Pre-Manipulative Tests

CHAPTER 5

Introduction

Spinal manipulative therapy (SMT) is a therapeutic intervention that is practised across the world by health care professionals in various specialities, including osteopaths, chiropractors, physical therapists and medical doctors (Shekelle et al., 1992; Rivett, Thomas and Bolton, 2005; Rubinstein et al., 2011). The therapy is considered relatively safe and effective for the treatment of musculoskeletal conditions (World Health Organization, 2005). Although serious complications following the therapy are rarely reported, there have been a number of case reports of adverse events, particularly following cervical spine manipulation (Maher, 2001). To rule out the risk of an undue injury, pre-manipulative functional tests have therefore been a part of SMT for many years (Magarey et al., 2004).

Over the last three decades, practitioners of SMT have adapted various protocols or clinical guidelines to detect patients at risk of complications (Thiel and Rix, 2005). These protocols are primarily developed to address all known risk factors and red flag symptoms that may contribute to serious complications (Refshauge, 2001). However, the existing pre-manipulative screening protocols have been subjected to critical reviews in recent years (Rivett et al., 2005). The appropriateness, sensitivity and specificity of these protocols have been questioned due to the provocative nature of the tests, controversy surrounding the reliability and validity of the test procedures, and lack of definitive investigations supporting the protocols (Refshauge, 2001; Magarey et al., 2004).

Moreover, there has been a lack of valid and reliable pre-manipulative screening tools that can accurately indicate which patients are at risk of complications from manipulative techniques (Rivett, 2001; Puentedura et al., 2012). Although the current pre-manipulative testing procedures continue to be carried out in daily clinical practice, the majority of available evidence underpinning these tests is based on low-quality evidence (Cote et al., 1995; Di Fabio, 1999; Licht, Christensen and Høilund-Carlsen, 2000; Westaway et al., 2003). Studies of moderate level evidence, however, have failed to applaud their use (Gross and Kay, 2001). For this reason, many researchers have suggested that practitioners should emphasise on through subjective examination and sound clinical reasoning, as there is still not enough scientific evidence to show the predictive value of existing pre-manipulative tests or justify their use (Di Fabio, 1999; Licht et al., 2000; Puentedura et al., 2012).

The aim of this chapter is to review various pre-manipulative screening tests that are widely practised and to discuss their validity and usefulness in light of recent scientific evidence.

Clinical Tests of the Spine

Because complications may spontaneously result from a manipulative procedure, physiotherapists/physical therapists and manipulative therapists routinely perform various pre-manipulative tests to assess patients presenting with a musculoskeletal condition. These tests are done as part of the treatment process so that SMT practitioners can identify the underlying cause(s) of a patient’s presenting condition, rule out the risk of an undue injury and determine a safe and appropriate treatment plan which will increase the likelihood of a positive clinical outcome (Stude, 2005).

In general, clinical tests have one or more of five functions (see Table 5.1). They are performed to detect risk factors for a specific condition and determine the safety of the manipulative therapy (Lang and Secic, 1997). However, such tests may still be utilised when a patient is seen for preventive treatment. In this case, a given test should not aim to detect the presence or absence of specific symptoms; rather, it should be done to assess and evaluate that patient’s suitability for wellness care (Stude, 2005).

Table 5.1 Functions of clinical tests
Name	Characteristics
Screening test	•Performed on people who are healthy and asymptomatic •Has high sensitivity – that is, a good screening test is able to detect a given condition in its primary or most treatable stages •Helps to identify patients with increased risk for a specific condition or disease •Used to justify subsequent testing with a more specific diagnostic test •Helps to determine whether direct preventive measures can be taken
Routine test	•Usually done on symptomatic patients as regular procedure •Serves as part of a battery of tests •Outcomes may be unrelated to the patient’s presenting condition
Diagnostic test	•Performed on symptomatic subjects to revise disease probability •Has high specificity •Used to determine the presence or absence of a specific disorder
Staging test	•Done to evaluate and characterise the nature or severity of a specific condition
Monitoring test	•Performed to track down the gradual progress of a disease, condition or illness over time
Sources: Lang and Secic (1997); Thiel and Rix (2005)

