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Cervical Manipulation for Neck Pain
Point/Counterpoint
Cervical Manipulation for Neck Pain
Guest Discussants: Michael Schneider, DC, PhD
CASE SCENARIO K.L. is a 48-year-old man with an acute episode of neck pain. He presents with sharp neck pain in the upper right side. He had neck pain before, but this is significantly more intense than what he has felt in the past. The pain radiates into the posterior aspect of his head. On examination, he has brisk 3⫹ reflexes throughout both his upper and lower limbs, and reports “I’ve always had strong reflexes.” He has a positive Hoffmann sign bilaterally but no ankle clonus, and downgoing toes to a Babinski stimulus. He is stable when performing both a Romberg and tandem Romberg maneuver. No focal weakness was noted within his upper or lower limb myotomes. Both the Sharp-Purser test and the modified lateral shear test were negative for segmental cervical instability. Manual cervical traction provided some relief of symptoms, and manual cervical palpation demonstrated hypomobility of the C1-2 and C2-3 segments on the right side, with concordant reproduction of symptoms. Results of the patient’s vascular examination reveal no evidence of carotid bruits and strong distal pulses in the upper and lower limbs. The patient has no vascular history but notes that his father, older brother, and paternal uncle have significant vascular histories, with his father dying from a ruptured abdominal aortic aneurysm, and his older brother had a 5-vessel coronary artery bypass graft when in his 40s. K.L. has worked with a chiropractor in the past for his low back and has responded well to high-velocity manipulations for his lumbar symptoms. He is interested in a trial of high-velocity manipulations for his neck as well, but, because of his family history of vascular complications, wants to know if it would be safe to have neck manipulations. Michael Schneider, DC, PhD, will argue that cervical manipulations should be performed. Stuart Weinstein, MD, will argue that cervical manipulations should be avoided.
School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA Disclosure: nothing to disclose
Stuart Weinstein, MD University of Washington Sports & Spine, Harborview Medical Center, University of Washington, School of Medicine, Seattle, WA Disclosure: nothing to disclose
Feature Editor: Gary P. Chimes, MD, PhD Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA. Address correspondence to: G.P.C.; e-mail: [email protected] Disclosure: nothing to disclose Disclosure Key can be found on the Table of Contents and at www.pmrjournal.org
Michael Schneider, DC, PhD, Responds This case describes the classic presentation of a patient with acute mechanical neck pain and associated occipital headache who would be expected to respond well to a brief course of cervical manipulation. Results of several studies have concluded that cervical manipulation is an effective treatment for acute neck pain and headache [1]. Recently, a large randomized trial showed that cervical manipulation was more effective than medication for acute and subacute mechanical neck pain [2]. There are no clinical “red flags” suggestive of serious pathology in this case. The patient does not have a history of cervical spine trauma, and the neurologic examination is essentially unremarkable. The physical examination was negative for signs of joint instability or hypermobility. There is no history of rheumatoid arthritis, previous surgery, or connective tissue disease that would be a relative contraindication for cervical manipulation. PM&R 1934-1482/12/$36.00 Printed in U.S.A.
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In summary, this patient appears to be an excellent candidate for spinal manipulation of the cervical spine. There would little argument about whether to consider cervical manipulation as clinical option if not for the insertion in the case scenario of the section about the family history of vascular disease and the brief mention of some neurologic signs. The finding of brisk reflexes and bilateral Hoffmann sign are probably a normal variant, given the fact that the remainder of the neurologic examination was unremarkable. Therefore, the issue of neurologic involvement is not relevant to the discussion about cervical manipulation as a potential treatment option. This case scenario raises a question about the general safety of cervical manipulation as a treatment option for neck pain and headache. This question carries with it 2 implied assumptions: (1) there is a significant increased risk of ad© 2012 by the American Academy of Physical Medicine and Rehabilitation Vol. 4, 606-612, August 2012 http://dx.doi.org/10.1016/j.pmrj.2012.07.003
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verse vascular events associated with cervical manipulation, and (2) this risk is increased with patients who have a family history of vascular or cardiac disease. Both of these assumptions are not supported by the current evidence. The early literature appears to suggest vertebral artery dissection (VAD) and ensuing posterior circulation stroke as a rare vascular complication of cervical manipulation. VAD is an extremely rare event with risk estimates of VAD associated with cervical manipulation that range from 1 per 400,000 manipulations to 1 per 5,000,000 manipulations [3,4]. However, analysis of the most recent evidence suggests that the relationship between cervical manipulation and stroke is not causal [5]. Research results have shown that the 2 strongest risk factors associated with VAD are age under 45 years and various collagen vascular diseases such as Marfan syndrome and Ehlers Danlos syndrome [6]. Fibromuscular dysplasia is found in up to 20% of patients with spontaneous dissections of the cervical internal carotid artery [7], which has led to the suspicion that the rare event of VAD may be caused by an underlying asymptomatic arteriopathy that is in part genetic [8]. Other risk factors for VAD may include recent respiratory infection, migraine, hyperhomocysteinemia, cervical spine trauma, and coughing [7]. Although an association has been observed between cervical manipulation and VAD, the same association has been found with other types of normal activities that involved rotation and/or extension of the neck such as driving, sports, getting a haircut, sneezing, and coughing [9]. A family history of aortic aneurysm and coronary artery disease does not suggest an increased risk of VAD or posterior circulation stroke. A systematic review reported that cervical artery dissections were less likely to be associated with vascular risk factors than noncervical artery dissection strokes [10]. VAD strokes occur in younger patients (⬍45 years) when the risk of atherosclerosis is low. There are no reliable family history questions that can be used to screen patients for risk of VAD, other than the presence of known collagen vascular disease as noted previously. In a large case-control study, several vascular risk factors were actually found to occur less frequently in cervical artery dissection cases than in controls [11]. These vascular risk factors included hypertension, diabetes, hypercholesterolemia, and current smoking. The assumption of increased risk from cervical manipulation leads to an important discussion of all treatment options within the context of evidence-based medicine (EBM), which is based upon 3 key principles: (1) the best current evidence, (2) clinician expertise, and (3) patient preference [12]. Any treatment option offered to a patient with neck pain and headache should be framed within these 3 parameters of EBM. The best current evidence on the topic of risk of vascular injury from cervical manipulation was a large populationbased case-control study of more than 100 million person-
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years [5]. This study found that the general incidence rate of vertebrobasilar artery (VBA) stroke was less than 1 per 100,000 person-years, an extremely rare event. Patients were about 3 times more likely to see a chiropractor or a primary care physician before their stroke than were controls. The investigators found no increased risk of VBA stroke associated with chiropractic care compared with primary care. The observed association between VBA stroke and an increased rate of chiropractic and primary care visits was likely due to patients with headache and neck pain from VBA dissection seeking care before their stroke. These patients had dissections and/or strokes in progress; the treatment rendered by the chiropractor or primary care physician most likely was irrelevant to the eventual outcome of the case. Clinician expertise is the second principle of EBM. The professions of chiropractic, osteopathy, and physical therapy have used various types of cervical manipulation and mobilization for more than a century with good clinical outcomes. It is important to recognize that the term “cervical manipulation” is used to describe a number of different techniques but is typically associated with high-velocity low-amplitude thrust procedures. There also are many other manual techniques used to treat neck pain, such as manual cervical traction, manual trigger point therapy, postisometric stretching, and nonthrust mobilizations. A recent randomized trial found that both thrust-manipulation and nonthrust mobilization methods were effective for relieving acute neck pain [13], and this also was the conclusion of a recent systematic review [14]. Adverse effects of cervical manipulation are common but are typically limited to transient local posttreatment muscle soreness and other mild symptoms. Patient preference is the last, but perhaps the most important, principle of EBM. Many patients simply prefer manipulation instead of medication for neck pain and headache. Some of these patients choose manual treatments because they want to avoid unnecessary medications and take a “natural healing” approach. Other patients have a history of gastric distress and cannot tolerate the adverse effects associated with over-the-counter medications such as ibuprofen and aspirin taken for neck pain. Serious adverse effects from nonsteroidal anti-inflammatory drugs (NSAID) account for a larger number of hospitalizations for gastrointestinal events with an estimated mortality rate of approximately 6% [15]. When considering the common adverse effects of these medications, the option of spinal manipulation as a safe and effective alternative treatment for neck pain and headache should be offered to patients. In summary, spinal manipulation is certainly a reasonable treatment option for the patient described in this hypothetical case scenario. The family history of a father with an abdominal aortic aneurysm and a brother with coronary artery disease is a “red herring,” which detracts from the real issue of whether spinal manipulation should be considered as a viable treatment option for this patient. The best available
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evidence suggests that cervical manipulation is a relatively safe and effective treatment option for neck pain and headache, especially when compared with NSAIDs and other medication options. It should be considered as one of a number of viable treatment options based upon clinician expertise and patient preferences.
