Brain Plasticity

Brain plasticity is an enormous source of hope for stroke patients !!! 

For the last century, research has been progressing on what is also known as neuroplasticity. But it's only in the last decade or two that what was a theory has gained general acceptance. And unfortunately, the medical profession is generally slow to adopt such items. Accordingly, stroke therapies often do not leverage this knowledge.

Brain plasticity is the brain's ability to reorganise itself and to change which parts of the brain are responsible for the functions performed by the brain.

This is really important !!!

Why? Well stroke is a brain injury. Part of the brain effectively dies as a result of the stroke, and the functions that were performed by that part of the brain are unable to be performed, or perhaps are able to be performed in limited ways.

Brain plasticity says that the brain can work around this injury and accommodate for it. But, it occurs as a result of directed effort, it doesn't just happen.

Traditional occupational therapy involves finding "work arounds" for what you can't do with your affected limb (or other body part). But what this does, is encourage what is known as "learned non-use". (Incidentally, there is some old research around this to do with a famous case known as the Silver Spring Monkeys.) So, a stroke patient ignores their affected limb and works around it. At this point, brain plasticity kicks in and "beefs up" the parts of the brain that support the non-affected limb. Any surviving brain matter supporting the affected limb pretty much withers away.

However, if you are able to reverse this learned non-use, you are able to force the brain to reorganise and regain some capability in the affected limb. A key technique for doing this is constraint induced therapy which was developed by Edward Taub.

Although brain plasticity was accepted as occurring in babies and children, for most of the 20th century the majority of researchers rejected it as occurring in adults. It's only now that it is generally accepted as having potential for people with traumatic brain injury or stroke.

	Recommended Reading About 8 months after Peter's stroke, I heard about Norman Doidge's book, The Brain that Changes Itself, in a radio interview. I only caught the end of the interview, but from the little I heard I was excited about the prospects of rehabilitating the brain. This book is a very readable explanation of brain plasticity. What is most encouraging is that there are case studies of people who have recovered significant capabilities after stroke. This book started us on the path of brain rehabilitation, and the ultimate result was this website. I strongly recommend this as a reference book for anyone who has suffered a stroke.

Brain Plasticity, Learning and Memory

Changes associated with learning occur mostly at the level of the connections between neurons. New connections are known to form and the internal structures of the existing synapses are also known to change with new learning.

If you become an expert in a specific domain, the areas in your brain that deal with this type of skill grow more. London taxi drivers have a larger hippocampus than London bus drivers because this region of the brain is specialized in acquiring and using complex spatial information in order to navigate efficiently. This occurs because taxi drivers need to navigate around London whereas bus drivers are required to follow a limited set of routes.

Plastic changes have been observed in the brains of bilinguals. The left inferior parietal cortex is larger in bilingual brains than in monolingual brains as learning a second language is known to be possible through functional changes in the brain.

Plastic changes also occur in the brains of musicians as compared to non-musicians. Researchers compared professional musicians (who practice at least 1hour per day) to amateur musicians and non-musicians. They discovered that gray matter volume was highest in professional musicians, intermediate in amateur musicians, and lowest in non-musicians in numerous brain areas involved in playing music.

	Example About five years ago, due to hitting middle age, Peter's short range vision started to decline and this necessitated reading glasses. Combined with his poor long range vision, this meant he was constantly swapping between glasses. This is a common problem for people which results in the use of bifocal or multifocal glasses being used. I had laser surgery in the mid 1990s for my short sightedness and found this fabulous, so Peter investigated this as an option. The technique had progressed by this stage, and the solution offered was to adjust one eye for short range vision and one for long range vision! Immediately after surgery this was disorientating and he thought that it wouldn't be suitable. However, within a few months, his brain had adjusted for the different messages coming in and now he can easily things both near and far with no need for optical assistance. This is a practical example of brain plasticity.

Brain Plasticity and Brain Injury

An astonishing outcome of neuroplasticity is that the brain activity associated with a given function can move to a different position as a result of a normal event or brain damage/recovery.

Extensive research has been done in the past on injury-induced plasticity. This research is still being done with the hopes of minimizing the effects of an injury on the brain.

For example in case of a brain injury due to stroke, functions of the brain such as motor control, memory, or language may be affected. A reorganization of these brain functions may occur through intact brain areas, allowing the distorted functions to be performed in a different way. Stroke patients are often successful in regaining a substantial amount of the brain function that is lost even after the brain cells die. Exercises to regain control over various movements or to recover the ability to speak or understand language often lead to significant post-stroke recovery.

In Norman Doidge's book (mentioned above), numerous examples of the stroke-induced plasticity are discussed. A surgeon in his 50s suffered a stroke and his left arm was paralyzed. During his rehabilitation, his good arm and hand are immobilized, and he was assigned a task to clean tables. The task seemed impossible in the first instance. Then slowly the bad arm remembered how to move. He learnt to write again, even to play tennis again. This showed that the functions of the brain areas damaged during stroke transferred themselves to healthy regions. The brain compensated for the damages by reorganizing and forming new connections between intact neurons.

Brain plasticity is an enormous source of hope for stroke patients.

Unfortunately, the medicos don't provide sufficient information to stroke patients and families to provide this important encouragement.

	Further Reading The Mind & The Brain (Neuroplasticity and the Power of Mental Force) by Jeffrey M Schwartz MD and Sharon Begley is a harder read than The Brain That Changes Itself mentioned above. However, if you're interested in understanding more about brain plasticity and the potential of this, it's worth the effort. It explains the history of research into brain plasticity and has some practical examples of how this has worked for stroke patients as well as for people suffering obsessive compulsive disorder (OCD). The hope I found on reading Doidge's book turned into massive excitement when I read this one!