brachial plexopathy, cervical radiculopathy, peripheral neuropathy, especially in cases where maybe there's additional medical conditions such as diabetes, where maybe multiple nerves could be affected. Here you're looking more at distribution of sensory and motor findings, and you're looking for patterns.
00:19:15
Speaker
So if you're not having sensory findings that are isolated to the median nerve, and if you're getting motor weakness that doesn't match up with median nerve innervation in the hand, and maybe you have reflex findings, you have diminished reflexes in a cervical radiculopathy pattern, then maybe you're shifting and thinking some of the other conditions may be more likely than carpal tunnel syndrome. Once you've kind of ruled out some competing diagnoses, how do you actually go about ruling in carpal tunnel syndrome?
00:19:43
Speaker
We're going to use a combination of the patient history and clusters of clinical exam findings. Keeping in mind there's no single best test for carpal tunnel syndrome. You'll see in the literature, and you may be familiar with Tenelle sign, Phelan sign, or mentioned, the evidence suggests that in isolation, these are pretty clinically useless.
00:20:02
Speaker
And maybe that's a hot take, but that's what the evidence is suggesting. When I would do him EMGs, I would document that I did Tenelles and Phelans, but those in isolation never shifted what I thought was going on.
00:20:14
Speaker
It was just one of those, I'll do it as part of my exam, and we'll see that the evidence does recommend phalens, but more to look at prognostic outcomes, but we're not going to hang our hat on, do we have a positive Tenels or phalens?
00:20:27
Speaker
Instead, we've got some test item clusters, and we've got some clinical practice guidelines that we're going to lean on. The first kind of test item cluster was published by Wehner et al., and they had a list of five items that you could look at to help rule in carpal tunnel syndrome.
00:20:44
Speaker
And getting back to the concepts of evidence-based practice, if all five tests are positive, it gives you a positive likelihood ratio of 18.3. And if four of the five are positive, it gives you a positive likelihood ratio of 4.6. What does that mean? Well, hopefully you remember from evidence-based practice, highly sensitive tests help you rule out conditions. That's your snout.
00:21:06
Speaker
Highly specific tests help you rule in conditions. That's your spin. Likelihood ratios build upon both of these and give you a more powerful way of using the evidence. And what you do is you'll take your pre-test likelihood,
00:21:18
Speaker
Here we've set it at 14%, giving the global prevalence. We may shift that upward depending on our practice location, whether our patient is female, obese, and or between the ages of 40 and 60. Then, if your positive likelihood ratio is 18.3, you get out something called a nomogram,
00:21:36
Speaker
You draw your line from pretest likelihood through the likelihood ratio, and that then shifts your post-test probability up to where you think, okay, I'm now at a point where I can go ahead and think I've ruled this condition in and I'm going to start treatment.
00:21:50
Speaker
So five out of five, very high positive likelihood ratio. Four out of five, still a pretty good positive likelihood ratio where it's going to shift your thinking that this person could in fact have carpal tunnel syndrome.
00:22:01
Speaker
Test item clusters include a symptom severity score greater than 1.9, and I've included the study in the show notes so you can read more about the specific test items. So symptom severity score greater than 1.9, positive flick sign, a wrist ratio index greater than 0.67,
00:22:20
Speaker
And the wrist ratio index real quickly is looking at the size of the carpal tunnel, considering that our predisposing factor in developing carpal tunnel syndrome would be an anatomically smaller carpal tunnel. And the wrist ratio is measured by dividing the anterior-posterior through the medial lateral wrist dimensions in centimeters with a caliper. So we've got symptom severity score,
00:22:42
Speaker
We've got flick sign, we've got wrist ratio, and then we've got age greater than 45 years is the next one. And then diminished sensation in the top of the thumb, so the kind of the pad of the thumb, compared to the thenar eminence or the muscle bulk of the thumb.
