OCS Field Guide: A PT Podcast

Neck Pain CPG: Red Flags, Imaging, and Outcome Measures

December 06, 2020 David Smelser and Austin Kercheville Season 1 Episode 10
OCS Field Guide: A PT Podcast
Neck Pain CPG: Red Flags, Imaging, and Outcome Measures
Show Notes Transcript Chapter Markers

The neck pain CPG expects physical therapists to screen for red flags, but it doesn't give much detail on how to do that. Dr. Austin Kercheville fills in those gaps with this discussion of neck pain red flags and indications for imaging.

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Hello and welcome back to another episode of OCS Field Guide. Before getting into today’s podcast, we want to say a big “thank you” to all of you who have supported us thus far by telling your friends, liking, sharing, and subscribing to our material. And an even bigger thank you to our new Patreon subscribers who are helping us defray our monthly costs in exchange for some exclusive content and perks. 

Today we will be continuing our series on the 2017 Neck Pain Clinical practice guideline update covering differential diagnosis and red flag screening, imaging criteria, and outcome tools related to neck pain. 

First lets cover differential diagnosis and red flags. Similar to what we know about low back pain, the CPG states: “There are numerous anatomical structures in the cervical region that can be sources of nociception, including zygapophyseal joints, vertebrae, muscles, ligaments, neural structures, and the intervertebral disc. However, evidence is lacking to support the hypothesis that these pathoanatomical features are a primary source of mechanical neck pain across the age spectrum in the majority of patients. The source of neck symptoms may on occasion be something more serious; therefore, screening for clinical conditions such as cervical myelopathy, cervical ligamentous instability, fracture, neoplasm, vascular insufficiency, or systemic disease is required” end quote, though I’ll add infection to that list. Unfortunately, the same level of research regarding red flags, such as David presented in the low back pain red flag episode, is not present for a lot the red flags that surrounding these conditions. So much so that the CPG does not even list red flags like the low back pain CPG does. However, I’ve pieced together what you should need to know from what they do include, some resources they refer to, and some general information you should remember.

First we’ll discuss cervical myelopathy. The CPG states “clinical tests used in the diagnostic process for cervical myelopathy generally have low sensitivity; therefore, they should not be used when screening for a diagnosing this condition.” And that rather, MRI is useful in determining the diagnosis of cervical myelopathy. And while this is true, there is a more sensitive clinical prediction cluster derived by Cook et al in 2010 that is likely useful to know and follow if you are suspecting cervical myelopathy. Though it has not been validated, at the very least, it will help us cover which signs and tests to know. The cook et al CPR describes 5 criteria which include: gait disturbance, positive hoffmann’s test, positive inverted supinator sign, positive Babinski test, and age over 45 years. Having one out of 5 of these criteria is actually relatively sensitive. Meaning if a patient DOES have CM, they will likely have at least one of these, but if they have none of these, they probably don’t have cervical myelopathy. This also means that if you don’t look at all 5 criteria, any individual negative test without negative tests in each of the other criteria doesn’t really mean anything. 

Conversely, having one out of the 5 does not mean someone does have CM, for instance, you obviously don’t need to refer out just because your patient is over 45. Though a positive in any of the other tests without a correlation to an existing diagnosis should prompt further investigation. In this retrospective study, where the pre-test probability of having CM was around 30%, 3/5 of these criteria positive has a positive likelihood ratio of 30 and a post-test probability of 94% of having cervical myelopathy, while 4/5 had an infinite positive likelihood ratio and a post-test probability of 99%.

Next, especially before performing manual therapy interventions, specialists need to be aware of the possibility of upper cervical ligamentous instability and cervical arterial insufficiency. However, none of the tests for either of these conditions, including imaging, are very sensitive and thus cannot be used for effective screening of everyone you on whom you will perform manual therapy. The CPG thus recommends using the 2012 IFOMPT framework for examination of the cervical region for potential of cervical arterial dysfunction prior to orthopaedic manual therapy intervention for a decision-making tree to assessing these factors. This will be linked in the notes because it’s a good document to check out since they mention using it specifically. Rather than read long lists of risk factors and associated red flags for these two conditions which could be a waste of time, I’ll summarize the overall takeaways and then direct you to pages 13 and 14 of the 2012 IFOMPT document for more detailed lists. For upper cervical ligamentous instability any history that could cause ligamentous or bony damage to the upper cervical spine should be considered a risk factor for such as trauma (which we will explore further in our imaging discussion), congenital collagenous issues like Down’s syndrome or Ehlor’s Danlos, throat infection, inflammatory arthritis conditions such as Rheumatoid arthritis or ankylosing spondylitis, and recent head/neck/or dental surgery. Red flags to consider for cervical instability include S/S such as needing to hold your head up, feeling of instability, severe limited ROM, or signs of cervical myelopathy should clue you in to potential upper cervical instability. For carotid and vertebrobasilar insufficiency, you should look out for Hx of issues affecting the cardiovascular and cerebrovascular system such as HBP, hx of TIA, clotting disorders, and systemic issues that could damage arteries such as diabetes and prolonged corticosteroid use. And then look out for red flags including any signs of TIA or CVA or the classic “5 d’s and 3 n’s”: dizziness (lightheadedness), diplopia, dysarthria, drop attacks, dysphagia, nausea, nystagmus, or facial numbness. 

The CPG stays pretty vague on red flags for the other diagnoses mentioned, but I’ll remind you of general red flags for spinal malignancy such as: previous Hx of cancer, age over 50, pain not alleviated or with rest, failure to improve with conservative management, and unintentional weight change. And remember S/S of infection, inflammatory or systemic disease such as fever, elevated heart rate and blood pressure, and general fatigue. 

 Next we’ll cover when imaging is going to be necessary for neck pain patients. 

First, when stable adult patients present following traumatic onset of neck pain, Canadian C-spine Rules or the NEXUS criteria to decide when imaging is appropriate. 

The Canadian C-Spine rules consists of a decision-making tree with high risk factors that indicate immediate decision to perform imaging, low risk factors that allow for safe ROM assessment, and finally a ROM assessment if the patient is in fact low risk. The high risk factors that indicate imaging include: (1) age over 65; (2) a dangerous mechanism of injury (this is defined as: Fall from =/> 3 feet; or 5 steps; an Axial load to the head; MVA that was high speed (>60mph or 100km/hr), or involved rollover or ejection; any motorized recreational vehicle accident; or if the patient was struck by a vehicle riding a bicycle); and the 3rd high risk factor is having paresthesias in the extremities. Any of these three factors leads you to imaging. IF they have none of the high risk factors, you assess the patient for these low risk criteria that could allow you to safely assess ROM. (1) If the patient can sit in the emergency department, (2) Had a simple rear end MVA, (3) is ambulatory at any time, (4) has had a delayed onset of neck pain, or (5) does not have midline cervical spine tenderness. If they do NOT meet any of these low risk criteria, you cannot safely assess ROM and thus must send for imaging. If they do have any one of these factors, you can proceed to assessing ROM. If the patient is able to actively rotate the head at least 45 degrees in each direction, the patient is classified as low risk, and no imaging is required. 

Although the CCR has the best diagnostic accuracy, the NEXUS low risk criteria are also recommended. These dictate that imaging always be performed after a traumatic mechanism unless they meet these 5 criteria: (1) no posterior midline cervical spine tenderness; (2) no evidence of intoxication; (3) a normal level of cognition, orientation, and alertness; (4) no focal neurologic deficit; and (5) no painful distracting injuries. If they meet all of these criteria, imaging is not indicated. Remember, the CCR and the nexus criteria are tools to be used to determine need for imaging specifically after a traumatic mechanism of injury. You don’t need to refer out for imaging just because you patient is 65 and has neck pain. What it does mean is anyone over 65 who is involved in a motor vehicle accident should have imaging before treatment. 

Once you have determined the need for imaging, now we must use the American College of Radiology Appropriateness Criteria to determine which type of imaging is most indicated. We’ll link this document, which is quite informative, in the show notes, but I’ll give you the spoilers. Patients that have meet the aforementioned criteria for imaging are typically MOST indicated for a CT over radiographs because they more reliably identify fractures than plain films. The only exception is patients 14 years old and younger due to the greater radiation exposure, who should just get plain radiographs.

So let’s make this a little more practical and give an example of how the OCS might test this information. Say a 45 year old female who is a past patient presents direct access to your outpatient clinic the day after being involved in a motor vehicle accident. She is wearing a soft collar she was given her by a family member but did not go to the emergency department or see her doctor after the accident. She is alert and oriented. She reports pain in her neck and that she has been trying to keep it still to keep it from hurting more. However, she remembers in the past that having manipulations to her beck and neck had helped with a previous bout of neck pain.

Which of the following would be the most important information in determining next step?

a.     Pain level at 7/10

b.     Numbness and tingling in her R UE

c.     Positive belief that manipulation would help

d.     Positive shoulder abduction sign

Questions like this are tricky because your brain will recognize elements of other criteria you may have learned. Answer a is one of the factors that could indicate a poor prognosis in a patient with traumatic onset of neck pain, but does not tell you what you should do next. Answers C and D are both part of CPRs that could indicate specific interventions, manipulation or traction respectively. However, the most important question that must first be answered at this point in time is, is the patient appropriate for physical therapy intervention. The combination of a traumatic mechanism and B. numbness and tingling in the R UE by both the Canadian C-spine rules and the Nexus criteria indicate that the patient should undergo imaging, specifically a CT scan or radiograph. You may be tempted to say the patient should undergo MRI due to the neurologic findings, however in the presence of trauma, CT is the best way to evaluate for fracture or upper cervical ligamentous instability as a potential source of symptoms and should thus be performed first. 

This covers when to image and how to image for traumatic onset of neck pain. For patients without a traumatic mechanism of injury, those that can be classified as neck pain with mobility deficits, in the absence of red flags signs or symptoms no imaging is indicated. However, for patients whose symptoms classify as neck pain with radiating pain, The CPG states that patients who have normal radiographs but present with neurologic signs and symptoms should undergo MRI. However, the CPG goes on to say that MRI is the best image to evaluate non-resolving radiculopathy or progressing myelopathy, which seems to leave some room for trial of treatment in the presence of radiculopathy as long as there is not progressive neurologic deficit. 

Finally, we’ll cover the outcome measures. The CPG mentions a few different outcome measurement tools, but the 2017 update takes the time to mention that the NDI is by far the most extensively studied OMT over the range of neck pain conditions. So its safe to say you should just know the NDI well. 

The NDI should be easy to remember because it is very similar to the ODI. It is a 10 item questionnaire where each item is rated 0-5, where the higher number indicates higher disability. 

0-4 points (0-8%) no disability, 5-14 points (10 – 28%) mild disability, 15-24 points (30-48% ) moderate disability, 25-34 points (50- 64%) severe disability, 35-50 points (70-100%) complete disability.

The MDC and MCID for the NDI are both considered 5 points, or 10%, which is the same as the ODI. 

That wraps up the information that we’ll cover in this episode. The overall point you should take away is to be familiar with CCR and Nexus criteria, as well as ACR appropriateness criteria for imaging, and be familiar with common more serious pathologies that could masquerade as neck pain. Oh yeah, and remember the NDI.

Differential Diagnosis and Red Flags
Cervical Myelopathy
Ligamentous Instability and Arterial Insufficiency
Trauma, Imaging, and Fractures
Practice Question
Imaging for Nontraumatic Neck Pain
Neck Outcome Measures