Brain plasticity following amputation

Robert Barry

The Biomechatronics group recently pioneered a new type of amputation surgery, the AMI amputation, that allows patients to use a bionic prosthesis with greater control and sensory feedback. 

After a year of seeing patients demonstrate significantly decreased pain, improved mobility, and speak about their vivid phantom limb sensations, we started wondering how the brains of these patients changed as compared to traditional amputees. This was especially interesting since traditional amputees experience quite a bit of phantom pain and irritating sensations, arising from the abnormal way in which their brain adapts to a loss of a limb. 

In collaboration with the MGH Martinos Center, we performed brain scanning (MRI) to look at changes between normal subjects, subjects with traditional amputations, and subjects with the AMI amputation. We found that AMI subjects had significantly less change and were receiving sensory feedback in the brain, just like the control subjects. We also learned that they rely less on their visual system to guide their limbs, unlike traditional amputees. The regions of their brain that coordinate sensorimotor activity also resembled the activity of normal brains to a greater degree. 

This study is significant because it reveals that a specialized surgical paradigm can go beyond improving the functionality of our limbs and external organs to also improving the mechanisms of the brain—having a profound impact on pain, sensation, and more! 

This project is in collaboration with the Martinos Center for Biomedical Imaging.