Tuesday, 31 May 2011

Developmental stimulation after brain injury.

A baby's brain has the capacity to grow at a phenomenal rate.  At birth it is only one quarter of its adult size, but by three ears of age it will be 80% the size of an adult brain.  At birth it is one of the only organs which has not yet fully developed and it is sensory stimulation derived from environmental experience which drives this growth and consequently which drives the development of the child.  

Billions of neurons are created throughout the primary stages of foetal development and through birth.  Indeed at birth, the only brain structure which is developed to anything like its mature form is the lower brainstem.  This part of the brain controls the primitive reflexes and vital functions such as respiration, cardiovascular function, etc.  Immediately after birth, baby's higher brain regions begin to make billions of connections between neurons.  These connections, called synapses, are used to transmit information based upon sensory experience.  Stimulation through the senses of touch, hearing, vision, smell and taste, in addition to vestibular and proprioceptive experience, directly influence these neurons and help in establishing these connections. 

The more frequently the neuron connections are used, the stronger and more efficient the new connections become, this is a phenomenon known as 'long term potentiation.' If some of the neural pathways are not used, they become weak and are pruned, (this is known as 'long term depression.').  This is why the repetition of the activities within a Snowdrop programme of developmental stimulation are so important.

We know that babies who are born into an impoverished environment do not develop the rich connection between neurons which develop in other babies. Children who are neglected, exposed to stress, trauma, abuse, have negative experiences which can have a detrimental effect upon brain growth and development. It has been shown, that those infants or children who are not exposed to adequate sensory stimuli because of these factors can develop brains which are smaller then those who have had those "good" sensory experiences.

So, you might ask, how does this apply to children who have suffered brain injury? Well, what effect does brain injury have on a child?  It acts as a barrier between the child and his environment. It does so because it prevents the child from interacting with his sensory environment. Because he is unable to gain the necessary sensory experience from his environment, due to the 'roadblock' of the injury, or because the injury is acting to distort incoming sensory information in some way, the brain is unable to make the same number, or quality of connection as it would otherwise have done and as a consequence baby's developmental processes are either stopped, slowed, or distorted.

Is there anything which an be done to rectify this situation? Well yes, at Snowdrop we believe there is. We take children who have suffered brain injuries and as a consequence are experiencing developmental difficulties and we provide them with an 'adapted sensory environment.' Where the injury is acting as a barrier between the child and his sensory environment, the adapted environment acts to amplify the sensory stimulation to which the child is exposed, breaking through the barrier and giving the child's brain the opportunity to form connections. Where the injury is acting to distort incoming sensory information, making the child hypersensitive, or unable to selectively tune in, or to mask sensory information, our adapted environment seeks to re-tune the neurological structures which are responsible for this. Again, in this way we encourage the brain to make the appropriate number and quality of connections and to consequently improve the developmental prospects of the child.

This is the basis of a Snowdrop developmental stimulation programme.  Anyone interested in learning more about Snowdrop's work should email snowdrop_cdc@btinternet.com

Friday, 20 May 2011

How Repetition Changes the Structure of the Brain.

The more we repeat something, the better we get at it; this much is uncontroversial.  But that doesn’t mean it isn’t worth examining. The connection between repeating an action or a skill and then improving because of that repetition is a concept that is so natural and intuitive, so well accepted as common knowledge, that we often fail to appreciate the fascinating mechanics behind the process of skill acquisition.  It follows the old adage, 'practice makes perfect!'

On the most basic level, learning a new skill or improving a skill involves changes in the brain.  There are a few different ways that our brains adapt to picking up new skills and changing environmental conditions.  The first involves a rewiring of the networks of neurons in the brain.  Each skill or action that a child performs involves the activation of neural pathways.  In Norman Doidge’s book on neuroplasticity, The Brain That Changes Itself, Dr. Alvaro Pascual-Leone has a beautiful little analogy for the way that these pathways relate to skilled performance (Page 209):

"The plastic brain is like a snowy hill in winter.  Aspects of that hill–the slope, the rocks, the consistency of the snow–are, like our genes, a given.  When we slide down on a sled, we can steer it and will end up at the bottom of the hill by following a path determined both by how we steer and the characteristics of the hill.  Where exactly we will end up is hard to predict because there are so many factors in play." But,” Pascual-Leone says, “what will definitely happen the second time you take the slope down is that you will more likely than not find yourself somewhere or another that is related to the path you took the first time.  It won’t be exactly that path, but it will be closer to that one than any other.  And if you spend your entire afternoon sledding down, walking up, sledding down, at the end you will have some paths that have been used a lot, some that have been used very little.”

