An article for Dystonia Network of Australia Newsletter, June 2016
At just a few weeks old a baby reaches out and grasps the finger extended to him by mother or father. A few months on and our baby is sitting in a high chair and able to pick up a spoon and drop it to the floor –repeatedly, while his carer retrieves the item each time. The baby seems to find enjoyment in doing this over and over but, as casual observers, we may not realise that he is also busy at the process of myelination of the neural pathway between brain and hand. Fast forward a couple of years and our same child is now engaged in finger painting, learning to play Cat’s Cradle, or counting using his fingers. This scenario reflects just the beginnings in the process of maturation of our motor circuitry, our brain in motion. What was a representation of a ‘hand’ on the surface of the brain of the baby changes over time and with input to establish individual representation of all ten fingers in the child’s brain topography. This brain representation or ‘map’ has changed and now reflects the way our child can use his fingers individually. Maturing of motor skills also requires that gross motor movements be inhibited to allow for fine motor control, so our child can now move an individual finger while simultaneously inhibiting the movement of the rest.
It has been known for some time that cells in the primary motor and sensory areas of the cerebral cortex are associated with different parts of the body. These cells are spatially arranged or ‘mapped’ in such a way to represent the anatomical correspondence of these parts in the body. The maps are dependent on the motor and sensory experiences of the person, with cortical areas being reorganised to suit the motor planning practices of each particular individual. So feedback from our movements shapes the map.
Since dystonia is a neurological disorder affecting the motor areas of the brain, support and resource sites often list movement re-education techniques like Alexander Technique or Feldenkrais Method among the options to assist sufferers with their symptoms. It is important to note that the desired end result of these techniques may well be relief and a change in movement for the person experiencing dystonia – but the process used is one of re-education of their brain. This is effective because, in a very real sense, your body has another existence in your brain. Any one part – your arm, your hand or jaw, is as much a network of sensory nerves as it is a physical form.
As a Body Mapping instructor I work with people to harness the power of their neuroplasticity for healthy movement outcomes. Neuroplasticity describes how the brain is malleable, how it changes as a result of inputs and can ‘repair’ its function by forming new connections between neurons. It seems that many of us use movement habits that are based on an inaccurate or incomplete perception of the anatomy of our bodies. Our faulty ‘map’ in the brain is dictating and reinforcing our faulty movement. We come to realise that the way we think our body is designed – whether true or not – dictates how we use our body. We function ‘as if’ our map were true.
The reason we develop faulty maps is cause for conjecture – it may be that our body maps don’t keep up with changes in growth rate or that culturally we place so little emphasis on the sensory information coming to us from our moving sense that the maps become out-dated. We teach children in school that there are five senses. But what of our forgotten sixth sense? Our kinaesthesia or moving sense. Just as little-used pathways in a landscape become indistinct, so too our maps can become vague and misaligned with our anatomical reality without kinaesthesia actively updating the information. Whatever the explanation, faulty body maps usually lead to excessive tension in our motor functioning and pathologic changes can result. Neuroplasticity means we can change our ‘body maps’ with grey matter able to grow, shrink, copy, refine, weaken and even sever neural connections. The changes are evident internally as measurable, observable difference in the way movement neurons fire in our brain and outwardly, as a change in our physical movement and abilities. Getting to know not just the truth of our anatomical design but also how to ‘embody’ that information can redraw our neural maps and deliver us our true movement potential.
The part of the brain known as the cerebellum is responsible for learning new patterns of movement, controlling equilibrium and balance, coordinating signals produced in other parts of the brain and integrating them with information from the spinal cord to plan complex motor actions. It allows us to carry out movements effortlessly. Equally important is its role in controlling the level of the sensations coming in from the body. The nature of these inputs seems to influence whether changes to the brain occur in an adaptive or maladaptive manner. The sensory information from the environment and from our own body is considered to be the ‘driver’ of our brain’s plasticity. The cerebellum has been shown using functional MRI scans to be underactive in dystonia patients and this could be responsible for the excessive response by the brain to feedback sensations from dystonic muscles.
The sustained co-contractions of opposing muscle groups that characterise dystonia cause the twisting or repetitive movements and abnormal postures. Co-contraction results in excessive tension and influences the nature of our sensory experience. In dystonia there is also a decrease in inhibitory mechanisms that can lead to a blurring of sensory motor representation in the brain. Our hand may lose its mature representation on our ‘map’ as 10 individual fingers with individual functioning and come to be represented in the topography more as a single entity with little ability for fine motor control – as was the starting point for our baby mentioned earlier.
Re-education of the relationship of brain to body, bringing it into full alignment with our true anatomical design, creates a new neural pathway to transmit commands and receive feedback. A new map with a new route to carry out actions and receive sensory information. The change in neural connections can alter the nature of the plasticity driver and the brain moves the body appropriately and easily in response to sensory information.
The discovery of the role of the cerebellum in dystonia paves the way for therapies and behavioural techniques targeting cerebellum functions. Movement therapies start from an empirically observed connection between dystonia and certain patterns of movement. An approach that emphasises overall coordination of the whole body has been shown to be generally more successful than concentrating on training just one part. It seems clear that developing a sense of embodiment, training the kinaesthetic sense, acquiring an accurate and adequate body map and constantly relating the part to the whole is vital in any resolution of symptoms of dystonia. These are the recurrent themes of Body Mapping.