Reflections on Mirror Therapy

By Ruth Werner
[Pathology Perspectives]

Let’s say you’re watching an action movie. In one scene, the main character comes around the corner and all of a sudden the villain jumps out and attacks him. Do you flinch? What just happened?
During massage, have you ever worked with someone exactly where and how you wish someone would work on you? As you poured your intention and breath into addressing your client’s pain or tension, did you feel your own pain or tension relax and release just a little?
These phenomena reveal some fascinating things about the brain that may eventually lead to noninvasive but successful strategies for pain management. We saw a hint of this in the last Pathology Perspectives column (“Amputation Adaptations,” Massage & Bodywork, November/December 2014, page 40), where one massage therapist described working with her client, an amputee, in this way:
I found it very helpful to work on his arm as if it was intact. Using pillows, I made an “arm” and continued my long strokes as if the arm was there, while he watched. That helped dramatically with the phantom pain.
What might have been happening in this session was something neurologists call mirror therapy, and this protocol, while not effective in every case, has great potential among people with chronic limb pain.  

The Problem
Chronic pain is a huge problem in our society. It is a potentially life-threatening problem, as people who can’t relieve their pain may seek an early exit from their lives. It is certainly a quality-of-life-threatening problem. It costs our economy untold billions of dollars, not only in direct medical care (much of which is risky, expensive, addicting, and ultimately ineffective), but also in terms of the lost productivity and lost contributions to the worlds of those who are affected.
Obviously, not all pain is a bad thing. Pain has the useful function of telling us about present or incipient damage. It gives us good reasons to avoid that damage, or to avoid activities that might make existing damage worse. In its best sense, pain is our friend. But when pain signals become amplified and self-sustaining, pain no longer serves a useful purpose. This is discussed in some detail in “Pervasive Pain” (Massage and Bodywork, March/April 2013, page 42).
When pathological pain is perceived as coming from a limb—including a “phantom” limb (a body part that has been amputated)—several complex processes allow for the possibility of rerouting central nervous system (CNS) signals to reduce that sensation and to improve motor function. But the body’s solution can sometimes lead to further problems, most often seen in these forms:
Phantom limb pain (PLP): This is a common complication of amputation and can be caused by several factors. The longer the problem persists, the more likely it is to be related to a CNS processing issue. A person with PLP may sense that their phantom muscles are cramping, that the limb is twisted uncomfortably, or that it itches, tingles, or has sharp, shooting pain.
Complex regional pain syndrome (CRPS): This used to be called reflex-sympathetic dystrophy. The label encompasses subtypes of trauma that lead to ongoing, centrally generated, and often spreading, sensations of pain, along with tissue changes that include swelling, accelerated hair and nail growth, and atrophy of the affected bones and joints.
Post-stroke: CRPS is a common post-stroke complication, but even some stroke survivors without CRPS find that their muscular paralysis and accompanying pain can be improved with mirror therapy.

The Tradition
Until quite recently, the common wisdom among neurologists was that the brain was hardwired and its functions strictly segregated. Everybody knew that the ability to make cross connections between areas in the brain was limited, and that any CNS damage was permanent. The best way to deal with CNS problems was to make the functioning part of the body able to do as much as possible and to give up on the nonfunctioning part.
The treatment options that arose out of this paradigm are still predominant, simply because they seem to be the best we have. They include pain medications, including highly addictive opioids; surgery to remove lesions (which can create its own set of problems) or to implant pain management devices; and nerve blocks that are often impermanent and unsuccessful.
We now know that the brain is far more complex than we thought. It changes and adapts, sometimes in ways that cause problems. It contains 100 billion neurons, and each one is capable of 1,000–10,000 connections with other neurons. Consequently, to suppose that our cognitive, sensory, and motor functions are fully separate is simply not realistic.

