Graded Motor Imagery: What is it, why is it used, and is it helpful?
As a person suffering from a neurological condition that evokes a good deal of nerve pain, I had not heard of graded motor imagery (GMI) until recently. The concept, foreign to me like many others, is a three-step process for chronic pain that serves to retrain the brain. Research studies have mostly explored GMI as a treatment component in Complex Regional Pain Syndrome Type I (CRPS-1), and phantom limb pain (PLP), but it is also being investigated for other chronic conditions such as low back pain. The program was originally conceptualized after it became apparent that chronic pain causes cortical (brain) reorganization. In response to the constant pain stimuli that are relayed to the brain in these conditions, the primary sensory cortex, which helps us process stimuli such as touch, pain and temperature, begins to change in a maladaptive way. The cycle then becomes a vicious one, wherein both the brain and the body are sending pain messages to one another, long after tissue healing has occurred. To quote my occupational therapist, “the issue is not in the tissue”.
In an article printed in The Journal of Pain (Doesn’t that sound like a magazine you want to read?), Tasha Stanton and her research team explained in their meta-analysis on the effects of GMI, that when pain becomes chronic, the brain’s representation of that body part becomes blurred. To cite her example, in low back pain, the representation of the back by the brain becomes smudged so that the painful area is perceived as larger and shifted to the middle of the cortex when compared to the representation of the back in healthy individuals.
Stanton’s team also found “behavioral issues” arise where individuals cannot discriminate between tactile stimuli within the region of the painful body part. I can attest to this, as I have trouble telling one area from another on certain parts of my affected leg. Luckily, though, as research has come to understand these cortical changes in people with CRPS-1, PLP, and chronic pain, therapeutic treatments have been developed and altered, all of which play on the idea of neuroplasticity.
Are now scratching your head asking what exactly is neuroplasticity? Neuroplasticity is the concept that the brain is plastic. While scientists and doctors once believed that changes in neural networks were permanent and non-malleable past childhood, we now know this is far from true. Just as the brain in people with chronic pain changes due to the formation and termination of neural networks throughout the cortex, it can change back with the pruning of old networks and growing of new ones These networks work to replace the maladaptive networks so that brain reorganization occurs in favor of the individual suffering from pain. And as these networks normalize, so does the pain!
So what exactly is graded motor imagery (GMI)? And does it work?
GMI has three steps (sometimes two if there is more than one limb affected). The first step is called left/right discrimination. This involves a person looking at pictures of the affected body part, say the foot, and determining whether it is the left or right foot. People enduring chronic pain frequently have trouble correctly identifying right and left of the painful body part due to brain changes in the cortex.. In addition, as compared to pain-free individuals, they are slower at attempting to do so. Functional brain imaging demonstrates that this task has been shown to directly activate the premotor cortex without activating the motor cortex, playing on the progressive reorganization of the brain. A therapist may do this for a patient by printing pictures, but there is also a wonderful app called Recognisethat anyone can use.
The second stage of GMI is called explicit motor imagery. Explicit motor imagery involves imagining a movement, but I mean really sitting there and imagining it. This technique is also used by athletes when preparing for competitions or when working on improving certain aspects of their athletic skills. As an example, imagine yourself going grocery shopping. In your mind you would place yourself in the store, imagining what you are seeing, feeling what you are wearing, hearing the sounds like the shopping cart rolling down the aisle and maybe smelling the bakery bread or the fish. The goal is to make the experience as real as possible. Explicit motor imagery can be used for any activity one wants to more fully enjoy.
When employed as a pain management technique, most individuals work progressively up to an activity they have stopped doing. If for example they want to exercise again, they may start with just imagining themselves being in the gym or stepping on a piece of equipment. Explicit motor imagery plays upon the concept of ‘mirror neurons’. Mirror neurons are neurons in our brain that start firing when we watch or imagine ourselves or others doing an activity. These neurons have a big impact as they comprise up to one-quarter of the neurons in our brain! And they directly activate the motor cortex. The explicit motor imagery process is so powerful that it can actually cause a person’s heart rate to speed up and it can elicit physiological symptoms such as sweating or muscle twitches. Studies have also shown that employing explicit motor imagery can actually make a person stronger and help maintain fitness when injured.
The one drawback is that explicit motor imagery can also at times cause an increase in pain. When this happens, this presents a good opportunity to work on relaxation and breathing techniques and learn to calm the nervous system while engaging in such activities.
The final stage of GMI is mirror therapy. (Although if more than one limb is affected this may be a bit tougher.) What happens during this stage is actually brain trickery. The individual stands or sits with the unaffected limb in front of the mirror keeping their eyes focused on the limb for a set period of time. Mirror feedback tricks the brain to believe it is seeing the affected limb. Think about this: when you look in a mirror, your left limb is reflected back to you as your right limb. With mirror therapy, while using the unaffected body part, the individual perceives the affected limb as non-painful and non-threatening. Again this trickery causes cortical reorganization.
So does GMI work? In my experience, GMI is effective but requires constant hard work. And just like anything, progress is not linear, so at times it can be challenging not to get caught up in the setbacks. Indeed, as I was writing this article, I was beginning to struggle with neurological symptoms. Although I felt my brain and body starting to panic (that only makes pain worse, but can be hard to deal with when you are feeling intense sensations), I took a step back. I focused on my breath for a few seconds, and because being mindful of the pain was hard for me in this moment, I looked at the fear thoughts and tried to reframe them. (Heck, I am writing an article on how we can change our brains!). And then I did something that I didn’t realize immediately I was doing…I started doing GMI. I started imagining myself typing this blog post, sitting here in a relaxed manner. The symptoms became less intense, as did the anxiety. And as I continued to imagine myself doing the task (I must interrupt to say, this is not usually how GMI is done), I was able to keep typing and not fall victim to the pain mentally or physically. The hard part about this is there are other times when this for whatever reason this may not have helped me in a tough moment with pain, but and when it does, I know my brain is reorganizing. Knowing the power to reorganize our brains lives within me and within anyone who is suffering, gives us the momentum to keep going–and pat ourselves on the back at the same time!
Okay, I will shut up about me now and explain what GMI is for all of you who went into this article actually reading it for that reason. What do studies show about the efficacy of GMI? For PLP and CRPS-1, studies have demonstrated that it is an effective way to reduce pain and normalize the brain allowing individuals suffering from these impairments some hope and ultimately relief. Stanton and her researchers also found that GMI reduces pain and disability much more significantly than physiotherapy in people with these conditions. One unknown is how the mechanism is able to effectively reorganize the brain. Another caveat is that, in order to be effective, GMI must be done in the step-wise order listed above, and is most helpful when guided by a knowledgeable therapist. Nonetheless if done correctly, it can be very successful at treating these conditions. So if you or someone you know is suffering from chronic pain, or just looking to improve your golf swing, give it a shot and see what you think!