Can you cause a stroke by manipulating a neck?

I rarely, rarely manipulate cervical spines. I hardly ever did CT junctions anyway, but that’s mostly because I never really got the hang of them. But necks, I used to love them. By far the easiest manipulation, I used a cradle hold, had really nice, high velocity and low amplitude and could easily produce a neat click. I felt like a ninja. Often there was an instant release of tissue tension and freer movement, and even though patients sometimes felt a bit nervous about it, I didn’t, not in the slightest, and was able to reassure them in a totally and genuinely confident manner, because that’s how I felt.

This was despite the fact that the marvellous Dr Peter Randall tried to put the fear of God into us at college.   He had formulated an extensive  protocol to perform before manipulating necks, and rendered half of year 3  therapeutically impotent with his grave warnings about the vulnerability of the arterial blood supply to the head, and the disastrous consequences of affecting that supply.  However I listened to other tutors too, and as long as the patient was ‘healthy’, aged 18-60, and I’d taken blood pressure and performed “Maigne’s Test”, I thought I’d be OK.

I was startled a few years into practice when a neurologist friend told me that his London hospital got about six strokes a year following neck manipulations; mostly vertebral artery dissections. (I honestly didn’t know exactly what that meant, imagining the artery wall tearing right through and blood spurting everywhere). They didn’t follow them up, he said. They were so used to adverse events that he seemed to just see it as a risk of treatment, not the result of negligence or incompetence.  He said they were probably something that “would have happened anyway” and treatment was only a trigger. They got roughly the same number following visits to the hairdressers. He seemed pretty relaxed about it, but didn’t like the idea of his own neck being clicked.

But the thing that stopped me in my tracks was when I chatted to an osteopath at a barbecue, who’d heard about someone in New Zealand whose patient had had some kind of neurovascular emergency on the treatment table following manipulation.  She told me that she didn’t manipulate necks any more.  And that’s when I stopped doing it so much. And do you know what? I don’t think I noticed any change in my clinical results. So little change that I don’t really do it at all now. The last time was probably 3 years ago, and only because a patient virtually demanded it.

If I’m honest, part of the reason I stopped clicking was defensive.  Patients perceive a click as a high risk technique, and if they happened to have a stroke that week that is what they might point to as the cause, the same way that if you stick a needle in someone they attribute their entire improvement to that needle.  But then I became uneasy again when I began to hear  that the kind of “safer” treatments that I used – inhibitions, articulations, Swedish massage – were possibly more risky than a quick manip.

So all things considered, I jumped at the chance to go on a UCO course entitled Cervical Spine Risk Assessment and Consent for Manual Therapists, hosted by Roger Kerry and Steve Vogel, both well known in their respective fields of physiotherapy and osteopathy for their work in this area.

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Roger Kerry and Steve Vogel shine a light on the risks associated with treating necks

The following question was put to us for a show of hands:

Treatment by manual therapists causes cervical artery dysfunction and stroke – yes or no.

I put my hand up as a “yes”.   I’ve read the sobering stories of angry stroke patients on the VOCA website – Victims of Chiropractic Abuse.  I’ve heard Edzard Ernst speak,  and read his books.  Anti-CAM campaigners  use the risk of stroke as one of the chief sticks with which to poke osteopathy and chiropractic, (even though physiotherapists use the technique they hold responsible as well.)  And they’re very persuasive.

But there was only a small  group of us ‘yes’ people on this course, and a slightly bigger group of ‘no’ people.  The majority sat on the fence.  It seems that either we manual therapists don’t really have a consensus on this, or we’re already aware of the shades of grey.

Roger Kerry and Steve Vogel have both spent years studying this field, and they admirably compressed vast amounts of information and research findings into roughly seven hours.  For a more thorough understanding, book onto their course, or if you want to do it the hard way, search out their work over the past decade.  All I can do is crunch an already compressed volume of understanding into a readable 1000 words or so. Hopefully you’ll pick up a few key messages, realise there’s a lot to learn, begin to feel your way around this important but complex area, and not use what I say in defence of your practice, which, in case you weren’t clear, is your responsibility.

Get used to referring to “CAD” or Cervical Artery Dysfunction

Totally confusingly, some people use the acronym CAD to mean cervical artery dissection, some use it to mean carotid artery dissection, and some (including us here) to mean cervical artery dysfunction, which includes atherosclerosis, stenosis, thrombosis, embolus, ischaemia or aneurysm.

It’s incredibly rare to cause a stroke in an otherwise healthy person

I don’t think anyone is saying it’s totally impossible, but it is extremely unlikely you’d cause a stroke in an otherwise healthy person, unless you used really unreasonable force.  The risks are more that you

  1. don’t pick up the early stages of ischaemic event, or you
  2. convert pre-existing cervical arterial dysfunction (CAD) into a stroke with your treatment.

The risk isn’t within the intervention, it’s about the risk within an emerging process.

It’s not all about clicking

HVT, or manipulation, or whatever you like to call it – that technique which causes an audible, tangible, click in the joint – is indeed not the most risky technique.

Not too long ago a non-clicking massage therapist in a spa in South East England was sued for causing a stroke.  I think the debate was about whether she used undue pressure in massaging the neck. But it could equally have been about posture, if the patient was lying  with neck fully rotated or extended for a while.  That’s because it’s the end of range position or the pressure that’s significant, not the click.  (I tried to find this story again online, but just try including stroke and massage in your search terms and you’re looking for a needle in a haystack!)

Another non-click example:  Roger Kerry told us about a physiotherapist doing home visits who was found to be causing weekly TIAs by doing neck rotations (or gliding apophyseals as he more poetically called it) to ease a patient’s stiff neck.

And another:  A hairdresser near me was sued for causing a stroke not long ago due to simply positioning the patient’s head in extension over the basin in standard hairwashing posture.  The client has ongoing problems years later.