Assessment and Treatment Processes

The application of SMT to the spine is associated with neurovascular and other complications (Di Fabio, 1999; Ernst, 2007; Gouveia, Castanho and Ferreira, 2009). To prevent severe complications resulting from SMT and to ensure correct patient selection, practitioners follow standard assessment methods that encompass thorough ‘screening protocols’ (Rivett et al., 2005). Such protocols usually involve a number of processes, including a careful evaluation of the recipient’s medical history, physical examination findings and provocative test results, assessment during and after treatment, and obtaining written informed consent (Magarey et al., 2004; Thiel and Rix, 2005). Figure 5.1 shows a general flow chart of the assessment processes to be followed during screening examination.

FIGURE 5.1 FLOW CHART FOR EXAMINATION OF PATIENTS PRESENTING WITH SPINAL PROBLEM

* A need to assess the spine will be recognised if the patient has a history of trauma, fever, incontinence, unexplained weight loss, a cancer history, long-term steroid use, parenteral drug abuse, and intense localized pain and an inability to get into a comfortable position (Bratton, 1999).

Vertebrobasilar Insufficiency Tests

Vertebrobasilar insufficiency (VBI) tests, also known as vertebral artery tests, are most commonly used for screening purposes before performing high-velocity thrust (HVT) and non-HVT manipulation (Magarey et al., 2004; Childs et al., 2005). These tests are provocative in nature. They are performed to test the collateral and vertebrobasilar blood supply to the brain in order to identify or recognise signs and symptoms of vertebral artery pathology, which may represent a pre-manipulation risk (Rivett et al., 2005). In addition, these tests are usually done in a clinical situation where practitioners of SMT are considering manipulation of the cervical spine as the treatment of choice (Thiel and Rix, 2005).

There have been a number of different tests to assess patients at risk of VBI, including the Barre-Lieou test, Maigne’s test, Hautant’s test, Underberg’s test, George’s cerebrovascular craniocervical functional test, the Hallpike manoeuvre, and deKleyn’s test (Carey, 1995). Among these tests, deKleyn’s test is one of the most commonly used. Although there are some differences in testing procedures, the general theme of all these tests is the same: extension and rotation of the head and/or neck in order to provoke cerebral ischaemia during positional change of the cervical spine (Licht et al., 2000).

Historical and Clinical Features Suggestive of VBI

•A sharp and severe non-specific, but distinct, pain – often there is no past history of a similar pain

•Pain in the head and neck – usually unilateral and sub-occipital

•A sensation of neck stiffness with or without any restriction of range of motion

•History of cervical trauma

•Limb weakness

•Ataxia/unsteadiness of gait

•Numbness – most often unilateral facial

•Nystagmus (i.e. involuntary eye movement), vestibular or cerebellar in origin

•Ipsilateral sensory abnormalities

•Hearing disturbances such as tinnitus

•Horner’s syndrome

•Other neurological symptoms (e.g. ipsilateral cranial nerve abnormalities, ipsilateral limb ataxia)

Sources: Hing and Reid (2004); Thiel and Rix (2005); Shirley, Magarey and Refshauge (2006)

PURPOSE

VBI tests do not mimic the techniques associated with the HVT. They are intended to detect unapparent vessel pathology (e.g. dissection and/or brainstem ischaemia) by purposively compromising the blood flow into the vertebral artery (Rivett et al., 2005).

PROCEDURE

The test is usually performed in either supine lying or sitting position. The procedure involves slow passive extension and/or rotation of the recipient’s head and neck to the maximum range of motion, keeping the recipient in either the supine or upright (standing or seated) position (Grant, 1996; Mitchell, 2003, 2007). The clinician sustains all positions for a minimum of ten seconds while observing for symptoms associated with VBI (Shirley et al., 2006; Alshahrani, Johnson and Cordett, 2014).