REFERENCES 1. Bronfort G, Haas M, Evans R, Leininger B, Triano J. Effectiveness of manual therapies: The UK evidence report. Chiropr Osteopat 2010;18:3. 2. Bronfort G, Evans R, Anderson A, Svendsen K, Bracha Y, Grimm R. Spinal manipulation, medication, or home exercise with advice for acute and subacute neck pain: A randomized trial. Ann Intern Med 2012;156:1-10. 3. Hurwitz EL, Coulter ID, Adams AH, Genovese BJ, Shekelle PG. Use of chiropractic services from 1985 through 1991 in the United States and Canada. Am J Public Health 1998;88:771-776. 4. Smith WS, Johnston SC, Skalabrin EJ, et al. Spinal manipulative therapy is an independent risk factor for vertebral artery dissection. Neurology 2003;60:1424-1428. 5. Cassidy JD, Boyle E, Cote P, et al. Risk of vertebrobasilar stroke and chiropractic care: Results of a population-based case-control and casecrossover study. J Manipulative Physiol Ther 2009;32(Suppl):S201208. 6. Micheli S, Paciaroni M, Corea F, Agnelli G, Zampolini M, Caso V. Cervical artery dissection: Emerging risk factors. Open Neurol J 2010; 4:50-55.
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7. Mokri B, Sundt TM Jr, Houser OW, Piepgras DG. Spontaneous dissection of the cervical internal carotid artery. Ann Neurol 1986;19:126138. 8. Grond-Ginsbach C, Debette S. The association of connective tissue disorders with cervical artery dissections. Curr Mol Med 2009;9:210214. 9. Haldeman S, Kohlbeck FJ, McGregor M. Risk factors and precipitating neck movements causing vertebrobasilar artery dissection after cervical trauma and spinal manipulation. Spine (Phila Pa 1976) 1999;24:785794. 10. Rubinstein SM, Peerdeman SM, van Tulder MW, Riphagen I, Haldeman S. A systematic review of the risk factors for cervical artery dissection. Stroke 2005;36:1575-1580. 11. Debette S, Metso T, Pezzini A, et al. Association of vascular risk factors with cervical artery dissection and ischemic stroke in young adults. Circulation 2011;123:1537-1544. 12. Straus SE, Glasziou P, Richardson WS, Haynes RB. Evidence-based Medicine: How to Practice and Teach It. 4th ed. New York: Churchill Livingstone; 2011. 13. Leaver AM, Maher C, Herbert R, et al. A randomized controlled trial comparing manipulation with mobilization for recent onset neck pain. Arch Phys Med Rehabil 2010;91:1313-1318. 14. Gross A, Miller J, D’Sylva J, et al. Manipulation or mobilisation for neck pain: A Cochrane Review. Man Ther 2010;15:315-333. 15. Lanas A, Perez-Aisa M, Feu F, et al. A nationwide study of mortality associated with hospital admission due to severe gastrointestinal events and those associated with nonsteroidal anti-inflammatory drug use. Am J Gastroenterol 2005;100:1685-1693.
Stuart M. Weinstein, MD, Responds INTRODUCTION Throughout my 27-year career I have seen the entire spectrum of usual and not-so-usual diagnoses. One of those not-so-usual diagnoses that I encountered early in my career was a stroke in a semiprofessional football player after a chiropractic cervical spine manipulation [1]. It is said that lightning does not strike twice in the same place, so I do not expect to see another manipulation-induced stroke for the rest of my career, but I considered myself warned as to the potential danger of cervical spine manipulation. Any trained and credentialed manual therapy provider can legally perform spinal manipulation. This argument will limit the terminology of manipulation to describe a forceful, sudden thrust (typically high velocity, low amplitude) performed by a chiropractor, osteopath, or similarly credentialed physical therapist (the latter, outside of the United States). For purposes of full disclosure, I refer patients to chiropractors, osteopaths, and physical therapists, and I receive referrals from all three. I believe that mobilization and manipulation have roles in the treatment of certain spinal disorders, specifically, those that involve segmental stiffness or dysfunction (note, I do not generally subscribe to the chiropractic term “subluxation”). I also realize that chiropractic is one of the most widely sought treatments in the world,
including by athletes, and that people routinely receive chiropractic care for chronic pain conditions or even so-called maintenance therapies. As I will identify below, the risk of catastrophic consequences is very low. However, I am very cautious about recommending manipulation of cervical spine in total and to the upper cervical spine in particular. My premise in this Point/Counterpoint debate is that the risk of stroke after chiropractic manipulation is real, and I would not recommend a treatment to a patient, athlete or otherwise, that I do not personally endorse. In the following argument, I will present pertinent functional anatomy of the upper cervical spine with an emphasis on the relationship of the vascular and bony anatomy, the purported mechanism and published incidence of vertebral artery injury and stroke after cervical spine manipulation, the current published guidelines that relate to manipulation of the cervical spine, and final thoughts on the subject, including my specific recommendations in this case scenario.
FUNCTIONAL AND VASCULAR ANATOMY OF THE UPPER CERVICAL SPINE As this case scenario implies, it is the risk to the vascular anatomy, specifically the vertebral artery, that is of primary
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concern and open to debate. To understand the potential risk of injury to the vertebral artery, it is necessary to understand the static and functional anatomy of the region. There is an intimate relationship between the vertebral arteries and the bony cervical spine. The course of the vertebral arteries can be divided into 4 segments, V1 to V4: V1 (or prevertebral), from its origin at the subclavian arteries (variations of origin do occur but are not germane to this discussion); V2 (or cervical), entering and extending from the transverse foramina at C6 to C2; V3 (or suboccipital), exiting from the transverse foramina at C2 and travelling toward the dura; and V4 (or intracranial), combining with the opposite vertebral artery to form the basilar artery. A more detailed inspection of segment V3 reveals that the vertebral artery emerges from the transverse foramina of C2, turns sharply laterally then superiorly through the transverse foramina of C1 (visually appearing as a loop), then passing sharply posteriorly hugging the lateral mass of C1, and finally turning superomedially to enter the dura. This redundant looping of vertebral artery serves as an intrinsic protective mechanism to tolerate the primary location of rotation of the cervical spine that occurs at the C1-2 level (⬎50%). As long ago as the 1960s, cadaveric studies were published that demonstrated the physiologic compression of the vertebral arteries associated with normal, physiologic cervical range of motion [2-4]. The main and consistent findings were that the vertebral artery could be occluded with extension and rotation to the contralateral side. The most comprehensive synthesis on this subject was done by Mitchell [5]. This was a meta-analysis of the relationship between Doppler identified changes in vertebral artery blood flow with cervical spine rotation in living people. Mitchell [5] assessed the historical literature, which indicated that numerous descriptive studies, when using various imaging modalities such as angiography, Doppler, and magnetic resonance imaging, supported the anatomically derived postulate that the vertebral artery was an “at risk” structure. The investigator’s aim in this meta-analysis was to determine whether there was reasonable evidence to support this claim. Only 9 studies met inclusion criteria. The study by Mitchell [5] concluded the following: there is a paucity of evidence, assessing vertebral artery blood flow via Doppler is position dependent (relevant differences noted between sitting and standing), vertebral artery blood flow was greater in healthy young subjects vs. those with known vertebral artery insufficiency in neutral spine postures, and a significant reduction in blood flow occurs contralateral to the side of full cervical rotation. Mitchell [5] suggested that the decrease in flow was most consistently in segment V4; a finding that supports the theory that mechanical compromise of the vertebral artery with rotation most likely occurs suboccipitally (in the V3 segment), thus reducing downstream flow.
