Friday June 8 2012
Spinal manipulation and stroke risk: experts debate the evidence
There has been a “warning over ‘quack’ osteopaths”, The Independent claimed today. The story was more accurately described by the BBC News headline: “Spinal manipulation for neck pain inadvisable”.
The news comes after experts debated the safety and effectiveness of spinal manipulation for neck pain in the pages of the British Medical Journal. The debate featured academics, some of whom said that spinal manipulation should be abandoned as a treatment for neck pain, and some who disagreed saying that it is a valid treatment that patients like.
The media predominantly covered the argument against spinal manipulation. Academics argued that the procedure carries a small risk of a very rare, but catastrophic, type of stroke, which results from a bleed at the base of the brain. They considered that when these safety concerns are coupled with the fact that it is not superior to other treatments, spinal manipulation is unnecessary and inadvisable.
However, the academics who defended spinal manipulation considered it a valuable addition to patient care. They argued that while there are benefits and harms with all treatments – including medications, exercise, mobilisation and manipulation for neck pain – there is “no clear winner” when it comes to the effect on patients’ overall quality of life.
Both articles are based on the professional opinion of the authors, who each presented evidence supporting their viewpoints. They are not systematic reviews and it is unclear whether all evidence relevant to spinal manipulation has been considered. No firm conclusions for or against spinal manipulation can be made based on these opinions alone. Neck pain may have different causes, and the same treatment is unlikely to be appropriate or advisable for everyone. People with persistent neck pain should consult their doctor and discuss the treatment options that would be appropriate for them.
What is spinal manipulation?
The current debates focus on spinal manipulation defined as a “high-velocity, low-amplitude end range thrust manoeuvre”. It is commonly described as a sudden turning or twisting movement of the spine, often accompanied by a “pop” or “click” sound. It is a common treatment for mechanical neck pain.
The debate, although loosely defined, appears to focus on spinal manipulation of the neck by chiropractors, rather than by osteopaths or both.
Where did the story come from?
Both sides of the debate were presented in a pair of articles in the British Medical Journal (BMJ). This “head to head” debate is part of a series of commentary articles designed to be provocative, using confrontational points of view. It is intended to be read by doctors to influence their thinking, rather than the general public.
The article in favour of spinal manipulation for mechanical neck pain was written by Professor J David Cassidy of the University of Toronto and colleagues from the US and Denmark. Professor Cassidy and colleagues declared that they had previously received research funding from chiropractic organisations. The argument against was written by Professor Benedict Wand of the University of Notre Dame, Australia, and colleagues from Australia and the UK. Professor Wand and colleagues declared no conflicts of interest.
The news stories predominantly focused on the editorial stating that spinal manipulation should be abandoned on safety grounds. The news reports did not make it apparent that these publications are academic opinion pieces only, intended to stimulate debate. It is unclear whether all evidence related to the issue has been consulted, so no firm conclusions can be made.
How is the case for spinal manipulation presented?
Professor Cassidy and colleagues believe that manipulation of the cervical spine (neck vertebrae) should not be abandoned. They report that a recent international, multidisciplinary team endorsed spinal manipulation as a “first-line” treatment option for neck pain and whiplash. This was based on the findings of a systematic review of clinical trial results of benefits and adverse effects. The reviewing team looked at the benefits and harms of:
- manipulation for neck pain
They report that “there was no clear winner” in terms of quality-of-life effects. The authors report that another systematic review examining conservative treatments for neck pain found that manipulation, multimodal physical therapy, neck exercises and certain painkillers all had significant short-term pain-relieving effects compared with placebo. Manipulation and acupuncture also had short-term effects on disability compared with placebo. Therefore, the authors consider that the evidence “clearly suggests that manipulation benefits patients with neck pain”. Professor Cassidy’s team also discusses a high-quality trial which found that spinal manipulation was more effective for acute neck pain than anti-inflammatories and paracetamol.
