Category Archives: Neuroscience


50 strokes

Ajahn Brahm tells the story of a monk who thought he deserved punishment for breaking a monastic rule. He had knowingly done wrong and expected reprimand, yet this was not the way. The monk insisted, so Ajahn Brahm prescribed 50 strokes. The thought of this ancient punishment undoubtedly filled the monk with fear yet he knew this was his fate. However, no whip was produced but instead a cat, which the monk was ordered to stroke—50 times. After the 50 strokes of the cat there was peace and calm and the passing of a learning experience. Change was afoot.

In physiotherapy we use our hands to treat and create calm in a body that is protecting itself, perceiving a range of cues to be threatening. It has been thought that moving joints, muscles and nerves bring about the desired changes (or not if unwisely applied) because of a change in the structures. Science has since taught us otherwise, and that in fact what we are really doing is changing the processing in the body systems and then the recipient has a different and better experience—pain eased and movement more natural and thoughtless.

Touch is very human. Touch is a part of the way we develop in the early years, a lack of touch being detrimental to normal development. So potent when the meaning is aligned with a sense of creating wellbeing and soothing woes both physical and emotional, touch should be part of therapy for any pain condition. Interweaving hands-on treatments during sessions, teaching patients how to use touch themselves, teaching carers and partners how they can use touch, all create the conditions for healthy change.

Touch send signals from the nerves in the skin and muscles to the spinal cord and then onwards to the brain. In this way, the body is an extension of the brain and the brain an extension of the body, demonstrating  how we are  a whole person with no system or structure being in isolation to any other. Using touch is literally sculpting the representation of the body that exists in the brain, like moulding clay into a humanly shape. And of course, a shape has a function and the two are not distinct. The more precise the shape, the better the function. The manifestation of this being a normal sense of self in how we think and feel and a move. Normalising, desensitising, to me are one and the same.

— 50 strokes of the area of the body being protected, much like stroking the cat then, sculpts our ever changing brain and sense of physical body. The physical body exists and occupies space with the ever-potential of action, yet this does not exists without thought—it is my thought, the meaning that I give to my body that creates what it is in any given moment. When the strokes feel pleasant, or at least not painful, then this is your body and brain perceiving the action as being non-threatening and learning that the area is safe. The more of this the better. The same applies with movement: any action that is tolerable or feels good is the body (your whole self) saying ‘yes, that’s ok’. And that’s what we practice and practice.

To overcome and change pain is to normalise and to alter one’s relationship with pain and overall perception. We have much more say in this than most people realise but once they understand their pain, what pain really is and what they can do, change occurs in the desired direction.



Want to feel happier, suffer less pain & anxiety, think more clearly?

Mindfulness for pain, health and performance

Mindfulness for pain, health and performance

Mindfulness programme

The brief practice of mindfulness for just 10 minutes each day has a positive affect upon physical and psychological health.

Mindful practice forms part of our treatment and proactive training programmes for chronic pain and health problems. However, learning the practice is beneficial for anyone who wishes to reduce feelings of tension, anxiety and stress; improve sleep, concentration and clarity of thought; and overall have a healthier and happier experience of life.

Mindfulness itself is very simple and practical. Much like we train our body in the gym to be fitter and stronger, mindfulness trains our ability to be aware of what is happening in the present moment, and without judgement.

How much time do you spend on autopilot? How much time do you spend noticing what is going on right now as opposed to dwelling on the past or constructing a future in your mind? Does the past or future make you feel bad or anxious? Do you relive scenarios that make you feel unhappy? The problem is that the brain does not distinguish between what is happening in reality and what is happening in our mind. The body still responds, often by protecting itself using different systems in the body such as the nervous system, the immune system and autonomic nervous system (‘fright or flight’). Gaining insight into the mechanisms and becoming skilled at being present not only creates time, but also disarms the effects of drifting into the past or the future.

Enhancing the potency of mindfulness

Alongside the practice of mindfulness, a simple exercise habit that includes strategies at work will create the conditions for the body systems to cultivate health. A rounded programme of physical and mental training that interlaces with normal living improves performance, sleep, clarity of thought, sense of self, social interactions and immune responses. These factors are related and positively affect each other once healthy habits are learned.