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THE MECHANISM AND RISK OF STROKE THAT RESULTS FROM MANIPULATION The hallmark pathomechanism of stroke after cervical spine manipulation is dissection of the vertebral artery. In simple terms, this condition evolves from an intimal tear to the development of a thrombus within the wall of the vertebral artery, thereby compressing the lumen, or within the lumen itself. In either situation, ischemia to the posterior cerebral circulation results, with varying clinical presentations, but most typically with cerebellar (eg, ataxia, vertigo), brainstem (eg, diplopia, dysphagia), and sensory (eg, ipsilateral face and contralateral body) deficits. Clearly, a stroke that results from a spinal manipulation is a devastating occurrence. Certainly, the key question is, what is the risk of such an event happening? There is limited evidence to attempt to answer this question with systematic reviews [6,7] and case controlled studies [8-10] far outweighed in number by many uncontrolled case reports. However, relative risk has been estimated, which ranged from 1.3 cases per 100,000 [8] to 1 case per 5.8 million [11]. Miley et al performed a critical analysis of the literature and concluded that the burden of evidence does support a relationship between cervical manipulation and stroke [11a]. The investigators determined that multiple observational studies reached the same conclusion: there is a biologic plausibility that supports the hypothesis that the greatest risk appears to be in younger adults (⬍45 years old) and within 1 week of receiving the manipulative treatment, although there is not a single cause and effect. To be certain, there is controversy regarding this described relationship between cervical manipulation, vertebral artery injury, and stroke. For example, Haldeman et al [12,13] determined that the literature is generally insufficient to allow the formulation of a risk analysis, and they have further suggested that perceived risk is in part a consequence of referral bias [11]. In this latter study, of Canadian chiropractic insurance claims over a 10-year period, the investigators determined that there was a 20-fold greater likelihood that a neurologist would be made aware of a given case of vascular complication from manipulation compared with a chiropractor [11]. Yet, this association becomes clearer if various risk factors are considered. Rubinstein et al [14] proposed a contextualbiologic model to explain the risk of stroke associated with cervical manipulation. The investigators opined that trauma alone is insufficient to result in VAD. They suggested an overlapping contribution of genetic risk for vascular disease, common medical risk factors (eg, hypertension, smoking, diabetes, hyperlipidemia), and environmental factors (eg, infection, birth control pills) in association with “trivial trauma,” such as resulting from sporting activity or spinal manipulation to result in vertebral artery injury and stroke.
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This risk factor analysis may support the finding of greater risk in younger people.
PUBLISHED GUIDELINES AND RECOMMENDATIONS A report of the association between cervical manipulation and stroke was first published in 1934 [15]. Since then, there have been more than a hundred case reports that described vertebrobasilar stroke as a consequence of manipulation. It is then curious to observe the impact of this evidence on the development of published clinical guidelines. In preparing this Counterpoint, I searched the Web sites of several organizations of the health care providers of mobilization and/or manipulation techniques to identify published guidelines. There are very few published organizational clinical guidelines that address this relationship. Only 2 non-United States groups, the Canadian Chiropractic Association and the Australian Physiotherapy Association, have published specific recommendations regarding manipulation of the cervical spine related to the risk of vascular injury and developing a stroke. I will briefly summarize those recommendations and nonrecommendations below:
Canadian Chiropractic Association The most extensive published document regarding the risk of vascular injury and recommendations for chiropractic manipulation of the cervical spine is the Canadian Chiropractic clinical practice guideline: Evidence-based treatment of adult neck pain not due to whiplash [16]. This publication distinguishes between the risk of VAD and the development of a stroke. It is emphasized that the evidence is weak and that the risks are uncertain (and probably rare). The primary conclusion is that manipulation does not cause VAD, but patients with underlying vertebral artery compromise and vascular disease (knowing or unknowing) will be treated by chiropractors. Thus, several clinical and/or risk management recommendations are presented: 1. clinically evaluate (by history, symptoms, and signs) risk factors for vascular disease or vertebrobasilar insufficiency; 2. pretreatment vascular testing (eg, Doppler) is not necessary; 3. caution regarding treatment of a patient with recent (but not ongoing) sharp, severe neck or occipital pain, or headache that is sudden and unfamiliar; 4. use of minimal rotatory movement in upper cervical manipulation or any modality associated with upper cervical spine treatment; and 5. use informed consent.
Australian Physiotherapy Association In Australia, physiotherapists are licensed to perform manipulation. A 2006 Clinical Guidelines for Assessing Vertebro-
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basilar Insufficiency in the Management of Cervical Spine Disorders [17] recognizes that vertebrobasilar insufficiency can be provoked or worsened by manipulation or sustained end-range rotation. Pretreatment testing through simulated manipulation position is recommended, and repeated assessment throughout treatment is also suggested. Patients are required to provide informed consent, including knowledge of risk of stroke and death, before manipulative treatment is initiated. Specific treatment recommendations to be followed by providers include the following: 1. start with mobilization techniques; 2. avoid upper cervical rotation, end-range rotation or extension, and neck traction; 3. avoid excessive thrusting force or range of movement; and 4. avoid multiple manipulations to the same joint in the same session.
American Chiropractic Association No specific guidelines are published, and no formal statements regarding contraindication to upper cervical manipulation or risk of manipulation and vertebrobasilar insufficiency [18]. NCMIC Chiropractic Solutions, the largest chiropractor professional liability carrier in Canada, published a 2005 Executive Summary [19] in which it was stated that no direct causative relationship between appropriately administered chiropractic spinal manipulation and stroke exists. Any cervical artery disease was considered likely coincidental.
American Physical Therapy Association A 2009 White Paper from the American Physical Therapy Association acknowledges that there is a risk of vertebrobasilar insufficiency but states that there are no higher claims losses for physical therapists who use thrust joint manipulation compared with other interventions [20]. It is recommended that proper screening for “red flag” symptoms be performed before treatment. Parenthetically, it is noteworthy that, in the United States, physical therapists are not licensed to perform a manipulative thrust (the highest grade of mobilization).
American Osteopathic Association An American Osteopathic Association Position Paper on Osteopathic Manipulative Treatment of the Cervical Spine [21] states that there is a very low risk of vascular injury from high-velocity low-amplitude manipulation and that this treatment method continues to be taught to trainees along with sufficient information to be aware of risks. No special precautions are recommended.