An Amazing Observation
Picture a person with an amputated hand, just above the wrist. She has PLP; it feels like her hand is cramping and her forearm is twisted, and she can’t do anything about it. She is sitting at a table. Her healthy hand is supine in front of her, and her phantom hand is hidden in a mirror box on the table. She is positioned in such a way that she can see the reflection of her intact hand in the mirror, exactly where the missing hand would be (Image 1).
If she slowly closes and opens her intact hand, and mentally does the same with her phantom hand while she watches in the mirror, a truly amazing thing may happen. Within a few minutes—if she’s lucky, longer if she’s not—sensation in the phantom limb may change. The cramping feeling may release, and the sense of being twisted may let go. This might take a while; 40–60 minutes a day for several days is not unusual. But the payoff is huge: for a while, at least, the PLP is resolved. And the next time it arises, she has an easy home-care protocol to deal with it.
Similar applications have been used with CRPS patients, spinal cord injury patients, and stroke survivors. In many patients, using a mirror to reflect a healthy limb allowed them to increase their range of motion and to decrease pain—without drugs or surgery.1
This approach, called mirror therapy, arises mainly from the work of neurologist V. S. Ramachandran. In 1996, he and his team published a paper on using mirrors to alter phantom limb pain. They went on to study mirror therapy in the context of stroke-induced paralysis, CRPS, and several other conditions. The results, while not universal, were successful often enough that mirror therapy is now a commonly employed strategy for physical and occupational therapists.

How Does Mirror Therapy Work?
The principal theory behind mirror therapy is that the mirror creates a visual perception of the limb, which then matches motor intent and proprioception. With repetition, this pathway is reinforced, and ultimately the phantom limb pain may subside.
The key players, according to Ramachandran, are motor neurons located in the frontal and parietal lobes called mirror neurons. These cells, which by some accounts comprise up to 20 percent of our motor neurons, are activated when we observe someone else’s movements. That is to say, when we watch someone walk or dance, mirror neurons in our own brains that could stimulate similar movements fire a signal. When we watch someone smile or laugh, the same thing happens. Under normal circumstances, these motor impulses are inhibited by other CNS signals before we act on them, but pain and paralysis are not normal circumstances, so these inhibitors may be bypassed. And, amazingly, when we watch someone get hurt (remember the action movie hero?), mirror neurons seem to convey a sensation of pain as well.
So, the theory goes, mirror therapy works by using mirror neurons to essentially re-establish functional pathways to connect visual messages, proprioception, and motor and sensory perceptions in a pain-free way. This theory is supported by fMRI tests before and after mirror therapy.2
Truthfully, the link between mirror neurons and the success of mirror therapy is only partially established. Ramachandran and others strongly suspect mirror neurons to be involved, but laboratory testing has not confirmed all the details. In the meantime, however, we are learning a great deal about how the brain works with pain, and that knowledge may be beneficial to a very wide audience.

When Does Mirror Therapy Work?
The research on mirror therapy has yielded mixed findings. It appears to work better for some people than for others, but it can be difficult to predict who is most likely to benefit. It is successful more often for upper limb dysfunction than for lower limb problems, but some people with leg and foot problems derive significant benefit, too. Several specific mirror therapy protocols have been developed, and one program called “graded motor imagery” uses it as part of a progression of motor challenges in paralyzed people, with significant success.3
One small study of six individuals for whom typical movement-centered mirror therapy was unsuccessful may be of special interest to massage therapists. In this study, a researcher added gentle stroking (that is, massage) of the healthy arm to the standard protocol. This additional element reduced pain for five of the six participants.4
This scenario is not radically different from the one cited at the beginning of this article, with the massage therapist working on the phantom arm of an amputee while he watched. It is possible to extrapolate that massage therapists are already doing work that employs mirror therapy mechanisms; if true, the implications are mind-boggling. Consider a client with pain, or another condition, that contraindicates massage for the affected arm. But if that arm is in a mirror box while we massage her healthy arm, she may get some relief. To her, that would seem miraculous. To us, it could be a way to ease pain while bypassing skin that cannot be touched.

