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:
The mirror box treatment is fascinating. It tricks the brain into thinking that a painfully clenched phantom hand has opened, relieving the pain sensations from this hand that is no longer there.
ReplyDeleteI think you may be missing the end of your first paragraph.
This is very interesting. As I read the beginning part of your post I was thinking the cause of this was psychological. Having a limb for so long, an individual will know how different stimulus would feel and basically where in space the limb would hang. Say you were standing to close to the stove. You brain would know your hand would be resting where the burner is located, and knowing how a burn feels, your brain would process a burn on your hand. I totally understand your explanation of the cause of this disorder but it were completely accurate, how does the mirror therapy work? The connection would still be laid and when an individual hurt his face his amputated arm would still hurt. The mirror therapy seems like a psychological treatment. What are your thoughts?
ReplyDeleteI believe it is psychological because, as professor Posner pointed out, it tricks the brain into thinking that both limbs are moving, thus relaxing the phantom limb.
DeleteYou point something interesting out, though. It might be possible that the therapy rewires the neurons again so that the two sections are not connected any longer. If not, then it is completely psychological.
This is really incredible, I also think this is psychological. I have been throwing around the idea of possibly having the patient take a placebo for the pain. If they take the "medication" it may provide relief for the pain the phantom limb is causing. I also think that the mirror box treatment is so interesting! Since the brain has so many amazing things going on it seems like it would be much harder to trick the brain, but here is proof that a mirror can do the trick!
ReplyDeleteI watched a show about this on the discovery channel. It is so insane to think that this is a real thing but I can totally see how it is.
ReplyDeleteI think that it would be very tough to deal with this disease on a daily basis, especially the painful aspect of it. I can only imagine hurting a phantom limb and attempting to treat it. The hardest part about having the disease would be the psychological aspect. The brain is a powerful muscle and a tricky one to work with.
ReplyDelete