Physical Exam in Carpal Tunnel Syndrome

A 45-year-old woman who works as a professional baker with a specialty in birthday and wedding cakes presents with a six-month history of progressive numbness and tingling in the thumb, index, and middle fingers of her right hand. She noticed that her symptoms are worse at night and are accompanied by hand weakness and reports being right hand dominant. She denies any injury to the area and states "This is getting in the way of my work. I'm having a much harder time holding the tools that I need to use to decorate a cake." Her concurrent health history includes a five-year history of type 2 diabetes, hypertension, and dyslipidemia, obesity with a BMI of 38. Her current meds include Metformin and an SGLT2I, and ARB with a thiazide diuretic and a statin. 

When considering the diagnosis of carpal tunnel syndrome, which of the following would be one of the earliest physical exam findings?

A. Pain reproduced with forced wrist flexion held for 60 seconds

B. Diminished radial pulse

C. thenar atrophy

D. tingling of the fingers when tapping on the median nerve

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Transcript

Voiceover 0:03

Welcome to NP Certification Q&A, presented by Fitzgerald Health Education Associates. This podcast is for NP students studying to pass their NP certification exam. Getting to the correct test answers means breaking down the exam questions themselves. Leading NP expert Dr. Margaret Fitzgerald shares her knowledge and experience to help you dissect the anatomy of a test question so you can better understand how to arrive at the correct test answer. So if you're ready, let's jump right in.

Margaret Fitzgerald 0:57

A 45-year-old woman who works as a professional baker with a specialty in birthday and wedding cakes presents with a six-month history of progressive numbness and tingling in the thumb, index, and middle fingers of her right hand. She noticed that her symptoms are worse at night and are accompanied by hand weakness and reports being right hand dominant. She denies any injury to the area and states, quote, this is getting in the way of my work. I'm having a much harder time holding the tools that I need to use to decorate a cake. Her concurrent health history includes a five-year history of type 2 diabetes, hypertension, and dyslipidemia, obesity with a BMI of 38. Her current meds include metformin and an SGLT2i, an ARB with a thiazide diuretic and a statin. When considering the diagnosis of carpal tunnel syndrome, which of the following would be one of the earliest physical exam findings with this diagnosis? Would it be

Margaret Fitzgerald 1:54

A. Pain reproduced with forced wrist flexion held for 60 seconds

Margaret Fitzgerald 2:01

B. Diminished radial pulse

Margaret Fitzgerald 2:04

C. Thenar atrophy

Margaret Fitzgerald 2:06

D. Tingling of the fingers when tapping over the median nerve.

Margaret Fitzgerald 2:12

The correct answer is A. Pain reproduced with forced wrist flexion held for 60 seconds. Where do you start with this question? First, determine what kind of a question it is. And given that we're presented with a clinical scenario where the patient's history of present illness gives a number of risk factors for carpal tunnel syndrome, and then we're asked which one of the findings would most strongly support the diagnosis of CTS. This is actually an assessment question. Why is it assessment? Because we're gathering additional information about the patient. And first, some background information. Carpal tunnel syndrome, often simply abbreviated CTS since we love abbreviations, is a painful condition caused by compression of the median nerve between the carpal ligament and other structures within the carpal tunnel. This compression leads to entrapment neuropathy, causing symptoms in the distribution of the median nerve. The resulting symptoms are most likely caused by nerve ischemia rather than nerve damage. The most common CTS risk factor is repetitive motion. And this is a condition common in workers such as cake decorators. That's what she has here. People who do soldering for a line of work where they must constantly grab a small object. Of course, carpal tunnel syndrome is often found in people who use keyboards, which pretty much cuts across almost all lines of work these days. In this case, usually the carpal tunnel syndrome symptoms are bilateral, because of course, if you're using your keyboard a lot, both hands are involved in this. I had one patient in my practice who initially developed carpal tunnel syndrome symptoms in her right hand and then developed it bilaterally. She worked as a solderer and she had to solder, put a drop of solder on two different places in a certain electronic piece of equipment. How did she end up with it in her right hand and then both? She taught herself how to solder with both hands equally accurately, so she increased her productivity and got paid more. I'd be doing the same thing. And so it's always really, really helpful to say to the person who has carpal tunnel symptoms whether unilateral or builateral, while you're in the exam room, is say to the person show me what you do with your hands while you're working. And then that will give you an idea of what triggers the symptomatology, how things might be altered. I'm not saying that I know how to do that kind of work, but I very often, when I see somebody with CTS, include a referral to OT or PT so that they can learn how to do their line of work adaptively and not make their symptoms worse.

Margaret Fitzgerald 5:33

Carpal tunnel syndrome can also be part of a manifestation of systemic illness, such as sarcodosis. That is the minority. What's going to crop up on your boards? The most common, something like this cake decorating. Now, one of the things you might say to yourself, well, how the heck am I supposed to know what a cake decorator does? Well, you might watch an episode or two of the Great British Bake Off and you'll learn that. But sometimes it's just common sense. Think through, think through how somebody would be doing this line of work. And then when in doubt, if you really and truly don't know, like the woman who was doing soldering as part of her work, I had no idea what that would look like. But then when I asked her, show me what you do with your hands while you're working, I could really conceptualize well what was triggering the symptomatology she had. Carpal tunnel syndrome can also be seen transangently at the end of pregnancy and in people with untreated hypothyroidism. I doubt those will come up on boards because they're fairly exotic reasons for CTS. With those conditions, the CTS signs and symptoms resolve quickly when the underlying cause is no longer present. In other words, once the baby is born, generally within a few weeks, the CTS goes away. And usually CTS symptoms during pregnancy are in fact bilateral, and it's associated with swelling that's often seen in the hands and forearms during late pregnancy. And with hypothyroidism, once the TSH is back into a normal range for a few weeks, the CTS resolves.

