Research Review By Dr. Josh Plener©

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Date Posted:

October 2020

Study Title:

Yes, we should abandon pre-treatment positional testing of the cervical spine

Authors:

Hutting N, Kranenburg HA & Kerry R

Author's Affiliations:

Department of Occupation and health, HAN University of Applied Sciences, Netherlands; Research Group on Healthy Aging, Allied Health Care and Nursing, Hanze University of Applied Sciences, Netherlands; Division of Physiotherapy and Rehabilitation Sciences, University of Nottingham, United Kingdom

Publication Information:

Musculoskeletal Science & Practice 2020; 49: 102181. https://doi.org/10.1016/j.msksp.2020.102181

Background Information:

Vertebrobasilar insufficiency (VBI) is an infrequent condition encountered by chiropractors and manual therapists in all disciplines, however, one must always be alert to the fact that these patients can walk into our offices. An approach that is used by some clinicians to help rule in or rule out a potential VBI includes cervical positional testing, which is thought to assess and determine the patient’s risk profile prior to performing cervical, high-velocity manipulation (1). This approach is also still being taught in some institutions, despite a lack of evidence directly establishing causality between SMT and cervical stroke. Further, the utility of these tests is unclear, resulting in some individuals calling for these tests to be altogether abandoned in clinical practice.

The proposed VBI screening tests typically consist of combined cervical extension and rotation and sustained end-range rotation (2). The pre-manipulative position has also been proposed as an alternative VBI test (3). Theoretically, these tests examine the mechanical stresses on the vertebral arteries during cervical spine movements by causing a narrowing of the vessel lumen (2). It is thought the contralateral side of head rotation is compromised (4), and when collateral circulation is unable to compensate for the decreased blood flow, symptoms of VBI would be seen through reduced brainstem perfusion (2, 5).

In this paper, the authors argue that – from professional and research perspectives – the use of VBI tests cannot be recommended.

Summary:

Risks Associated with Cervical Spinal Manipulation (SMT)

The risk of major adverse events (MAE) following cervical spine manipulation range between one per 50,000 to one per 5.85 million (6). A recent systematic review reported the most frequently described MAEs related to cervical SMT include craniocervical arterial dissection (7), however this link must be considered as an association, rather than implying direct causation.

Risk Assessment:

Although the best available evidence does not suggest a causal link between cervical SMT and craniocervical arterial dissection, it is important to perform a risk assessment to determine if any potential cervical arterial dysfunction is present (8). The patient interview/history is an essential step in the clinical assessment, and allows practitioners to sufficiently identify risk factors, red flags and contraindications to treatment (8).

Recently, Hutting and colleagues (6) proposed three important steps in the clinical reasoning process, which include:
  1. Identify a possible vasculogenic contribution or other serious pathology
  2. Determine whether there is an indication or contraindication for mobilisation or manipulation
  3. Assess the presence of any potential risk factors associated with a potential MAE
Validity of the VBI Tests:

Despite the validity of these tests being questioned, they are still taught to students, performed in clinical practice and even present in some clinical guidelines (4, 9). As these tests are employed to determine if complications will arise when performing cervical spine manipulation, it is important that they produce a small number of false-negative results (in other words, that they are highly sensitive). However, in a systematic review of diagnostic accuracy of VBI tests, the sensitivity ranged from 0-57%, which means a large number of patients would be missed when these tests are performed (10)! Despite the specificity of VBI tests being higher, false-positives have fewer serious consequences than false-negatives (10). Therefore, although the Hutting systematic review (published in 2013) was based on low quality studies, the best available evidence does not support the validity of these tests. Importantly, there is no high-, or even lower-quality evidence suggesting that the opposite is true. These tests were, quite simply, born out of a number of assumptions.