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FINAL THOUGHTS AND RECOMMENDATIONS As a clinician, I base my medical decisions and recommendations on published evidence, clinical experience, personal bias, a healthy balance of conservatism and progressivism, and the basic tenant of “do no harm.” For me, this case scenario epitomizes and incorporates all of these factors. The issue at hand is, very simply stated, is the vertebral artery at risk with manipulation of the upper cervical spine? It is known from both cadaveric and live-person studies that even cervical range of motion that is considered normal can result in alteration of vertebral artery blood flow. One can easily extrapolate that forceful movement into and even beyond this at-risk range of motion has the potential to be problematic. Admittedly, the clinical evidence of experiencing a stroke from a cervical manipulation is not overwhelming, but it does exist, and, as the saying goes, “It only takes one.” I have experienced that “one.” Further, if the leadership of some chiropractic organizations did not consider this important, then there would not be any clinical guidelines produced. Let us also take a closer look at this case as it regards the contextual and guideline-specific risk factors. First, there is a strong family history of vascular disease. This patient has not had an individualized workup, and it is assumed that he does not have diabetes or hereditary homocysteinemia, but it is reasonable to conclude that he does have dyslipidemia. Second, historically, he has intense, sharp upper cervical pain radiating to his occiput that is different than previous episodes of neck pain that he has experienced. He does not have clinical evidence for segmental instability, and no flexionextension radiographs were reported, but the new symptom complex raises concern (see the Canadian Chiropractic Association guidelines above). Third, he is relatively young, barely over the age of people considered to be at higher risk for manipulation-associated VAD and stroke. Last, the issue at hand is not the risk to the spinal neural elements (ie, spinal cord and nerve roots), so the finding of hyperreflexia is not relevant and probably is physiologic. The balance tests are more relevant but likely of limited sensitivity for any baseline central nervous system deficits. In conclusion, one may argue that the risk is so low that conceptually it parallels other potentially “risky” life activities that most of us do not hesitate to participate in, for example, travelling from point A to point B, so why worry? Well, travelling is more or less required in our mobile society, but cervical spine manipulation is not mandatory; in fact, it is elective, and I have elected to not recommend upper cervical spine manipulation to my patients. There are less-risky alternatives, including segmental mobilization within defined limits of motion, manually controlled traction, and, in my opinion, even fluoroscopically guided C2-3 zygapophysial joint injections (if clinically indicated) are less risky than upper cervical manipulation. If the patient remains absolutely
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insistent, then I would strongly recommend a more detailed history and examination for symptoms and signs of posterior circulatory compromise, an exhaustive cardiovascular assessment, including vertebral artery Doppler or magnetic resonance angiography, serum lipid profile, and homocysteine level, and I would strongly suggest to the manipulator that he or she present a very clearly worded informed consent.
REFERENCES 1. Weinstein SM, Cantu RC. Cerebral stroke in a semi-pro football player: A case report. Med Sci Sports Exerc 1991;23:1119-1121. 2. Brown BSTJ, Tissington-Tatlow WF. Radiographic studies of the vertebral arteries in cadavers. Radiology 1963;81:80-88. 3. Selecki BR. The effects of rotation of the atlas on the axis: Experimental work. Med J Aust 1969;1:1012-1015. 4. Toole JF, Tucker SH. Influence of head position upon cerebral circulation. Arch Neurol 1960;2:616-623. 5. Mitchell J. Vertebral artery blood flow velocity changes associated with cervical spine rotation: A meta-analysis of the evidence with implications for professional practice. J Man Manip Ther 2009;17:46-57. 6. Ernst E. Adverse effects of spinal manipulation: A systematic review. J R Soc Med 2007;100:330-338. 7. Stevinson C, Ernst E. Risks associated with spinal manipulation. Am J Med 2002;112:566-571. 8. Rothwell DM, Bondy SJ, Williams JI. Chiropractic manipulation and stroke. A population-based case-control study. Stroke 2001;32:10541060. 9. Dittrich R, Rohsbach D, Heidbreder A, et al. Mild mechanical traumas are possible risk factors for cervical artery dissection. Cerebrovasc Dis 2007;23:275-281. 10. Smith WS, Johnston SC, Skalabrin EJ, et al. Spinal manipulative therapy is an independent risk factor for vertebral artery dissection. Neurology 2003;60:1424-1428. 11. Haldeman S, Carey P, Townsend M, Papadopoulos C. Clinical perceptions of the risk of vertebral artery dissection after cervical manipulation: The effect of referral bias. Spine J 2002;2:334-342. 11a.Miley ML, Wellik KE, Wingerchuk DM, Demaerschalk BM. Does cervical manipulative therapy cause vertebral artery dissection and stroke? Neurologist 2008;14:66-73. 12. Haldeman S, Kohlbeck FJ, McGregor M. Unpredictability of cerebrovascular ischemia associated with cervical spine manipulation therapy: A review of sixty-four cases after cervical spine manipulation. Spine (Phila Pa 1976) 2002;27:49-55. 13. Haldeman S, Kohlbeck FJ, McGregor M. Risk factors and precipitating neck movements causing vertebrobasilar artery dissection after cervical trauma and spinal manipulation. Spine (Phila Pa 1976) 1999;24:785794. 14. Rubinstein SM, Haldeman S, van Tulder MW. An etiologic model to help explain the pathogenesis of cervical artery dissection: Implications for cervical manipulation. Physiol Ther 2006;29:336-338. 15. Thornton FV. Malpractice: Death resulting from chiropractic treatment of headache (medicolegal abstract). JAMA 1934;103:1260. 16. Canadian Chiropractic Association, Canadian Federation of Chiropractic Regulatory Boards, Clinical Practice Guidelines Development Initiative, et al. Chiropractic clinical practice guideline: Evidence-based treatment of adult neck pain not due to whiplash. J Can Chiropr Assoc 2005;49:158209. Available at http://files.chiropracticcanada.ca/2011/cpg_whiplash/ publishedguideline_en.pdf. Accessed June 7, 2012. 17. Rivett D, Shirley D, Magarey M, Refshauge K. Clinical Guidelines for Assessing Vertebrobasilar Insufficiency in the Management of Cervical Spine Disorders Available at http://physiotherapy.asn.au/images/Document_ Library/Clinical_Guidelines/guidelines%20spine%20disorders.pdf. Accessed June 7, 2012.
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18. http://www.acatoday.org/index.cfm. Accessed June 7, 2012. 19. Current Concepts. Spinal Manipulation and Cervical Arterial Incidents. 2005. https://www.ncmic.com/microsites/CVA/CVA_ExecSummary.pdf. Accessed June 7, 2012. 20. American Physical Therapy Association. Position on Thrust Joint Manipulation Provided by Physical Therapists. February 2009. Available at http://www.apta.org/uploadedFiles/APTAorg/
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Advocacy/State/Issues/Manipulation/WhitePaperManipulation.pdf#search⫽ %22guidelines%20vertebral%20artery%20dissection%22. Accessed June 7, 2012. 21. American Osteopathic Association. Position Paper on Osteopathic Manipulative Treatment of the Cervical Spine. Available at https://www. do-online.org/pdf/aoa_position_manipcerspine.pdf. Accessed June 7, 2012.
Feature Editor Commentary From Gary Chimes, MD, PhD Both Dr Weinstein and Dr Schneider agree on a few points in this case scenario, namely that the true risk of cervical manipulation is not known, the patient’s hyperreflexia probably does not influence the next best treatment option, and the largest concern is the potential risk to the vertebra-basilar blood supply, including VAD and stroke. A key point in weighing the view points of both discussants is what, in the absence of cervical manipulation, will the patient choose to do? Dr Schneider noted the risk of NSAIDs as a possible treatment alternative, and Dr Weinstein posited cervical facet injections as a possible alternative, both of which have some associated risk. This is the challenge of truly consenting a patient when the risks are not known. All clinicians are influenced by the personal experiences. As Dr Weinstein noted, he is in his 27th year after residency, and the serious adverse event he personally encountered occurred early in his career. Because he does not routinely recommend upper cervical manipulations to his patients, we have no way of knowing how many
patients he has saved from possible complications; that number may be zero or it may be something substantial, and that has to be weighed with the cost associated with other treatment options. In full disclosure, in my own practice I do offer cervical manipulation as a treatment option, as well as alternatives, including cervical facet injections, lower-velocity manual therapy, cervical traction, ice, postural retraining, and other options (I do not routinely offer NSAIDs, both because patients have usually already trialed them before being seen in the office and because I share Dr Schneider’s concern regarding their long-term risk profile). With regard to the true risk of the manipulation, I think that both parties agree that we do not know, and I think that is the fairest perspective that can be offered with the current data. Both Dr Schneider’s personal experience of successful manipulations and Dr Weinstein’s perspective of a bad outcome are relevant to the discussion but ultimately do not provide a definitive answer.