Call us now to book your first mindfulness session: 07932 689081

The Specialist Pain Physio Clinics in London – expert treatment and training to tackle the problem of chronic pain and injury.


Where do we tackle pain?

When someone tells you that they have a painful knee, it makes sense to have a look at the joint to see what has gone wrong. Perhaps an x-ray or a scan would help to determine the state of the cartilage, bone and surrounding soft tissue. An assessment of the range of motion, motor control and the responses to sensory testing reveal any functional limitations and adaptations. Is this enough to truly understand where pain really sits? Is it enough to decide where to intervene? In some cases yes is the answer, but not always!

Important that this kind of evaluation maybe, we must consider the significant pile of literature that points out pain is not an accurate indicator of tissue damage, as so eloquently concluded by Lorimer Moseley. One has only to think about phantom limb pain to realise that there is no need to have an arm, or a leg, or indeed any body part, for there to be pain in that location.

Phantom limb pain is the condition that illustrates the concept that pain is allocated a space. This space could be the knee as in our example above, any other body region or regions, or even outside of the body. A study by Lorimer Moseley also suggested that pain is felt in a space and not within the tissues. Subjects were asked to cross their arms, placing the affected hand into the space usually occupied by the unaffected hand. The effect? Pain relief. This is of course one study, however there was an impact that needs to be further investigated. Assuming that pain is allocated a space, this would explain why, when you position the hand in that of the non-painful side, both the pain and movement quality improve.

This is easily tested in the clinic with both hands and feet. The demonstration is a potent one for the individual as their limb experience can change. Seemingly there is an ease of the tension and guarding as well as the sensitivity. It can be profound, especially when someone has been suffering with a nasty pain such as in complex regional pain syndrome (CRPS) or neuropathic pain. The caveat is that this is not a cure, and it does not work every time, however in those that the effect is apparent, the ability to move more normally promotes healthy tissue and perception by the brain, especially if you are looking at the movement — extra sensory feedback via the visual system.

In summary, as best we know, pain is allocated a space. This can be a space that is occupied by a body region that why we feel pain in the tissues, the place where the pain emerges. The actual location of the pain is determined by the brain as it decides where we need to attend for protection. Recall that pain is a protective device involving a widespread network of neurons within the brain. There is no higher pain centre, but rather a network that monitors the sensory situation and responds as needed. On the basis that the sensory feedback suggests something dangerous is happening, the network will create an output that we experience in the body via a space that is deemed to need protection. Unfortunately, this output can occur without sensory input in some cases of persisting pain as the neuroimmune system becomes very sensitised and responsive to a range of stimuli including those that are not actually dangerous, hence why normal activities can hurt.

On this basis, when considering where to treat pain, we have to consider the space where the brain feels we need protecting. With the emergent property that is pain, the sensation is at the end of a process and it is therefore wise to target the entire biology from top to bottom and bottom to top. This means we need to address the higher centres, for example developing the individual’s understanding of their pain, reducing fears and using strategies for the brain maps of the body concurrent with using techniques within the space, i.e. the body area where the pain is felt.

For more about our comprehensive treatment and training programmes for persisting pain and injury, call us on 07932 689081 to make an appointment. Clinics in London & Surrey.



A quick note on brain~body — body~brain

The brain is where it’s at. Or so it seems if you read the press or look at the bookshelves. The notion that brain is everything has been challenged recently and so it should — see here. We need enquiry at every point, challenging the comfort of thinking that we know.

Despite this, it seems logical to think that the brain is involved with much of our existence. The ‘hows’ and ‘whys’ need continued clarification. In a crude sense, on the end of our brain lies a body. This body is where we feel life whether that be the experience of an external stimulus such as touch or the result of a thought that always triggers a physical and emotional response once we engage with that thought.

