Looking into the brain

Our understanding of pain has transformed largely because we can now look into the brain and observe what is going on there when the body appears to hurt.

Neuroscience (including advanced imaging where we can see nerve and brain activity in real time) has opened a window where none existed before.  We can actually see the behaviour or activitiy of the brain when a person is thinking, emoting, in chronic pain, acute pain, moving, imagining, crying, etc.  In the past we saw outward human behaviour but couldn't see brain activity so our ideas and theories were based on an understanding that the brain was static and hard wired; kind of an innert computer like machine.  Coupled with that is the fact that the various health professions and their specialties tend to view human function from different perspectives. Furthermore some problems result in various signs and symptoms of apparently somatic (or in body) aches and pains but defy a single diagnosis.

Fibromyalgia is one such condition which is often diagnosed when an individual has chronic diffuse musculoskeletal pain.  That patient is also likely to see a gut specialist for gut sensitivity, a Neurologist for head and face pain, their psychologist for cognitive symptoms such as 'feeling muzzy or foggy' and the GP for any of the above.  And of course they may see a chiropractor or physiotherapist for 'aches and pains'  While it's certainly possible for any one individual to be suffering from multiple maladies it is most likely that there is a systemic or widespread cause which manifests in a variety of ways.  Confusing?

Eric Kandel (who won a Nobel for neural science) describes pain as an emotional reaction to sensation and also as a complex behaviour.  This is quite different from the old idea that a brain is like a computer hence the title of a recent book 'The brain that changes itself'.  If we want to race that marathon we train.  Why?  When we stress our bodies they can adapt and become stronger however if we do too much too soon we can overdo it, break down and accumulate injuries.  Because we all have a unique set of genes we are all slightly more and less predisposed to certain problems.  It turns out that the brain can do the same thing.  It can respond to stress by developing better coping mechanisms or respond to too much stress by becoming dysfunctional.

Fibromyalgia is characterised by combinations of diffuse musculoskeletal pain often including head ache and TMJ or jaw pain, gut sensitivity, cognitive difficulties (feeling dull or fuzzy in the head) and psychological or emotional lability.  So what used to happen to people in the past when we understood pain to be purely due to serious pathology (say infection or blood disorder) injury or scarring OR a psychosomatic issue (all in your head)?

Tests often come back negative.  This is good when we're trying to pin point a diagnosis.  Then we read the scientific literature which says a few things about FM

1.  There appears to be a familial (genetic) predisposition.  A first level relative is 8 times more likely to develop similar symptoms.
2. Symptoms seem triggered by the environment (often a combination of severe or sustained emotional stress coupled with musculoskeletal injury (more often injury to the axial skeleton (spine and pelvis) and trunk)
3. Dysfunction in the HPA (hypothalamopituitary axis) and ANS (autonomic nervous system)
4. Impaired pain and sensory processing
5. Cognitive, behavioural and psychological impairments.

In effect the brain becomes 'globally' sensitive so any structure of the body can begin to hurt even though there may be little, even no actual structural injury.

Depressingly much of the freely available information regarding FM will say that there is no cure.  It's important to understand the nature of FM - It is not a disease with a cure rather a genetically linked predisposition to brain sensitivity.  Furthermore because we now understand the brain to be plastic or changeable it is theoretically possible to reverse some of these changes.

So FM can be complex and difficult to manage and although it does respond slowly and less predictably than other simple joint and muscle problems it can respond well over time.

Stem cell research and spinal cord injuries

In the early 90s while studying at university I worked as an orderly in a spinal unit.  There were 3 wards - acute, rehab and 13west which dealt with complications following discharge.  It was here I first heard of stem cells.  These days animal trials (my colleague refers to them as 'volunteer' rat trials such as this http://stemcellres.com/content/4/5/57/abstract)) suggest that they are indeed close to treating humans affected by spinal cord damage.  It's a huge leap forward in this area.

The chiropractic profession does not of course deal directly with such problems however it is not uncommon for us to be a part of an individuals rehabilitation or provide some measure of support during the long term.  Having worked with individuals coming to grips with such dramatic, life altering events I sincerely hope that human trials begin soon (if they haven't already in China :).

Douglas Scown

Thoracic outlet syndrome TOS

TOS can involve a range of conditions which may compress or irritate the blood vessels and/or the nerves which pass through the region between the neck and the shoulder (the cervicoaxillary area).  As such it is more an umbrella term rather than a specific diagnosis.  Why?

The following is a list of SOME of the things which can lead to TOS (adapted from http://cdi.edu.au/diagnostics/drill14q3o.php

Congenital (born with) abnormalities include:

• Anomalies of C7 transverse process
• Cervical ribs
• Anomalies of first rib shape
• Enlarged scalene tubercle
• Variations in scalene muscle formation and insertion (including neural components travelling through its substance)
• Anomalies of costoclavicular ligament structure
• Anomalies of pectoralis minor or subclavius muscle structure

 

Trauma is another recognised cause of stretch or compression to the neurovascular bundle:

• Impact to the shoulder or neck
• Excessive bone remodelling after fractures of the clavicle or first rib
• Posterior subluxation of the acromioclavicular joint

 

Soft tissue causes implicated in TOS:

• Hypertrophy of the anterior scalene muscles (such as during increased use of the accessory muscles of respiration)
• Muscle fibre type adaptive transformation
• Spasm and excessive contraction following cervical spine injury
• Poor posture due to occupational stress and repetitive overuse – especially prolonged positions that include lowering of the anterior chest wall, forward slouching of the shoulders and forward movement of the head
• Excessive breast tissue

In effect an individuals symptoms may be due to one of the above or many (multifactorial) particularly as we age.