00:22:59
Speaker
Those are your five. If all five are positive, positive likelihood ratio of 18.3. If four to five are positive, positive ratio, positive likelihood ratio of 4.6. There's also been some updated recommendations. JOSPT published a clinical practice guideline for carpal tunnel syndrome in 2019 that mentions not only the Wehner et al. test item cluster, but adds some additional tests.
00:23:23
Speaker
And here again, I think if we consider evidence-based practice where we have our pretest likelihood, Once we've ruled out competing diagnoses and have stacked multiple positive findings arguing for carpal tunnel syndrome, we're probably getting to the threshold for treatment. And we're going to talk about treatment next because we'll see that overall, there's really no risk to initiating conservative treatment. regardless of clinical stage of carpal tunnel syndrome. So once I don't think we have to move very far to get to a treatment threshold because the risk reward does favor treatment and conservative measures.
Diagnostic Tests and Treatment Thresholds
00:24:00
Speaker
If you're talking about surgical intervention, we probably need to get more definitive in terms of the diagnosis.
00:24:05
Speaker
But to start someone out with risk bracing, the treatment threshold here is actually pretty low.
00:24:16
Speaker
So let's talk about additional testing that may be needed, especially if you're considering, is surgery possibly indicated? Two main additional testing measures or diagnostic tests are going to be electrodiagnostic testing and ultrasound. Electrodiagnostic testing, consisting of nerve conduction studies and electromyography, really going to be considered the gold standard.
00:24:37
Speaker
It's going to assess the speed of conduction and the function of the median nerve across the carpal tunnel, but it's also going to help to rule out cervical radiculopathy and other competing neuropathy. So it's excellent at ruling in carpal tunnel syndrome, and it can help rule out competing diagnoses as well. Keep in mind that EMG and nerve conduction studies is highly specific.
00:25:01
Speaker
So if we get a positive test, we can really say, yes, this person has carpal tunnel syndrome, and it's great at quantifying the extent of damage. It'll pick up, is this demyelinating? Is this axon loss? Keep in mind though, electrodiagnostic testing is not highly sensitive, so you could get some false negatives. That's not a huge problem though, because if someone comes back as negative for carpal tunnel syndrome and they don't have any other abnormalities found on their electrodiagnostic test, there's no risk to initiate conservative treatment for carpal tunnel syndrome. And you know that from a physiologic perspective, the median nerve's in good shape, so you can go ahead and initiate conservative treatment for carpal tunnel syndrome.
00:25:43
Speaker
Ultrasound's the other test that's gotten more traction in the evidence. The nice thing about ultrasound is it's less invasive, less expensive than electrodiagnostic testing. Potential drawback with ultrasound is you can't really assess for peripheral neuropathy or cervical radiculopathy, but if you're pretty convinced that you've ruled out these other conditions, Ultrasound could be very helpful in terms of ruling in carpal tunnel syndrome.
00:26:07
Speaker
Clinically, you're thinking about referring for electrodiagnostic testing and or referring to the physician as soon as you see someone or you're working with someone with severe carpal tunnel syndrome. So if you're seeing that thenar atrophy, you can go ahead and initiate conservative treatment, but that needs to be a referral out. Keeping in mind that as soon as we see that atrophy,
00:26:29
Speaker
That tells us there's axon loss, there's a disruption of the neuromuscular junction. We need to get that patient referred out because surgery is going to be indicated. The other cases where we're going to refer out is if we're conservatively treating mild to moderate carpal tunnel syndrome and it's not responding well, we need to go ahead and refer out.
00:26:48
Speaker
And this is the treatment or the decision making algorithm is mentioned in the JOSPT article. So if we've got mild to moderate carpal tunnel syndrome, we can keep those within physical therapy practice, treat conservatively.
00:27:01
Speaker
But we're going to refer out if conservative treatment's not working. And we're going to refer out if we see severe carpal tunnel syndrome where there's thenar atrophy. So let's talk about how we're going to approach treatment.