The term ‘body-mind’ has been used countless times by both mainstream practitioners of medicine and health and alternative or complimentary therapists. Most people understand the concept although many still try to deny the links. Can a thought really change the physiology in my body? Of course it can. It happens all the time. In fact, I would argue that our body functioning is the emergent physical manifestation of all the processing going on in the mind.

The way in which we move, posture, position ourselves is dependent upon the task at hand but also the task that we may engage with at some point in the near future. The brain is the greatest predictor and will continually analyse the environment, the situation and compare this to what it knows to create the actions necessary. In cases of chronic pain or stress, the brain becomes hypervigilant and responsive to a range of cues that would not normally evoke a protective response but now does via the the autonomic nervous system (‘fright or flight’), the nervous and immune systems.

Much of the activity in our body systems we are unaware of as the brain and reflexive activity takes care so we can attend to the necessary survival tasks. Filtering out the millions of stimuli, the brain draws our attention to what is deemed to be salient for that moment.

In a state of anxiety, this is usually felt in the body — churning stomach, tension, sweaty palms etc. We use the body as a yardstick as to how we are feeling although the thoughts evoking these bodily and physiological responses are not always immediately apparent. The thoughts will eventually pop in there, or emerge, this from an unspecified network of neurons in the brain.

In essence, we can think about the body~brain or brain~body relationship as a needy one; they need each other for full function. To separate makes no sense bit neither does to blame one or the other. Thinking about the emergent features of the synchrony appears to provide a better way of considering problems such as pain, stress and other conditions.

RS — Specialist Pain Physio Clinics, London 


Uncomfortably numb

Feeling numb can mean that the self has lost its physical presence, or in an emotional sense, feelings have become blunted. These are both different constructs of loss for which we are compelled to seek an answer, often causing great angst. To step out of the normal sense of self is profound, difficult to define and causes suffering, whereby one has lost his or her role.

Physical numbness, if we can say this, will usually be described in terms of a body region feeling different. Altered body sense is a common finding in persisting pain states and in post-traumatic stress disorder (PTSD). In extreme situations, an out of body experience can be described where the person views themselves from an outsider’s perspective, in the third person. Often though, one refers to numbness as an area with reduced or no sensation. This can be objective such as when a stimulus (eg/ a pin prick; a light brush) is applied to the body surface and the sensation is lacking; or subjective when an area is felt to be numb yet a stimulus can be felt normally.

Although numbness in the the body is not painful per se, it is often tarnished with an aversive element that is described as unpleasant. This seems to be a particular issue in the extremities; conditions that involve nerves such as Morton’s neuroma. The mismatch between what is physically present and can be seen yet not felt, is difficult to understand and compute until the construct is explained.

An explanation: the body is felt via its physical presence in space, interacting with the immediate environment, yet is ‘constructed’ by networks of neurons in the brain. These neurons or brain regions are integrated, working like superhighways in many cases, thereby enhancing certain experiences or responses. At any given moment, the feelings that we feel and the physical sensations that we experience are a set of responses that the brain judges to be meaningful and biologically useful. The precision with which we sense our physical self and move is determined by accurate brain (cortical) representations or maps of the body. These maps are genetically determined yet moulded with experience, for example the way the hand representation changes in a violinist. Similarly, when pain persists we know that the maps change and thereby contribute to the altered body sense that is frequently described. It is worth noting that patients can be reluctant to charge their altered body experiences for fear of disbelief when in fact they are a vital part of the picture.

Emotional numbness is consistent with physical numbness in the sense of a stunted experience, whereby the expected or normal feeling in response to a situation fails to emerge. Rather, something else happens thereby creating a mismatch between the expected feeling and that which occurs. This experience manifests as a negative and is not discriminatory, affecting a range of emotional responses. A sense of detachment from the world often accompanies the lack of feeling. One could argue that this is a form of protection against feelings of vulnerability where we can also use our physical body, our armour, to shield us from the threat. Of course the threat is down to our own perception of a situation, another example of a brain construct. A situation is a situation but we provide the meaning based upon our own belief system and respond accordingly, often automatically.