MECHANISM OF ACTION

The manoeuvre has been reported to decrease blood flow in the vertebral artery by causing a reduction of the vessel lumen, typically within the artery contralateral to the direction of rotation (Haynes and Milne, 2001; Haynes, 2002; Thiel and Rix, 2005). This compromising of vertebral artery circulation causes an ischaemia because of sudden blood loss in the brain, particularly at the pons and the medulla oblongata (Mitchell, 2007).

POSITIVE SIGNS

In patients with VBI, the brief neurovascular event provoked by the manoeuvre often results in brainstem symptoms (Mitchell et al., 2004; Shirley et al., 2006). These include:

•dizziness or lightheadedness

•nausea and vomiting

•drop attacks

•temporary vision or hearing loss

•pins and needles in the tongue

•diplopia (double vision)

•pallor and sweating

•paralysis or paresis

•dysphagia and dysarthria.

If the occurrence or development of dizziness or any of the above symptoms of VBI is provoked during the manoeuvre, it has generally been considered to be a positive finding (Magee, 2008; Thiel and Rix, 2005). However, additional tests (e.g. cervical extension) should be carried out to confirm whether the provoked symptoms are potentially associated with VBI (Hing and Reid, 2004). To differentiate between symptoms related to VBI and those related to the vestibular system, the provocative VBI test should be repeated in the alternative position (Shirley et al., 2006). For example, if the test procedure is performed in supine position, to confirm or differentiate the symptoms the test should be repeated in sitting position.

AFTERCARE

If the presence of VBI becomes evident in a patient, the practitioner should immediately cease the provocative testing and return the patient’s neck to the neutral position (Rivett et al., 2005). In addition, because VBI is an absolute contraindication for cervical spine manipulation, manipulative procedures should be discontinued, and the patient should be referred to specialist for further medical investigation (World Health Organization, 2005; Shirley et al., 2006).

Validity of the VBI Tests

VBI tests have been thought to be an indirect technique to measure vertebral artery haemodynamics. For this reason, they are generally used to measure the degree of lumenal patency, or absence thereof, by provoking brainstem symptoms of transient ischemia (Thiel and Rix, 2005). However, the use of VBI tests as a screening tool to rule out patients at risk of cerebrovascular complications from SMT has been controversial, as reviews of literature on vertebral artery circulation studies have demonstrated varying results with regard to the effects of these tests (Grant, 1996; Rivett, Milburn and Chapple, 1998; Rivett, Sharples and Milburn, 2000; Rivett et al., 2005; Di Fabio, 1999; Ernst, 2007; Puentedura et al., 2012). Moreover, there have been reports of both false positive and false negative test results (Bolton, Stick and Lord, 1989; Cote et al., 1995; Licht et al., 1998); hence, considerable controversy exists concerning the sensitivity and specificity of these tests.

Bolton et al. (1989), using digital subtraction angiography, first demonstrated in a single case report that a test result might be negative, despite known occlusion of the vertebral artery. Later studies on the validity of VBI tests done by Thiel et al. (1994) and Licht et al. (1998) have suggested that these tests can also result false positive provocative findings. More recently, Haldeman, Kohlbeck and McGregor (2002) and Westaway, Stratford and Symons (2003) reported cases in which patients had VBI, but provocative screening tools, involving end-range rotation and/or extension of the head to detect the patency of the vertebral artery, did not provoke any brainstem symptoms that would contraindicate cervical spine manipulation.

In recent years, studies investigating the haemodynamic effects of cervical spine movement have employed duplex ultrasound to measure the volume, velocity or resistance to contralateral vertebral artery flow during the provocative positional manoeuvres (Licht et al., 1998; Yi-Kai and Shi-Zhen, 1999; Rivett et al., 2000; Haynes, 2000; Johnson et al., 2000; Haynes, 2002; Mitchell, 2003; Zaina et al., 2003). These studies have inconsistently demonstrated either a decrease or reduction in some of these flow parameters or no significant differences in blood flow velocity or flow rate at all, when applying pre-manipulative manoeuvres. As a result, many authors have questioned the sensitivity and positivity of the VBI tests to detect vertebral artery patency and have raised concerns about their validity to determine impedance changes to cerebrovascular circulation (Puentedura et al., 2012; Rivett et al., 2005; Westaway et al., 2003; Rivett et al., 2000; Di Fabio, 1999; Licht et al., 1998; Cote et al., 1995).

