Using a mirror to combat phantom pain

CNN has a story about a Navy neurologist who tried using mirrors to help soldiers from Iraq with phantom pain. Phantom pain is pain in amputees that is perceived to originate in the amputated limb. What causes it is not exactly clear although many theories exist. However, it is often refractory to pain medication (this is common in so-called central pain or pain originating in the brain), so it can be really difficult to make these patients feel better.

Dr. Jack Tsao, the Navy neurologist, had the idea that if you used a mirror to show the image of the opposing, intact limb where the missing limb should be, you could trick the brain into believing it was there and end the pain. Turns out it works pretty well:

Dr. Jack Tsao, a Navy neurologist with the Uniform Services University, was looking for ways to help soldiers like Paupore. He remembered reading in graduate school a paper by Dr. V.S. Ramachandran that talked about an unusual treatment for amputees suffering "phantom limb pain," using a simple $20 mirror.

The mirror tricks the brain into "seeing" the amputated leg, overriding mismatched nerve signals.

Here's how it works: The patient sits on a flat surface with his or her remaining leg straight out and then puts a 6-foot mirror lengthwise facing the limb. The patient moves the leg, flexing it, and watches the movement in the mirror. The reflection creates the illusion of two legs moving together.

"I was laying in bed and it just, all of a sudden, it felt like I was getting shocked," he said. "I called the nurse, 'cause I was like, 'What's going on?' " The nurse told him, "This is probably your phantom pain."

Tsao explains it this way: "It's the sensation that the limb is still present, and phantom pain in particular is the sensation that the limb is experiencing pain of some form."

That pain is intense, and often medication brings very little relief. For Paupore [a soldier from Iraq with an amputated leg], it was relentless.

"All of a sudden, it was like someone kept turning on and off the Taser, and my whole leg started twitching. ... I sat up, and I was holding on to my stump, and it just wouldn't stop. At that time, I was hooked up to the Dilaudid [a powerful narcotic], and I was pushing it. But you can push all the medicine in the world, and it won't stop it."

Paupore and 17 other amputees who joined Tsao's mirror therapy trial were randomly assigned to one of three groups. The first group used the mirror to look at their reflected image as they tried to move both legs. The second group used a covered mirror and did the same. And members of the third group were asked to visualize moving their amputated limbs.
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After a month of treatment, all of the patients in the mirror group had significantly less phantom pain. In the covered mirror group, only one patient experienced a decrease in pain, and for half of those patients, the pain worsened. Sixty-seven percent of the patients visualizing their limbs got worse instead of better. The pain decreased in almost 90 percent of the patients who then switched to mirror therapy.

It worked wonders for Paupore, 32. Within five months, he was off painkillers completely. Tsao says the difference is like night and day.

The cause of phantom pain is still under debate. The most current theory suggests that phantom pain is caused by the cortical reorganization. When the limb is amputated sensory information about where the limb is in space -- termed proprioception -- no longer comes into the brain. The brain compensates for this absence of information by reorganizing and in a sense over-representing areas that are intact -- they take over the area of the brain that used to represent the lost part of the body. During this process of reorganization, the patient can feel pain. (The subject is reviewed here.)

Let's speculate about why this mirror thing would work.

I think it is because the brain gets proprioceptive information directly from the limbs through receptors in the skin and muscle, but it also gets information about the limbs through the visual system.

You can prove this to yourself. Try taking a drunk test. Hold out your arms and touch your nose. Pretty easy. (...if you are sober, and consider you are probably reading this at work I sure as hell hope you are.) Now try doing that with your eyes closed. A little bit harder right. Your visual system assists the proprioceptive system in telling your brain where your limbs are in space.

What I think is happening with this mirror thing is that visual system is supplementing the proprioceptive system and tricking the brain into believing the limb is there. This helps alleviate the pain.

It shows that if you understand a system, a very simple solution can often achieve great medical results. Hive five to Dr. Tsao for thinking outside the box.

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If phantom pain is associated with brain "reorganization", does eliminating or reducing that pain (using mirrors) also slow or stop this "reorganization"? And does that matter?

It would be too bad if the treatment for the pain made long-term recovery harder, or less, ...

As I understand it, the reorganization goes on regardless of the mirror. Furthermore, phantom pain tends to diminish over a period of a couple years, so this mirror thing would be an interim treatment.

Whether the mirror slows or affects the rate of reorganization, I don't think anyone has studied that.

?

I thought this was demonstrated by Vilayanur Ramachandran some time back.

The article recognizes Ramachandran as the innovator of this idea.

Recommended reading: Phantoms in the Brain, by V.S. Ramachandran. He is the pioneer of research in phantom limb (as well as other sensorimotor / perceptive neurological disorders). His philosophy and approach towards his work is entirely inspiring.

Haha I was about to jump all over this defending Rama as well, one of the psychologists I work with at UCSD. Rama has even had some success at using this technique to reduce stroke induced paralysis (when the paralysis is to a large degree associated with the edema, not actual motor cortex damage).

I am sorry if I suggested that Ramachandran didn't come up with this idea originally -- that I certainly know. I am just impressed that someone is actually using it successfully. I don't get the sense that Walter Reed is often ground zero for experimental treatments.

This doesn't necessarily surprise me. The mind is an incredible tool for curing many ailments. If we believe something will work, then it will work. Why do drugs that cost more work better?, and why do so many believe that antidepressants will solve all of their mental health problems?. These are things that society will eventually have to accept and embrace. No matter how much of a snake oil they may seem, they still seem to have some sort of effect. But should we be paying $100 a pill for what basically amounts to well-hidden sugar tablets? That's the real question, and one which I hope will play a major role in upcoming policy.

While I don't deny that mirror therapy may help, what is missing here in this is that there is a physiological component here. I have had an increase in severity and frequency of this "tasor" like feeling when there has been an increase in pressure on the residual limb due to an improper fit due to changes in the prosthesis or my own physical limb due to weight loss for example. Right after the accident when phantom pain was more constant, I was given amytriptelene as part of a regemine and that seemed to numb the phantom pain significantly. It isn't a drug however that you can just take like an aspirin for immediate relief. It is a terrible sensation when it's at the tasor level.

My husband has lived longer without his leg (AK) than with it, 43 years without, now age 62. I was looking around on the internet today as he has spent the past 32 hours suffering from phantom pain. I am going to fix up a mirror box, he is very negative on any type of treatment and says he has done it all, so wish me luck. Thanks to you all for this information.

By Vicki Agro (not verified) on 27 Mar 2009 #permalink

I was in a very bad accident and lost my left leg traumatically...not by amputation. My entire leg,left half of hip and pelvis were also lost. I have been suffering from extreme phantom pain for just over nine years now and the pain is so bad that some days I am unable to function or I sometimes faint. Thank you so much for this information, I am scheduled for a very invasive surgery today at 6pm (electric spinal implant surgery) and I was just given this information about the mirror therapy from a Red Cross worker about 15 minutes ago. I am going immediatley to try this...maybe I will not have to go thru surgery again after all.
P.S. My husband is going to be home today (NAVY) from deployment to spend the next two weeks with me and our children while I go thru and recover from surgery...wouldn't it be wonderful to just have fun together as a family and not go to surgery :)
Thank you again, Melodi

By Melodi Sevilla (not verified) on 24 Sep 2009 #permalink