Focus on Alternative and Complementary Therapies
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Focus Alternat Complement Ther©2005 Pharmaceutical Press
Focus Altern Complement Ther 2006; 11: 9–13
Over many years spinal manipulation has evolved to a popular form of treatment for a variety of conditions, notwithstanding the debate about its clinical efficacy. Most of the results support, but do not prove, that spinal manipulation provides at least a short-term benefit to some patients.1–9 However, there is no evidence to support the idea that spinal manipulation achieves better clinical outcomes than mobilisation.
Besides the discordant results of studies on its effectiveness, the lack of scientific investigations regarding the safety of spinal manipulation contrasts sharply with the popularity of manipulative techniques.4,6,10–16
Although it is not always obvious, it is essential to make an appropriate distinction between side- and adverse effects. Side-effects can be described as ‘a consequence other than the one for which an agent, medium or therapy is used’, whereas adverse effects or complications can be defined as ‘a change in body function or the structures of cells due to an agent, medium or therapy that can lead to disease, health problems or even death’.17
According to a literature review, the incidence of serious complications in spinal manipulation is generally considered to be low.18 Apparently they are more frequently linked to manipulation of the cervical spine than to other spinal manipulations. The published cases are probably only the tip of the iceberg, resulting in a wide variation in estimations of the rate of complications. Notwithstanding this reflection, it is shown by these published cases that of all injuries after cervical manipulation, the majority (82%) can be classified as vertebrobasilar insufficiency (VBI).
With respect to transient side-effects after manipulation, the results of a prospective observational survey indicate that more than 60% of all patients will experience this kind of effect.19 The most commonly noted unwanted consequences are headache, stiffness, local discomfort, radiating discomfort and fatigue. Reports of dizziness and nausea are uncommon. These side-effects tend to appear within 4 h and generally disappear within the next 24 h. Women are more likely to report side-effects than men. The location of treatment also determines whether or not side-effects will occur: headache, dizziness and nausea are significantly more apparent after cervical manipulation than after lumbar and thoracic treatment.
A comparison of the regional cerebral blood flow pre- and post manipulation revealed a significantly decreased perfusion in the anterior lobe of the left cerebellum, which may clarify some of the symptoms patients experience after manipulation of the cervical spine.20
In view of the occurrence of side- and adverse effects after cervical manipulation, the potential role of the vertebral artery may be crucial. The unique anatomy of the vertebral artery and the biomechanics of the cervical spine as it relates to the vertebral arteries are thought to render these arteries particularly vulnerable to injury.10,14,21,22 Congenital anomalies as well as intrinsic and extrinsic factors impeding the arterial blood flow should be considered in view of these adverse effects.23–25
These congenital anomalies as well as other anatomical factors (i.e. osteophytes and atherosclerotic plaques) may influence the interpretation of pre-manipulative testing and may have some clinical consequences during manipulation of the cervical spine.23–25 Several testing procedures as well as manipulation techniques place the head in a rotation-extension position, thereby occluding one vertebral artery. Vertebral artery occlusion is mostly asymptomatic as long as adequate compensation is achieved by a competent contralateral vertebral artery and anterior carotic circulation. When one vertebral artery is narrowed, it may not be capable of compensating for the positional occlusion of the larger one.
In any patient for whom manual examination or treatment of the cervical spine is to be undertaken, the presence or development of VBI symptoms should be carefully assessed. If cervical manipulation or techniques involving end-range rotation technique (ERRT) are considered, a specific series of examination procedures is recommended.
A set of guidelines in the form of a clinical decision algorithm is preferred above a rather rigid formal protocol (Figure 1).26 This leaves the ultimate decision on appropriate action to the therapist in the context of any particular individual presentation. Whether the potential risk outweighs the positive benefits is the practitioner’s decision. The clinical decision algorithm is based on the factors shown in Figure 1.
Figure 1. Clinical decision algorithm for testing the presence or development of VBI symptoms in patients presenting with a cervical problem. Adapted from Magarey et al.26
As with any patient complaint, a good history is essential to assess the nature of the presenting complaint and to determine if the problem has the potential to respond to spinal manipulation or needs further referral. A range of symptoms has been reported as being associated with VBI. The most important symptoms are dizziness/vertigo, diplopia, dysarthria, dysphagia, drop attacks and/or nausea.
Dizziness is the major symptom associated with VBI although it can also be associated with other pathological entities. Benign paroxysmal positional vertigo as well as cervical vertigo should be considered in differential diagnosis.
Although this algorithm relates to VBI, the identification of symptomatology indicative of other conditions, which would contraindicate cervical manipulation, is of equal importance. The absolute clinical contraindication is non-mechanical neck pain due to a specific spinal disorder (i.e. fracture, tumour, infection, malformation or inflammation), a visceral disorder or a vascular disorder (i.e. VBI).27 Relative clinical contraindications include disc protrusion, radicular symptoms with nerve root injury and segmental instability. Besides the usual clinical contraindications, improperly performed manipulation and patient fear are technical contraindications to manipulation. Only with the patient’s consent can a manipulation can be performed. According to Magarey et al express consent is considered essential prior to techniques over which the patient has no control, such as cervical manipulation, and should be re-established prior to every individual manipulative technique.26 Express consent means that an individual explicitly indicates agreement, either orally or in writing.
