Cause and Potential Treatment of Phantom Limb Pain Found – May Translate to Other Chronic Pain Conditions

Cause and Potential Treatment of Phantom Limb Pain Found – May Translate to Other Chronic Pain Conditions

by Staff

Researchers just found out two important things about phantom limb pain.  First is that a “reorganization” of the wiring of the brain is the primary cause of phantom limb pain.  The second is that using artificial intelligence techniques, phantom limb pain may be treated.

Researchers used a brain-machine interface to train ten amputees with phantom limb pain to control a robotic arm with just the use of their brains.   What they learned is that when the individuals tried to control the prosthetic arm by associating the movement with their missing arm, their phantom limb pain increased.  But, when they were trained to associate the movement of the prosthetic arm associated with their existing arm, their pain decreased.

Their results, reported in the journal Nature Communications, demonstrate that in patients with chronic pain associated with amputation or nerve injury, there are “crossed wires” in the part of the brain associated with sensation and movement, and that by mending that disruption, the pain can be treated.

The authors also note that the findings could also be applied to those with other forms of chronic pain.

“Even though the hand is gone, people with phantom limb pain still feel like there’s a hand there – it basically feels painful, like a burning or hypersensitive type of pain, and conventional painkillers are ineffective in treating it,” said study co-author Dr. Ben Seymour, a neuroscientist based in Cambridge’s Department of Engineering.

“We wanted to see if we could come up with an engineering-based treatment as opposed to a drug-based treatment,” he added.

The cause of phantom limb pain is theorized to be associated with faulty “wiring” of the sensorimotor cortex, which is the part of the brain responsible for processing sensory inputs and executing movements.

Seymour and his colleagues, led by Takufumi Yanagisawa from Osaka University, used a brain-machine interface to “decode the neural activity of the mental action needed for a patient to move their missing hand, and then converted the decoded phantom hand movement into that of a robotic neuroprosthetic using artificial intelligence techniques.”

“We found that the better their affected side of the brain got at using the robotic arm, the worse their pain got,” said Yanagisawa. “The movement part of the brain is working fine, but they are not getting sensory feedback – there’s a discrepancy there.”

The researchers then altered their technique to train the “wrong” side of the brain.  When they were trained in this technique, the patients found that their pain significantly decreased.  As they learned to control the arm in this way, it takes advantage of the ability of the brain to restructure and learn new things.

Noting that the effects are temporary and require expensive equipment, Seymour said, “Ideally, we’d like to see something that people could have at home, or that they could incorporate with physio treatments.  But the results demonstrate that combining A.I. techniques with new technologies is a promising avenue for treating pain, and an important area for future UK-Japan research collaboration.”

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Authored by: Staff

There are 6 comments for this article
  1. Mary Ellen at 4:15 pm

    As I read this adverticle I was shaking my head. I am qualified to shake my head because I have a partially amputated right hand with phantom pain at times and fibro +osteoarthritis w/ chronic pain daily. It reminded me of the pain group I used to go to. The doc was a very caring MD/psyD who is still my pain doc. He had put together a big list of the ways people have addressed their Chronic pain. Before the group he shared the list with me and wanted my opinion. I told him it made me mad. Not having health insurance has colored my world and I have no patience for mental mxxxxxbation. His face fell. As I ripped into the list of the highly suspect options on the basis of cost and availability, I ended with recommending sharing the list with patients who are new to pain and have excellent insurance. To the rest of us it’s offensive.

  2. Jennifer Picciotto at 2:43 pm

    I was very interested in this article because this research is providing hard evidence of cortical reorganization in pain patients, and that the brain can be re-trained to make new pathways that don’t carry the pain signal. It was not so long ago that scientists believed that the brain had no plasticity. Our ability to change the brain is a hopeful avenue of research for many pain conditions. I agree that there are some interesting similarities to mirror therapy, however in this case they are converting brain signals into electrical signals that move a prosthetic. Thank you for the link to the research article.

    “Recently, it has been shown that brain–machine interfaces (BMIs) can not only reconstruct motor function in severely paralysed patients but also induce plastic changes in cortical activity. A BMI works by first decoding neural activity of the mental action to move the affected hand, for example, and then by converting the decoded phantom hand movement into that of a robotic neuroprosthesis…. Moreover, training to use BMIs induces plastic changes in cortical activity and, potentially, associated clinical symptoms.” (Source: http://www.nature.com/articles/ncomms13209)

  3. Carol levy at 10:27 am

    sounds like a form of “mirror” therapy which is not expensive and with which there is been success.

  4. Laurie Otto at 9:50 am

    This article really aligns well with the mysterious alkaloids in kratom’s effectiveness. So much pain is felt in the brain (messages from the body). I’m no expert, but I believe Kratom’s effectiveness is entirely related to hitting this same sweet spot. It’s gaining huge amounts of new interest due to the DEA ban threat. That threat ended up alerting people to options they may not have known about (many doctors don’t. But many doctors don’t know anything about nutrition and supplements, either). Thank you for this article.

  5. Kathy C at 9:02 am

    “Temporary and requires expensive equipment”. This is just one more of those sensationalist,interesting, but meaningless bits of fluff. These kinds of publicized “Studies” make it appear there is some real research going on. This has everything Artificial Intelligence, the curiosity of Phantom Limb Pain, The false narrative that technology is a fix for everything. The “hook” of a good Headline for the Article. We have to read the whole Article to find that the “relief” was temporary. The use of the word “May” and the implication that this might “Translate to other Pain. This is a pile of Non News, the real take away is that this is promoted as “research.” The pain reduction was likely due to distraction and novelty.
    The one take away, is that there is so little actual “Pain Research,”that an experiment like this gets top billing. The Title is misleading, and gives the casual reader the idea, that something is in the works, that the “Scientists” are working on it. The focus on these non drug pain cures, amplifies these irrelevant “Studies.” It was an interesting Experiment, in the grand scheme of things, it should add to our understanding of Phantom Limb Pain. A condition that gets interpreted according to previous Bias. Since the limb does not exist anymore, they chose to interpret this broadly. They also chose to apply this to other pain conditions, since the “pain” is clearly located in the brain. Publicizing this as a “breakthrough” is really just advertising. The narrative is being reinforced, the pursuit of a non drug pain cure. They have a Proprietary Interest in following this technology, whether it works or not. That is the problem, these so called “News” releases are only attempts to promote this “research” as a funding opportunity. They are shamelessly promoting this in the absence of much other real research. This is an Advertising and promotional stunt.