Web Poll Question For the Case Scenario presented in this Point/Counterpoint, which approach would you recommend? a. cervical manipulation b. no cervical manipulation To cast your vote, visit www.pmrjournal.org
Results of April’s Web Poll For the case scenario presented in The Appropriateness of Long-Term Opioids to Treat Chonic Back Pain, which approach would you take? 11% - long-term opioid therapy as part of a comprehensive pain management plan 89% - transition patient to nonopioid treatment
Cervical Manipulation for Neck Pain
Guest Discussants: Michael Schneider, DC, PhD
CASE SCENARIO K.L. is a 48-year-old man with an acute episode of neck pain. He presents with sharp neck pain in the upper right side. He had neck pain before, but this is significantly more intense than what he has felt in the past. The pain radiates into the posterior aspect of his head. On examination, he has brisk 3⫹ reflexes throughout both his upper and lower limbs, and reports “I’ve always had strong reflexes.” He has a positive Hoffmann sign bilaterally but no ankle clonus, and downgoing toes to a Babinski stimulus. He is stable when performing both a Romberg and tandem Romberg maneuver. No focal weakness was noted within his upper or lower limb myotomes. Both the Sharp-Purser test and the modified lateral shear test were negative for segmental cervical instability. Manual cervical traction provided some relief of symptoms, and manual cervical palpation demonstrated hypomobility of the C1-2 and C2-3 segments on the right side, with concordant reproduction of symptoms. Results of the patient’s vascular examination reveal no evidence of carotid bruits and strong distal pulses in the upper and lower limbs. The patient has no vascular history but notes that his father, older brother, and paternal uncle have significant vascular histories, with his father dying from a ruptured abdominal aortic aneurysm, and his older brother had a 5-vessel coronary artery bypass graft when in his 40s. K.L. has worked with a chiropractor in the past for his low back and has responded well to high-velocity manipulations for his lumbar symptoms. He is interested in a trial of high-velocity manipulations for his neck as well, but, because of his family history of vascular complications, wants to know if it would be safe to have neck manipulations. Michael Schneider, DC, PhD, will argue that cervical manipulations should be performed. Stuart Weinstein, MD, will argue that cervical manipulations should be avoided.
School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA Disclosure: nothing to disclose
Stuart Weinstein, MD University of Washington Sports & Spine, Harborview Medical Center, University of Washington, School of Medicine, Seattle, WA Disclosure: nothing to disclose
Feature Editor: Gary P. Chimes, MD, PhD Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA. Address correspondence to: G.P.C.; e-mail: [email protected] Disclosure: nothing to disclose Disclosure Key can be found on the Table of Contents and at www.pmrjournal.org
Michael Schneider, DC, PhD, Responds This case describes the classic presentation of a patient with acute mechanical neck pain and associated occipital headache who would be expected to respond well to a brief course of cervical manipulation. Results of several studies have concluded that cervical manipulation is an effective treatment for acute neck pain and headache [1]. Recently, a large randomized trial showed that cervical manipulation was more effective than medication for acute and subacute mechanical neck pain [2]. There are no clinical “red flags” suggestive of serious pathology in this case. The patient does not have a history of cervical spine trauma, and the neurologic examination is essentially unremarkable. The physical examination was negative for signs of joint instability or hypermobility. There is no history of rheumatoid arthritis, previous surgery, or connective tissue disease that would be a relative contraindication for cervical manipulation. PM&R 1934-1482/12/$36.00 Printed in U.S.A.
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In summary, this patient appears to be an excellent candidate for spinal manipulation of the cervical spine. There would little argument about whether to consider cervical manipulation as clinical option if not for the insertion in the case scenario of the section about the family history of vascular disease and the brief mention of some neurologic signs. The finding of brisk reflexes and bilateral Hoffmann sign are probably a normal variant, given the fact that the remainder of the neurologic examination was unremarkable. Therefore, the issue of neurologic involvement is not relevant to the discussion about cervical manipulation as a potential treatment option. This case scenario raises a question about the general safety of cervical manipulation as a treatment option for neck pain and headache. This question carries with it 2 implied assumptions: (1) there is a significant increased risk of ad© 2012 by the American Academy of Physical Medicine and Rehabilitation Vol. 4, 606-612, August 2012 http://dx.doi.org/10.1016/j.pmrj.2012.07.003
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verse vascular events associated with cervical manipulation, and (2) this risk is increased with patients who have a family history of vascular or cardiac disease. Both of these assumptions are not supported by the current evidence. The early literature appears to suggest vertebral artery dissection (VAD) and ensuing posterior circulation stroke as a rare vascular complication of cervical manipulation. VAD is an extremely rare event with risk estimates of VAD associated with cervical manipulation that range from 1 per 400,000 manipulations to 1 per 5,000,000 manipulations [3,4]. However, analysis of the most recent evidence suggests that the relationship between cervical manipulation and stroke is not causal [5]. Research results have shown that the 2 strongest risk factors associated with VAD are age under 45 years and various collagen vascular diseases such as Marfan syndrome and Ehlers Danlos syndrome [6]. Fibromuscular dysplasia is found in up to 20% of patients with spontaneous dissections of the cervical internal carotid artery [7], which has led to the suspicion that the rare event of VAD may be caused by an underlying asymptomatic arteriopathy that is in part genetic [8]. Other risk factors for VAD may include recent respiratory infection, migraine, hyperhomocysteinemia, cervical spine trauma, and coughing [7]. Although an association has been observed between cervical manipulation and VAD, the same association has been found with other types of normal activities that involved rotation and/or extension of the neck such as driving, sports, getting a haircut, sneezing, and coughing [9]. A family history of aortic aneurysm and coronary artery disease does not suggest an increased risk of VAD or posterior circulation stroke. A systematic review reported that cervical artery dissections were less likely to be associated with vascular risk factors than noncervical artery dissection strokes [10]. VAD strokes occur in younger patients (⬍45 years) when the risk of atherosclerosis is low. There are no reliable family history questions that can be used to screen patients for risk of VAD, other than the presence of known collagen vascular disease as noted previously. In a large case-control study, several vascular risk factors were actually found to occur less frequently in cervical artery dissection cases than in controls [11]. These vascular risk factors included hypertension, diabetes, hypercholesterolemia, and current smoking. The assumption of increased risk from cervical manipulation leads to an important discussion of all treatment options within the context of evidence-based medicine (EBM), which is based upon 3 key principles: (1) the best current evidence, (2) clinician expertise, and (3) patient preference [12]. Any treatment option offered to a patient with neck pain and headache should be framed within these 3 parameters of EBM. The best current evidence on the topic of risk of vascular injury from cervical manipulation was a large populationbased case-control study of more than 100 million person-
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years [5]. This study found that the general incidence rate of vertebrobasilar artery (VBA) stroke was less than 1 per 100,000 person-years, an extremely rare event. Patients were about 3 times more likely to see a chiropractor or a primary care physician before their stroke than were controls. The investigators found no increased risk of VBA stroke associated with chiropractic care compared with primary care. The observed association between VBA stroke and an increased rate of chiropractic and primary care visits was likely due to patients with headache and neck pain from VBA dissection seeking care before their stroke. These patients had dissections and/or strokes in progress; the treatment rendered by the chiropractor or primary care physician most likely was irrelevant to the eventual outcome of the case. Clinician expertise is the second principle of EBM. The professions of chiropractic, osteopathy, and physical therapy have used various types of cervical manipulation and mobilization for more than a century with good clinical outcomes. It is important to recognize that the term “cervical manipulation” is used to describe a number of different techniques but is typically associated with high-velocity low-amplitude thrust procedures. There also are many other manual techniques used to treat neck pain, such as manual cervical traction, manual trigger point therapy, postisometric stretching, and nonthrust mobilizations. A recent randomized trial found that both thrust-manipulation and nonthrust mobilization methods were effective for relieving acute neck pain [13], and this also was the conclusion of a recent systematic review [14]. Adverse effects of cervical manipulation are common but are typically limited to transient local posttreatment muscle soreness and other mild symptoms. Patient preference is the last, but perhaps the most important, principle of EBM. Many patients simply prefer manipulation instead of medication for neck pain and headache. Some of these patients choose manual treatments because they want to avoid unnecessary medications and take a “natural healing” approach. Other patients have a history of gastric distress and cannot tolerate the adverse effects associated with over-the-counter medications such as ibuprofen and aspirin taken for neck pain. Serious adverse effects from nonsteroidal anti-inflammatory drugs (NSAID) account for a larger number of hospitalizations for gastrointestinal events with an estimated mortality rate of approximately 6% [15]. When considering the common adverse effects of these medications, the option of spinal manipulation as a safe and effective alternative treatment for neck pain and headache should be offered to patients. In summary, spinal manipulation is certainly a reasonable treatment option for the patient described in this hypothetical case scenario. The family history of a father with an abdominal aortic aneurysm and a brother with coronary artery disease is a “red herring,” which detracts from the real issue of whether spinal manipulation should be considered as a viable treatment option for this patient. The best available
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evidence suggests that cervical manipulation is a relatively safe and effective treatment option for neck pain and headache, especially when compared with NSAIDs and other medication options. It should be considered as one of a number of viable treatment options based upon clinician expertise and patient preferences.
