Neuroplasticity and practical principles of practice for brain injured patients
Neuroplasticity is the ability of the brain whether injured or uninjured to learn new behaviours and functions by neurons altering their structure, function and forming neural pathways for the adaption to take place.
This post is going to look at neuroplasticity and its relevance to rehabilitation as well as a summary of the principles of experience-dependent plasticity in rehabilitation. (Kleim and Jones, 2008)
There is significant evidence which indicate that the brain is creating new connections and neural pathways to store new experiences and to allow for behavioural changes. This is a process which is taking place constantly. (Black, Jones, Nelson and Greenough, 1997; Grossman, Churchill, Bates, Kleim and Greenough, 2002).
After a brain injury, learning and re-learning is an essential part of brain adaptation. We often see how the brain re-learns movements by the way the individual develops compensatory behavioural movements to functionally adapt after a brain injury. This can be seen by an individual with hemiplegia (one side affected) being dominant and reliant on the unaffected side. Eg. Weight bearing only on the one leg. The process of rehabilitation looks at correcting these functional maladaptations using neuroplasticity and the principles discussed later in combination with a structured exercise program.
Brain damage changes the way the brain responds to learning. A brain injury not only affects movements but can also affect speech, cognition, mood and we therefore require a multidisciplinary approach to treating individuals with a brain injury.
Principles of experience-dependent plasticity in rehabilitation.
Kleim and Jones (2008), identified 10 principles which hold relevance to outcomes in brain plasticity in the injured and uninjured brain.
- Use it or lose it
There seems to be functional loss in behavioural movements and patterns if there is no specific training in the functional movements.
- Use it and improve it
In rehabilitation it is important to understand what the intended outcome of our rehabilitation process is. Plasticity can be induced by training on specific movements and behavioural patterns which can bring about improvements in the task.
Specificity of the movements is key to bring about the desired plastic changes to the brain.
Repetition of the specific movements is required to induce lasting changes in the neural circuits for a specific movement or behavioural pattern. With increased repetition we wish to drive long lasting effects so that the skill/movement or behaviour is resistant to decay when there is a period of no stimulus.
The intensity of the stimulus is important to carry out plastic changes. The greater the intensity of the stimulus the greater the impact of neuroplasticity. A higher number of repetitions of a task as well as it being driven with a great deal of intensity has shown to increase the number of synapses in the motor cortex. (Kleim, Barbay, et al. 2002).
It is important to note with intensity however, there needs to be careful consideration to patients being exposed to overuse injuries using this rule. A clinician should use good judgement as to find the appropriate intensity for the person being treated.
The brain is a complex structure and unit and something which we still don’t fully understand as its ability and potential is still being analysed. We can not fix a set time in which we will see neuroplastic changes and say when specific adaptations will occur. We should look at neuroplasticity as a process. We see different adaptations taking place depending on the persons injury and where they are in the rehabilitation process.
The exercise or therapy done needs to be quality in nature. Exercises need to be significant and time needs to be utilised effectively. The person needs to feel that they are important as well, as emotion has a contribution to memory consolidation.
- Age matters
In the normal brain, with time we are subject to cognitive decline. In the younger individual, the impact of neuroplasticity is much higher, and they can adapt to changes and responses much quicker than the older individual. This does not mean that an older individual with a brain injury will not benefit from therapy, it just means that the timeline for improvement might take a bit longer compared to a younger individual.
Plasticity of developing a skill in one task may have a transfer onto another skill or task. A multidisciplinary approach is important in treating persons with a brain injury as it makes use of this principle and we have experienced this in the rehabilitation setting.
Another principle which highlights the importance of a multidisciplinary approach is interference. Plasticity of developing a skill in one task or behaviour may have a negative impact in another area. Therefore, it is important that we not only highlight and focus on the positive gains, but we also look holistically and notice if there have been any deteriorations in another aspect.
As stated by Kleim and Jones, 2008, this list is not a comprehensive list, but it brings forth keys principles which researchers have found to be relevant to rehabilitation of persons with brain injury. It gives a guideline for individuals who are looking into therapy for themselves or people they know who have had a brain injury and aids clinicians who wish to design and structure their rehabilitation program. As a Biokineticist we aim to use these principles in a structured exercise rehabilitation program to maximise the benefits of therapy for the individual.
Kleim, J.A., Jones, T.A., (2008). Principles of experience dependent neural plasticity: Implications for rehabilitation after brain damage. Journal of Speech, Language, and Hearing Research, 51, 225-239.
Black, J. E., Jones, T. A., Nelson, C. A., & Greenough, W. T. (1997). Neuronal plasticity and the developing brain. In J. D. Noshpitz, N. E. Alessi, J. T. Coyle, S. I. Harrison, & S. Eth (Eds.), Handbook of child and adolescent psychiatry (Vol. 6, pp. 31–53). New York: Wiley.
Grossman, A. W., Churchill, J. D., Bates, K. E., Kleim, J. A., & Greenough, W. T. (2002). A brain adaptation view ofplasticity:Issynapticplasticityanoverlylimitedconcept? Progress in Brain Research, 138, 91–108.
Kleim, J. A., Barbay, S., Cooper, N. R., Hogg, T. M., Reidel,C.N.,Remple,M.S.,etal.(2002).Motorlearningdependent synaptogenesis is localized to functionally reorganized motor cortex. Neurobiology of Learning and Memory, 77, 63–77.