Where Does Massage Fit?
Mirror therapy was developed mainly to recruit and strengthen motor responses. A relatively unexplored aspect of this therapy is what happens when the element of touch is added to the illusion.
This begs the question: is mirror therapy within the scope of practice for massage therapists who have clients with intractable limb pain?
The answer is not clear. This is a relatively new protocol and, outside of specialized occupational and physical therapy, it is not widely practiced. But since mirror therapy protocols are freely available for anyone to observe and try (several YouTube videos show patients using this protocol), and because home practice is considered safe and effective,5 I would suggest that massage therapists could consider incorporating aspects of this approach, with the following caveats:
• Clients who live with chronic, intractable pain are likely to have a health-care team. For the benefit of the client, massage therapists on this team need to communicate with other members about their work—and this, of course, must occur within standard reporting and privacy boundaries. These communications need to include the massage therapist’s intentions and rationale, and an invitation for input from other members of the team.
• When an intervention has the potential to be powerfully positive, it also has the potential to be powerfully negative. In other words, mirror therapy is not risk-free. Some adverse effects include patients reporting that the pain is made worse, that the sensation of cramping increases, or that the affected limb feels frozen, and they may have dizziness, sweating, and emotional reactions.6 These are not trivial problems, and part of the point of being on a health-care team is to be ready to deal with them, should they arise. For instance, because dizziness is one reaction, it is important to be sure that the client is not left unattended and that a possible stumble or fall is not likely to cause significant injury.
• If you have the chance to try mirror therapy with a client, please benefit your profession by writing down and reporting the results in a case report, then sharing your experience at www.massagetherapyfoundation.org.
Preparing this article has been like looking at a field of pristine snow. No one in our field has documented any exploration of this modality yet. We hear stories every day about how powerful massage therapy is in the context of many kinds of pain, and the research strongly supports this point of view. But for the population of people dealing with intractable chronic limb pain, the options are few. Let’s see if massage therapy might be one of them.

Notes
1. Farshad Hasanzadeh Kiabi et al., “Mirror Therapy as an Alternative Treatment for Phantom Limb Pain: A Short Literature Review,” Korean Journal of Pain 26, no. 3 (July 2013): 309–11; See Young Kim and Yun Young Kim, “Mirror Therapy for Phantom Limb Pain,” Korean Journal of Pain 25, no. 4 (October 2012): 272–4; G. L. Moseley, “Graded Motor Imagery is Effective for Long-Standing Complex Regional Pain Syndrome: A Randomised Controlled Trial,” Pain 108, no. 1 (March 2004): 192–8; V. S. Ramachandran and Eric L. Altschuler, “The Use of Visual Feedback, in Particular Mirror Visual Feedback, in Restoring Brain Function,” Brain 132 (2009): 1,693–1,710.
2. J. Foell et al., “Mirror Therapy For Phantom Limb Pain: Brain Changes and the Role of Body Representation,” European Journal of Pain 18, no. 5 (May 2014): 729–39.
3. G. L. Moseley, “Graded Motor Imagery is Effective for Long-Standing Complex Regional Pain Syndrome: A Randomised Controlled Trial.”
4. L. Schmalzl, C. Ragnö, and H. H. Ehrsson, “An Alternative to Traditional Mirror Therapy: Illusory Touch Can Reduce Phantom Pain When Illusory Movement Does Not,” Clinical Journal of Pain 29, no. 10 (October 2013): e10–18.
5. D. M. Nilsen and T. DiRusso, “Using Mirror Therapy in the Home Environment: A Case Report,” American Journal of Occupational Therapy 68, no. 3 (May/June 2014): e84–9.
6. A. Hagenberg and C. Carpenter, “Mirror Visual Feedback for Phantom Pain: International Experience on Modalities and Adverse Effects Discussed by an Expert Panel: A Delphi Study,” Physical Medicine and Rehabilitation 6, no. 8 (August 2014): 708–15.

Resources
Moseley, L. “The Mirror Cure for Phantom Pain.” Scientific American. April 16, 2008. Accessed December 2014. www.scientificamerican.com/article/the-mirror-cure.
Samuel, J., S. Buxton, and W. Walker. “Mirror Therapy.” Accessed December 2014. www.physio-pedia.com/Mirror_Therapy.
Thieme, H., et al. “Mirror Therapy for Improving Motor Function After Stroke.” Cochrane Database Systematic Reviews 14, no. 3 (March 2014): CD008449. Accessed December 2014. www.ncbi.nlm.nih.gov/pubmed/22419334.

Ruth Werner, BCTMB, is a former massage therapist, a writer, and an NCTMB-approved continuing education provider. She wrote A Massage Therapist’s Guide to Pathology (Lippincott Williams & Wilkins, 2013), now in its fifth edition, which is used in massage schools worldwide. Werner is available at www.ruthwerner.com.