False-negatives are a critical failing of these tests, which was further demonstrated in a review of 64 medico-legal cases of cerebrovascular accidents associated with cervical SMT. Twenty-seven of these cases utilized VBI tests, however no adverse responses were demonstrated prior to treatment (11). That is, the tests did not identify those who went on to suffer a cervical stroke. Unfortunately, these false-negative results can provide a (correspondingly false) sense of security to the clinician. Due to the lack of diagnostic accuracy of the VBI tests, there does not appear to be a role for these tests in assessing the risk of serious neurovascular pathology (1, 12).

In addition, the face validity of these tests is weak, as there is no literature to support their use in differentiating the cause of positional symptom response. For example, the tests involve movement of the vascular structures, vestibular apparatus and upper cervical spine segments, and there is a lack of literature to support their ability to differentiate these structures in terms of which is/are provoking the symptomatology (12).

Rationale for the VBI Tests:

VBI tests were designed to unilaterally compress an artery in order to determine the collateral blood supply (2, 4). However, studies that have examined the haemodynamic parameters of cervical and craniocervical arteries have suggested there are no significant changes that occur during maximal rotation, combined movement of maximum extension and maximum rotation, nor during high velocity thrust positioning (13). As a result, the underlying construct/concept of the VBI tests appears to be flawed, as decreased blood flow is not consistently observed in the contralateral vertebral artery in a healthy population (recent work has also demonstrated this in those with cervical joint restrictions) (19, 20).

Vertebrobasilar Insufficiency:

In a minority of cases, there has been a reported onset of VBI symptoms with head positioning where blood flow occlusion has been confirmed (14-17). These reports, however, relate to Bow Hunter’s syndrome, which is a rare syndrome leading to severe stenosis or transient occlusion of a dominant vertebral artery during rotation (18). These patients have (some severe!) symptoms consisting of syncope with sustained head rotation (18), vertigo relieved by maintaining a neutral neck position, numbness and tingling in the occipital region (17), dizziness and loss of consciousness with head rotation (16), neck pain associated with dizziness, headache and tinnitus (15), and dizziness spells and near syncope upon head rotation (14). These are red flag symptoms that can and should be determined through the history, making the use of VBI tests a (further) moot point. A proper, comprehensive patient history combined with cranial nerve examination is proposed to be more appropriate than preforming the VBI screening tests.

Clinical Application & Conclusions:

The use of VBI screening tests in clinical practice is a point of contention for many. Thomas and Treleavan contended that VBI tests should be used as a test of collateral blood flow, rather than assessing a unilateral artery (1). However, as Hutting and colleagues discuss in this paper, the existing research cannot justify this standpoint, as the face validity of VBI tests is weak and they do not provide clinicians with enough information to differentiate symptoms as vascular versus vertiginous versus cervicogenic causes.

Both sides to this debate do agree that more research is required as the current state of the literature is low quality. Hutting argues that due to the low sensitivity and high rate of false-negative results, the use of these tests cannot be justified in clinical practice, as they only serve to confuse or mislead clinicians (and hence, their patients). There are more robust clinical assessments, such as an in-depth history, in order to raise one’s “spidey-sense” of a possible serious pathology occurring. If further research demonstrates these tests to be useful, they can then safely be (re)incorporated into clinical practice. However, until such time, the risks of using these tests outweigh the benefits. As such, they are no longer recommended in clinical practice and should not be taught to students in our professions.

Study Methods:

This article acted as a rebuttal to an article by Thomas and Treleavan (published in 2019) regarding the use of VBI tests. Therefore, no statistical analysis was conducted nor was a specific description of their methodology provided.

Study Strengths / Weaknesses:

Strengths:
  • The article provides a logical, easy to follow argument regarding whether or not to use VBI screening tests in clinical practice.
Weaknesses:
  • The authors could have expanded on some aspects of the literature to provide a more in-depth discussion.
  • The body of literature in this area is not perfect, primarily reflecting the difficulty in studying this concept via high-level, prospective methods.