Pressing too hard, or using too much end-of-range rotation, or prolonged end-of-range motion, is probably riskier than a low amplitude thrust technique within comfortable range of motion.  

So don’t do functional positional testing

Yet another one for my bulging “Everything I learnt at college was wrong” file.  The legendary Dr Randall aside, the general rule when I was an undergraduate was that you do this test before you manipulate a neck to ensure that it is safe to proceed.

However,  functional positional testing (or Maigne’s test as we learnt it) is, as mentioned above, one of the worst things you can do!  It could certainly precipitate stroke in a patient with cervical artery dysfunction (CAD).  The test involves putting the patient in a position of neck rotation/extension and holding it for quite a long time, and looking for nystagmus or diplopia or other quite extreme signs and symptoms to develop.  For years I performed this test, deludedly believing I was being ultra safe and that “Maigne’s: negative” in my notes would demonstrate in any court of law that I had done everything I could to ensure that neck HVT was safe.    Not the case.

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Roger Kerry explains the surprisingly interesting pathophysiology of cervical artery dysfunction and dissection

It’s not all about the vertebral artery

When I learnt about risks previously, it was all focussed on the vertebral artery.  Yes it is a small artery, and yes it does actually thread right through the bones and go through 90 degree twists;  however, according to Roger Kerry, the vertebral artery is counterintuitively not as vulnerable as you would think, and we should not forget about  the internal carotid, which is not immune from risk because it is bigger and straighter.  In fact the small bore of the vertebral artery lumen, plus those kinks, actually make it more efficient at “self-cleaning”.  This is because there is less turbulence in a narrower artery, and the kinks create continual compression and “helicoidal flow” which helps to avoid the buildup of atherosclerosis.  The figures are difficult to analyse because the numbers are so very tiny, but in one sample, more internal carotid dissections had occurred after manipulation than vertebral artery dissections.

Risk managing:  It’s a bit like cauda equina syndrome, only not like cauda equina syndrome

In terms of risk management, you can think of ischaemic events a bit like cauda equina, except it’s not as easy to diagnose as cauda equina.   I screen for cauda equina all the time.  I long ago got over the embarrassment of warning about bladder and bowel incontinence, or asking if people can feel the toilet paper when they go to the loo.  I’ve never seen cauda equina in my clinic, nor has any osteopath I have worked with, as far as I know.  But despite it being rare, it is still in the foreground of my consciousness, because the catastrophic consequences of missing it outweigh the unlikelihood it will happen.  Of course I don’t tell every patient about it, but I probably perform some subconscious mental algorithm which means that I do a risk assessment without realizing I’m doing it.

The thing is, though, that cauda equina syndrome signs and symptoms are quite dramatic, and easy to  spot if they happen, whereas the early stages of an ischaemic event in the head and neck might be indistinguishable from neck strain or tension headache.  The symptoms and signs of early ischaemia can be subtle and ambiguous. Pain, not CNS or vascular symptoms, is the presenting feature.  By the time dysarthria, vertigo or nystagmus appear,  the patient either wouldn’t be presenting to you or you’d be packing them straight off to the medics anyway.  So it’s a case of familiarising ourselves with the clinical features (there are typical patterns and pain  descriptors), and of being well-versed in the risk factors, as you need to be picking those up from the history.  Following this course I am going to start screening blood pressure and cranial nerves a bit more often.  And I know better what questions to ask.   But no one, I’m afraid, is going to be able to give you an absolute test or question or protocol which will enable you to rule CAD/early ischaemia out.  It’s always going to be a risk management situation.

Spot it in the early stages and a stroke can be prevented

Yes there’s a really good reason to consider every patient with head and/or neck pain for cervical artery dysfunction or early ischaemia, and that is that a fatal or traumatic event can be completely and fairly easily prevented by the doctors if it’s caught in time.

So there’s no conclusive yes or no to that initial question, and no way to ensure 100% safety, but I know a lot more than I did, and that’s given me confidence, rather than nervousness.  I am reassured that it is incredibly rare for a patient to stroke out following  treatment.   I also know what a vertebral artery dissection actually is,  I am more equipped to spot CAD based on clinical features and history, more aware of what questions to ask, to know which treatments are  risky, and what to tell patients if I have concerns.  My advice is to learn about it: don’t stress about it.


13 thoughts on “Can you cause a stroke by manipulating a neck?

  1. If you haven’t read it there’s a brilliant masterclass in IJOM by Steve Vogel and others entitled ‘Manual therapy and cervical artery dysfunction: Identification of potential risk factors in clinical encounters’. It discusses risk factors like history of migraine and various other stuff that was new to me. All osteopaths can access this via their o-zone login.

    Liked by 1 person

  2. Hi!

    Good post, but I was yearning for some more clinical tips at the end.

    What is the typical pain presentation ?
    Which questions are you now more inclined to ask ?
    What blood-pressure readings will heighten your assessment of risk ?

    Liked by 1 person

  3. Nice post Penny.
    I have been firmly in the no CSpine manipulation camp for a while now mostly because of the fear instilled into me on my degree course regarding potential risks. Also because I never found them easy and get good results from a CT lift so haven’t felt the need to manipulate the CSpine directly.
    The big question is whether or not you will start manipulating again based on your new-found knowledge?

    Liked by 2 people

  4. Great blog topic Penny

    I’m a physio and CAD was my MSc dissertation topic. Great literature available and further insight from Roger Kerry et al. I’d recommend other fellow manual therapists check out his papers which contain guidelines for practice. Share the word!


    Liked by 1 person

    • Thanks Mads, much appreciated that you read it and took time to comment, yes there seem to be quite a few recent studies, some have been circulated on Twitter too in response to the blog.


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