Cultivating a normal sense of self is, in my view, the primary aim of rehabilitation and this encompasses both the physical and emotional dimensions. Both are influenced by thoughts, the cognitive dimension, that emerge from our belief system that drives behaviours. Hence, a programme design must reflect the interaction as it presents in the individual, most of the clues residing in the patient’s narrative that we must attend to in great detail. Validating the story and creating meaning is the first step towards a normal sense of self, to be enhanced with specific sensorimotor training and cognitive techniques such as mindfulness based stress reduction and mindfulness per se.

Wider thinking and practice is desperately required in tackling the problem of persisting pain. One of many responses to threat, pain is part of the way in which we protect ourselves along with changes in movement and other drivers to create the conditions for recovery. Sadly, many people ignore or miss these cues in the early stages through being fed inaccurate information about pain and injury. Many common ailments that can become highly impacting and distressing such as irritable bowel syndrome, headaches, pelvic pain, widespread musculoskeletal pain, anxiety, fertility issues and low mood, gradually creep up on us as the sensitivity builds over a period of time; the slow-burners. An answer to these problems that are typically underpinned by central sensitisation and altered immune-endocrine functioning, is to create awareness and habits that do not continually provoke ‘fright or flight’ responses that essentially shut down many systems in readiness for the wild animal that is not present. Actually, the wild animal is the emotional brain that when untamed can and does create havoc through the body, affecting every system.

The ever-evolving science and consequent understanding now puts us in a great position to trigger change. Initially discussing numbness, I have purposely drifted toward a more comprehensive view looking down on the complexity of the problems that we are creating in modern existence, manifesting as common functional pains. As much as we are knowing more and more about these conditions, we are actually describing the workings of the different body systems in response to a perceived threat that may or may not exist. This is always multi-system: nervous, immune, endocrine etc. and all must be considered when we are thinking about a pain response. But let’s not just think about pain as this is one aspect of the problem, one part of the emergent experience for the individual — think movement, think language, think body language, think ‘how can we reduce the threat’ for this individual so as to change their experience of their body responses. It is at this point that we see a shift and it is possible in all of us. We are designed to change and grow and develop, so let’s create the conditions for that change physically, cognitively and emotionally.


The dark side — the brain’s creations

The popular press is awash with neuroscience, now to the point that some authors are becoming ‘anti’. We need debate, so hats off to those contributors who rightly ask questions. We should never sit back and accept a ‘fact’ but instead, test, test, test. Despite this fresh discussion, we do accept that the brain has a great deal to do with our experiences of life.

A single centre for consciousness has not been identified in the brain and is not likely to be discovered. Instead, our unique sensory and emotional experiences are created by vast, interconnected networks of brain cells, maintained and influenced by immune cells that populate the brain and spinal cord. The pain matrix theory of Ron Melzack is a great example of such a functioning network. From these networks emerge feelings, thoughts, movements, senses and pain to name but a few. Where we actually experience these emergent properties can vary enormously, although one could argue that the role of the brain is to create the most biologically appropriate experience for that given moment and context.

Recently, Mick Thacker and Lorimer Moseley wrote a brief paper discussing the idea that pain is emergent. This is a relevant and sensible calling upon philosophy to help us explain pain to patients at a time when there has been a trend to suggest that the brain is at fault. Indeed we need a brain to feel pain — see Lorimer talk here — just as we need a brain to see and hear, but how helpful is this to the patient with back pain? Even if they grasp the concept of the pain neuromatrix, to suggest that the pain is coming from the brain can be a challenging leap. Preferable is the explanation that pain emerges from the body but there is a significant part played by a widespread web of neurons and immune cells in the brain and spinal cord; this requiring a careful description to give meaning to the individual.

To take this a stage further, one could argue that a depressed state underpinned by ruminating thoughts is emergent from a network of neurons within the brain, yet often felt deep within the body in a multitude of unique ways––visceral. The heaviness of thought is usually reflected within the physical self via posturing, movement and gut instinct. Our minds that exist within the brain networks––who knows where––stream with thoughts that are occasionally useful, frequently the same, and always driving bodily responses. The brain does not discriminate between thinking about being somewhere and actually being there; a similar response ensues. This can be wonderful if the memory or thought cultivates the tape of a happy time. How often does this happen in comparison to a train of worrying or troubling thoughts? Especially if one’s mood is low, the impact of a negative situation or comment is far greater. This is the dark side of the brain’s creation of our multisensory experience; seeing, hearing, feeling, thinking.

