Screen Shot 2015-12-08 at 8.19.26 AM.pngI read with interest this Johnson et al 2008 Manual Therapy by Dr. Johnson on a patient responding to manual therapy after having a (modified) positive vertebral artery test.  This article is not open access but feel free to contact me if you would like it @

The Case

The gist is a 24 year old female patient has a 1 year history of dizziness provoked by left cervical rotation and describes it as feeling of anxiety and difficulty communicating.

The clinician’s decision making prompted him to perform the modified vertebral artery test (VAT)—-which was negative to left—-but positive to right for concordant symptoms of dizziness/slow ability to communicate.

Therefore, he referred out for further investigation via duplex ultrasound—which was negative for any significant stenosis in carotids and vertebral arteries.

Considering the negative radiology report—he then proceeded to examine the cervical spine to identify other possible reasons for the symptomology—in this case, finding several tender points bilaterally in the upper trapezius, SCM, levator scapula and anterior scalene muscles.

Only strain-counterstrain techniques were performed—which resulted in a negative finding of modified VAT immediately, after several weeks and again at one year.


Overall, I think this is a great case to add to the literature on the limitations (false-positives) of the VAT and I appreciate the authors for taking the time to write it in a respected manual journal.

My big take home from this is :

  • from knowing the limitations behind the VAT,
  • a one year history of symptomology (it wasn’t stated in article why the patient finally sought care from physio—such as an exacerbation, etc)
  • — I wonder if clinical reasoning to refer out for duplex ultrasound due to positive VAT could be trumped by vascular testing (blood pressure, auscultation).

So my question to you is—

If this patient arrived to your clinic with the above symptomology and vascular examination unremarkable, in other words, blood pressure not elevated, negative bruits—-yes, this is a broad statement—

—-would you make the decision to proceed to a manual examination to confirm or refute your hypothesis that the symptomology is arising from a rotational vertebral artery dizziness condition PRIOR to having duplex ultrasound results?

Looking forward to hearing from you!  We can have more discussion in comment section.

Keep learning—Harrison




  1. Harrison,

    I think we all agree that the sensitivity (the ability to find out who is truly positive on the test) for vertebral artery testing is pretty bad. Matter of fact, I have heard it argued that the position of testing itself could lead to an adverse event so why would we choose to use a test that could yield the same adverse event as a given technique (cervical manipulation is usually the comparative intervention). Roger Kerry has done exceedingly good work in this area and a large part of our clinical reasoning process involves looking into the patient health history for factors of potential arterial compromise as you have suggested (HTN, hypercholesterolemia, known other PVD, smoking, birth control pill use, previous MI/CVA/TIA, etc). His article is here:
    Going back to this specific case, this person’s dizziness could have been cervicogenic from upper cervical dysfunction (clinical instability of Co-1, C1-2, or C2-3 could yield an afferent barrage into the trigeminocervical nucleus and yield bizarre symptoms due to trigeminal facilitation not the least of which could be dizziness). The dysarthric (can I call it that.. it wasn’t too clear what the communication deficits were in the paper) symptoms are questionably significant and I think it was the right call to refer to ultrasound. Thing is, cervical artery testing is a dynamic test if you will, purported to cause dynamic occulsion of the contralateral artery through rotation and end range hold. So if this is the case and they are getting symptoms when the artery is dynamically occluded and held at a functionally occluded position, does that match the same positioning of the ultrasound? I have had frustration with this in the past in that I have asked for ultrasound to confirm my suspicion of VBI but then the test always comes back negative. I have also had to specifically ask for vertebrals to get included as most dopplers just focus on carotids. My questions is if they are doing the doppler with the head straight, in which case its a drastically different test position than held cervical rotation which could explain the difference in this case report as well as many of my own personal experiences. For me, I think a pre-manipulative hold is the key and is most likely to catch people that are going to have symptoms with the thrust because they should get the symptoms in the pre-manip position. I mean, I have heard chad cook talk about research that showed that grade 4 oscillations yield more force through a segment than a quick grade 5 because your in and out and not banging away for 30 seconds… anyway, that’s a tangent. I share in your struggle with coming to a place where we can be confident with testing for VBI. If we every develop a test that is sensitive to yield good clinical utility, I feel like it should be called FSTSW test – “Finally something that stinking works”

    1. Steve,
      Ha! I love the FSTSW test comment! Yes…I”m sure we will keep waiting for that test for a long time.

      Thanks for the feedback and link to Kerry/Taylor’s paper. I really enjoy reading their work, and more recent work by Lucy Thomas and some more information on connective tissue conditions, such as this one by Giossi:

      Overall good points on the head/neck position with Dopplar. This will definitely alter the results, provide false negatives, etc. May not give any other pertinent data that we can’t use with bedside approaches in our own clinics…

      Through my training too, it is always said that mobilizations are never scrutinized as much as manipulation. This echoes your comment about some of the actual stress placed through the arteries with different approaches (even traction, full rotation, etc). Here is a good article too summarizing:

      Looks like we have a very common interest in this aspect of differential diagnosis/treatment. Let’s chat more about it soon!

      1. The article by Giossi is interesting. I can’t remember where I heard it but I do remember hearing something about the overall anomalies of the vertebral arteris in that the overall lumen diameter can’t be significantly different side to side in about 10% of the population which leads me to believe they would respond differently to VBI testing due to the anatomical variance possibly? The other paper by Thomas is great too, however it appears that the opinion about how using cardiovascular risk factor may not be helpful is different from that of what Kerry would suggest.. who’s right?… I also think taking relative risk with number needed to harm data is important to give cervical OMT perspective. Far more (multiple times more) people doe each year for GI bleeds secondary to OTC NSAID use than have an adverse event with cervical OMT.. educating the patient with that outcomes data I think puts some of the fear we have about cervical manual therapy into context.

      2. Great points. Not sure about the overall lumen diameter…not up to date on that info. But you would think that people will respond differently side to side (just like BP in L vs R brachiums).

        I think Kerry & Thomas show us that we still do not know who is at risk, but is multiple factors. Risk is always present in our treatments. If cover all bases in examination procedures, then you practice with least amount of risk necessary. But, I’m sure there arguments against even our risky treatments…manipulation / dry needling in particular….even though very low risk considering other healthcare approaches.


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