Phantom Limb Pain (Targeted Muscle Reinnervation and Mirror Therapy)

    Many face the unfortunate event of requiring amputation, the surgical removal of a body part due to certain trauma, or cases of onset disease such as diabetes or infections. That being said, “Many of the 2 million amputees in the United States suffer from chronic pain, either isolated to the residual limb itself or as phantom limb pain (PLP)” (Dumanian, et al., 2019). Limb pain after amputation can be explained by cut nerve endings that cause disorganized axons, terminal-neuromas, causing pain. The site of amputation sends signals to the brain that the limb is still there, and pain can range in intensity, but there is no real effective treatment for this experience. There are many treatments for after-care, such as massage, acupuncture, antidepressants, scar tissue removal, or prosthetic implementation (Moseley, 2008).

    Gregory A. Dumanian and his team explored targeted muscle reinnervation to muscle for postamputation pain in their article “Targeted Muscle Reinnervation Treats Neuroma and Phantom Pain in Major Limb Amputees.” Targeted muscle reinnervation can be able to organize these axons and nerves so that there is less pain post-procedure. The neuroma is removed, and a new nerve is attached to grow with the amputated muscle. This procedure focuses on healing the nerves rather than hiding the nerves that cause pain. The pain was measured via a Numerical Rating Scale based on patient information with pain intensity and pain interference. Although there is not a significant change in pain, however, there is a decrease in values

    Another method that has been explored by scientists is Mirror Therapy cited from Brenda Chan and her team’s research in the article “Mirror Therapy for Phantom Limb Pain.” This article refers to the pain of phantom limbs to the “conflict between visual feedback and proprioceptive representation of the amputated limb.” Mirror therapy is the illusion of having an intact limb by placing their affected limb behind a mirror, it is used to simulate having two intact hands. This illusion works best for those who experience hand or arm amputation to minimize pain (Chan, et al, 2007). The patients performed the therapy for 15 minutes daily and recorded pain via a visual analog scale. In this study the researchers concluded that mirror neurons that are relevant to the amputated limb hemisphere in the brain fire after a person perceives a limb, reducing pain altogether.

    These two methods, targeted muscle reinnervation and mirror therapy are both used to reduce pain, but TMR has more success than mirror therapy. Due to trauma and illnesses, many people must suffer prolonged pain of losing a limb after amputation but with these methods, and many others, scientists may relieve pain from amputation more efficiently in the future.

Chan, B. L., Charrow, A. P., Howard, R., Pasquina, P. F., Heilman, K. M., & Tsao, J. W. (2007). Mirror therapy for phantom limb pain. The New England journal of medicine, 357(21), 2206.

Dumanian, G. A., Potter, B. K., Mioton, L. M., Ko, J. H., Cheesborough, J. E., Souza, J. M., Ertl, W. J., Tintle, S. M., Nanos, G. P., Valerio, I. L., Kuiken, T. A., Apkarian, A. V., Porter, K., & Jordan, S. W. (2019). Targeted Muscle Reinnervation Treats Neuroma and Phantom Pain in Major Limb Amputees: A Randomized Clinical Trial. Annals of surgery, 270(2), 238–246. https://doi.org/10.1097/SLA.0000000000003088

Moseley GL, et al. (2008). Is mirror therapy all it is cracked up to be? Current evidence and future directions. Pain, 138(1): 7–10.