REFERENCES 1. Bronfort G, Haas M, Evans R, Leininger B, Triano J. Effectiveness of manual therapies: The UK evidence report. Chiropr Osteopat 2010;18:3. 2. Bronfort G, Evans R, Anderson A, Svendsen K, Bracha Y, Grimm R. Spinal manipulation, medication, or home exercise with advice for acute and subacute neck pain: A randomized trial. Ann Intern Med 2012;156:1-10. 3. Hurwitz EL, Coulter ID, Adams AH, Genovese BJ, Shekelle PG. Use of chiropractic services from 1985 through 1991 in the United States and Canada. Am J Public Health 1998;88:771-776. 4. Smith WS, Johnston SC, Skalabrin EJ, et al. Spinal manipulative therapy is an independent risk factor for vertebral artery dissection. Neurology 2003;60:1424-1428. 5. Cassidy JD, Boyle E, Cote P, et al. Risk of vertebrobasilar stroke and chiropractic care: Results of a population-based case-control and casecrossover study. J Manipulative Physiol Ther 2009;32(Suppl):S201208. 6. Micheli S, Paciaroni M, Corea F, Agnelli G, Zampolini M, Caso V. Cervical artery dissection: Emerging risk factors. Open Neurol J 2010; 4:50-55.
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7. Mokri B, Sundt TM Jr, Houser OW, Piepgras DG. Spontaneous dissection of the cervical internal carotid artery. Ann Neurol 1986;19:126138. 8. Grond-Ginsbach C, Debette S. The association of connective tissue disorders with cervical artery dissections. Curr Mol Med 2009;9:210214. 9. Haldeman S, Kohlbeck FJ, McGregor M. Risk factors and precipitating neck movements causing vertebrobasilar artery dissection after cervical trauma and spinal manipulation. Spine (Phila Pa 1976) 1999;24:785794. 10. Rubinstein SM, Peerdeman SM, van Tulder MW, Riphagen I, Haldeman S. A systematic review of the risk factors for cervical artery dissection. Stroke 2005;36:1575-1580. 11. Debette S, Metso T, Pezzini A, et al. Association of vascular risk factors with cervical artery dissection and ischemic stroke in young adults. Circulation 2011;123:1537-1544. 12. Straus SE, Glasziou P, Richardson WS, Haynes RB. Evidence-based Medicine: How to Practice and Teach It. 4th ed. New York: Churchill Livingstone; 2011. 13. Leaver AM, Maher C, Herbert R, et al. A randomized controlled trial comparing manipulation with mobilization for recent onset neck pain. Arch Phys Med Rehabil 2010;91:1313-1318. 14. Gross A, Miller J, D’Sylva J, et al. Manipulation or mobilisation for neck pain: A Cochrane Review. Man Ther 2010;15:315-333. 15. Lanas A, Perez-Aisa M, Feu F, et al. A nationwide study of mortality associated with hospital admission due to severe gastrointestinal events and those associated with nonsteroidal anti-inflammatory drug use. Am J Gastroenterol 2005;100:1685-1693.
Stuart M. Weinstein, MD, Responds INTRODUCTION Throughout my 27-year career I have seen the entire spectrum of usual and not-so-usual diagnoses. One of those not-so-usual diagnoses that I encountered early in my career was a stroke in a semiprofessional football player after a chiropractic cervical spine manipulation [1]. It is said that lightning does not strike twice in the same place, so I do not expect to see another manipulation-induced stroke for the rest of my career, but I considered myself warned as to the potential danger of cervical spine manipulation. Any trained and credentialed manual therapy provider can legally perform spinal manipulation. This argument will limit the terminology of manipulation to describe a forceful, sudden thrust (typically high velocity, low amplitude) performed by a chiropractor, osteopath, or similarly credentialed physical therapist (the latter, outside of the United States). For purposes of full disclosure, I refer patients to chiropractors, osteopaths, and physical therapists, and I receive referrals from all three. I believe that mobilization and manipulation have roles in the treatment of certain spinal disorders, specifically, those that involve segmental stiffness or dysfunction (note, I do not generally subscribe to the chiropractic term “subluxation”). I also realize that chiropractic is one of the most widely sought treatments in the world,
including by athletes, and that people routinely receive chiropractic care for chronic pain conditions or even so-called maintenance therapies. As I will identify below, the risk of catastrophic consequences is very low. However, I am very cautious about recommending manipulation of cervical spine in total and to the upper cervical spine in particular. My premise in this Point/Counterpoint debate is that the risk of stroke after chiropractic manipulation is real, and I would not recommend a treatment to a patient, athlete or otherwise, that I do not personally endorse. In the following argument, I will present pertinent functional anatomy of the upper cervical spine with an emphasis on the relationship of the vascular and bony anatomy, the purported mechanism and published incidence of vertebral artery injury and stroke after cervical spine manipulation, the current published guidelines that relate to manipulation of the cervical spine, and final thoughts on the subject, including my specific recommendations in this case scenario.
FUNCTIONAL AND VASCULAR ANATOMY OF THE UPPER CERVICAL SPINE As this case scenario implies, it is the risk to the vascular anatomy, specifically the vertebral artery, that is of primary
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concern and open to debate. To understand the potential risk of injury to the vertebral artery, it is necessary to understand the static and functional anatomy of the region. There is an intimate relationship between the vertebral arteries and the bony cervical spine. The course of the vertebral arteries can be divided into 4 segments, V1 to V4: V1 (or prevertebral), from its origin at the subclavian arteries (variations of origin do occur but are not germane to this discussion); V2 (or cervical), entering and extending from the transverse foramina at C6 to C2; V3 (or suboccipital), exiting from the transverse foramina at C2 and travelling toward the dura; and V4 (or intracranial), combining with the opposite vertebral artery to form the basilar artery. A more detailed inspection of segment V3 reveals that the vertebral artery emerges from the transverse foramina of C2, turns sharply laterally then superiorly through the transverse foramina of C1 (visually appearing as a loop), then passing sharply posteriorly hugging the lateral mass of C1, and finally turning superomedially to enter the dura. This redundant looping of vertebral artery serves as an intrinsic protective mechanism to tolerate the primary location of rotation of the cervical spine that occurs at the C1-2 level (⬎50%). As long ago as the 1960s, cadaveric studies were published that demonstrated the physiologic compression of the vertebral arteries associated with normal, physiologic cervical range of motion [2-4]. The main and consistent findings were that the vertebral artery could be occluded with extension and rotation to the contralateral side. The most comprehensive synthesis on this subject was done by Mitchell [5]. This was a meta-analysis of the relationship between Doppler identified changes in vertebral artery blood flow with cervical spine rotation in living people. Mitchell [5] assessed the historical literature, which indicated that numerous descriptive studies, when using various imaging modalities such as angiography, Doppler, and magnetic resonance imaging, supported the anatomically derived postulate that the vertebral artery was an “at risk” structure. The investigator’s aim in this meta-analysis was to determine whether there was reasonable evidence to support this claim. Only 9 studies met inclusion criteria. The study by Mitchell [5] concluded the following: there is a paucity of evidence, assessing vertebral artery blood flow via Doppler is position dependent (relevant differences noted between sitting and standing), vertebral artery blood flow was greater in healthy young subjects vs. those with known vertebral artery insufficiency in neutral spine postures, and a significant reduction in blood flow occurs contralateral to the side of full cervical rotation. Mitchell [5] suggested that the decrease in flow was most consistently in segment V4; a finding that supports the theory that mechanical compromise of the vertebral artery with rotation most likely occurs suboccipitally (in the V3 segment), thus reducing downstream flow.
