Phantom limb syndrome is a condition in which patients, after an amputation, experience sensations coming from the missing limb.
These sensations can be either painless or painful, with the latter being classified into phantom limb pain (PLP) and residual limb pain (RLP).
Neurophysiological theories suggest that this phenomenon may arise from neuromas in the stump or from central sensitization of the nervous system.
Another explanation is linked to the “neuromatrix”, a representation of the body in the brain that, after amputation, becomes altered, causing a discrepancy between perception and reality.
The concept of mirror neurons, discovered in the 1990s, is relevant to understanding this condition.
Mirror neurons activate both when performing an action and when observing someone else doing it, and they are involved in learning and empathy. In the case of phantom limb syndrome, observing motor actions performed by others can activate brain areas that reflect the amputee’s bodily experience, but the absence of the limb creates a “perceptual incongruity”.