Phantom Limb Pain After Amputation : New Research
A trial is under way to evaluate a surgical method that could help treat chronic phantom limb pain following on from an amputation.
Northwestern Medicine researchers are leading a new multi-centre clinical trial into targeted muscle reinnervation. Around a quarter of all amputees develop chronic pain in the remaining portion of their amputated limb, which can include phantom limb pain syndrome, which is pain perceived in the portion of the limb that is gone, and prevents many patients from using their prosthesis.
Northwestern Medicine’s chief of plastic surgery and principal investigator for the study, Gregory A. Dumanian, MD, said:
‘The problem for amputees that experience chronic pain isn’t that the limb itself was removed. The problem is that the nerves used to control the amputated limb are incomplete, but also remain active, constantly sending signals to the brain. These separated nerves cannot heal properly without the chance to connect to other nerve tissue, and end up creating painful growths called neuromas”
The current standard of care for a painful amputee neuroma is to remove the nerve growth and then place the nerve ending in to a nearby muscle for extra cushioning. While this treatment can reduce neuroma pain, it is not always successful and still leaves the nerve active and disconnected to inevitably create a new neuroma.
The TMR therapy’s goal is to transfer a nerve that has been cut off from the muscles it used to control and essentially plug it into a functioning muscle nearby. This is accomplished by removing the neuroma from the damaged nerve, and then surgically joining it with a healthy nerve that controls the existing target muscle. Joining these nerves together allows them to grow into, or reinnervate the target muscle and prevent the neuroma from forming.
‘TMR is a completely new approach to treating neuroma pain for amputees. Instead of trying to treat a painful neuroma by burying it, this procedure provides damaged nerves with a new purpose’.