The ability to sense our environment is something that many of us
take for granted. It's the simple, general things that we encounter every day;
this pillow feels soft, the concrete is hard, snow is cold. But what if you
were feeling things with a part of you that wasn't there?
No, this isn't something
from a science fiction show, it's a real disorder that often occurs in amputees
called phantom limb syndrome. And it's more common than you probably think; 80 percent
of amputees will experience this phenomenon at some point.
Symptoms
The
symptoms are very straight forward – if a person can feel something from a part
of the body where a limb is not present, then they have phantom limb. The types
of sensations are divided between non-painful and painful. Non-painful sensations
are very much like the feelings described above. They can range from feeling
differences in temperature to itching. The latter subdivision includes pains
such burning and prickling.
The painful feelings are unfortunately
the most common sensations related to phantom limb syndrome. Oftentimes the
pain is intrusive and debilitating. It can severely interfere with daily life
and is difficult to effectively cure.
Cause
Normally
the body is able to interpret sensations through sensory receptors under the
skin. These receptors create electrical signals that are able to be carried
from the peripheral nervous system to the central nervous system, where it can
be interpreted and responded to accordingly.
Amputees
obviously do not have these receptors. So what’s triggering the brain’s
response?
Scientist Vilayanur S. Ramachandran believes
that the syndrome has something to do with neurons changing connections in the
brain (a process called neuroplasticity). Basically, certain sections of the
brain are used for specific areas of sensory input. When area is lacking any
sort of stimulation because of the amputation, other parts of the brain are connected
to this area.
For
example, in one of Ramachandran’s experiments he discovered that an arm amputee
was receiving signals from sensory receptor in the face. The section of the
brain used for interpreting messages from the arm was not receiving any input,
so neurons connected to the sensory receptors for the face.
Treatments
A very basic form of
relief for those that suffer from the painful effects of phantom limb is pain
medication. Of course this is not very helpful for those that suffer from
non-painful effects and even those on medication may not fully be pain free.
An interesting outlet
for relief can be found in a very specific type of acupuncture. This
traditional medical technique has been used for thousands of years for a
variety of ailments and disease. In phantom limb specifically, a small, precise
prick of the ear has been known to alleviate pain. There are also a few pin
pricks on the scalp, but the ear is the key. This treatment is usually supplemental
to medication.
 |
| Mirror treatment |
A newer treatment that
is now commonly associated with phantom limb relief is mirror-box therapy. It requires
patients to insert their intact limb in a box with a mirror where they cannot
see their amputated limb. The effectiveness is questionable, but has been noted
to help at least 60 percent of patients in two different studies.
Sources:
http://www.amputee-coalition.org/inmotion/mar_apr_07/phantom_treatment.html
http://www.wellcome.ac.uk/en/pain/microsite/medicine2.html
Picture sources:
