This is a common test performed in the clinic. The article goes into great detail (again not written about here because I don’t really have an opinion about the technique) of how to perform the test. I highly recommend reading the article for all health care practitioners that care for patients with spinal pain.
- “neuropathic pain (NeP) as “pain caused by a lesion or disease of the somatosensory system”
This is a great start to what will be a good read. If I were to say this to most PT students that come into my clinic, I would get the “Bambi in the head light look”. The fastest way to say this is that neuropathic pain is a pain that may be coming from a structure that is innervated (has nerves). This doesn’t really tell me anything though.
- the presence of NeP has been linked with poor recovery, along with higher health care costs and lower quality of life.”
This makes sense to me. If you have pain, that is coming from somewhere, you are more likely to require more treatment than someone that has pain coming from nowhere and are less likely to enjoy your life than someone that is pain-free.
- “The diagnosis of NeP typically consists of a thorough history and an extensive neurosensory examination to identify both positive (exaggerated responses to stimuation, such as allodynia) and negative (various sensory and motor losses) signs…usually performed by a specialist, requires a lot of time to complete, and in many regions involves a long waiting period for the consultation”
As a Doctor of Physical Therapy, I happen to be said specialist. This type of patient typically takes longer to evaluate than someone that only consists of weakness or deconditioning. There is much more to look at. I don’t know if I would say that it involves a long waiting period for the consultation. I think that this has more to do with a person’s type of insurance regarding wait time. For instance, if you are willing to pay out of pocket for the assessment, and pay what the “chargemaster” (an inflated charge board that no one ever really pays…unless they can’t afford insurance) states, then I am sure that I can fit you in for a $400-600 evaluation tomorrow. (We don’t actually make that much for an evaluation, but insurance companies would love you to believe that we do).
- “The straight leg raise (SLR) test is the most commonly used neurodynamic test for the lower extremity. The slump test is another…”
The SLR test is easy to perform and most physicians are aware of its implication in discogenic pain. I include it when I am trying to make a point to physicians and insurance companies regarding a possible pain generator. I prefer to use the slump test because it is easier for me to test when I already have the patient sitting in the chair testing lower extremity strength (testing nerve electrical power). If I have a positive slump test, then I will typically perform a SLR test in order to “paint a better picture” of the patient to the insurance company.
- “the SLR test demonstrated 100% specificity in patients clinically diagnosed with NeP.”
I don’t expect the lay person to understand this because this is such a difficult concept for most physical therapy students to understand. Basically, if you have a positive test, then your symptoms may be coming from the nerve. If you have a negative test, then we can effectively rule out nervous tissue pain.
- “Key components of the clinical exam included pain (location, behavior, quality), motor function (strength/weakness, reflexes), sensory function (mechanical/thermal sensation), autonomic function (sweating, hypotension), and the SLR test”
You’d be surprised (or may you wouldn’t if this also describes you) regarding how many patients are surprised that a PT would take their blood pressure. I read a statistic years back regarding the following: 50% of patients seen in an outpatient clinic have undocumented hypertension. I can’t tell you how many times I have had to stop a session to call a doctor to inform them of a patient’s hypertension. I had one patient argue with me years ago that he wasn’t there for blood pressure issues, but to have his pain fixed. Unfortunately, his BP was higher than the maximal allowable threshold for exercise and I sent him back to the doctor. (Mind you, my current state is not a direct access state, which means that the patient had to be referred by someone prior to coming to therapy). The patient was apologetic the next session when the doctor told him what the numbers could mean regarding DEATH! That’s right…I save lives. Just kidding, but not really. If you see a therapist, your blood pressure should be checked at least on the first visit. If it is not, question the intentions/ignorance of the therapist. Could be oversight on the therapist’s part. I used to be that therapist.
Also, your sensation and strength should be tested in certain circumstances. Again, just ask your therapist why/why not the above testing was/wasn’t completed. There should be a good rationale for the answer. We love to teach…at least I do.
- The authors of the article did an excellent job of describing positioning for testing, so if you are in health care and would use the slump test, it is a good refresher. Highly recommend it.
- “…designated as positive if the following conditions were met: (1) pain or sensations were reduced with neck extension, and (2) there was a right-to-left difference in pain distribution or there was a difference between right and left knee extension.”
This is something that most PT students, and I must surmise that new professionals miss while in the clinic. This is the small details of the test. Is there a loss of knee extension on one knee? The only way to know is to have someone teach it to the student or for the student to go out on his/her own to learn it. What profession are you in? In your profession, who is the best in your workplace? What separates that person from anyone else in the workplace? Usually it is initiative, persistence, self-learning, confidence, experience, etc. This same thing can be said for the PT profession. We aren’t all born with these characteristics; they are honed over years of working and studying. If all we do is work, then we may gain experience, but the experience may be that of missed details.
- “From these data, a difference of 10 degrees or more was used to indicate a positive slump test component.”
Again, small details. Many students are not looking at the angle change in the slump test and although 10 degrees is small when eye-balled, it can be huge when it is the difference between being able to stretch out and push the gas pedal with or without pain.
- “very little can be interpreted when the slump test is positive but the pain does not extend below the knee.”
Students need to know this stuff! We learn in school that if it produces pain, that the test is positive, especially if the pain is reduced when the patient is then asked to look up. This means little in terms of telling us important information.
- “The sequential combination of the 2 tests provided an effective means of ruling out those without NeP and ruling in a large proportion of those with NeP.”
This is important for students and PT’s to understand. If the patient has no pain production with the slump test, then “nerve pain” can effectively be ruled out due to the small rate of false negatives. When a patient has pain below the knee, then “nerve pain” can be ruled in.
This was an excellent article going more in depth than anything we learn in school. I have been using this test for years and have slowly incorporated the information into practice over the years, but I now know that there is a good reason to look at the knee extension change. When studying the McKenzie Method (MDT), we are taught to look at the angle changes when performing these “dural tension” based tests. It is informal when taught in the course, but here is the formal information.
Quotes taken from:
Urban LM. Macneil BJ. Diagnostic Accuracy of the Slump Test for Identifying Neuropathic Pain in the Lower Limb. J Orthop Sports Phys Ther. 2015;45(8):596-603.