In cadavers as well as in living humans, rotation has been demonstrated to apply the greatest stress to the vertebral arteries in the upper cervical spine, between the atlas and axis transverse foramina. In contrast, lateral flexion of the neck apparently has little effect on vertebral artery blood flow. This functional ascertainment should be considered when a rationale is developed for the application of manipulative therapy to the cervical spine. A number of provocative tests have been developed that mechanically stress the vertebral artery, all of which incorporate a combination of cervical rotation and extension.28 This position has to be sustained for a minimum of 10 s unless symptoms are provoked sooner. The therapist has to examine the patient’s eyes for the production of nystagmus while the head is held in the sustained position, and simultaneously question the patient about the reproduction of symptoms.29
The effect of cervical movement on vertebral artery blood flow in view of these tests has been investigated in vivo using Doppler ultrasound. The findings of these studies are conflicting, leading some researchers to question the validity of pre-manipulative testing.30–32 The major drawback to all of the pre-manipulative testing procedures is their high rate of false-positives and false-negatives. False-positives are likely to occur because it is difficult to determine whether the dizziness results from VBI or cervical dizziness. Conversely, false-negatives are likely to occur because positional occlusion of a small vessel, as is the case in hypoplasia, non-union or progressive stenosis due to atherosclerosis or osteophytes, may have so little influence on the blood supply to the brain stem and cerebellum that its action is easily compensated for by the larger one.23–25 This gives the practitioner a false sense of security.
Given that a change in blood flow related to rotation is detected in the majority of studies and that literature data highlight more incidents related to rotation than any other movements, sustained rotation is reasoned to be the most appropriate test to include as mandatory.26 However, in the presence of degenerative diseases, the contralateral vertebral artery may be pressed against the lateral prominent osteophytes of the uncinate process during side bending25 therefore checking the permeability and compensatory ability of the vertebral arteries should not be done only in rotation positions, but also in the specific position from which the manipulation will be performed.
Manipulation should be avoided in advanced degenerative diseases (osteophytes and atherosclerotic plaques) or in the presence of congenital anomalies. In the suspicion of such disease and in cases of trauma, appropriate medical imaging is necessary to recognise such pathology. Routine X-rays of the cervical spine are widely available and allow the practitioner to detect uncovertebral osteophytes or ossified stylohyoid ligaments on lateral X-rays and osteophytes of zygapophysial joints on oblique views.24,25 In the presence of an angiography, the therapist should be aware of the possible existence of vascular problems. If there is the slightest doubt, it is better to abstain from manipulation.
On the basis of clinical and biomedical knowledge and the strength of the subjective and physical evidence presented in any particular clinical situation, the therapist must decide whether cervical manipulation or ERRT should be considered as treatment options. It is essential that therapists follow the algorithm step by step. If there is evidence at any time that symptoms are clearly associated with VBI, thrust manipulation or ERRT should not be undertaken. In all other situations, the final decision depends on the therapist’s reasoning in any particular patient presentation.26 In further manipulation sessions, the patient should always be asked about any self-limited, undesirable effects after previous manipulation. Cervical manipulations are contraindicated for patients who experience dizziness, nausea or acute headache persisting for more than 2 days.27
In addition to the algorithm, the following clinical practice guidelines can be recommended. If manipulation is the choice of treatment, incorporate this technique within an overall multi-modal management strategy. The recommended multi-modal treatment strategy to use in combination with manipulation or mobilisation is exercise. A single session for manipulation or mobilisation to decrease pain is not recommended.
Serious complications of cervical spine manipulation seem to be rare, whereas less serious side-effects occur frequently. Irrespective of the innocence and harmlessness of the majority of these side-effects, practitioners have the professional obligation to inform patients regarding the potential consequences and/or risks of spinal manipulation. This information is a fundamental prerequisite for consenting to treatment.
The main emphasis should be placed on assuring the safety of the patient during manipulation, in view of the seriousness of these complications and the risk of permanent neurological deficits. Pre-manipulative testing procedures have come under scrutiny in recent years because of their high rate of false-positives and false-negatives. A rationale for the prevention of complications from spinal manipulation should be based on a larger entity, i.e. knowledge of the patient’s history and contraindications, thorough skilled manipulative training, pre-manipulative testing, appropriate medical imaging and avoidance of certain techniques in patients thought to be at risk. A clinical decision algorithm is proposed as a guide to clinical reasoning in patient examination and management. Subtle clues obtained during the clinical reasoning process should alert the aware clinician of a potential vascular problem, which will contribute to the decision with regard to management and potential spinal manipulative therapy.
Screening protocols should not only be restricted to the upper cervical spine but should be performed before any cervical manipulation, as the V2 segment might also be involved in the occurrence of complications as a result of osteophytes and atherosclerotic plaques.
One should always remember that manipulative treatment is rarely an irreplaceable therapeutic modality. It is, of course, attractive because of its rapid action and its elegance, but it is valuable only if it is well executed. It is better to do something else than to manipulate wrongly: primum non nocere.