Every action we perform, every new skill we pick up, involves beating down and refining a kind of neural trail.  We are making real changes in the brain.  And our brains are remarkably efficient to change in response to training.  In one study, video game players who played the dark, fast-moving action-based game Call of Duty for 9 weeks were not only better at the game, but were able to see significantly more shades of gray, post-training, than a group who played a simulation strategy game that did not exercise those skills.

Over a longer time span, it is also possible to see significant structural changes in the brain.  For example, the brain area associated with motor control of the right index finger in blind subjects who are braille readers has been found to be significantly larger than that of sighted individuals.  Similarly, a famous study of london cabbies, famous for their ability to navigate the twisting streets of the city, found that they had greater brain volume in the hippocampus, a structure heavily involved in both memory and spatial navigation, than bus drivers who followed a predefined route every day.

With respect to the brains of children who have developmental disabilities, the brain injuries or abnormalities they suffer might slow that response to training down a little, but the response is still possible.  

Evidence for neuroplasticity abounds, - from the structural differences which have been found between experienced athletes and novices, through to the Chinese study of expert divers which found increased gray matter volume in brain areas associated with skilled motor control.  Along the same lines, an Australian study of skilled racket-sport players found that brain areas associated with the racket arm were larger than in a matched group of non-athletes.  The evidence is irrefutable! 

The overarching theme here is that the brain is malleable–it changes with training.  It is an interesting concept to keep in mind, especially with respect to brain injured children and it is the overarching principle of the Snowdrop programme.  

It’s easy and natural to think about training in terms of muscles, the body and physical skills.  But every new skill that a child learns is accompanied also by neural changes that may be harder to see, but are equally important.

If you would like more information about the Snowdrop programme, just visit our website on http://www.snowdrop.cc  - email us at snowdrop_cdc@btinternet.com or call on 01884 38447

Sunday, 8 May 2011

Snowdrop's principles of treatment for brain injury.

Stimulating and directing brain plasticity.

What is brain plasticity? – It is the ability of the brain to change its structure and functioning in response to demand from the environment, by either pruning connections which are no longer used, or creating new connections.

My programme is built around the latest knowledge of how brain plasticity responds to environmental stimulation and how we can combine that knowledge with what we know about how developmental processes proceed in the child, I use the combination of this knowledge to stimulate the child's development in all areas.

We know that it is an interplay between the genetic expression of the child and the influence of the developmental environment provided for the child which drives development forward.  We can do very little about genetic expression, but what we can do is to influence the developmental environment to which the child is exposed.

How can we influence the developmental environment?

This is where the activities of the programme play their part.  The first thing I will do is to assess the functional capability of your child in all areas of development.  In terms of sensory development that is visual, auditory and tactile development.  In terms of the brain’s output functions, these are the areas of gross motor and fine motor development, in addition to social development and language and communication development.  You will note that I have omitted cognitive development from this list and you might wonder why?  It is because I see cognitive development as being intertwined with all other areas.  Consider this for a moment, - we don’t just develop the ability to see, hear and feel; - we develop the ability to understand what we see, hear and feel.  Similarly, cognitive ability is expressed through the brain’s output functions of movement, hand function, language and social ability.

Once I have a ‘baseline’ of your child’s achievements in each area of development and an intimate understanding of his / her difficulties, I will develop a series of activities which are designed to stimulate your child to achieve the next stage higher in each developmental area.  It is the implementation of these activities and recommendations by you, his / her parents, which will create your child’s new developmental environment.  It is the repetition of these activities, which will create the increased ‘environmental demand’ for function which will hopefully stimulate the brain to make new connections; - new connections which will support the function which we are trying to stimulate.  How well these functions develop depends upon many factors including the precise nature and severity of the brain injury and our success in breaking down the barriers which it places between the child and the environment.  This is how brain plasticity works!