Douglas Scown

Chiropractic didn't work

Physiotherapists, Surgeons and General Practitioners often hear this while we (members of the Chiropractic profession) hear the opposite. Who's right?

I suspect that all clinicians are experts at overestimating themselves.  My mentors suggested that 'it's all unreliable' but to remind myself that all health professionals deal with the same thing.  Ironically you begin to get better at it once you accept that you'll never be 100% certain.  Rationally we know this but we constantly entertain the fantasy that we can be certain and deal with 'everything'.  We can't.

Chiropractors in one respect occupy an enviable position.  We deal with and are perceived as dealing with only one 'part' of the body - the spine.  We are well placed to be the 'go to' profession for spine diagnosis and the conservative management of it's related disorders.  Our biggest obstacle isn't how we are perceived but how we view ourselves and our reluctance to accept our position as just one of the many other health professions whose job it is to look after the populations health - if that's what they want.  That role requires self examination, humility and the willingness to communicate with medical professionals about THEIR patients using common language.

Chiropractic doesn't work or not work.  Techniques and treatments come and go depending on development but what we can say is we're a health profession with a long history of relative success in a particular field.  We overrate ourselves and are soundly underrated by the public and other professions.  Whose fault is that?  Ours.

Douglas Scown

TMJ (jaw) disorder (TMD)

TMD is surprisingly common and usually self limiting however a small group of the population (mainly women) can suffer from chronic pain and while we know a certain amount about this problem there is still robust debate about what is going on and how best to treat.  The good news is it's estimated that over 80% of cases respond well to non invasive, conservative approaches.  The most important aspect again is making as accurate a diagnosis as possible, trialing treatments and being prepared to revise or refer if progress is not sustained.

It's such a simple joint but unique with regards to the amount of use it gets (eating, talking, yawning) it's vulnerability to insignificant but repeated trauma and it's inherent mobility.  It's also a part of the face and thus neurologically highly sensitive so perhaps it's surprising that humans (who apparently love to talk:)) don't have more trouble with it.

There isn't enough room in a blog to go into the details of TMD suffice to say that a reasonable clinical approach is to consider what they call peripheral and central components to the problem.  Peripheral = the joint itself (which can include the skull) and central is when the central nervous system becomes sensitive to the joint.

Who do you see?  I suggest that people ask specifically if TMD diagnosis and management is something a practice commonly deals with.  As such what profession you consult is less relevant than if the professional is familiar with TMD and if they have a reasonable degree of success with it. 

Doug Scown

My Chiropractor didn't do that?

Like all health professionals we get stuck in our opinions as to the cause of dysfunction and what best approach to take when treating.  Most experienced practitioners understand that things change over time and we learn that not all our patients appear to respond equally to the same stimulus or treatment.  Why would it matter what treatment you use?  Surely it works the same way every time.

Treatment choices are numerous and confusing but thankfully science and research has given us clues as to why they might all be effective.  Physically based treatments involve applying a force to certain body structures.  Some of these structures (particularly the spine and neck) are the most sensitive structures to movement (especially rapid movement) and many of the issues we see involve to some degree a weakening or lack of responsiveness of the brain-muscle system which keeps us upright and oriented and any reintroduction of normal movement will potentially help.  It also appears that small rapid movements send a bigger 'signal' to the brain.  Slow muscle stretch for example sends a signal without a sharp high peak in electrical activity.  In effect the brain can be re sensitised to joint sensation using a variety of movement and sensation based approaches.  The clinical challenge is to determine what 'variety' will help which individual.

Can we predict chronic spinal pain?

We're familiar with spine pain as a result of trauma but why do some people develop chronic spine pain well after initial injury and can we predict who those people will be BEFORE they get symptoms?  It appears we might be able to do that.

Studies indicate that some people develop errors in sensorimotor control following neck injury.  This is the way your brain has control over the body.  All body part locations and movements are perceived by the brain via the nerves which are embedded in the mechanical structures.  So it's clear that damage to a joint may damage these sensation detecting endings and deprive the brain of the information it requires to control movement.  The term 'sensorimotor deficit' encompasses the errors we observe and is not only due to damaged nerves but the ability of the brain to rewire itself 'wrong' (maladaptive plastic changes).

The presence of these errors can predict the development of chronic pain before it happens and interestingly some individuals can experience these errors without any obvious trauma (so called idiopathic neck pain (or pain of unknown origin)).

Our brain is involved with perceiving the world around us and making sure we safely navigate our way through it moment by moment.  Body sway, poor balance, joint movement inaccuracy, head tilt, joint clicking, jerky eye movement and even difficulty concentrating are all aspects of sensorimotor deficit and are predictors of the development of chronic spinal pain.  Furthermore stress and anxiety are both known to exacerbate and even be associated with such disorders of movement.

Why some individuals experience these cognitive disturbances is thought to be genetically influenced (as is most everything:)) but a quick look at how we are wired up reveals that our emotional responses are influenced by how 'stable' we are.

These 'higher' relationships are less predictable in part because the neurology is far more complex and interwoven once we venture into the brain proper.