Additional References:

  1. Thomas L, Treleavan J. Should we abandon positional testing for vertebrobasilar insufficiency? Musculoskelet Sci Pract. 2019.
  2. Mitchell J, Keene D, Dyson C, et al. I s cervical spine rotation, as used in the standard vertebrobasilar insufficiency test, associated with a measurable change in intracranial vertebral artery blood flow?. Man Ther 2004; 9(4): 220-227.
  3. Australian Physiotherapy Association, 2006. Clinical Guidelines for Assessing Vertebrobasilar Insufficiency in the Management of Cervical Spine Disorders.
  4. Thiel H, Rix G. Is it time to stop functional pre-manipulation testing of the cervical spine?. Man Ther 2005; 10(2): 154-158.
  5. Kuethe TA, Nesbit GM, Clark WM, et al. Rotational vertebral artery occlusion: a mechanism of vertebrobasilar insufficiency. Neurosurgery 1997; 41(2): 427-433.
  6. Hutting N, Kerry R, Coppieters MW, Scholten-Peeters GGM. Considerations to improve the safety of cervical spine manual therapy. Musculoskelet Sci Pract 2018; 33: 41-45.
  7. Kranenburg HA, Schmitt MA, Puentedura, et al. Adverse events associated with the use of cervical spine manipulation or mobilization and patient characteristics: A systematic review [published correction appears in Musculoskelet Sci Pract 2017; 28: 32-38.
  8. Rushton A, Rivett D, Carlesso L, et al. International framework for examination of the cervical region for potential of Cervical Arterial Dysfunction prior to Orthopaedic Manual Therapy intervention. Man Ther 2014; 19(3): 222-228.
  9. Thomas, L., Shirley, D., Rivett, D. Clinical guide to safe manual therapy practice in the cervical spine. https://australian.physio/tools/clinical-practice/cervical-spine. 2017.
  10. Hutting N, Verhagen AP, Vijverman V, et al. Diagnostic accuracy of premanipulative vertebrobasilar insufficiency tests: a systematic review. Man Ther 2013; 18(3): 177-182.
  11. Haldeman S, Carey P, Townsend M, et al. Arterial dissections following cervical manipulation: the chiropractic experience. CMAJ 2001; 165(7): 905-906.
  12. Kerry R, Hutting N, Kranenburg HAR. Letter to the editor on the continued use of the “vertebrobasilar insufficiency” test. Musculoskelet Sci Pract 2019.
  13. Kranenburg HAR, Tyer R, Schmitt M, et al. Effects of Head and Neck Positions on Blood Flow in the Vertebral, Internal Carotid, and Intracranial Arteries: A Systematic Review. J Orthop Sports Phys Ther 2019; 49(10): 688-697.
  14. Buch V.P, Madsen P.J, Vaughan K.A, et al. Rotational vertebrobasilar insufficiency due to compression of a persistent first intersegmental vertebral artery variant: case report. J Neurosurg Spine 2017; 26(2): 199-202.
  15. Hernandez RN, Wipplinger C, Navarro-Ramirez R, et al. Bow Hunter Syndrome with Associated Pseudoaneurysm. World Neurosurg 2019; 122: 53-57.
  16. Schunemann V, Kim J, Dornbos D et al. C2-C3 Anterior Cervical Arthrodesis in the Treatment of Bow Hunter's Syndrome: Case Report and Review of the Literature. World Neurosurg 2018; 118: 284-289.
  17. Strickland B.A., Pham M.H., Bakhsheshian J, et al. Bow Hunter's Syndrome: Surgical Management (Video) and Review of the Literature. World Neurosurg 2017; 103: 953.e7-953.e12.
  18. Ng S, Boetto J, Favier V, et al. Bow Hunter's Syndrome: Surgical Vertebral Artery Decompression Guided by Dynamic Intraoperative Angiography. World Neurosurg 2018; 118: 290-295.
  19. Leenarts T, Molenaar W & Cattrysse E. Changes in vertebral arterial blood flow during premanipulative tests in participant with upper cervical spine motion restriction. JMPT 2020; 43(2):134-143.
  20. Yelverton C, Wood J, Petersen DL & Peterson C. Changes in vertebral artery blood flow in different head positions and post-cervical manipulative therapy. JMPT 2020; 43(2): 144-151.