00:27:14
Speaker
At baseline, our first treatment's going to be a wrist orthosis or a wrist brace for night use and setting that brace at or near a neutral position. I distinctly remember a lot of off-the-shelf wrist braces I used to get in the clinic, and unfortunately, they would be set up in a little bit of wrist extension, like 20 to 30 degrees of wrist extension. So immediately, we would go in there and push that little metal piece or that little plastic piece down to really put that wrist in a neutral position. What we're wanting to do is we're wanting to keep the wrist in a neutral position for when the person's sleeping at night.
00:27:48
Speaker
We're not trying to put them into wrist extension. We're definitely trying to keep them out of wrist flexion. And the thought being that if everyone sleeps kind of curled up at night and puts pressure on the median nerve, that wrist brace puts them in an offloaded position, and that should help take some pressure off the median nerve. So regardless of whether you're working with someone with suspected mild, moderate, or severe carpal tunnel syndrome, right off the bat, you can put them in a wrist brace, definitely educate them on wearing schedule for night use, educate them on skin checks, but there's really minimal risk of any skin breakdown or adverse events.
Surgical vs. Conservative Treatment Options
00:28:23
Speaker
This is why I said earlier I think the threshold to actually start treating is very low. If you've ruled out competing conditions, you have some with carpal tunnel syndrome, evidence says get them in a wrist brace to start out.
00:28:35
Speaker
If you're dealing with cases of mild to moderate carpal tunnel syndrome, the clinical practice guideline does suggest that you can consider other treatments, such as er ergonomic interventions, interferential current, superficial heat, phonophoresis, manual therapy, and or exercise.
00:28:52
Speaker
Keep in mind, though, these are all rated as C-level evidence, so it's really up to you. There's not great evidence. It's a you can do this. I'd encourage you to think about possible treatment costs, risk benefit, utilizations of services. All of these are good things to keep in mind if you're deciding on other conservative measures. They may be appropriate, but these are all rated as C-level evidence.
00:29:17
Speaker
Now for those patients that don't improve with conservative measures and for those cases of severe carpal tunnel syndrome, so we've got that thenar atrophy, we're going to refer out to the physician. Really, we're thinking this person is probably going to need a surgical intervention.
00:29:32
Speaker
Depending on your practice area, maybe you can be the one that refers out for electrodiagnostic testing, and that would be fine. But keep in mind, if you're the referring provider, you now need to manage what comes back with the test results and where that patient's going.
00:29:45
Speaker
So from an overall patient management perspective, referring to the physician to then possibly pursue surgical intervention might be more reasonable. But again, if you feel comfortable and you're in a setting where you can refer out for electrodiagnostic testing, if you see that thenar atrophy, that's really what needs to happen so we can quantify how severe the damage is confirm that it's carpal tunnel, and really get the patient lined up for surgery. Now, what outcomes do we see with carbotunnel syndrome? Unfortunately, and I say unfortunately because I'm a physical therapist and i work hard to try and prevent surgery, but unfortunately more than 50% of patients who start on non-surgical management progress to surgery within a year. That's not saying don't do conservative
Prognosis and Treatment Outcomes
00:30:29
Speaker
measures.
00:30:29
Speaker
I just think this is helpful to know that the general course of this condition based on our best evidence now seems to be a progression towards surgery with most patients doing really well after surgery.
00:30:40
Speaker
There are some prognostic indicators for patients who may not do as well with conservative measures. So these are good to keep in mind that if your patient presents with some of these prognostic factors, you might be thinking, well, this person may not do as well.
00:30:54
Speaker
These prognostic factors include greater intensity of nighttime symptoms, thenar atrophy, more than one failed prior conservative treatment, so they haven't responded well to non-surgical intervention, a positive phalanx test,
00:31:08
Speaker
and higher scores on the Boston Carpal Tunnel questionnaire symptom severity, and also symptoms greater than a year. These all make intuitive sense, and you can memorize all of those, or I think we can conceptualize this as patients who have a higher severity, irritability, and whose symptoms have been around longer. aren't going to do as well with conservative measures. That makes a lot of sense. I don't want to digress too far into pain neuroscience, but this also may be a case that the nervous system has changed, whether peripherally and or possibly centrally, and so conservative measures may not be as beneficial at this point as well, and really getting pressure off the nerve is what's needed.