Margaret Fitzgerald 7:24

Patients with CTS, the most commonly encountered peripheral compression neuropathy, usually report a burning, aching, or tingling pain radiating to the forearm with the distribution within the median nerve and occasionally to the shoulder, neck, and chest. Symptoms are often worse at night. One of the most common findings is acroparesthesia, and this is awakening at night with numbness and burning in the fingers. As with the diagnosis of many conditions, the clinician should be aware of when certain signs and symptoms occur, whether it's earlier or later disease. And that's one of the things we're being asked here is what would be an early finding in CTS? With this information in mind, let's take another look at the question. A 45-year-old woman who works as a professional baker with a specialty in birthday and wedding cakes presents with a six-month history of progressive numbness and tingling in the thumb, index, and middle finger on the right. She notices her symptoms are worse at night and are accompanied by hand weakness. She also reports being right hand dominant. She denies any injury to the area and states, quote, this is getting the way of my work. I'm having a much harder time handling the tools I need to decorate a cake. Her concurrent health problems include a five-year history of type 2 diabetes, hypertension, and dyslipidemia, and obesity with a BMI of 38. Her current meds include metformin, an SGLT2I, an ARB with a thiazide diuretic, and a statin. All right, I'm going to stop here for a moment and just go over her meds so that you're clear on them. Metformin for a drug class, technically it's a biguanide. It's the only biguanide that's used. And so we kind of forget what drug class it is. So just think of it as metformin, a product that helps sensitize an individual to the insulin their body is making. And SGLT2I, one of the glyflosin drugs like Canagliflozin, drugs like Invokana, Jardiance, et cetera, and ARB, a sartin suffix, med like thalmasartin or the like. And a thiazide diuretic, probably hydrochlorothiazide or perhaps Chlorthalidone. And a statin, those meds all have a statin suffix, atorvastatin, Rosuvastatin, et cetera. Their full technical name, drug class name is HMG COA reductase inhibitor. Do you wonder why we just don't, why we just call them statins? That's the reason why.

Margaret Fitzgerald 10:25

So back to the question. When considering the diagnosis of carpal tunnel syndrome, which of the following would be one of the earliest physical exam findings in this diagnosis? So why are we being asked about earliest physical exam findings? So we're picking up early disease. It's always better to pick up disease earlier. Would it be A. pain reproduced with forced wrist flexion held for 60 seconds? This is a description of Phalen's sign sign and is the correct answer. Keep in mind with when performing this physical exam maneuver to Phalen's sign sign, you're asking the patient to increase pressure within the carpal tunnel and is typically the earliest physical exam finding in CTS. And in fact, very often in super early carpal tunnel syndrome, the physical exam is really can be even normal, but we're nonetheless suspicious for this because of the history and the risk factor. Option B, diminished radial pulse. Well, clearly this is incorrect because if the radial pulse was diminished, it would be indicative of arterial disease, not nerve entrapment. This is a great example why knowledge of the pathophysiology of a given disease is important. Thenar atrophy, option C. That is not correct. And first of all, what is it? Thenar atrophy is the visible wasting and flattening of the thenar eminence, the fleshing mound found at the base of the thumb on the palmer aspect of the hand due to chronic compression of the median nerve. It's most often noted in advanced CTS. In other words, you're only going to see this in a patient after the nerve entrapment has been present for a protracted period of time. And I know this patient has had these symptoms for a number of months, but generally it's more like years of that before you see the thenar atrophy. By the way, thenar atrophy is sometimes incorrectly mentioned as thegular atrophy. And so it's important to know the difference there. And if you're still having a hard time conceptualizing that, quick Google image search of the theanar prominence and the palm of the hand, and then what the atrophy looks like, and all of a sudden this is going to come true to you. D, tingling of the fingers when tapping over the median nerve. This describes Tinell's sign. Think it through. Phalen's sign, you cause nerve entrapment by asking the patient to do a dynamic maneuver. With Tinell sign, the compression of the nerve is constant, and you elicit the sign simply by tapping over the median nerve. And what this means is more advanced disease than with Phalen's sign. Do people have positive Tinels and often have positive Phalen's and the other way around? Certainly, but that's because people often come in with moderately advanced CTS. With this question, specifically, one more time, every word in the question is important. And what this question particularly mentioned is earliest physical exam findings in this diagnosis. Key takeaway: as a nurse practitioner, you are now a diagnostician. And that's often one of the most challenging parts of this role transition. Knowing how common diseases unfold, directed by the conditions, pathophysiology with its earlier and its later findings. This is the key to honing your diagnostician skills.

Voiceover 14:39

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