A phantom limb is a complex phenomenon involving a
sensation that an amputated or a missing limb is still attached to the body.
60 to 80 % of individuals who have undergone amputations have reported this
sensation. Phantom sensation is also observed in those who are born without
limbs and in those who are paralyzed.
phantom limb feels shorter, distorted and, is often, painful. The pain occurs
intermittently, can be quite agonizing and is aggravated by stress, anxiety and
by weather changes. The frequency of these painful attacks is usually
ameliorated with time.
is not reported by all the amputees, however, various types of phantom sensations,
have been reported such as itches, twitching, tightness, burning, gesturing or
even as if they are picking up something. Phantom sensations also occur when
other body parts have been removed, such as breasts, tooth and eye.
Until recently, it was assumed that the irritation caused at the
nerve endings, or the neuromas, of the amputated limbs was the reason behind
During amputation, several nerve endings become terminated at the
residual part of the limb. It was once believed that these nerve endings send
the wrong signal to the brain, which is interpreted as pain. Treatment based on
this assumption was never successful.
In some cases, when the pain was too severe, the surgeon would
perform a second amputation to further remove the end of the amputated limb, in
order to provide temporary relief to the patient. However, in many, the pain
increased after the second surgery and the phantom sensation doubled.
In the late
1980s, Ronald Melzack proposed the theory of the ‘‘neuromatrix.’ According
to this theory, our body’s experience is created by a large network of
interconnecting neural structures. In 1991, Tim Pons and colleagues at the NIH
demonstrated that sensory areas of the brain get substantially reorganized following
loss of sensory inputs.
All this information caught the attention of V.S. Ramachandran, who
theorized that phantom limb sensations could be the result of reorganization of
the sensory areas of the brain, which receive inputs from all over the body,
including the limbs. Ramachandran and colleagues proved this point through
an amazing illustration - while stroking various parts of the face, the
patient perceived that various parts of the missing limb was being touched.
According to Ramachandran, this perception was because the brain cortex became
reorganized after the amputation.
In 2009, researchers Lorimer Moseley and Peter Brugger
experimented with seven arm amputees who were encouraged to use visual imagery
to contort their phantom limbs into various impossible configurations. Four of
the seven patients succeeded in using their phantom limbs to achieve impossible
movements. The study revealed that motor commands were modified to execute
these movements. These experiments have put forth the fact that the brain is a
plastic entity, and that the way we perceive our body parts can be changed by
changing the internal mechanisms of the brain.
In 2012, Karen Reilly and colleagues proposed that the movement of
phantom limbs is "real" and that they obeyed a motor command. Phantom
past two decades, doctors have attempted to treat phantom limb pain with a
variety of methods including antidepressants, spinal cord stimulation,
hypnosis, acupuncture and biofeedback. Unfortunately, most methods have failed
to bring about any constant relief.
which was far more effective than the rest is the ‘mirror box’ developed by V.S
Ramachandran and colleagues. They carried out an experiment on a 57-year old
woman who lost a hand in an accident when she was 18 yrs old. This woman
experienced phantom sensation in the amputated arm. Using a mirror box,
Ramachandran super imposed the image of the normal hand onto the amputated arm
for 30 minutes each day. After two weeks, the woman was able to move her
phantom fingers, which she now perceived to be of normal length, and was
totally relieved of pain.
Of late, graded motor
imagery, which employs mirror therapy and sensory discrimination training to
the affected individuals, has emerged as another promising tool for treatment.
Further research is warranted to study the underlying mechanisms of the phantom
disease in order to generate better treatment options for this strangely
delusive but very “real” disorder.