00:31:47
Speaker
According to the Cochrane Review, they were not able to determine a clear difference between corticosteroid injection and surgery in terms of outcomes, so that's something to keep in mind. Not that we as PTs will be doing the injection, but in terms of patients thinking about what to do, corticosteroid injection and surgery may have comparable outcomes. In terms of overall outcomes comparing surgery to...
00:32:09
Speaker
splinting and conservative measures surgery has a higher rate of clinical improvement compared to splinting however surgery may or may not be more beneficial for splinting in terms of quality of life and hand function This is really interesting to me because from a face perspective,
00:32:26
Speaker
It would make sense that you do a carpal tunnel release, you open up more space, you remove compression on the nerve, and things should be a lot better across the board. If it's a demyelinating condition, the nerve's going to remyelinate.
00:32:37
Speaker
If there is some form of axon damage, but everything's in continuity, you would expect things overall to get better. This really, to me, emphasizes that carpal tunnel syndrome is a syndrome that and there's associated environmental, occupational, and personal factors, and that there could be other components to what constitutes a good recovery. So I would really advise, no matter how you've labeled the severity of carpal tunnel syndrome of the patient you're working with, really think about looking at how you're going to measure improvement. Again, I'd refer you to the JOSPT clinical practice guidelines. They have a good discussion of ways to look at where the patient's at now and how to measure improvement.
00:33:14
Speaker
But really think about looking at severity of symptoms, not just from a tingling, numbness, pain perspective, but also a quality of life perspective. Get a good sense of, are my interventions working? And really, this is just good clinical practice. This applies to anyone you're working with, not just carpal tunnel syndrome.
00:33:32
Speaker
Keep your ICF model in mind. We want to be thinking about that, and we'd like to be making improvements across the ICF continuum, not just focusing on body structure and function.
Summary and Conclusion
00:33:42
Speaker
To summarize, then, what we've talked about with carpal tunnel syndrome is the most common focal entrapment neuropathy, with prevalence estimated to be around 14% or so globally, with incidents or new cases about 1% to 5% per year. CTS, or carpal tunnel syndrome, is going to be more common in females,
00:34:00
Speaker
in patients who are obese and most common in the age ranges between 40 and 60. the diagnosis of carpal tunnel syndrome is going to be made via combination of history and clinical exam and you want to make sure you're ruling out competing diagnoses while ruling in carpal tunnel syndrome i've mentioned your upper motor neuron exam and that's helpful in ruling out central conditions such as stroke multiple sclerosis cervical myelopathy And the nice thing about the upper motor neuron screen is that in most cases, doesn't take you very long to do and gives you really valid information. Anecdotally, there's been times where I've been going too quickly clinically and keeping the upper motor neuron screen in there has helped me catch some things that I otherwise would have missed.
00:34:41
Speaker
So do your upper motor neurons screen to rule out any central causes, then consider how you're going to rule out competing peripheral nerve conditions and or lower motor neuron conditions by looking at the distribution of symptoms and really using test item clusters to rule in carpal tunnel syndrome.
00:34:56
Speaker
For staging, we're going to consider carpal tunnel syndrome as existing as mild, moderate, or severe. And for all these stages, we're going to start out with a wrist orthosis set to neutral for night use, always reasonable to initiate conservative measures. But as we're progressing to moderate and severe, we're thinking about physician referral. And we're keeping in mind that the evidence suggests that 50% or more, or even a little higher than that, started on conservative measures will end up progressing towards surgical intervention.
00:35:25
Speaker
Thanks for listening to the NeuroPowerHour. I'm your host, Michael Powers, and I hope to catch you next time continue learning. Thank you.