The depths to which one can slip or drop are seemingly endless. It does appear modern life is contributing to this endlessness as the figures on depression rise. Perhaps it is the expectation that we should be happy, with all the convenience of immediate service and advancing knowledge, yet there is greater striving for this state. Bookshelves are packed with self-help books, Facebook and Twitter saturated with quotations about how to think positively, and the growing industry that is life coaching all pay homage to the fact that we are not achieving as ‘alchemists of joy’.

Where neuroscience can make a contribution is to give us the understanding of the mechanisms that can be translated into practical tools for everyone. There have been numerous steps in the right direction with some great discoveries that inform; for example: the similarities of physical and social pain (e.g. rejection, isolation), neuroplasticity, the way in which immune cells prune synapses, communication between the gut and the brain, and mirror neurons (a deliberately provocative inclusion — see here) to name but a few.

The idea that experiences are emergent from a neuronal network influenced by many factors including epigenetics (the blend of genetics and experience), is a very credible way of thinking about how we can re-shape our thinking, feeling selves. The basic neuroplastic characteristic of our neuroimmune system, or the ability to learn, means that by creating the right conditions with the right understanding and individualised strategies based upon fact, we can cultivate change. This does not preclude the use of medication or other medical interventions but this alongside sensible and wise action based on sound science to move us into the light.

** Please note that this is not an exhaustive discussion of either depression or neuroscience but rather an observation. I am aware that this may trigger thinking and discussion that are both welcome in the hope of advancement.

Specialist treatment, training and coaching for persisting pain, chronic pain and injury in London – call for appointments 07932 689081



How do you know where you are? | Neil Burgess speaks

It is useful to know where you are. Neil Burgess spends his time studying this important function by looking at the brain, the hippocampus to be specific.

It would appear that the same brain cells that create our sense of where we are and recalling that information for practical use are also at play when we imagine movement, such as a motor imagery task for a painful condition.


Lorimer Moseley talks about pain (2013)

Here is the latest video of Dr Lorimer Moseley talking about the current understanding of pain. Regular readers will know that Lorimer’s work is some of the most influential upon the approach that I take to pain and in particular persisting pain. By thinking brain we can devise individualised treatment and training programmes for your pain problem. Read on and watch the video.

“If you have a brain, you will experience pain. If you don’t, you won’t”

“We feel pain in our body and we feel it in a particular location. But it is impossible to feel pain without a brain and it is completely possible to feel pain without the body part”

Lorimer tells the story of the man with the prosthetic limb who gave him a hitch out of Adelaide. This is a great illustration of the brain creating the experience of pain but without a message of danger. The questions arises: is all pain phantom pain? The notion that the brain produces pain, it does not recognise pain coming from somewhere.

What burdens society?





Pain is about protection. Pain is a most sophisticated device and hence the brain must decide how much to protect an area of the body.

The danger message is not pain. Nociceptors send danger signals to the brain but you do not need this to feel pain.

Can you spot the disconnect between damage and pain? Can you think of an example in your life? Pain is produced by the brain and the brain is the most trainable part of the body. Pain depends on how much danger your brain THINKS you are in, not how much you are actually in. It’s an evaluation of danger.

Watch the video for more…


BBC Horizon ‘The Secret World of Pain’ | #pain

BBC’s Horizon programme in 2011 that looked at the latest research in pain. Understanding has rolled on since this time, but some interesting features nonetheless. It is worth remembering that pain is a conscious experience that emerges from the body although the actual representation is within the brain–a widespread matrix of neurons in the brain. The bottom line is ‘threat’. When the brain determines that our body is in danger, we will feel pain in the area that needs protecting. This is of course very useful biologically in an acute situation (although the intensity of the pain or even the existence of pain is hugely–consider the many tales in A & E and on the battlefield where significant trauma causes no pain) but not so if it persists. The underlying activity and certainly the focus of treatment is very different.