My approach receives a great deal of support from recent evidence concerning neuroplasticity.  One example out of many I could cite is from the Max Plank Institute for Biological Cybernetics at Tubingen, who have succeeded in demonstrating for the first time that the activities of large parts of the brain can be altered in the long term.  The scientists were able to trace how large populations of brain cells in the human forebrain are able to reorganise and change their connections to other brain cells as a consequence of environmental stimulation.  (Current Biology, March 10th, 2009)

Further evidence to support my philosophy comes from a recent study at MIT which clearly shows that in people who are born with brain injuries, parts of the brain which aren’t normally connected with a particular function can be recruited to take over the functions of brain cells which have been lost to injury.  This ability of brain cells to ‘switch functions’ is seemingly driven by the demands of environmental stimulation which creates competition for brain cells to be allocated specific functions.  http://www.eurekalert.org/pub_releases/2011-02/miot-mpo022811.php  

The Snowdrop programme creates such a ‘competition’ for allocation of function in the brain, - the repetition of the developmental activities within the programme creating the increased environmental demand necessary for creating such a situation.

Friday, 6 May 2011

Injury to the Cerebellum.

The word 'cerebellum' actually means 'little cortex' and it is not without justification, as at first site it does look like a smaller version of the cortex. It is located at the rear of the brain, behind the brainstem and it forms massive connections with the brainstem structures, (particularly with the vestibular nuclei of the pons) and with the cerebral cortex. It is the only structure within the brain which is not fully formed at birth, taking a further two years to develop to it's full complement of neurons.
The proper functioning of the cerebellum ensures that any movements we make are smooth and well coordinated. It seems that the motor cortex supplies commands to the body musculature, which are then refined by the cerebellum to ensure smooth coordination. Feedback on the success of the movement is then supplied from the cerebellum back to the motor cortex where the original movement command can be refined if the movement has been unsuccessful.
One might imagine then that an injury to the cerebellum will interfere with these functions. Movement can become slow and uncoordinated, the child may display problems with balance and equilibrium, the child might experience an 'intention tremor' - (a tremor which is made worse when the child tries to move). Injury to this part of the brain causes 'Ataxia' - a form of cerebral palsy where the muscle tone is hypotonic (floppy).
Higher cognitive functions, like language and visual processing, have long been thought to reside primarily in the brain's cortex, however recent research involving premature infants is documenting an important role for the cerebellum -- previously thought to be principally involved in motor coordination -- and shows that cerebellar injury can have far-reaching developmental consequences.
This work also demonstrates that the cortex and cerebellum are tightly interconnected. Sophisticated MRI imaging of 74 pre-term infants' brains revealed that when there was injury to the cerebrum, the cerebellum failed to grow to a normal size. When the cerebral injury was confined to one side, it was the opposite cerebellar hemisphere that failed to grow normally. The reverse was also true: when injury occurred in one cerebellar hemisphere, the opposite cerebral hemisphere was smaller than normal. So, there seems to be an important developmental link between the cerebrum and the cerebellum, - it seems that the two structures modulate each other's growth and development. The way the brain forms connections between structures may be as important as the injury itself. The cerebellum has also been implicated in the development of some types of literacy problems, including dyslexia.
So the question is, can cerebellar injuries be treated? The answer has to be 'yes!' We know the brain has inherent qualities of plasticity, this is particularly so in the cerebral cortex. If we can stimulate cortical plasticity and re-wiring as a consequence of our treatment then the previous research suggests that we might well also see cerebellar development. Combined with exercises directly aimed at improving cerebellar functioning itself, we believe that Snowdrop rehabilitation programmes provide the best hope for recovery of function in children who have experienced cerebellar injuries.
If you would like to learn more about Snowdrop programmes for brain injured children, then please click here to visit our website. Or you can email atsnowdrop_cdc@btinternet.com