Phantom Limb and Mirror Box Therapy

Phantom limb is a syndrome suffered by some people who have lost a limb.

The Phantom Limba term introduced by Silas Weir Mitchell in 1872, refers to a syndrome suffered by some people who have lost an arm, a leg or an organ and who continue to experience the sensations of amputated limbs.

Patients suffering from this syndrome, feel as if they were making a gesture, feel itching or intense pain.

The brain and the body

According to the neurologist at the Center for Brain and Cognition at the University of California, San Diego, Vilayanur S. Ramachandrannearly 70 percent of amputees continue to experience intermittent pain in the missing limb even decades after being amputated, producing devastating consequences in the lives of the patients who suffer from it.

Unfortunately, for many years, treatment had been ineffective because its Biological basis was not sufficiently clear.. Phantom limb sensations may appear immediately after limb amputation or late, but the pain usually appears in the first week post-amputation. It usually evolves with a reduction in both frequency and pain crises, but sometimes the pain may persist for years. In addition, it should be noted that phantom limb syndrome can cause psychological disorders such as depression, anxiety or stress in those who suffer from it.

What is the cause of phantom limb syndrome?

There are several theories that try to explain the cause of phantom limb. Not long ago, a simple and univocal relationship between injury and pain was proposed, but a recent school of thought has placed the genesis of the phantom limb in the brain, since cognitive and affective spheres are involved.

The research of Ronald Melzack gave rise to the neuromatrix theoryin which the diffusion of pain and its transmission through the organism is attributed to a complex system in which various areas of the central and peripheral nervous system, autonomic nervous system and endocrine system intervene, directly influenced by various psychological, emotional, genetic and social factors. This theory explains that we can feel pain sensations in the organism caused from within us, that is to say from our own organism, and by means of this system we ourselves can make these sensations increase, modify or decrease at a given moment. If this matrix is activated in the absence of peripheral sensory information (amputated limb) it would produce the sensation of having a limb present after the loss.

Another line of research is that of the scientist Ramachandranwho in his book "Ghosts of the Brain", gives an astonishing explanation. A patient with phantom limb complained of itching in the missing hand. Dr. Ramachandran, with a cotton swab for the ears, scratched the patient on the face relieving the itching of his hand. What is the explanation for this? The explanation is found in the Penfield's Homunculus. In the 1950s, Penfield and Rasmussen demonstrated the existence of a cortical map of body representation in two aspects: motor and somatosensory.

This This neurological map has particular characteristics: each part of the body is represented according to its sensorimotor importance (e.g., the lips or the hands are represented according to their (for example: the lips or the hands have more cortical representation than the trunk, that is why they are more sensitive), that is to say, one thing is the body and another the representation of the body in the brain. If a person loses a leg, an arm or an organ, its representation in the Penfield homunculus stops receiving information from that effector, but then, that area of the map can be invaded by the adjacent representation. In the case of the amputated hand, the adjacent representation is that of the face. Thus, stimulation on the face can make one feel a hand (phantom).

Mirror box therapy (Mirror Box)

This seems to demonstrate the plasticity of the brain, but what about phantom limb pain? Most patients, after an accident, are left with a useless and painful arm. After amputation of the limb, the pain often persists. Ramachandran thinks that the basis of this phenomenon is to be found in learned paralysisThe phantom limb also lacks mobility because the brain is fixed on the idea of a non-moving arm. For this, the neurologist invented the mirror box.

The mirror box is a box with a mirror in the center, when the patient inserts the unamputated arm, he can see the reflection of his arm in the mirror. When he sees his arm, he feels that the limb is present even though it is amputated. The patient then moves the arm, and through the use of visual feedback and by eliminating the visual feedback and by eliminating potentially painful positions, the patient then moves the arm, and through the use of visual feedback and by eliminating potentially painful positions, the patient moves the arm.The phantom limb, manages to give feedback to the brain and alleviate the pain it feels. Sometimes, even the phantom limb disappears.