Central sensitisation is more common than you may think

Clifford Woolf recently said this about central sensitisation:

Nociceptor inputs can trigger a prolonged but reversible increase in the excitability and synaptic efficacy of neurons in central nociceptive pathways, the phenomenon of central sensitization. Central sensitization manifests as pain hypersensitivity, particularly dynamic tactile allodynia, secondary punctate or pressure hyperalgesia, aftersensations, and enhanced temporal summation. It can be readily and rapidly elicited in human volunteers by diverse experimental noxious conditioning stimuli to skin, muscles or viscera, and in addition to producing pain hypersensitivity, results in secondary changes in brain activity that can be detected by electrophysiological or imaging techniques. Studies in clinical cohorts reveal changes in pain sensitivity that have been interpreted as revealing an important contribution of central sensitization to the pain phenotype in patients with fibromyalgia, osteoarthritis, musculoskeletal disorders with generalized pain hypersensitivity, headache, temporomandibular joint disorders, dental pain, neuropathic pain, visceral pain hypersensitivity disorders and post-surgical pain. The comorbidity of those pain hypersensitivity syndromes that present in the absence of inflammation or a neural lesion, their similar pattern of clinical presentation and response to centrally acting analgesics, may reflect a commonality of central sensitization to their pathophysiology. An important question that still needs to be determined is whether there are individuals with a higher inherited propensity for developing central sensitization than others, and if so, whether this conveys an increased risk in both developing conditions with pain hypersensitivity, and their chronification. Diagnostic criteria to establish the presence of central sensitization in patients will greatly assist the phenotyping of patients for choosing treatments that produce analgesia by normalizing hyperexcitable central neural activity. We have certainly come a long way since the first discovery of activity-dependent synaptic plasticity in the spinal cord and the revelation that it occurs and produces pain hypersensitivity in patients. Nevertheless, discovering the genetic and environmental contributors to and objective biomarkers of central sensitization will be highly beneficial, as will additional treatment options to prevent or reduce this prevalent and promiscuous form of pain plasticity.

And Latremolier

Central sensitization represents an enhancement in the function of neurons and circuits in nociceptive pathways caused by increases in membrane excitability and synaptic efficacy as well as to reduced inhibition and is a manifestation of the remarkable plasticity of the somatosensory nervous system in response to activity, inflammation, and neural injury. The net effect of central sensitization is to recruit previously subthreshold synaptic inputs to nociceptive neurons, generating an increased or augmented action potential output: a state of facilitation, potentiation, augmentation, or amplification. Central sensitization is responsible for many of the temporal, spatial, and threshold changes in pain sensibility in acute and chronic clinical pain settings and exemplifies the fundamental contribution of the central nervous system to the generation of pain hypersensitivity. Because central sensitization results from changes in the properties of neurons in the central nervous system, the pain is no longer coupled, as acute nociceptive pain is, to the presence, intensity, or duration of noxious peripheral stimuli. Instead, central sensitization produces pain hypersensitivity by changing the sensory response elicited by normal inputs, including those that usually evoke innocuous sensations. PERSPECTIVE: In this article, we review the major triggers that initiate and maintain central sensitization in healthy individuals in response to nociceptor input and in patients with inflammatory and neuropathic pain, emphasizing the fundamental contribution and multiple mechanisms of synaptic plasticity caused by changes in the density, nature, and properties of ionotropic and metabotropic glutamate receptors.

In essence we are talking about changes within the central nervous system that underpin the widespread, unpredictable and varied nature of persisting pain.

When I am listening to a patient, observing their movements and performing a ‘multi-system’ examination, I am in part looking for the pain mechanisms at play, including central sensitisation. Several of my questions are: ‘what is going on here to create this experience for the person in front of me?’, ‘why are the nervous and other systems responding in such a way?’ and ‘what is influencing the behaviour of those systems?’. I really need to know what it is that is prolonging this protection and is it really worthwhile for the individual.