Tackling the potential harms, Professor Cassidy and colleagues say that while there has been a reported association with vertebrobasilar stroke (discussed in more detail below), this has also been associated with other simple activities including:
- rotation or extension of the neck during yoga
- looking up
- hair washing at a salon
They identify that the association between neck manipulation and this type of stroke comes from case reports, and that these provide the lowest level of evidence and cannot be used to show causation.
The authors point out that because vertebrobasilar stroke is a rare event, case-control studies are an appropriate study design to evaluate any associations. They acknowledge that two of these published case-control studies have found an association between this type of stroke and neck manipulation. However, they observe that this type of stroke was associated with manipulation as frequently as it was associated with GP visits. This latter study, they say, further raises doubt about any causal relationship between manipulation and stroke.
The authors’ final point in favour is that patients often prefer spinal manipulation. They say that it is one of the most common treatments for neck pain and that “6–12% of the population receives it annually”.
What did these authors conclude?
Professor Cassidy and colleagues concluded that “the evidence supports manipulation as a treatment option for neck pain, along with other interventions such as advice to stay active and exercise.” When risk, benefit and patient preference are considered, they say, there is currently no preferred first-line treatment and no evidence that mobilisation is safer or more effective than manipulation. The authors conclude: “say no to abandoning manipulation and yes to more rigorous research on the benefits and harms of this and other common interventions for neck pain.”
How is the case against spinal manipulation presented?
Professor Wand and colleagues state that although manipulation of the cervical spine is a common treatment option for muscular neck pain, it carries the risk of causing a bleed of the vertebral artery, which would result in a vertebrobasilar stroke. The vertebral arteries supply the brainstem and cerebellum at the base of the brain. A stroke in this part of the brain carries a high risk of death or serious disability, including paralysis and problems with speaking, swallowing and vision. The authors state that vertebral artery bleeds are extremely rare (estimated incidence of 1 to 1.7 per 100,000 person-years in the US) and strokes are rarer still (0.75 to 1.12 per 100,000 person-years). They say that many of these are unlikely to be the result of cervical manipulation, but they also say that various case studies have observed neurovascular complications to occur after cervical spine manipulation.
They acknowledge that other studies have found this association to be comparable to associations between vertebrobasilar stroke and GP visits. However, Professor Wand’s team maintain that though some cases of vertebrobasilar stroke may be misattributed to manipulation, this does not rule out the possibility that manipulation could cause this type of stroke, or that people who have already had this type of stroke could have their symptoms made worse by subsequent neck manipulation.
Professor Wand and colleagues say that, given the potential “catastrophic” risks, neck manipulation should be used only if it has a clear, unique benefit over other treatments. However, they believe that this is not the case. In their argument against spinal manipulation, they highlight the findings of a recent Cochrane review of clinical trials of neck manipulation or mobilisation. This review concluded that as a single treatment, manipulation provides only moderate short-term pain relief compared with waiting list control, sham manipulation or muscle relaxants. It also gives no benefit compared with other manual therapy techniques, such as cervical mobilisation, according to the Cochrane review. The authors say that other recent large, high-quality trials reinforce the message that manipulation is not superior to other physical interventions such as exercise, and gives no benefit when added to them.
What did these authors conclude?
Professor Wand and colleagues concluded: “The potential for catastrophic events and the clear absence of unique benefit lead to the inevitable conclusion that manipulation of the cervical spine should be abandoned as part of conservative care for neck pain.”
Can we say if spinal manipulation is dangerous?
Newspaper reports that spinal manipulation is dangerous are based on an academic debate in which experts offered their professional opinion and a potentially selective view of the evidence. Although the debate appears in the august, peer-reviewed British Medical Journal, this was not a systematic review. It is not clear whether all evidence relevant to the issue of spinal manipulation has been considered.
These articles were designed to stimulate debate in a controversial area rather than to offer conclusions. No conclusions for or against spinal manipulation can be made based on these opinion pieces alone. Neck pain may have a variety of causes, and the same treatment is unlikely to be appropriate or advisable for everyone. People with persistent neck pain should consult their doctor to discuss the treatment options that would be appropriate for them.
Analysis by Bazian. Edited by NHS Choices.