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THE MECHANISM AND RISK OF STROKE THAT RESULTS FROM MANIPULATION The hallmark pathomechanism of stroke after cervical spine manipulation is dissection of the vertebral artery. In simple terms, this condition evolves from an intimal tear to the development of a thrombus within the wall of the vertebral artery, thereby compressing the lumen, or within the lumen itself. In either situation, ischemia to the posterior cerebral circulation results, with varying clinical presentations, but most typically with cerebellar (eg, ataxia, vertigo), brainstem (eg, diplopia, dysphagia), and sensory (eg, ipsilateral face and contralateral body) deficits. Clearly, a stroke that results from a spinal manipulation is a devastating occurrence. Certainly, the key question is, what is the risk of such an event happening? There is limited evidence to attempt to answer this question with systematic reviews [6,7] and case controlled studies [8-10] far outweighed in number by many uncontrolled case reports. However, relative risk has been estimated, which ranged from 1.3 cases per 100,000 [8] to 1 case per 5.8 million [11]. Miley et al performed a critical analysis of the literature and concluded that the burden of evidence does support a relationship between cervical manipulation and stroke [11a]. The investigators determined that multiple observational studies reached the same conclusion: there is a biologic plausibility that supports the hypothesis that the greatest risk appears to be in younger adults (⬍45 years old) and within 1 week of receiving the manipulative treatment, although there is not a single cause and effect. To be certain, there is controversy regarding this described relationship between cervical manipulation, vertebral artery injury, and stroke. For example, Haldeman et al [12,13] determined that the literature is generally insufficient to allow the formulation of a risk analysis, and they have further suggested that perceived risk is in part a consequence of referral bias [11]. In this latter study, of Canadian chiropractic insurance claims over a 10-year period, the investigators determined that there was a 20-fold greater likelihood that a neurologist would be made aware of a given case of vascular complication from manipulation compared with a chiropractor [11]. Yet, this association becomes clearer if various risk factors are considered. Rubinstein et al [14] proposed a contextualbiologic model to explain the risk of stroke associated with cervical manipulation. The investigators opined that trauma alone is insufficient to result in VAD. They suggested an overlapping contribution of genetic risk for vascular disease, common medical risk factors (eg, hypertension, smoking, diabetes, hyperlipidemia), and environmental factors (eg, infection, birth control pills) in association with “trivial trauma,” such as resulting from sporting activity or spinal manipulation to result in vertebral artery injury and stroke.
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This risk factor analysis may support the finding of greater risk in younger people.
PUBLISHED GUIDELINES AND RECOMMENDATIONS A report of the association between cervical manipulation and stroke was first published in 1934 [15]. Since then, there have been more than a hundred case reports that described vertebrobasilar stroke as a consequence of manipulation. It is then curious to observe the impact of this evidence on the development of published clinical guidelines. In preparing this Counterpoint, I searched the Web sites of several organizations of the health care providers of mobilization and/or manipulation techniques to identify published guidelines. There are very few published organizational clinical guidelines that address this relationship. Only 2 non-United States groups, the Canadian Chiropractic Association and the Australian Physiotherapy Association, have published specific recommendations regarding manipulation of the cervical spine related to the risk of vascular injury and developing a stroke. I will briefly summarize those recommendations and nonrecommendations below:
Canadian Chiropractic Association The most extensive published document regarding the risk of vascular injury and recommendations for chiropractic manipulation of the cervical spine is the Canadian Chiropractic clinical practice guideline: Evidence-based treatment of adult neck pain not due to whiplash [16]. This publication distinguishes between the risk of VAD and the development of a stroke. It is emphasized that the evidence is weak and that the risks are uncertain (and probably rare). The primary conclusion is that manipulation does not cause VAD, but patients with underlying vertebral artery compromise and vascular disease (knowing or unknowing) will be treated by chiropractors. Thus, several clinical and/or risk management recommendations are presented: 1. clinically evaluate (by history, symptoms, and signs) risk factors for vascular disease or vertebrobasilar insufficiency; 2. pretreatment vascular testing (eg, Doppler) is not necessary; 3. caution regarding treatment of a patient with recent (but not ongoing) sharp, severe neck or occipital pain, or headache that is sudden and unfamiliar; 4. use of minimal rotatory movement in upper cervical manipulation or any modality associated with upper cervical spine treatment; and 5. use informed consent.
Australian Physiotherapy Association In Australia, physiotherapists are licensed to perform manipulation. A 2006 Clinical Guidelines for Assessing Vertebro-
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basilar Insufficiency in the Management of Cervical Spine Disorders [17] recognizes that vertebrobasilar insufficiency can be provoked or worsened by manipulation or sustained end-range rotation. Pretreatment testing through simulated manipulation position is recommended, and repeated assessment throughout treatment is also suggested. Patients are required to provide informed consent, including knowledge of risk of stroke and death, before manipulative treatment is initiated. Specific treatment recommendations to be followed by providers include the following: 1. start with mobilization techniques; 2. avoid upper cervical rotation, end-range rotation or extension, and neck traction; 3. avoid excessive thrusting force or range of movement; and 4. avoid multiple manipulations to the same joint in the same session.
American Chiropractic Association No specific guidelines are published, and no formal statements regarding contraindication to upper cervical manipulation or risk of manipulation and vertebrobasilar insufficiency [18]. NCMIC Chiropractic Solutions, the largest chiropractor professional liability carrier in Canada, published a 2005 Executive Summary [19] in which it was stated that no direct causative relationship between appropriately administered chiropractic spinal manipulation and stroke exists. Any cervical artery disease was considered likely coincidental.
American Physical Therapy Association A 2009 White Paper from the American Physical Therapy Association acknowledges that there is a risk of vertebrobasilar insufficiency but states that there are no higher claims losses for physical therapists who use thrust joint manipulation compared with other interventions [20]. It is recommended that proper screening for “red flag” symptoms be performed before treatment. Parenthetically, it is noteworthy that, in the United States, physical therapists are not licensed to perform a manipulative thrust (the highest grade of mobilization).
American Osteopathic Association An American Osteopathic Association Position Paper on Osteopathic Manipulative Treatment of the Cervical Spine [21] states that there is a very low risk of vascular injury from high-velocity low-amplitude manipulation and that this treatment method continues to be taught to trainees along with sufficient information to be aware of risks. No special precautions are recommended.