In contrast, Mitchell (2007) found a lot of inconsistencies in studies not finding significant reduction in vertebral artery blood flow during the provocative positional tests. Out of 20 studies reviewed, seven studies had design flaws in blood flow analyses. In addition, it was also found that only five studies measured blood flow in the fourth division of the vertebral artery and none in the third division. Therefore, it is evident that very limited research has been done to analyse the blood flow distal to the location where the resistance is believed to occur (Mitchell, 2003). In support of the early work, Mitchell (2009) later concluded in a meta-analysis that blood flow compromise due to full or sustained contralateral rotation occurred particularly in the fourth division of the vertebral artery. Based on the review of early literature, the author also stated that sustained, full-range rotation of the cervical spine is so far the most reliable procedure to indicate the functional state of an individual’s vertebrobasilar and collateral circulation.

Taken together, in light of the above discussion, it can be said that there is definitely a lack of meticulously controlled clinical trials to measure velocity changes of vertebral artery flow during sustained end-range rotation of the cervical spine. Therefore, given the inconsistencies in today’s literature about the validity of VBI tests, SMT practitioners should not use those controversial results to guide evidence-based practice. Instead, they should study and appraise those findings to support the need for educated caution in pre-manipulative screening of the patients.

Is There Any Valid Screening Tool for VBI?

There has been a lack of a reliable and valid screening tool for VBI (Childs et al., 2005; Puentedura et al., 2012; Alshahrani et al., 2014). To date, the most reliable method to determine the functional state of a patient’s collateral and vertebrobasilar circulation is the pre-manipulation provocative VBI test, particularly the sustained, full-range rotation of the cervical spine (Mitchell, 2009). Still, given the inconsistencies in current literature and the limited validity of existing VBI tests, the use of these tests have been controversial (Rivett et al., 2005; Mitchell, 2007). As a result, many authors have proposed continuous-wave duplex ultrasound to assess the status of blood flow in the vertebral artery during VBI tests; however, the use of such a device has not been a practical or affordable option (Rivett, 2001; Thiel and Rix, 2005; Rivett et al., 2005; Alshahrani et al., 2014). As an alternative to duplex ultrasound, Haynes (2002) and Rivett (2001) suggested a simpler ultrasound device, known as the Doppler velocimeter, to indicate changes in vertebral artery blood flow during the pre-treatment VBI test. Furthermore, in a recent study, Mitchell (2009), based on a review of the literature, suggested pulsed-wave Doppler insonation with colour flow imaging as a reliable method to investigate vertebral artery blood flow during full or sustained contralateral rotation.

Craniocervical Ligament Stability Tests

Craniocervical ligament screening is usually performed on patients who have conditions or disorders that affect the integrity of the cervical spine ligaments, such as rheumatoid arthritis and Down syndrome, or who have suffered cervical spine trauma (i.e. hyperflexion, whiplash) (Hing and Reid, 2004). A number of tests have been advocated as part this screening, including Sharp–Purser test, anterior shear test, distraction test for the tectorial membrane, and many more. In general, these testing procedures are done prior to the application of SMT to the upper cervical spine, so that the clinician can identify any sign of upper cervical instability (Osmotherly, Rivett and Rowe, 2012).

Potential Signs of Craniocervical Damage and Instability

•Hypermobility or empty end-feel during test movements

•Complaints of neck pain and/or headaches during sustained weight-bearing postures

•Signs of vertebral artery compromise (e.g. cerebellar ataxia)

•Catching/locking in the neck

•Paraesthesia of the lip and chin area

•Orthostatic intolerance (blood pressure drops when standing upright)

•Reproduction of symptoms of cervical instability

•Downward nystagmus (irregular eye movements)

•Poor cervical muscle strength

Sources: Hing and Reid (2004); Magee, Zachazewski and Quillen (2009)

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