Suspecting that there is a component of central sensitisation at play in many cases of chronic pain that I see, it is pleasing to see a group looking at this closely and finding evidence to support this thinking:

J Bone Joint Surg Br. 2011 Apr;93(4):498-502.

Evidence that central sensitisation is present in patients with shoulder impingement syndrome and influences the outcome after surgery.

Gwilym SE, Oag HC, Tracey I, Carr AJ.


Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Nuffield Orthopaedic Centre, Windmill Road, Headington, Oxford OX3 7LD, UK. [email protected]


Impingement syndrome in the shoulder has generally been considered to be a clinical condition of mechanical origin. However, anomalies exist between the pathology in the subacromial space and the degree of pain experienced. These may be explained by variations in the processing of nociceptive inputs between different patients. We investigated the evidence for augmented pain transmission (central sensitisation) in patients with impingement, and the relationship between pre-operative central sensitisation and the outcomes following arthroscopic subacromial decompression. We recruited 17 patients with unilateral impingement of the shoulder and 17 age- and gender-matched controls, all of whom underwent quantitative sensory testing to detect thresholds for mechanical stimuli, distinctions between sharp and blunt punctate stimuli, and heat pain. Additionally Oxford shoulder scores to assess pain and function, and PainDETECT questionnaires to identify ‘neuropathic’ and referred symptoms were completed. Patients completed these questionnaires pre-operatively and three months post-operatively. A significant proportion of patients awaiting subacromial decompression had referred pain radiating down the arm and had significant hyperalgesia to punctate stimulus of the skin compared with controls (unpaired t-test, p < 0.0001). These are felt to represent peripheral manifestations of augmented central pain processing (central sensitisation). The presence of either hyperalgesia or referred pain pre-operatively resulted in a significantly worse outcome from decompression three months after surgery (unpaired t-test, p = 0.04 and p = 0.005, respectively). These observations confirm the presence of central sensitisation in a proportion of patients with shoulder pain associated with impingement. Also, if patients had relatively high levels of central sensitisation pre-operatively, as indicated by higher levels of punctate hyperalgesia and/or referred pain, the outcome three months after subacromial decompression was significantly worse.



Arthritis Rheum. 2009 Sep 15;61(9):1226-34.

Psychophysical and functional imaging evidence supporting the presence of central sensitization in a cohort of osteoarthritis patients.

Gwilym SE, Keltner JR, Warnaby CE, Carr AJ, Chizh B, Chessell I, Tracey I.


University of Oxford, Oxford, UK. [email protected]



The groin pain experienced by patients with hip osteoarthritis (OA) is often accompanied by areas of referred pain and changes in skin sensitivity. We aimed to identify the supraspinal influences that underlie these clinical manifestations that we consider indicative of possible central sensitization.


Twenty patients with hip OA awaiting joint replacement and displaying signs of referred pain were recruited into the study, together with age-matched controls. All subjects completed pain psychology questionnaires and underwent quantitative sensory testing (QST) in their area of referred pain. Twelve of 20 patients and their age- and sex-matched controls underwent functional magnetic resonance imaging (MRI) while the areas of referred pain were stimulated using cold stimuli (12 degrees C) and punctate stimuli (256 mN). The remaining 8 of 20 patients underwent punctate stimulation only.


Patients were found to have significantly lower threshold perception to punctate stimuli and were hyperalgesic to the noxious punctate stimulus in their areas of referred pain. Functional brain imaging illustrated significantly greater activation in the brainstem of OA patients in response to punctate stimulation of their referred pain areas compared with healthy controls, and the magnitude of this activation positively correlated with the extent of neuropathic-like elements to the patient’s pain, as indicated by the PainDETECT score.


Using psychophysical (QST) and brain imaging methods (functional MRI), we have identified increased activity with the periaqueductal grey matter associated with stimulation of the skin in referred pain areas of patients with hip OA. This offers a central target for analgesia aimed at improving the treatment of this largely peripheral disease.