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FINAL THOUGHTS AND RECOMMENDATIONS As a clinician, I base my medical decisions and recommendations on published evidence, clinical experience, personal bias, a healthy balance of conservatism and progressivism, and the basic tenant of “do no harm.” For me, this case scenario epitomizes and incorporates all of these factors. The issue at hand is, very simply stated, is the vertebral artery at risk with manipulation of the upper cervical spine? It is known from both cadaveric and live-person studies that even cervical range of motion that is considered normal can result in alteration of vertebral artery blood flow. One can easily extrapolate that forceful movement into and even beyond this at-risk range of motion has the potential to be problematic. Admittedly, the clinical evidence of experiencing a stroke from a cervical manipulation is not overwhelming, but it does exist, and, as the saying goes, “It only takes one.” I have experienced that “one.” Further, if the leadership of some chiropractic organizations did not consider this important, then there would not be any clinical guidelines produced. Let us also take a closer look at this case as it regards the contextual and guideline-specific risk factors. First, there is a strong family history of vascular disease. This patient has not had an individualized workup, and it is assumed that he does not have diabetes or hereditary homocysteinemia, but it is reasonable to conclude that he does have dyslipidemia. Second, historically, he has intense, sharp upper cervical pain radiating to his occiput that is different than previous episodes of neck pain that he has experienced. He does not have clinical evidence for segmental instability, and no flexionextension radiographs were reported, but the new symptom complex raises concern (see the Canadian Chiropractic Association guidelines above). Third, he is relatively young, barely over the age of people considered to be at higher risk for manipulation-associated VAD and stroke. Last, the issue at hand is not the risk to the spinal neural elements (ie, spinal cord and nerve roots), so the finding of hyperreflexia is not relevant and probably is physiologic. The balance tests are more relevant but likely of limited sensitivity for any baseline central nervous system deficits. In conclusion, one may argue that the risk is so low that conceptually it parallels other potentially “risky” life activities that most of us do not hesitate to participate in, for example, travelling from point A to point B, so why worry? Well, travelling is more or less required in our mobile society, but cervical spine manipulation is not mandatory; in fact, it is elective, and I have elected to not recommend upper cervical spine manipulation to my patients. There are less-risky alternatives, including segmental mobilization within defined limits of motion, manually controlled traction, and, in my opinion, even fluoroscopically guided C2-3 zygapophysial joint injections (if clinically indicated) are less risky than upper cervical manipulation. If the patient remains absolutely
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insistent, then I would strongly recommend a more detailed history and examination for symptoms and signs of posterior circulatory compromise, an exhaustive cardiovascular assessment, including vertebral artery Doppler or magnetic resonance angiography, serum lipid profile, and homocysteine level, and I would strongly suggest to the manipulator that he or she present a very clearly worded informed consent.
REFERENCES 1. Weinstein SM, Cantu RC. Cerebral stroke in a semi-pro football player: A case report. Med Sci Sports Exerc 1991;23:1119-1121. 2. Brown BSTJ, Tissington-Tatlow WF. Radiographic studies of the vertebral arteries in cadavers. Radiology 1963;81:80-88. 3. Selecki BR. The effects of rotation of the atlas on the axis: Experimental work. Med J Aust 1969;1:1012-1015. 4. Toole JF, Tucker SH. Influence of head position upon cerebral circulation. Arch Neurol 1960;2:616-623. 5. Mitchell J. Vertebral artery blood flow velocity changes associated with cervical spine rotation: A meta-analysis of the evidence with implications for professional practice. J Man Manip Ther 2009;17:46-57. 6. Ernst E. Adverse effects of spinal manipulation: A systematic review. J R Soc Med 2007;100:330-338. 7. Stevinson C, Ernst E. Risks associated with spinal manipulation. Am J Med 2002;112:566-571. 8. Rothwell DM, Bondy SJ, Williams JI. Chiropractic manipulation and stroke. A population-based case-control study. Stroke 2001;32:10541060. 9. Dittrich R, Rohsbach D, Heidbreder A, et al. Mild mechanical traumas are possible risk factors for cervical artery dissection. Cerebrovasc Dis 2007;23:275-281. 10. Smith WS, Johnston SC, Skalabrin EJ, et al. Spinal manipulative therapy is an independent risk factor for vertebral artery dissection. Neurology 2003;60:1424-1428. 11. Haldeman S, Carey P, Townsend M, Papadopoulos C. Clinical perceptions of the risk of vertebral artery dissection after cervical manipulation: The effect of referral bias. Spine J 2002;2:334-342. 11a.Miley ML, Wellik KE, Wingerchuk DM, Demaerschalk BM. Does cervical manipulative therapy cause vertebral artery dissection and stroke? Neurologist 2008;14:66-73. 12. Haldeman S, Kohlbeck FJ, McGregor M. Unpredictability of cerebrovascular ischemia associated with cervical spine manipulation therapy: A review of sixty-four cases after cervical spine manipulation. Spine (Phila Pa 1976) 2002;27:49-55. 13. Haldeman S, Kohlbeck FJ, McGregor M. Risk factors and precipitating neck movements causing vertebrobasilar artery dissection after cervical trauma and spinal manipulation. Spine (Phila Pa 1976) 1999;24:785794. 14. Rubinstein SM, Haldeman S, van Tulder MW. An etiologic model to help explain the pathogenesis of cervical artery dissection: Implications for cervical manipulation. Physiol Ther 2006;29:336-338. 15. Thornton FV. Malpractice: Death resulting from chiropractic treatment of headache (medicolegal abstract). JAMA 1934;103:1260. 16. Canadian Chiropractic Association, Canadian Federation of Chiropractic Regulatory Boards, Clinical Practice Guidelines Development Initiative, et al. Chiropractic clinical practice guideline: Evidence-based treatment of adult neck pain not due to whiplash. J Can Chiropr Assoc 2005;49:158209. Available at http://files.chiropracticcanada.ca/2011/cpg_whiplash/ publishedguideline_en.pdf. Accessed June 7, 2012. 17. Rivett D, Shirley D, Magarey M, Refshauge K. Clinical Guidelines for Assessing Vertebrobasilar Insufficiency in the Management of Cervical Spine Disorders Available at http://physiotherapy.asn.au/images/Document_ Library/Clinical_Guidelines/guidelines%20spine%20disorders.pdf. Accessed June 7, 2012.
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18. http://www.acatoday.org/index.cfm. Accessed June 7, 2012. 19. Current Concepts. Spinal Manipulation and Cervical Arterial Incidents. 2005. https://www.ncmic.com/microsites/CVA/CVA_ExecSummary.pdf. Accessed June 7, 2012. 20. American Physical Therapy Association. Position on Thrust Joint Manipulation Provided by Physical Therapists. February 2009. Available at http://www.apta.org/uploadedFiles/APTAorg/
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Advocacy/State/Issues/Manipulation/WhitePaperManipulation.pdf#search⫽ %22guidelines%20vertebral%20artery%20dissection%22. Accessed June 7, 2012. 21. American Osteopathic Association. Position Paper on Osteopathic Manipulative Treatment of the Cervical Spine. Available at https://www. do-online.org/pdf/aoa_position_manipcerspine.pdf. Accessed June 7, 2012.
Feature Editor Commentary From Gary Chimes, MD, PhD Both Dr Weinstein and Dr Schneider agree on a few points in this case scenario, namely that the true risk of cervical manipulation is not known, the patient’s hyperreflexia probably does not influence the next best treatment option, and the largest concern is the potential risk to the vertebra-basilar blood supply, including VAD and stroke. A key point in weighing the view points of both discussants is what, in the absence of cervical manipulation, will the patient choose to do? Dr Schneider noted the risk of NSAIDs as a possible treatment alternative, and Dr Weinstein posited cervical facet injections as a possible alternative, both of which have some associated risk. This is the challenge of truly consenting a patient when the risks are not known. All clinicians are influenced by the personal experiences. As Dr Weinstein noted, he is in his 27th year after residency, and the serious adverse event he personally encountered occurred early in his career. Because he does not routinely recommend upper cervical manipulations to his patients, we have no way of knowing how many
patients he has saved from possible complications; that number may be zero or it may be something substantial, and that has to be weighed with the cost associated with other treatment options. In full disclosure, in my own practice I do offer cervical manipulation as a treatment option, as well as alternatives, including cervical facet injections, lower-velocity manual therapy, cervical traction, ice, postural retraining, and other options (I do not routinely offer NSAIDs, both because patients have usually already trialed them before being seen in the office and because I share Dr Schneider’s concern regarding their long-term risk profile). With regard to the true risk of the manipulation, I think that both parties agree that we do not know, and I think that is the fairest perspective that can be offered with the current data. Both Dr Schneider’s personal experience of successful manipulations and Dr Weinstein’s perspective of a bad outcome are relevant to the discussion but ultimately do not provide a definitive answer.
Web Poll Question For the Case Scenario presented in this Point/Counterpoint, which approach would you recommend? a. cervical manipulation b. no cervical manipulation To cast your vote, visit www.pmrjournal.org
Results of April’s Web Poll For the case scenario presented in The Appropriateness of Long-Term Opioids to Treat Chonic Back Pain, which approach would you take? 11% - long-term opioid therapy as part of a comprehensive pain management plan 89% - transition patient to nonopioid treatment