The Learning Zone
The mind and rehabilitation of movement after a stroke
Did you know that the power of our mind is such that one can significantly improve the rehabilitation of movement after a stroke? According to Dr Edward Taub (University of Alabama at Birmingham) who developed a revolutionary therapy called Constraint-Induced Movement therapy (or CI therapy): “It is hard work. But if you put the work in, over a period of time, there is almost no limit to the amount of recovery that you can have. And this is predicated on the fact that the brain remains a very plastic instrument throughout the lifespan.”
Dr Edward Taub’s approach to rehabilitation is very different to traditional neurorehabilitation done in people who have suffered from a stroke or other neurological injuries. The traditional approach consists in attempting to use more the affected limb and this is usually done one to two months after the stroke onset. “And when a plateau is reached, then the therapist would move on to the arm that had not been affected by a stroke and try to train the person to use it so that it the work of both arms. This had the unfortunate consequence of stamping in the non-use”
The idea behind CI is to prevent the person from using the good limb and to motivate the use of the affected limb by passing a “behavioral contract” whereby the patient commits to carry out a number (and most) of standard daily tasks, like brushing one’s teeth, filling a glass, as much as possible with the affected limb. The “behavioral contract” is simply an official commitment, so to speak, taken by the patient with his therapist and also in front of a witness. This serves to create a degree of psychological pressure on the patient to use the affected limb. It is similar to those situations when one commits to do certain things with friends, family and colleagues, and where one then feels forced to honor his/her commitment. Dr Taub who is a psychologist (and neuroscientist) by training, who focuses on brain behavior relationships, feels that the behavioral contract is a key success factor of the CI therapy.
Let’s look at the clinical data. Although, CI therapy is very time-consuming, the results seem very encouraging. In an initial rigorous study (published in 2006) involving patients who had had their strokes, on average, 4½ years before, 21 patients were treated (6 hours a day for 10 days) and 21 were controls. The group that was treated showed significant improvement after 2 weeks, and the improvement lasted for 2 years after the study had been completed. More recently a multi-site randomized clinical trial was published, providing gold standard evidence for the efficacy of CI therapy.
To this day, CI therapy has been used with thousands of stroke patients in the USA, Germany and Scandinavia, and there are more than 200 publications on CI Therapy applied to stroke in the literature.
But how does CI Therapy work? By using a technique that enables to determine, through the non-invasive use of an intense magnetic field (called transcranial magnetic stimulation), how excitable a particular part of the brain is for producing a contraction or movement of a muscle, Dr Taub and other researchers were able to make a number of interesting observations about parts of the nervous system and movement production, such as:
the part of the brain, also referred to as the motor output area, responsible for contracting, moving a muscle, could shrink to a half after a stroke; the same motor output area could return to normal size after CI Therapy, in other words, a change in the ability to use a certain muscle was correlated to an observable change in the nervous system (brain); there was also a recruitment of the motor areas on the healthy side of the brain after CI Therapy.
Since 1997, when he first started to use CI Therapy, Dr. Taub has received numerous awards from national professional societies and CI therapy was named by the Society for Neuroscience as one of top 10 Translational Neuroscience Accomplishments of the 20th century (2003) and one of the 10 “most exciting lines of neuroscience” currently being carried out (2005).
Reference: Brain Science Podcast with Ginger Campbell, MD
By the Horizon Research Foundation editorial board