What is neural plasticity and why does it matter with dysphagia?
Neural plasticity is the mechanism that we take advantage of when we provide therapy. It describes the ability for neurons to change in structure and function in response to external experiences. This is the mechanism that allows individuals with damage to their brain from stroke, TBI, or other conditions to regain lost function. The healthy neurons can change to restore a given function.
Ok, great. But how do we use the principles of neural plasticity in dysphagia rehabilitation? There are 10 principles to include in your therapy to best take advantage of neural plasticity.
- Use it or lose it
We know that if you don’t use a certain muscle for a while, it is going to get weaker and weaker. The same idea applies to the brain- if we don’t use an area of the brain, it can degenerate. Why is this important to dysphagia? Think about if someone is on a feeding tube and is made strict NPO. We are stopping this individual from using the parts of the brain related to swallowing. If someone has difficulty swallowing but then we don’t let them swallow, we don’t let them do the one thing that they need to work on, how do we ever expect them to improve? Physical therapists don’t make people bed bound because they have trouble walking so why are we doing this to people with dysphagia?
2. Use it and improve it
We need to provide the right experiences in order to improve that function. So if we want to improve someone’s ability to swallow, we need to let them swallow.
We have to rehabilitate the specific skill we want to improve. So if we want to improve swallowing, we need to have the person swallow. Non-swallow tasks such as saying k- and g- words will not improve swallowing. Just as swallowing therapy won’t improve a person’s ability to produce voicing.
4. Repetition matters
We need to include many repetitions of a given skill in order to initiate neural plastic changes. A person may demonstrate behavioral changes quickly, but we need multiple sessions targeting that skill over multiple days to provide changes to the brain. We also want to provide the person with the opportunity to complete the skill outside of therapy too.
5. Intensity matters
Having someone complete 10 effortful swallows in a given therapy session is not going to cause change. We need to ask them to complete many more swallows in order to take advantage of their neural plasticity.
6. Time matters
We want to start therapy as soon as possible. Better outcomes have been recorded when treatment starts within a week of the injury. We know that recovery from stroke or TBI is a lifelong process, however, we also know that the greatest and fastest changes occur closer to the time of the injury. Additionally, people may self-teach compensatory strategies that can make it more difficult to learn the accurate way to complete a skill.
7. Salience matters
The treatment we provide must be important and interesting to the person. Think about that one class that you took that didn’t really matter to you. How much do you remember from it? Not much probably. What about that book that caused all kinds of emotions and kept you up all night reading? You probably remember a lot more of that.
8. Age matters
The younger the brain is, the faster changes will occur and the amount of change will be greater. Of course age is not something we can change, but can be important in thinking of prognosis.
If we target one skill and cause neural plastic changes, it can cause similar improvements in other similar areas of the brain.
Training of one skill can interfere or block changes in another area. If a person learns a maladaptive behavior, it may complicate learning the effective behavior. So with swallowing, we don’t want the person to self-teach behaviors or strategies that will reduce the effectiveness of the training of the correct skill. We don’t want people to develop bad habits.
Neural plasticity may seem complicated but it is so important to understand when providing therapy. What principles do you implement in your therapy? Which principles do you need to start including?
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 : JSLHR, 51(1), S225–S239. https://doi.org/10.1044/1092-4388(2008/018)